Victor Nussenzweig, Ph.D., M.D.

TLR5-dependent immunogenicity of a recombinant fusion protein containing an immunodominant epitope of malarial circumsporozoite protein and the FliC flagellin of Salmonella Typhimurium
Camacho, Ariane Guglielmi Ariza; Teixeira, Lais Helena; Bargieri, Daniel Youssef; Boscardin, Silvia Beatriz; Soares, Irene da Silva; Nussenzweig, Ruth Sonntag; Nussenzweig, Victor; Rodrigues, Mauricio Martins
2011 Aug;106 Suppl 1:167-171, Memorias do Instituto Oswaldo Cruz
Recently, we described the improved immunogenicity of new malaria vaccine candidates based on the expression of fusion proteins containing immunodominant epitopes of merozoites and Salmonella enterica serovar Typhimurium flagellin (FliC) protein as an innate immune agonist. Here, we tested whether a similar strategy, based on an immunodominant B-cell epitope from malaria sporozoites, could also generate immunogenic fusion polypeptides. A recombinant His6-tagged FliC protein containing the C-terminal repeat regions of the VK210 variant of Plasmodium vivax circumsporozoite (CS) protein was constructed. This recombinant protein was successfully expressed in Escherichia coli as soluble protein and was purified by affinity to Ni-agarose beads followed by ion exchange chromatography. A monoclonal antibody specific for the CS protein of P. vivax sporozoites (VK210) was able to recognise the purified protein. C57BL/6 mice subcutaneously immunised with the recombinant fusion protein in the absence of any conventional adjuvant developed protein-specific systemic antibody responses. However, in mice genetically deficient in expression of TLR5, this immune response was extremely low. These results extend our previous observations concerning the immunogenicity of these recombinant fusion proteins and provide evidence that the main mechanism responsible for this immune activation involves interactions with TLR5, which has not previously been demonstrated for any recombinant FliC fusion protein
— id: 138010, year: 2011, vol: 106 Suppl 1, page: 167, stat: Journal Article,

Identification of non-CSP antigens bearing CD8 epitopes in mice immunized with irradiated sporozoites
Mishra, Satish; Rai, Urvashi; Shiratsuchi, Takayuki; Li, Xiangming; Vanloubbeeck, Yannick; Cohen, Joe; Nussenzweig, Ruth S; Winzeler, Elizabeth A; Tsuji, Moriya; Nussenzweig, Victor
2011 Oct 6;29(43):7335-7342, Vaccine
Immunization of BALB/c mice with irradiated sporozoites (IrSp) of Plasmodium yoelii can lead to sterile immunity. The circumsporozoite protein (CSP) plays a dominant role in protection. Nevertheless after hyper-immunization with IrSp, complete protection is obtained in CSP-transgenic BALB/c mice that are T-cell tolerant to the CSP and cannot produce antibodies [CSP-Tg/JhT(-/-)]. This protection is mediated exclusively by CD8(+) T cells [1]. To identify the non-CSP protective T cell antigens, we studied the properties of 34 P. yoelii sporozoite antigens that are predicted to be secreted and to contain strong Kd-restricted CD8(+) T cell epitopes. The synthetic peptides corresponding to the epitopes were used to screen for the presence of peptide-specific CD8(+) T cells secreting interferon-gamma (IFN-gamma) in splenocytes from CSP-Tg/JhT(-/-) BALB/c mice hyper immunized with IrSp. However, the numbers of IFN-gamma-secreting splenocytes specific for the non-CSP antigen-derived peptides were 20-100 times lower than those specific for the CSP-specific peptide. When mice were immunized with recombinant adenoviruses expressing selected non-CSP antigens, the animals were not protected against challenge with P. yoelii sporozoites although large numbers of CD8(+) specific T cells were generated
— id: 138108, year: 2011, vol: 29, page: 7335, stat: Journal Article,

Mixed results for a malaria vaccine
Nussenzweig, Victor; Good, Michael F; Hill, Adrian V S
2011 Dec;17(12):1560-1561, Nature medicine
— id: 149955, year: 2011, vol: 17, page: 1560, stat: Journal Article,

From the circumsporozoite protein to the RTS, S/AS candidate vaccine
Cohen, J; Nussenzweig, V; Nussenzweig, R; Vekemans, J; Leach, A
2010 JAN ;6(1):90-96, Human vaccines
The RTS, S/AS01(E) malaria vaccine candidate has recently entered Phase 3 testing. Reaching this important milestone is the culmination of more than 20 years of research and development by GlaxoSmithKline and partners and collaborators. The vaccine has been developed to protect young children and infants living in sub-Saharan Africa against clinical and severe disease caused by Plasmodium falciparum infection. Over the past 9 years, RTS, S/AS has been evaluated in multiple Phase 2 studies. The vaccine was shown to have a favorable safety profile and to be well tolerated in all age groups in which it was tested, including the intended target population of infants and young children in sub-Saharan Africa. Data obtained so far suggest that RTS, S/AS can be coadministered with other vaccines included in the routine Expanded Program of Immunization (EPI). In Phase 2 testing, the vaccine candidate was shown to confer significant protection against P. falciparum infection and clinical disease, including severe malaria. Furthermore, a trend towards an indirect beneficial effect of the vaccine on non-malarial morbidities has been observed in several trials. In this paper, we will describe the genesis of the RTS, S/AS concept, including the rationale for selecting the circumsporozoite protein (CSP) as the target antigen. Early development history of the vaccine will be briefly described. We will present the most salient results from recent Phase 2 studies conducted in the target pediatric population, which have led to the decision to progress RTS, S/AS to Phase 3 testing. If the Phase 3 results confirm the observations made during Phase 2 testing, the RTS, S/AS vaccine, when broadly implemented and judiciously integrated with other malaria-prevention measures, would have a major public-health impact in sub-Saharan Africa
— id: 107739, year: 2010, vol: 6, page: 90, stat: Journal Article,

A bicomponent Plasmodium falciparum investigational vaccine composed of protein-peptide conjugates
Kubler-Kielb, Joanna; Majadly, Fathy; Biesova, Zuzana; Mocca, Christopher P; Guo, Chunyan; Nussenzweig, Ruth; Nussenzweig, Victor; Mishra, Satish; Wu, Yimin; Miller, Louis H; Keith, Jerry M; Liu, Teh-Yung; Robbins, John B; Schneerson, Rachel
2010 Jan 19;107(3):1172-1177, Proceedings of the National Academy of Sciences of the United States of America
There is yet no licensed vaccine against malaria, a serious human disease affecting mostly children, with an annual death rate of about one million. Plasmodia, the malaria-causing parasites, have two obligatory hosts: mammals or birds, in which they multiply asexually, and mosquitoes with sexual multiplication. The most common and serious type of malaria is caused by Plasmodium falciparum. The circumsporozoite protein (CSP), a major surface antigen of sporozoites, is a protective antigen. A unique feature of P. falciparum CSP is its large central domain composed of over 30 tetrapeptide repeats of Asn-Ala-Asn-Pro (NANP). Several NANP peptide-protein conjugates were tested clinically but elicited a low level of CSP antibodies for a short duration. To provide a CSP-based candidate vaccine, we investigated recombinant CSP and NANP conjugates of various peptide lengths, with different N-terminal amino acids, bound at different ratios to various carrier proteins. Injected into mice, CSP alone and CSP or NANP conjugates induced antibodies with booster responses and were positive by the sporozoite immunofluorescent assay. The use of the mosquito stage P. falciparum ookinete surface protein, Pfs25, cross-linked onto itself as a carrier for NANP, induced in mice high levels of uniquely long-lasting antibodies to both vaccine components with secondary biological activities, that will provide immunity to liver infection by sporozoites and block transmission by mosquitoes
— id: 134978, year: 2010, vol: 107, page: 1172, stat: Journal Article,

Lipophilic bisphosphonates are potent inhibitors of Plasmodium liver-stage growth
Singh, Agam Prasad; Zhang, Yonghui; No, Joo-Hwan; Docampo, Roberto; Nussenzweig, Victor; Oldfield, Eric
2010 Jul;54(7):2987-2993, Antimicrobial agents & chemotherapy
Nitrogen-containing bisphosphonates, drugs used to treat bone resorption diseases, also have activity against a broad range of protists, including blood-stage Plasmodium spp. Here, we show that new-generation 'lipophilic' bisphosphonates designed as anticancer agents that block protein prenylation also have potent activity against Plasmodium liver stages, with a high (>100) therapeutic index. Treatment of mice with the bisphosphonate BPH-715 and challenge with Plasmodium berghei sporozoites revealed complete protection (no blood-stage parasites after 28 days). There was also activity against blood-stage forms in vitro and a 4-day delay in the prepatent period in vivo. The lipophilic bisphosphonates have activity against a Plasmodium geranylgeranyl diphosphate synthase (GGPPS), as well as low nM activity against human farnesyl and geranylgeranyl diphosphate synthases. The most active inhibitor in vitro and in vivo had enzyme inhibitory activity similar to that of the other, less active compounds but was more lipophilic. Lipophilic bisphosphonates are thus promising leads for novel antimalarials that target liver-stage infection
— id: 134365, year: 2010, vol: 54, page: 2987, stat: Journal Article,

The mechanisms of latency of malaria parasites in the mosquito salivary glands
Zhang M.; Fennell C.; Ranford-Cartwright L.; SaktHIVel R.; Gueirard P.; Meister S.; Caspi A.; Doerig C.; Nussenzweig R.S.; Tuteja R.; Sullivan Jr. W.J.; Roos D.S.; Menard R.; Fontoura B.M.; Winzeler E.A.; Nussenzweig V.
2010 ;83(5 SUPPL 1):111-111, American journal of tropical medicine & hygiene
Sporozoites, the invasive form of malaria parasites transmitted by mosquitoes, are quiescent while in the insect salivary glands. Sporozoites only differentiate inside of the hepatocytes of the mammalian host. We show that sporozoite latency is an active process controlled by a eukaryotic initiation factor-2a (eIF2a) kinase (IK2) and a phosphatase. IK2 activity is dominant in salivary gland sporozoites leading to an inhibition of translation and accumulation of stalled mRNAs into granules. When sporozoites are injected into the mammalian host, an eIF2a phosphatase removes the PO4 from eIF2a-P, and the repression of translation is alleviated to permit their transformation into liver stages. In IK2 knockout sporozoites eIF2a is not phosphorylated and the parasites transform prematurely into liver stages and lose their infectivity. Thus, to complete their life cycle, Plasmodium sporozoites exploit the mechanism that regulates stress responses in eukaryotic cells
— id: 134759, year: 2010, vol: 83, page: 111, stat: Journal Article,

The Plasmodium eukaryotic initiation factor-2alpha kinase IK2 controls the latency of sporozoites in the mosquito salivary glands
Zhang, Min; Fennell, Clare; Ranford-Cartwright, Lisa; Sakthivel, Ramanavelan; Gueirard, Pascale; Meister, Stephan; Caspi, Anat; Doerig, Christian; Nussenzweig, Ruth S; Tuteja, Renu; Sullivan, William J Jr; Roos, David S; Fontoura, Beatriz M A; Menard, Robert; Winzeler, Elizabeth A; Nussenzweig, Victor
2010 Jul 5;207(7):1465-1474, Journal of experimental medicine
Sporozoites, the invasive form of malaria parasites transmitted by mosquitoes, are quiescent while in the insect salivary glands. Sporozoites only differentiate inside of the hepatocytes of the mammalian host. We show that sporozoite latency is an active process controlled by a eukaryotic initiation factor-2alpha (eIF2alpha) kinase (IK2) and a phosphatase. IK2 activity is dominant in salivary gland sporozoites, leading to an inhibition of translation and accumulation of stalled mRNAs into granules. When sporozoites are injected into the mammalian host, an eIF2alpha phosphatase removes the PO4 from eIF2alpha-P, and the repression of translation is alleviated to permit their transformation into liver stages. In IK2 knockout sporozoites, eIF2alpha is not phosphorylated and the parasites transform prematurely into liver stages and lose their infectivity. Thus, to complete their life cycle, Plasmodium sporozoites exploit the mechanism that regulates stress responses in eukaryotic cells
— id: 110688, year: 2010, vol: 207, page: 1465, stat: Journal Article,

Conserved protective mechanisms in radiation and genetically attenuated uis3(-) and uis4(-) plasmodium sporozoites
Kumar, Kota Arun; Baxter, Peter; Tarun, Alice S; Kappe, Stefan H I; Nussenzweig, Victor
2009 ;4(2):e4480-e4480, PLoS ONE
Immunization with radiation attenuated Plasmodium sporozoites (RAS) elicits sterile protective immunity against sporozoite challenge in murine models and in humans. Similarly to RAS, the genetically attenuated sporozoites (GAPs) named uis3(-), uis4(-) and P36p(-) have arrested growth during the liver stage development, and generate a powerful protective immune response in mice. We compared the protective mechanisms in P. yoelii RAS, uis3(-) and uis4(-) in BALB/c mice. In RAS and GAPs, sterile immunity is only achieved after one or more booster injections. There were no differences in the immune responses to the circumsporozoite protein (CSP) generated by RAS and GAPs. To evaluate the role of non-CSP T-cell antigens we immunized antibody deficient, CSP-transgenic BALB/c mice, that are T cell tolerant to CSP, with P. yoelii RAS or with uis3(-) or uis4(-) GAPs, and challenged them with wild type sporozoites. In every instance the parasite liver stage burden was approximately 3 logs higher in antibody deficient CSP transgenic mice as compared to antibody deficient mice alone. We conclude that CSP is a powerful protective antigen in both RAS and GAPs viz., uis3(-) and uis4(-) and that the protective mechanisms are similar independently of the method of sporozoite attenuation
— id: 96885, year: 2009, vol: 4, page: e4480, stat: Journal Article,

Plasmodium pre-erythrocytic stages: what's new?
Menard, Robert; Heussler, Volker; Yuda, Masao; Nussenzweig, Victor
2008 Dec;24(12):564-569, Trends in parasitology
The pre-erythrocytic (PE) phase of malaria infection, which extends from injection of sporozoites into the skin to the release of the first generation of merozoites, has traditionally been the 'black box' of the Plasmodium life cycle. However, since the advent of parasite transfection technology 13 years ago, our understanding of the PE phase in cellular and molecular terms has dramatically improved. Here, we review and comment on the major developments in the field in the past five years. Progress has been made in many diverse areas, including identifying and characterizing new proteins of interest, imaging parasites in vivo, understanding better the cell biology of hepatocyte infection and developing new vaccines against PE stages of the parasite
— id: 96886, year: 2008, vol: 24, page: 564, stat: Journal Article,

Class II-restricted protective immunity induced by malaria sporozoites
Oliveira, Giane A; Kumar, Kota Arun; Calvo-Calle, J Mauricio; Othoro, Caroline; Altszuler, David; Nussenzweig, Victor; Nardin, Elizabeth H
2008 Mar;76(3):1200-1206, Infection & immunity
The irradiated-sporozoite vaccine elicits sterile immunity against Plasmodium parasites in experimental rodent hosts and human volunteers. Based on rodent malaria models, it has been proposed that CD8+ T cells are the key protective effector mechanism required in sporozoite-induced immunity. To investigate the role of class II-restricted immunity in protective immunity, we immunized beta2-microglobulin knockout (beta2M-/-) mice with irradiated Plasmodium yoelii or P. berghei sporozoites. Sterile immunity was obtained in the CD8+-T-cell-deficient mice immunized with either P. berghei or P. yoelii sporozoites. beta2M-/- mice with the BALB/c (H-2d) genetic background as well as those with the C57BL (H-2b) genetic background were protected. Effector mechanisms included CD4+ T cells, mediated in part through the production of gamma interferon, and neutralizing antibodies that targeted the extracellular sporozoites. We conclude that in the absence of class I-restricted CD8+ T cells, sporozoite-induced protective immunity can be effectively mediated by class II-restricted immune effector mechanisms. These results support efforts to develop subunit vaccines that effectively elicit high levels of antibody and CD4+ T cells to target Plasmodium pre-erythrocytic stages
— id: 76387, year: 2008, vol: 76, page: 1200, stat: Journal Article,

Evidence-based annotation of the malaria parasite's genome using comparative expression profiling
Zhou, Yingyao; Ramachandran, Vandana; Kumar, Kota Arun; Westenberger, Scott; Refour, Phillippe; Zhou, Bin; Li, Fengwu; Young, Jason A; Chen, Kaisheng; Plouffe, David; Henson, Kerstin; Nussenzweig, Victor; Carlton, Jane; Vinetz, Joseph M; Duraisingh, Manoj T; Winzeler, Elizabeth A
2008 ;3(2):e1570-e1570, PLoS ONE
A fundamental problem in systems biology and whole genome sequence analysis is how to infer functions for the many uncharacterized proteins that are identified, whether they are conserved across organisms of different phyla or are phylum-specific. This problem is especially acute in pathogens, such as malaria parasites, where genetic and biochemical investigations are likely to be more difficult. Here we perform comparative expression analysis on Plasmodium parasite life cycle data derived from P. falciparum blood, sporozoite, zygote and ookinete stages, and P. yoelii mosquito oocyst and salivary gland sporozoites, blood and liver stages and show that type II fatty acid biosynthesis genes are upregulated in liver and insect stages relative to asexual blood stages. We also show that some universally uncharacterized genes with orthologs in Plasmodium species, Saccharomyces cerevisiae and humans show coordinated transcription patterns in large collections of human and yeast expression data and that the function of the uncharacterized genes can sometimes be predicted based on the expression patterns across these diverse organisms. We also use a comprehensive and unbiased literature mining method to predict which uncharacterized parasite-specific genes are likely to have roles in processes such as gliding motility, host-cell interactions, sporozoite stage, or rhoptry function. These analyses, together with protein-protein interaction data, provide probabilistic models that predict the function of 926 uncharacterized malaria genes and also suggest that malaria parasites may provide a simple model system for the study of some human processes. These data also provide a foundation for further studies of transcriptional regulation in malaria parasites
— id: 78755, year: 2008, vol: 3, page: e1570, stat: Journal Article,

Aldolase provides an unusual binding site for thrombospondin-related anonymous protein in the invasion machinery of the malaria parasite
Bosch, Jurgen; Buscaglia, Carlos A; Krumm, Brian; Ingason, Bjarni P; Lucas, Robert; Roach, Claudia; Cardozo, Timothy; Nussenzweig, Victor; Hol, Wim G J
2007 Apr 24;104(17):7015-7020, Proceedings of the National Academy of Sciences of the United States of America
An actomyosin motor located underneath the plasma membrane drives motility and host-cell invasion of apicomplexan parasites such as Plasmodium falciparum and Plasmodium vivax, the causative agents of malaria. Aldolase connects the motor actin filaments to transmembrane adhesive proteins of the thrombospondin-related anonymous protein (TRAP) family and transduces the motor force across the parasite surface. The TRAP-aldolase interaction is a distinctive and critical trait of host hepatocyte invasion by Plasmodium sporozoites, with a likely similar interaction crucial for erythrocyte invasion by merozoites. Here, we describe 2.4-A and 2.7-A structures of P. falciparum aldolase (PfAldo) obtained from crystals grown in the presence of the C-terminal hexapeptide of TRAP from Plasmodium berghei. The indole ring of the critical penultimate Trp-residue of TRAP fits snugly into a newly formed hydrophobic pocket, which is exclusively delimited by hydrophilic residues: two arginines, one glutamate, and one glutamine. Comparison with the unliganded PfAldo structure shows that the two arginines adopt new side-chain rotamers, whereas a 25-residue subdomain, forming a helix-loop-helix unit, shifts upon binding the TRAP-tail. The structural data are in agreement with decreased TRAP binding after mutagenesis of PfAldo residues in and near the induced TRAP-binding pocket. Remarkably, the TRAP- and actin-binding sites of PfAldo seem to overlap, suggesting that both the plasticity of the aldolase active-site region and the multimeric nature of the enzyme are crucial for its intriguing nonenzymatic function in the invasion machinery of the malaria parasite
— id: 78751, year: 2007, vol: 104, page: 7015, stat: Journal Article,

Modeling the interaction between aldolase and the thrombospondin-related anonymous protein, a key connection of the malaria parasite invasion machinery
Buscaglia, Carlos A; Hol, Wim G J; Nussenzweig, Victor; Cardozo, Timothy
2007 Feb 15;66(3):528-537, Proteins
A complex molecular motor empowers substrate-dependent motility and host cell invasion in malaria parasites. The interaction between aldolase and the transmembrane adhesin thrombospondin-related anonymous protein (TRAP) transduces the motor force across the parasite surface. Here, we analyzed this interaction by using state-of-the-art flexible docking. Besides algorithms to account for induced fit in the side-chains of the Plasmodium falciparum aldolase (PfAldo) structure, we used additional in silico receptors modeled upon crystallographic structures of evolutionarily related aldolases to incorporate enzyme backbone flexibility, and to overcome structure inaccuracies due to the relatively low resolution (3.0 A) of the genuine PfAldo structure. Our results indicate that, in spite of multiple intermolecular contacts, only the six C-terminal residues of the TRAP cytoplasmic tail bind in an ordered manner to PfAldo. This portion of TRAP targets the PfAldo active site, with its n-1 Trp residue, which is essential for this interaction, buried within the PfAldo catalytic pocket. Docking of a TRAP peptide bearing a Trp to Ala mutation rendered the lower energy configurations either bound weakly outside the active site or not bound to PfAldo at all. The position of the bound TRAP peptide, and particularly the close proximity between the carbonyl of its n-2 Asp residue and the experimentally determined position of the phosphate-6 group of fructose 1,6-phosphate bound to mammalian aldolases, predicts an inhibitory effect of TRAP on catalysis. Enzymatic and TRAP-binding assays using mutant PfAldo molecules strongly support the overall structural model. These results might provide the initial framework for the identification of novel antiparasitic compounds
— id: 70859, year: 2007, vol: 66, page: 528, stat: Journal Article,

Exposure of Plasmodium sporozoites to the intracellular concentration of potassium enhances infectivity and reduces cell passage activity
Kumar, Kota Arun; Garcia, Celia R S; Chandran, Vandana R; Van Rooijen, N; Zhou, Yingyao; Winzeler, Elizabeth; Nussenzweig, Victor
2007 Nov;156(1):32-40, Molecular & biochemical parasitology
Malaria sporozoites migrate through several cells prior to a productive invasion that involves the formation of a parasitophorous vacuole (PV) where sporozoites undergo transformation into Exo-erythorcytic forms (EEFs). The precise mechanism leading to sporozoite activation for invasion is unknown, but prior traversal of host cells is required. During cell migration sporozoites are exposed to large shifts in K(+) concentration. We report here that incubation of sporozoites to the intracellular K(+) concentration enhances 8-10 times the infectivity of Plasmodium berghei and 4-5 times the infectivity of Plasmodium yoelli sporozoites for a hepatocyte cell line, while simultaneously decreasing cell passage activity. The K(+) enhancing effect was time and concentration dependent, and was significantly decreased by K(+) channel inhibitors. Potassium-treated P. berghei sporozoites also showed enhanced numbers of EEFs in non-permissive cell lines. Treated sporozoites had reduced infectivity for mice, but infectivity was enhanced upon Kupffer cell depletion. Transcriptional analysis of K(+) treated and control sporozoites revealed a high degree of correlation in their levels of gene expression, indicating that the observed phenotypic changes are not due to radical changes in gene transcription. Only seven genes were upregulated by more than two-fold in K(+) treated sporozoites. The highest level was noted in PP2C, a phosphatase known to dephosphorylate the AKT potassium channel in plants
— id: 75368, year: 2007, vol: 156, page: 32, stat: Journal Article,

Plasmodium circumsporozoite protein promotes the development of the liver stages of the parasite
Singh, Agam Prasad; Buscaglia, Carlos A; Wang, Qian; Levay, Agata; Nussenzweig, Daniel R; Walker, John R; Winzeler, Elizabeth A; Fujii, Hodaka; Fontoura, Beatriz M A; Nussenzweig, Victor
2007 Nov 2;131(3):492-504, Cell
The liver stages of malaria are clinically silent but have a central role in the Plasmodium life cycle. Liver stages of the parasite containing thousands of merozoites grow inside hepatocytes for several days without triggering an inflammatory response. We show here that Plasmodium uses a PEXEL/VTS motif to introduce the circumsporozoite (CS) protein into the hepatocyte cytoplasm and a nuclear localization signal (NLS) to enter its nucleus. CS outcompetes NFkappaB nuclear import, thus downregulating the expression of many genes controlled by NFkappaB, including those involved in inflammation. CS also influences the expression of over one thousand host genes involved in diverse metabolic processes to create a favorable niche for the parasite growth. The presence of CS in the hepatocyte enhances parasite growth of the liver stages in vitro and in vivo. These findings have far reaching implications for drug and vaccine development against the liver stages of the malaria parasite
— id: 75403, year: 2007, vol: 131, page: 492, stat: Journal Article,

Characterization of an aldolase-binding site in the Wiskott-Aldrich syndrome protein
Buscaglia, Carlos A; Penesetti, Deepak; Tao, Mingyuan; Nussenzweig, Victor
2006 Jan 20;281(3):1324-1331, Journal of biological chemistry
The thrombospondin-related anonymous protein (TRAP) is an essential transmembrane molecule in Plasmodium sporozoites. TRAP displays adhesive motifs on the extracellular portion, whereas its cytoplasmic tail connects to actin via aldolase, thus driving parasite motility and host cell invasion. The minimal requirements for the TRAP binding to aldolase were scanned here and found to be shared by different human proteins, including the Wiskott-Aldrich syndrome protein (WASp) family members. In vitro and in vivo binding of WASp members to aldolase was characterized by biochemical, deletion mapping, mutagenesis, and co-immunoprecipitation studies. As in the case of TRAP, the binding of WASp to aldolase is competitively inhibited by the enzyme substrate/products. Furthermore, TRAP and WASp, but not other unrelated aldolase binders, compete for the binding to the enzyme in vitro. Together, our results define a conserved aldolase binding motif in the WASp family members and suggest that aldolase modulates the motility and actin dynamics of mammalian cells. These findings along with the presence of similar aldolase binding motifs in additional human proteins, some of which indeed interact with aldolase in pull-down assays, suggest supplementary, non-glycolytic roles for this enzyme
— id: 61945, year: 2006, vol: 281, page: 1324, stat: Journal Article,

The circumsporozoite protein is an immunodominant protective antigen in irradiated sporozoites
Kumar, Kota Arun; Sano, Gen-ichiro; Boscardin, Silvia; Nussenzweig, Ruth S; Nussenzweig, Michel C; Zavala, Fidel; Nussenzweig, Victor
2006 Dec 14;444(7121):937-940, Nature
Malaria infection starts when mosquitoes inject sporozoites into the skin. The parasites enter the blood stream and make their way to the liver where they develop into the exo-erythrocytic forms (EEFs). Immunization with irradiated sporozoites (IrSp) leads to robust protection against malaria infection in rodents, monkeys and humans by eliciting antibodies to circumsporozoite protein (CS) that inhibit sporozoite infectivity, and T cells that destroy the EEFs. To study the role of non-CS antigens in protection, we produced CS transgenic mice that were tolerant to CS T-cell epitopes. Here we show that in the absence of T-cell-dependent immune responses to CS, protection induced by immunization with two doses of IrSp was greatly reduced. Thus, although hundreds of other Plasmodium genes are expressed in sporozoites and EEFs, CS is a dominant protective antigen. Nevertheless, sterile immunity could be obtained by immunization of CS transgenics with three doses of IrSp
— id: 69706, year: 2006, vol: 444, page: 937, stat: Journal Article,

A surface phospholipase is involved in the migration of plasmodium sporozoites through cells
Bhanot, Purnima; Schauer, Kristine; Coppens, Isabelle; Nussenzweig, Victor
2005 Feb 25;280(8):6752-6760, Journal of biological chemistry
Plasmodium sporozoites, injected by mosquitoes into the skin of the host, traverse cells during their migration to hepatocytes where they continue their life cycle. The mechanisms used by the parasite to rupture the plasma membrane of the host cells are not known. Here we report the presence of a phospholipase on the surface of Plasmodium berghei sporozoites (P. berghei phospholipase; Pb PL) and demonstrate that it is involved in the establishment of a malaria infection in vivo. Pb PL is highly conserved among the Plasmodium species. The protein is about 750 amino acids, with a predicted signal sequence and a carboxyl terminus that is 32% identical to the vertebrate lecithin:cholesterol acyltransferase, a secreted phospholipase. Pb PL contains a motif characteristic of lipases and a catalytic triad of a serine, aspartate, and histidine that is found in several phospholipases. We have verified its lipase and membrane lytic activity in vitro, using recombinant baculovirus-expressed protein. To study its role in vivo, we have disrupted the P. berghei PL open reading frame and generated mutants in its active site. During an infection through mosquito bite, the infectivity of the knock-out parasites in the liver is decreased by approximately 90%. The prepatent period of the resulting blood infection is 1 day longer as compared with wild type. Further, the mutant sporozoites are impaired in their ability to cross epithelial cell layers. Thus, the Pb PL functions as a lipase to damage cell membranes and facilitates sporozoite passage through cells during their migration from the skin to the bloodstream
— id: 51095, year: 2005, vol: 280, page: 6752, stat: Journal Article,

Yellow fever 17D as a vaccine vector for microbial CTL epitopes: protection in a rodent malaria model
Tao, Deng; Barba-Spaeth, Giovanna; Rai, Urvashi; Nussenzweig, Victor; Rice, Charles M; Nussenzweig, Ruth S
2005 Jan 17;201(2):201-209, Journal of experimental medicine
The yellow fever vaccine 17D (17D) is safe, and after a single immunizing dose, elicits long-lasting, perhaps lifelong protective immunity. One of the major challenges facing delivery of human vaccines in underdeveloped countries is the need for multiple injections to achieve full efficacy. To examine 17D as a vector for microbial T cell epitopes, we inserted the H-2K(d)-restricted CTL epitope of the circumsporozoite protein (CS) of Plasmodium yoelii between 17D nonstructural proteins NS2B and NS3. The recombinant virus, 17D-Py, was replication competent and stable in vitro and in vivo. A single subcutaneous injection of 10(5) PFU diminished the parasite burden in the liver by approximately 70%. The high level of protection lasted between 4 and 8 wk after immunization, but a significant effect was documented even 24 wk afterwards. Thus, the immunogenicity of a foreign T cell epitope inserted into 17D mimics some of the remarkable properties of the human vaccine. Priming with 17D-Py followed by boosting with irradiated sporozoites conferred sterile immunity to 90% of the mice. This finding indicates that the immune response of vaccine-primed individuals living in endemic areas could be sustained and magnified by the bite of infected mosquitoes
— id: 48028, year: 2005, vol: 201, page: 201, stat: Journal Article,

Exit of Plasmodium sporozoites from oocysts is an active process that involves the circumsporozoite protein
Wang, Qian; Fujioka, Hisashi; Nussenzweig, Victor
2005 Sep;1(1):e9-e9, PLoS pathogens
Plasmodium sporozoites develop within oocysts residing in the mosquito midgut. Mature sporozoites exit the oocysts, enter the hemolymph, and invade the salivary glands. The circumsporozoite (CS) protein is the major surface protein of salivary gland and oocyst sporozoites. It is also found on the oocyst plasma membrane and on the inner surface of the oocyst capsule. CS protein contains a conserved motif of positively charged amino acids: region II-plus, which has been implicated in the initial stages of sporozoite invasion of hepatocytes. We investigated the function of region II-plus by generating mutant parasites in which the region had been substituted with alanines. Mutant parasites produced normal numbers of sporozoites in the oocysts, but the sporozoites were unable to exit the oocysts. In in vitro as well, there was a profound delay, upon trypsin treatment, in the release of mutant sporozoites from oocysts. We conclude that the exit of sporozoites from oocysts is an active process that involves the region II-plus of CS protein. In addition, the mutant sporozoites were not infective to young rats. These findings provide a new target for developing reagents that interfere with the transmission of malaria
— id: 61947, year: 2005, vol: 1, page: e9, stat: Journal Article,

Mutational analysis of the GPI-anchor addition sequence from the circumsporozoite protein of Plasmodium
Wang, Qian; Fujioka, Hisashi; Nussenzweig, Victor
2005 Nov;7(11):1616-1626, Cellular microbiology
The plasma membrane of Plasmodium sporozoites is uniformly covered by the glycosylphosphatidylinositol (GPI)-anchored circumsporozoite (CS) protein. Sporozoites form in the mosquito midgut through a budding process that occurs within a multinucleate oocyst underneath the basal lamina of the gut. Earlier genetic studies established that normal sporozoite development requires CS. Mutant parasites lacking CS [CS (-)] do not form sporozoites. Ultrastructural analysis of the oocysts from these parasites revealed that there is an early block in the cytokinesis that occurs within the multinucleate oocysts to generate individual sporozoites. Parasites that are hypomorphic for CS expression gave rise to sporozoites with abnormal morphology. These results proved that CS plays a direct role in the maturation of oocysts and in the normal budding of sporozoites. In this article, we examined if the membrane localization of CS via a GPI-anchor, is crucial for its function during sporozoite formation. We generated three mutants in Plasmodium berghei CS, CS-DeltaGPI, CS-TM1 and CS-TM2. In CS-DeltaGPI, we deleted the signal sequence required for the addition of a GPI-anchor to CS. The resulting protein was found only in the cytoplasm of the oocyst. In CS-TM1 and CS-TM2, the GPI-anchor addition sequence of CS was substituted by the transmembrane domain and truncated (to different degrees) cytoplasmic tail of Plasmodium thrombospondin-related anonymous protein (TRAP). The resulting CS protein was detected on the plasma membrane of the oocysts. The amount of CS in the mutants was similar to that of wild type. The sporozoite budding and development were abrogated in both CS-DeltaGPI and CS-TM mutants. The ultrastructure of the mutant oocysts was indistinguishable from that of the CS (-) parasites. Our results suggest that the GPI-anchor of the CS protein is required for sporogenesis
— id: 61946, year: 2005, vol: 7, page: 1616, stat: Journal Article,

Apicomplexan gliding motility and host cell invasion: overhauling the motor model
Kappe, Stefan H I; Buscaglia, Carlos A; Bergman, Lawrence W; Coppens, Isabelle; Nussenzweig, Victor
2004 Jan;20(1):13-16, Trends in parasitology
— id: 61949, year: 2004, vol: 20, page: 13, stat: Journal Article,

Plasmodium sporozoite molecular cell biology
Kappe, Stefan H I; Buscaglia, Carlos A; Nussenzweig, Victor
2004 ;20:29-59, Annual review of cell & developmental biology
Plasmodium sporozoites display complex phenotypes including gliding motility and invasion of and transmigration through cells in the mosquito vector and the vertebrate host. Sporozoite studies have been difficult to perform because of technical concerns. Nevertheless, they have already provided insights into several aspects of sporozoite biology, shared in part with other apicomplexan invasive stages. Structure/function analysis of the thrombospondin-related anonymous protein paved the way to the understanding of the molecular mechanisms of apicomplexan gliding motility and host cell invasion. Functional studies of circumsporozoite protein revealed its role in Plasmodium sporozoite morphogenesis in addition to its well-known function in host cell invasion. Transcriptional surveys, which facilitate the investigation of gene expression programs that control sporozoite phenotypes, have revealed a high degree of previously unappreciated complexity and novel proteins that mediate sporozoite host cell infection
— id: 61948, year: 2004, vol: 20, page: 29, stat: Journal Article,

Quantitative Plasmodium sporozoite neutralization assay (TSNA)
Kumar, Kota Arun; Oliveira, Giane A; Edelman, Robert; Nardin, Elizabeth; Nussenzweig, Victor
2004 Oct;292(1-2):157-164, Journal of immunological methods
The circumsporozoite (CS) protein is the major surface protein of Plasmodium sporozoites. Antibodies to the immunodominant repeat domain of CS immobilize sporozoites and prevent infection of hepatocytes. Plasmodium falciparum vaccines containing CS repeats are undergoing human trials in endemic areas, and proof of efficacy has been obtained. The correlates of protection are under investigation. Levels of anti-repeat antibodies in the serum of the human volunteers have been measured mostly by enzyme-linked immunosorbent assay (ELISA) and IFA. Assays that measure the effect of the serum antibodies on parasite infectivity (serum neutralization assays SNAs) are not usually performed because they require a susceptible host and P. falciparum sporozoites are highly infectious only to humans. To overcome this limitation, we developed a new assay named transgenic sporozoite neutralization assay (TSNA) that uses as neutralization target, a transgenic rodent malaria parasite Plasmodium berghei that bears the P. falciparum CS repeats [CS(Pf)]. Following incubation with human serum, CS(Pf) infectivity of HepG2 cells is evaluated by real-time PCR. We have compared ELISA titers and TSNAs in a limited number of sera from humans immunized with (T1B)4 MAP, a peptide vaccine containing P. falciparum CS repeats. A comparison between the two assays did not reach significance (p=0.175) when analyzed by non-parametric Spearman correlation method. Ongoing human trials of CS-based vaccines should provide an opportunity to determine whether TSNAs will provide better correlates of protective immunity than ELISA assays
— id: 46107, year: 2004, vol: 292, page: 157, stat: Journal Article,

Transcriptome of axenic liver stages of Plasmodium yoelii
Wang, Qian; Brown, Stuart; Roos, David S; Nussenzweig, Victor; Bhanot, Purnima
2004 Sep;137(1):161-168, Molecular & biochemical parasitology
Plasmodium liver stages or early exo-eythrocytic forms (EEFs) contain antigens that are essential for achieving sterile, protective immunity against malaria. Yet, attempts at identifying these antigens have been hampered by the challenge of obtaining large numbers of purified EEFs, uncontaminated with hepatocyte material. Using a recently described system for producing axenically cultured EEFs from Plasmodium yoelii, we have constructed a cDNA library and generated 1453 expressed sequence tags (ESTs) resulting in 652 unique transcripts. Analysis of the library provides insight into processes required for the initiation and development of Plasmodium liver stages, such as protein degradation, cell cycle progression and nutrient transport. Analysis of the gene expression profile of liver stages, as revealed by this library, suggests that liver stages represent a shift from 'sporozoite-like' to 'blood-stage-like'. This is the first study of the transcriptional repertoire of Plasmodium liver stages
— id: 48869, year: 2004, vol: 137, page: 161, stat: Journal Article,

Myosin A tail domain interacting protein (MTIP) localizes to the inner membrane complex of Plasmodium sporozoites
Bergman, Lawrence W; Kaiser, Karine; Fujioka, Hisashi; Coppens, Isabelle; Daly, Thomas M; Fox, Sarah; Matuschewski, Kai; Nussenzweig, Victor; Kappe, Stefan H I
2003 Jan 1;116(Pt 1):39-49, Journal of cell science
Apicomplexan host cell invasion and gliding motility depend on the parasite's actomyosin system located beneath the plasma membrane of invasive stages. Myosin A (MyoA), a class XIV unconventional myosin, is the motor protein. A model has been proposed to explain how the actomyosin motor operates but little is known about the components, topology and connectivity of the motor complex. Using the MyoA neck and tail domain as bait in a yeast two-hybrid screen we identified MTIP, a novel 24 kDa protein that interacts with MyoA. Deletion analysis shows that the 15 amino-acid C-terminal tail domain of MyoA, rather than the neck domain, specifically interacts with MTIP. In Plasmodium sporozoites MTIP localizes to the inner membrane complex (IMC), where it is found clustered with MyoA. The data support a model for apicomplexan motility and invasion in which the MyoA motor protein is associated via its tail domain with MTIP, immobilizing it at the outer IMC membrane. The head domain of the immobilized MyoA moves actin filaments that, directly or via a bridging protein, connect to the cytoplasmic domain of a transmembrane protein of the TRAP family. The actin/TRAP complex is then redistributed by the stationary MyoA from the anterior to the posterior end of the zoite, leading to its forward movement on a substrate or to penetration of a host cell
— id: 61950, year: 2003, vol: 116, page: 39, stat: Journal Article,

Defective sorting of the thrombospondin-related anonymous protein (TRAP) inhibits Plasmodium infectivity
Bhanot, Purnima; Frevert, Ute; Nussenzweig, Victor; Persson, Cathrine
2003 Feb;126(2):263-273, Molecular & biochemical parasitology
Thrombospondin-related anonymous protein (TRAP) is a type 1 transmembrane protein that plays an essential role in gliding motility and cell invasion by Plasmodium sporozoites. It is stored in micronemes-secretory organelles located primarily in the apical end of the parasites and is also found on the parasite surface. The mechanisms that target TRAP and other sporozoite proteins to micronemes and subsequently to the parasite surface are not known. Here we report that the micronemal and surface localization of TRAP requires a tyrosine-based motif located in its cytoplasmic tail. This motif is analogous to the YXXphi motif (Y: tyrosine, X: any amino acid; phi: hydrophobic amino acid) that targets eukaryotic proteins to certain sub-cellular compartments and to the plasma membrane. Abrogating the Y motif substantially reduces micronemal and cell surface localization of TRAP. The infectivity of mutant parasites is substantially inhibited. However, there is no significant difference in the amounts of TRAP secreted into the culture medium by wild type and mutant parasites, suggesting that TRAP destined for secretion bypasses micronemal localization
— id: 39282, year: 2003, vol: 126, page: 263, stat: Journal Article,

Sites of interaction between aldolase and thrombospondin-related anonymous protein in plasmodium
Buscaglia, Carlos A; Coppens, Isabelle; Hol, Wim G J; Nussenzweig, Victor
2003 Dec;14(12):4947-4957, Molecular biology of the cell
Gliding motility and host cell invasion by apicomplexan parasites are empowered by an acto-myosin motor located underneath the parasite plasma membrane. The motor is connected to host cell receptors through trans-membrane invasins belonging to the thrombospondin-related anonymous protein (TRAP) family. A recent study indicates that aldolase bridges the cytoplasmic tail of MIC2, the homologous TRAP protein in Toxoplasma, and actin. Here, we confirm these unexpected findings in Plasmodium sporozoites and identify conserved features of the TRAP family cytoplasmic tail required to bind aldolase: a subterminal tryptophan residue and two noncontiguous stretches of negatively charged amino acids. The aldolase substrate and other compounds that bind to the active site inhibit its interaction with TRAP and with F-actin, suggesting that the function of the motor is metabolically regulated. Ultrastructural studies in salivary gland sporozoites localize aldolase to the periphery of the secretory micronemes containing TRAP. Thus, the interaction between aldolase and the TRAP tail takes place during or preceding the biogenesis of the micronemes. The release of their contents in the anterior pole of the parasite upon contact with the target cells should bring simultaneously aldolase, TRAP and perhaps F-actin to the proper subcellular location where the motor is engaged
— id: 48183, year: 2003, vol: 14, page: 4947, stat: Journal Article,

Plasmodium yoelii sporozoites infect Syndecan-1 deficient mice
Bhanot, Purnima; Nussenzweig, Victor
2002 Aug 28;123(2):143-144, Molecular & biochemical parasitology
— id: 39402, year: 2002, vol: 123, page: 143, stat: Journal Article,

Plasmodium sporozoite invasion into insect and mammalian cells is directed by the same dual binding system
Matuschewski, Kai; Nunes, Alvaro C; Nussenzweig, Victor; Menard, Robert
2002 Apr 2;21(7):1597-1606, EMBO journal
Plasmodium sporozoites, the transmission form of the malaria parasite, successively invade salivary glands in the mosquito vector and the liver in the mammalian host. Sporozoite capacity to invade host cells is mechanistically related to their ability to glide on solid substrates, both activities depending on the transmembrane protein TRAP. Here, we show that loss-of- function mutations in two adhesive modules of the TRAP ectodomain, an integrin-like A-domain and a thrombospondin type I repeat, specifically decrease sporozoite invasion of host cells but do not affect sporozoite gliding and adhesion to cells. Irrespective of the target cell, i.e. in mosquitoes, rodents and cultured human or hamster cells, sporozoites bearing mutations in one module are less invasive, while those bearing mutations in both modules are non-invasive. In Chinese hamster ovary cells, the TRAP modules interact with distinct cell receptors during sporozoite invasion, and thus act as independently active pass keys. As these modules are also present in other members of the TRAP family of proteins in Apicomplexa, they may account for the capacity of these parasites to enter many cell types of phylogenetically distant origins
— id: 39687, year: 2002, vol: 21, page: 1597, stat: Journal Article,

Infectivity-associated changes in the transcriptional repertoire of the malaria parasite sporozoite stage
Matuschewski, Kai; Ross, Jessica; Brown, Stuart M; Kaiser, Karine; Nussenzweig, Victor; Kappe, Stefan H I
2002 Nov 1;277(44):41948-41953, Journal of biological chemistry
Injection of Plasmodium salivary gland sporozoites into the vertebrate host by Anopheles mosquitoes initiates malaria infection. Sporozoites develop within oocysts in the mosquito midgut and then enter and mature in the salivary glands. Although morphologically similar, oocyst sporozoites and salivary gland sporozoites differ strikingly in their infectivity to the mammalian host, ability to elicit protective immune responses, and cell motility. Here, we show that differential gene expression coincides with these dramatic phenotypic differences. Using suppression subtractive cDNA hybridization we identified highly up-regulated mRNAs transcribed from 30 distinct genes in salivary gland sporozoites. Of those genes, 29 are not significantly expressed in the parasite's blood stages. The most frequently recovered transcript encodes a protein kinase. Developmental up-regulation of specific mRNAs in the infectious transmission stage of Plasmodium indicates that their translation products may have unique roles in hepatocyte infection and/or development of liver stages
— id: 39415, year: 2002, vol: 277, page: 41948, stat: Journal Article,

Cutting edge: a new tool to evaluate human pre-erythrocytic malaria vaccines: rodent parasites bearing a hybrid Plasmodium falciparum circumsporozoite protein
Persson, Cathrine; Oliveira, Giane A; Sultan, Ali A; Bhanot, Purnima; Nussenzweig, Victor; Nardin, Elizabeth
2002 Dec 15;169(12):6681-6685, Journal of immunology
Malaria vaccines containing the Plasmodium falciparum Circumsporozoite protein repeat domain are undergoing human trials. There is no simple method to evaluate the effect of vaccine-induced responses on P. falciparum sporozoite infectivity. Unlike the rodent malaria Plasmodium berghei, P. falciparum sporozoites do not infect common laboratory animals and only develop in vitro in human hepatocyte cultures. We generated a recombinant P. berghei parasite bearing P. falciparum Circumsporozoite protein repeats. These hybrid sporozoites are fully infective in vivo and in vitro. Monoclonal and polyclonal Abs to P. falciparum repeats neutralize hybrid parasite infectivity, and mice immunized with a P. falciparum vaccine are protected against challenge with hybrid sporozoites
— id: 39354, year: 2002, vol: 169, page: 6681, stat: Journal Article,

Levels of circumsporozoite protein in the Plasmodium oocyst determine sporozoite morphology
Thathy, Vandana; Fujioka, Hisashi; Gantt, Soren; Nussenzweig, Ruth; Nussenzweig, Victor; Menard, Robert
2002 Apr 2;21(7):1586-1596, EMBO journal
The sporozoite stage of the Plasmodium parasite is formed by budding from a multinucleate oocyst in the mosquito midgut. During their life, sporozoites must infect the salivary glands of the mosquito vector and the liver of the mammalian host; both events depend on the major sporozoite surface protein, the circumsporozoite protein (CS). We previously reported that Plasmodium berghei oocysts in which the CS gene is inactivated do not form sporozoites. Here, we analyzed the ultrastructure of P.berghei oocyst differentiation in the wild type, recombinants that do not produce or produce reduced amounts of CS, and corresponding complemented clones. The results indicate that CS is essential for establishing polarity in the oocyst. The amounts of CS protein correlate with the extent of development of the inner membranes and associated microtubules underneath the oocyst outer membrane, which normally demarcate focal budding sites. This is a first example of a protein controlling both morphogenesis and infectivity of a parasite stage
— id: 39688, year: 2002, vol: 21, page: 1586, stat: Journal Article,

The ubiquitin-proteasome pathway plays an essential role in proteolysis during Trypanosoma cruzi remodeling
de Diego JL; Katz JM; Marshall P; Gutierrez B; Manning JE; Nussenzweig V; Gonzalez J
2001 Jan 30;40(4):1053-1062, Biochemistry
Here, we document for the first time the presence of the 26S proteasome and the ubiquitin pathway in a protozoan parasite that is in an early branch in the eukaryotic lineage. The 26S proteasome of Trypanosoma cruzi epimastigotes was identified as a high molecular weight complex (1400 kDa) with an ATP-dependent chymotrypsin-like activity against the substrate Suc-LLVY-Amc. This activity was inhibited by proteasome inhibitors and showed same electrophorectic migration pattern as yeast 26S proteasome in nondenaturating gels. About 30 proteins in a range of 25-110 kDa were detected in the purified T. cruzi 26S proteasome. Antibodies raised against the AAA family of ATPases from eukaryotic 26S proteasome and the T. cruzi 20S core specifically recognized components of T. cruzi 26S. To confirm the biological role of 26S in this primitive eukaryotic parasite, we analyzed the participation of the ubiquitin (Ub)-proteasome system in protein degradation during the time of parasite remodeling. Protein turnover in trypomastigotes was proteasome and ATP-dependent and was enhanced during the transformation of the parasites into amastigotes. If 20S proteasome activity is inhibited, ubiquitinated proteins accumulate in the parasites. As expected from the profound morphological changes that occur during transformation, cytoskeletal proteins associated with the flagellum are targets of the ubiquitin-proteasome pathway
— id: 26801, year: 2001, vol: 40, page: 1053, stat: Journal Article,

Exploring the transcriptome of the malaria sporozoite stage
Kappe SH; Gardner MJ; Brown SM; Ross J; Matuschewski K; Ribeiro JM; Adams JH; Quackenbush J; Cho J; Carucci DJ; Hoffman SL; Nussenzweig V
2001 Aug 14;98(17):9895-9900, Proceedings of the National Academy of Sciences of the United States of America
Most studies of gene expression in Plasmodium have been concerned with asexual and/or sexual erythrocytic stages. Identification and cloning of genes expressed in the preerythrocytic stages lag far behind. We have constructed a high quality cDNA library of the Plasmodium sporozoite stage by using the rodent malaria parasite P. yoelii, an important model for malaria vaccine development. The technical obstacles associated with limited amounts of RNA material were overcome by PCR-amplifying the transcriptome before cloning. Contamination with mosquito RNA was negligible. Generation of 1,972 expressed sequence tags (EST) resulted in a total of 1,547 unique sequences, allowing insight into sporozoite gene expression. The circumsporozoite protein (CS) and the sporozoite surface protein 2 (SSP2) are well represented in the data set. A BLASTX search with all tags of the nonredundant protein database gave only 161 unique significant matches (P(N) < or = 10(-4)), whereas 1,386 of the unique sequences represented novel sporozoite-expressed genes. We identified ESTs for three proteins that may be involved in host cell invasion and documented their expression in sporozoites. These data should facilitate our understanding of the preerythrocytic Plasmodium life cycle stages and the development of preerythrocytic vaccines
— id: 25508, year: 2001, vol: 98, page: 9895, stat: Journal Article,

Identification of the class XIV myosins Pb-MyoA and Py-MyoA and expression in Plasmodium sporozoites
Matuschewski K; Mota MM; Pinder JC; Nussenzweig V; Kappe SH
2001 Jan 15;112(1):157-161, Molecular & biochemical parasitology
— id: 26792, year: 2001, vol: 112, page: 157, stat: Journal Article,

Phosphatidylinositol-specific phospholipase C (PI-PLC) cleavage of GPI-anchored surface molecules of Trypanosoma cruzi triggers in vitro morphological reorganization of trypomastigotes
Mortara RA; Minelli LM; Vandekerckhove F; Nussenzweig V; Ramalho-Pinto FJ
2001 Jan-Feb;48(1):27-37, Journal of eukaryotic microbiology
Trypanosoma cruzi trypomastigotes treated with phosphatidylinositol-specific phospholipase C (PI-PLC) in vitro are rapidly induced to differentiate into round forms. Using confocal microscopy, we were able to show that trypomastigotes treated with PI-PLC initiate the process of flagellum remodeling by 30 sec after contact with the enzyme and amastigote-like forms are detected as early as 10 min after PI-PLC treatment. Scanning and transmission electron microscopy indicate that trypomastigotes undergo a previously undescribed process of flagellum circularization and internalization. Analysis of the flagellar complex with monoclonal antibody 4D9 shows heterogeneous labeling among the parasites, suggesting a remodeling of these molecules. After PI-PLC treatment, parasites rapidly lose the surface marker Ssp-3 and 24 h post-treatment they begin to exhibit a circular nucleus and a rod-shaped kinetoplast. By flow cytometry analysis and confocal microscopy, the Ssp-4 amastigote-specific epitope can be detected on the parasite surface. This indicates that the release of trypomastigote GPI-anchored molecules by exogenous PI-PLC in vitro can trigger morphological changes
— id: 61951, year: 2001, vol: 48, page: 27, stat: Journal Article,

Migration of Plasmodium sporozoites through cells before infection
Mota MM; Pradel G; Vanderberg JP; Hafalla JC; Frevert U; Nussenzweig RS; Nussenzweig V; Rodriguez A
2001 Jan 5;291(5501):141-144, Science
Intracellular bacteria and parasites typically invade host cells through the formation of an internalization vacuole around the invading pathogen. Plasmodium sporozoites, the infective stage of the malaria parasite transmitted by mosquitoes, have an alternative mechanism to enter cells. We observed breaching of the plasma membrane of the host cell followed by rapid repair. This mode of entry did not result in the formation of a vacuole around the sporozoite, and was followed by exit of the parasite from the host cell. Sporozoites traversed the cytosol of several cells before invading a hepatocyte by formation of a parasitophorous vacuole, in which they developed into the next infective stage. Sporozoite migration through several cells in the mammalian host appears to be essential for the completion of the life cycle
— id: 16067, year: 2001, vol: 291, page: 141, stat: Journal Article,

Gene targeting in the rodent malaria parasite Plasmodium yoelii
Mota MM; Thathy V; Nussenzweig RS; Nussenzweig V
2001 Apr 6;113(2):271-278, Molecular & biochemical parasitology
It is anticipated that the sequencing of Plasmodium falciparum genome will soon be completed. Rodent models of malaria infection and stable transformation systems provide powerful means of using this information to study gene function in vivo. To date, gene targeting has only been developed for one rodent malaria species, Plasmodium berghei. Another rodent species, Plasmodium yoelii, however, is favored to study the mechanisms of protective immunity to the pre-erythrocytic stages of infection and vaccine development. In addition, it offers the opportunity to investigate unique aspects of pathogenesis of blood stage infection. Here, we report on the stable transfection and gene targeting of P. yoelii. Purified late blood stage schizonts were used as targets for electroporation with a plasmid that contains a pyrimethamine-resistant form of the P. berghei dihydrofolate reductase-thymidylate synthase (Pbdhfr-ts) fused to green fluorescent protein (gfp) gene. After drug selection, fluorescent parasites contained intact, non-rearranged plasmids that remain stable under drug-pressure. In addition, we used another dhfr-ts/gfp based plasmid to disrupt the P. yoelii trap (thrombospondin-related anonymous protein) locus by site-specific integration. The phenotype of P. yoelii TRAP knockout was identical to that previously reported for the P. berghei TRAP knockout. In the absence of TRAP, the erythrocytic cycle, gametocyte and oocyst development of the mutant parasites were indistinguishable from wild type (WT). Although the sporozoites appeared morphologically normal, they failed to glide and to invade the salivary glands of mosquitoes
— id: 26746, year: 2001, vol: 113, page: 271, stat: Journal Article,

Host-microbe interactions: Parasites parasitology, genetics and cell biology intertwined. Editorial overview
Nussenzweig V
2001 ;4(4):399-401, Current opinion in microbiology
— id: 26879, year: 2001, vol: 4, page: 399, stat: Journal Article,

Complementation of Plasmodium berghei TRAP knockout parasites using human dihydrofolate reductase gene as a selectable marker
Sultan AA; Thathy V; de Koning-Ward TF; Nussenzweig V
2001 Mar;113(1):151-156, Molecular & biochemical parasitology
Previously we have used the Plasmodium dihydrofolate reductase thymidylate synthase (DHFR-TS) selectable marker to generate Plasmodium berghei TRAP null mutant parasites. These TRAP null mutants do not glide and they showed a great reduction in their ability to infect mosquito salivary glands and the hepatocytes of the vertebrate host. Thus far, complementation of these knockout parasites was not possible due to the lack of additional selectable markers. Recently, a new selectable marker, based on the human dihydrofolate reductase (hDHFR) gene, has been developed which confers resistance to the antifolate drug WR99210. This drug has been found to be highly active against pyrimethamine-sensitive and -resistant strains of P. berghei. In this study, we have used the hDHFR gene as a second selectable marker for the complementation of P. berghei TRAP null mutant parasites. Restoration of the TRAP null mutant parasites to the wild-type phenotype was achieved in this study via autonomously replicating episomes bearing a wild-type copy of the TRAP gene. This is the first report of complementation of a mutant phenotype in malaria parasites
— id: 21233, year: 2001, vol: 113, page: 151, stat: Journal Article,

The ubiquitin-proteasome pathway plays an essential role in proteolysis during Trypanosoma cruzi remodeling
de Diego, JL; Gonzalez, J; Marshall, P; Manning, JE; Nussenzweig, V
2000 Nov 06-08;95(Suppl. 2):271-271, Memorias do Instituto Oswaldo Cruz
— id: 15769, year: 2000, vol: 95, page: 271, stat: Journal Article,

Antibodies against thrombospondin-related anonymous protein do not inhibit Plasmodium sporozoite infectivity in vivo
Gantt S; Persson C; Rose K; Birkett AJ; Abagyan R; Nussenzweig V
2000 Jun;68(6):3667-3673, Infection & immunity
Thrombospondin-related anonymous protein (TRAP), a candidate malaria vaccine antigen, is required for Plasmodium sporozoite gliding motility and cell invasion. For the first time, the ability of antibodies against TRAP to inhibit sporozoite infectivity in vivo is evaluated in detail. TRAP contains an A-domain, a well-characterized adhesive motif found in integrins. We modeled here a three-dimensional structure of the TRAP A-domain of Plasmodium yoelii and located regions surrounding the MIDAS (metal ion-dependent adhesion site), the presumed business end of the domain. Mice were immunized with constructs containing these A-domain regions but were not protected from sporozoite challenge. Furthermore, monoclonal and rabbit polyclonal antibodies against the A-domain, the conserved N terminus, and the repeat region of TRAP had no effect on the gliding motility or sporozoite infectivity to mice. TRAP is located in micronemes, secretory organelles of apicomplexan parasites. Accordingly, the antibodies tested here stained cytoplasmic TRAP brightly by immunofluorescence. However, very little TRAP could be detected on the surface of sporozoites. In contrast, a dramatic relocalization of TRAP onto the parasite surface occurred when sporozoites were treated with calcium ionophore. This likely mimics the release of TRAP from micronemes when a sporozoite contacts its target cell in vivo. Contact with hepatoma cells in culture also appeared to induce the release of TRAP onto the surface of sporozoites. If large amounts of TRAP are released in close proximity to its cellular receptor(s), effective competitive inhibition by antibodies may be difficult to achieve
— id: 11693, year: 2000, vol: 68, page: 3667, stat: Journal Article,

Plasmodium sporozoites invade cells with targeted deletions in the LDL receptor related protein
Marshall P; Rohlmann A; Nussenzweig V; Herz J; Sinnis P
2000 Mar 5;106(2):293-298, Molecular & biochemical parasitology
— id: 10109, year: 2000, vol: 106, page: 293, stat: Journal Article,

Structure-function analysis of malaria proteins by gene targeting
Menard R; Nussenzweig V
2000 Jun;16(6):222-224, Parasitology today
— id: 61952, year: 2000, vol: 16, page: 222, stat: Journal Article,

Plasmodium trap as a target of humoral immunity against sporozoites
Gantt, Soren; Keith, Rose; Abagayan, Ruben; Nussenzweig, Victor
1999 Nov 09-11;94(SUPPL. 2):211-211, Memorias do Instituto Oswaldo Cruz
— id: 15818, year: 1999, vol: 94, page: 211, stat: Journal Article,

Conservation of a gliding motility and cell invasion machinery in Apicomplexan parasites
Kappe S; Bruderer T; Gantt S; Fujioka H; Nussenzweig V; Menard R
1999 Nov 29;147(5):937-944, Journal of cell biology
Most Apicomplexan parasites, including the human pathogens Plasmodium, Toxoplasma, and Cryptosporidium, actively invade host cells and display gliding motility, both actions powered by parasite microfilaments. In Plasmodium sporozoites, thrombospondin-related anonymous protein (TRAP), a member of a group of Apicomplexan transmembrane proteins that have common adhesion domains, is necessary for gliding motility and infection of the vertebrate host. Here, we provide genetic evidence that TRAP is directly involved in a capping process that drives both sporozoite gliding and cell invasion. We also demonstrate that TRAP-related proteins in other Apicomplexa fulfill the same function and that their cytoplasmic tails interact with homologous partners in the respective parasite. Therefore, a mechanism of surface redistribution of TRAP-related proteins driving gliding locomotion and cell invasion is conserved among Apicomplexan parasites
— id: 11916, year: 1999, vol: 147, page: 937, stat: Journal Article,

Pre-erythrocytic malaria vaccine: mechanisms of protective immunity and human vaccine trials
Nardin E; Zavala F; Nussenzweig V; Nussenzweig RS
1999 Sep;41(1-3):397-402, Parassitologia
In order to provide a rational basis for the development of a pre-erythrocytic malaria vaccine we have aimed at: (a) elucidating the mechanisms of protection, and (b) identifying vaccine formulations that best elicit protection in experimental animals and humans. Based on earlier successful immunization of experimental animals with irradiated sporozoites, human volunteers were exposed to the bites of large numbers of Plasmodium falciparum or P. vivax infected irradiated mosquitoes. The result of this vaccine trial demonstrated for the first time that a pre-erythrocytic vaccine, administered to humans, can result in their complete resistance to malaria infection. However, since infected irradiated mosquitoes are unavailable for large scale vaccination, the alternative is to develop subunit vaccines. The human trials using irradiated sporozoites provided valuable information on the human immune responses to pre-erythrocytic stages and studies on mice an excellent experimental model to characterize protective immune mechanisms. The circumsporozoite protein, the first pre-erythrocytic antigen identified, is present in all malaria species, displaying a similar structure, with a central region of repeats, and two conserved regions, essential for parasite development. Most pre-erythrocytic vaccine candidates are based on the CS protein, expressed in various cell lines, microorganisms, and recently the corresponding DNA. We and others have identified CS-specific B and T cell epitopes, recognized by the rodent and human immune systems, and used them for the development of synthetic vaccines. We used synthetic peptide vaccines, multiple antigen peptides and polyoximes, for immunization, first in experimental animals, and recently in two human safety and immunogenicity trials. We also report here on our work on T cell mediated immunity, particularly the protection of mice immunized with viral vectors expressing CS-specific cytotoxic CD8+ T cell epitopes, and the striking booster effect of recombinant vaccinia virus. To what degree CD8+ T cells, and/or other T cells specific for sporozoites and/or liver stage epitopes, contribute to pre-erythrocytic protective immunity in humans, remains to be determined
— id: 11814, year: 1999, vol: 41, page: 397, stat: Journal Article,

Rationale for the development of a malaria vaccine
Nussenzweig, V
1999 FEB ;6(1):64-64, Transfusion clinique & biologique
— id: 98322, year: 1999, vol: 6, page: 64, stat: Journal Article,

Gliding motility and cell invasion by Malariasporozoites
Nussenzweig, Victor
1999 Nov 09-11;94(SUPPL. 2):12-12, Memorias do Instituto Oswaldo Cruz
— id: 15819, year: 1999, vol: 94, page: 12, stat: Journal Article,

Characterization of a novel trypanosome lytic factor from human serum
Raper J; Fung R; Ghiso J; Nussenzweig V; Tomlinson S
1999 Apr;67(4):1910-1916, Infection & immunity
Natural resistance of humans to the cattle pathogen Trypanosoma brucei brucei has been attributed to the presence in human serum of nonimmune factors that lyse the parasite. Normal human serum contains two trypanosome lytic factors (TLFs). TLF1 is a 500-kDa lipoprotein, which is reported to contain apolipoprotein A-I (apoA-I), haptoglobin-related protein (Hpr), hemoglobin, paraoxonase, and apoA-II, whereas TLF2 is a larger, poorly characterized particle. We report here a new immunoaffinity-based purification procedure for TLF2 and TLF1, as well as further characterization of the components of each purified TLF. Immunoaffinity-purified TLF1 has a specific activity 10-fold higher than that of TLF1 purified by previously described methods. Moreover, we find that TLF1 is a lipoprotein particle that contains mainly apoA-I and Hpr, trace amounts of paraoxonase, apoA-II, and haptoglobin, but no detectable hemoglobin. Characterization of TLF2 reveals that it is a 1,000-kDa protein complex containing mainly immunoglobulin M, apoA-I, and Hpr but less than 1% detectable lipid
— id: 6065, year: 1999, vol: 67, page: 1910, stat: Journal Article,

Green fluorescent protein as a marker in Plasmodium berghei transformation
Sultan AA; Thathy V; Nussenzweig V; Menard R
1999 May;67(5):2602-2606, Infection & immunity
We present a new marker that confers both resistance to pyrimethamine and green fluorescent protein-based fluorescence on the malarial parasite Plasmodium berghei. A single copy of the cassette integrated into the genome is sufficient to direct fluorescence in parasites throughout the life cycle, in both its mosquito and vertebrate hosts. Erythrocyte stages of the parasite that express the marker can be sorted from control parasites by flow cytometry. Pyrimethamine pressure is not necessary for maintaining the cassette in transformed parasites during their sporogonic cycle in mosquitoes, including when it is borne by a plasmid. This tool should thus prove useful in molecular studies of P. berghei, both for generating parasite variants and monitoring their behavior
— id: 56430, year: 1999, vol: 67, page: 2602, stat: Journal Article,

Adhesive proteins of the malaria parasite
Coppel RL; Brown GV; Nussenzweig V
1998 Aug;1(4):472-481, Current opinion in microbiology
Malaria infection of the host cells requires host-parasite recognition events mediated by adhesion and signaling molecules. Recent development of systems for stable transformation and targeted integration of exogenous DNA in malaria parasites provides a powerful tool to study the structure and function of Plasmodium attachment motifs, and their role in infection and disease
— id: 7537, year: 1998, vol: 1, page: 472, stat: Journal Article,

Proteasome inhibitors block development of Plasmodium spp
Gantt SM; Myung JM; Briones MR; Li WD; Corey EJ; Omura S; Nussenzweig V; Sinnis P
1998 Oct;42(10):2731-2738, Antimicrobial agents & chemotherapy
Proteasomes degrade most of the proteins inside eukaryotic cells, including transcription factors and regulators of cell cycle progression. Here we show that nanomolar concentrations of lactacystin, a specific irreversible inhibitor of the 20S proteasome, inhibit development of the exoerythrocytic and erythrocytic stages of the malaria parasite. Although lactacystin-treated Plasmodium berghei sporozoites are still invasive, their development into exoerythrocytic forms (EEF) is inhibited in vitro and in vivo. Erythrocytic schizogony of P. falciparum in vitro is also profoundly inhibited when drug treatment of the synchronized parasites is prior, but not subsequent, to the initiation of DNA synthesis, suggesting that the inhibitory effect of lactacystin is cell cycle specific. Lactacystin reduces P. berghei parasitemia in rats, but the therapeutic index is very low. Along with other studies showing that lactacystin inhibits stage-specific transformation in Trypanosoma and Entamoeba spp., these findings highlight the potential of proteasome inhibitors as drugs for the treatment of diseases caused by protozoan parasites
— id: 57151, year: 1998, vol: 42, page: 2731, stat: Journal Article,

Characterization of the human serum trypanosome toxin, haptoglobin-related protein
Muranjan M; Nussenzweig V; Tomlinson S
1998 Feb 13;273(7):3884-3887, Journal of biological chemistry
Haptoglobin-related protein (HPR) is a serum protein that is >90% homologous to the acute-phase reactant haptoglobin (Hp). Haptoglobin binds and removes free hemoglobin (Hb) from the circulation. Hpr levels are elevated with tumor progression in the serum of some cancer patients, but the relevance of this observation is not understood. HPR is an integral part of two distinct high molecular weight complexes (trypanosome lytic factor 1 (TLF1) and TLF2) that are lytic for the African parasite Trypanosoma brucei brucei. Previous data indicate that HPR represents the toxic component of both trypanosome lytic factors. It has been proposed that after uptake by the parasite, Hb bound to HPR causes lysis in a peroxidase-dependent process. We report that the molecular architecture of HPR in normal human serum is different from that of Hp and that HPR does not bind Hb in normal human serum. Immunodepletion of all detectable Hb from TLF1 does not deplete TLF1 of HPR or trypanolytic activity, suggesting that the mechanism of parasite lysis is Hb-independent
— id: 7699, year: 1998, vol: 273, page: 3884, stat: Journal Article,

Proteasome function is required for encystation of Entamoeba invadens
Gonzalez J; Frevert U; Corey EJ; Nussenzweig V; Eichinger D
1997 ;28 Spec No:139-140, Archives of medical research (Mexico)
— id: 12421, year: 1997, vol: 28 Spec No, page: 139, stat: Journal Article,

Circumsporozoite protein is required for development of malaria sporozoites in mosquitoes
Menard R; Sultan AA; Cortes C; Altszuler R; van Dijk MR; Janse CJ; Waters AP; Nussenzweig RS; Nussenzweig V
1997 Jan 23;385(6614):336-340, Nature
Malaria parasites undergo a sporogonic cycle in the mosquito vector. Sporozoites, the form of the parasite injected into the host during a bloodmeal, develop inside oocysts in the insect midgut, then migrate to and eventually invade the salivary glands. The circumsporozoite protein (CS), one of the major proteins synthesized by salivary gland sporozoites, is a surface-associated molecule which is important in sporozoite infectivity to the host. Here, by gene targeting, we created Plasmodium berghei lines in which the single-copy CS gene was disrupted. The CS(-) and wild-type parasites produced similar numbers of oocysts of comparable size in the mosquito midgut. In the CS(-) oocysts, however, sporozoite formation was profoundly inhibited. CS therefore appears to have a pleiotropic role and to be vital for malaria parasites in both the vector and the host: in mosquitoes, CS is essential for sporozoite development within oocysts, and in the vertebrate host it promotes sporozoite attachment to hepatocytes
— id: 57532, year: 1997, vol: 385, page: 336, stat: Journal Article,

Malaria sporozoites and chylomicron remnants compete for binding sites in the liver
Nussenzweig V
1997 Mar;(99):85-89, Behring Institute mitteilungen
Like Malaria sporozoites and the circumsporozoite protein, remnants of lipoproteins are rapidly cleared from the circulation and enter hepatocytes. Here we review the evidence that the same set of liver heparan sulfate proteoglycans are the initial binding sites of malaria sporozoites and the lipoprotein remnants
— id: 12288, year: 1997, vol: , page: 85, stat: Journal Article,

Same surface proteins of malaria sporozoites are required for parasite development in mosquitoes and in mammalian hosts
Nussenzweig, V
1997 NOV ;8(5):1372-1372, Molecular biology of the cell
— id: 53167, year: 1997, vol: 8, page: 1372, stat: Journal Article,

Sporozoites of Plasmodium yoelii infect mice with targeted deletions in ICAM-1 and ICAM-2 or complement components C3 and C4
Sultan AA; Briones MR; Gerwin N; Carroll MC; Nussenzweig V
1997 Sep;88(1-2):263-266, Molecular & biochemical parasitology
— id: 57000, year: 1997, vol: 88, page: 263, stat: Journal Article,

TRAP is necessary for gliding motility and infectivity of plasmodium sporozoites
Sultan AA; Thathy V; Frevert U; Robson KJ; Crisanti A; Nussenzweig V; Nussenzweig RS; Menard R
1997 Aug 8;90(3):511-522, Cell
Many protozoans of the phylum Apicomplexa are invasive parasites that exhibit a substrate-dependent gliding motility. Plasmodium (malaria) sporozoites, the stage of the parasite that invades the salivary glands of the mosquito vector and the liver of the vertebrate host, express a surface protein called thrombospondin-related anonymous protein (TRAP) that has homologs in other Apicomplexa. By gene targeting in a rodent Plasmodium, we demonstrate that TRAP is critical for sporozoite infection of the mosquito salivary glands and the rat liver, and is essential for sporozoite gliding motility in vitro. This suggests that in Plasmodium sporozoites, and likely in other Apicomplexa, gliding locomotion and cell invasion have a common molecular basis
— id: 57001, year: 1997, vol: 90, page: 511, stat: Journal Article,

Haptoglobin-related protein and apolipoprotein AI are components of the two trypanolytic factors in human serum
Tomlinson S; Muranjan M; Nussenzweig V; Raper J
1997 May;86(1):117-120, Molecular & biochemical parasitology
— id: 7272, year: 1997, vol: 86, page: 117, stat: Journal Article,

Human alternative complement pathway-mediated lysis of rabbit erythrocytes is enhanced by natural anti-Galalpha1-3Gal antibodies
Tomlinson S; Nussenzweig V
1997 Dec 1;159(11):5606-5609, Journal of immunology
Human serum is effective at lysing unsensitized rabbit erythrocytes due to activation of the alternative complement pathway. Hemolysis is known to be enhanced by the addition of human IgG. We demonstrate that the enhancement of alternative pathway-mediated rabbit E lysis by human Ig is due to natural Abs specific for galactosyl (Gal)alpha1-3Gal. Depletion of normal human serum (NHS) of anti-Galalpha1-3Gal Abs removes almost all hemolytic activity from NHS, and activity can be restored by repletion with anti-Galalpha1-3Gal affinity-purified Abs. Factor B-depleted serum (inactive alternative pathway) did not lyse rabbit erythrocytes. Although C2-depleted serum was fully hemolytic, activity was removed by depletion of anti-Galalpha1-3Gal Abs. Of the total anti-Galalpha1-3Gal Abs affinity isolated from NHS, about one-third were IgM and two-thirds were IgG. Both anti-Galalpha1-3Gal IgG and IgM enhanced alternative pathway-mediated erythrocyte lysis
— id: 7977, year: 1997, vol: 159, page: 5606, stat: Journal Article,

Mapping the active site of CD59
Yu J; Abagyan R; Dong S; Gilbert A; Nussenzweig V; Tomlinson S
1997 Feb 17;185(4):745-753, Journal of experimental medicine
CD59 is a widely distributed membrane-bound inhibitor of the cytolytic membrane attack complex (MAC) of complement. This small (77 amino acid) glycoprotein is a member of the Ly6 superfamily of proteins and is important in protecting host cells from the lytic and proinflammatory activity of the MAC. CD59 functions by binding to C8 and/or C9 in the nascent MAC and interfering with C9 membrane insertion and polymerization. We present data obtained from a combination of molecular modeling and mutagenesis techniques, which together indicate that the active site of CD59 is located in the vicinity of a hydrophobic groove on the face of the molecule opposite to a 'hydrophobic strip' suggested earlier. In addition, removal of the single N-linked glycosylation site at Asn18 of CD59 resulted in an enhancement of complement inhibitory activity
— id: 8361, year: 1997, vol: 185, page: 745, stat: Journal Article,

The large difference in infectivity for mice of Plasmodium berghei and Plasmodium yoelii sporozoites cannot be correlated with their ability to enter into hepatocytes
Briones MR; Tsuji M; Nussenzweig V
1996 Apr;77(1):7-17, Molecular & biochemical parasitology
Sporozoites of P. yoelii nigeriensis are 50-100-times more infective to mice than the strain NK65 of P. berghei. To study the mechanisms involved in this striking difference in the infectivity of these closely related species of malaria parasites, we have developed a quantitative PCR targeted to parasite-specific ribosomal RNA. Using this method, we detect RNA from a single sporozoite, and exo-erythorcytic forms of RNA in the livers of mice injected with 200 sporozoites. We find that 20 h after sporozoite injection, there is no significant difference between the amounts of P. berghei and P. yoelii rRNA in the livers of C57/BL6 mice, indicating that these two parasite species invade hepatocytes with similar efficiency. Between 20 and 40 h, however, P. yoelii RNA increases 11 times, while P. berghei RNA increases only 1.6 times. We conclude that the greater infectivity of P. yoelii sporozoites in these mice reflects, at least in part, their superior development in hepatocytes. These data provide for the first time in vivo evidence supporting the notion that species-specificity of malaria is not determined by mechanisms associated with sporozoite attachment and penetration into the hepatocytes
— id: 7914, year: 1996, vol: 77, page: 7, stat: Journal Article,

Cell surface glycosaminoglycans are not obligatory for Plasmodium berghei sporozoite invasion in vitro
Frevert U; Sinnis P; Esko JD; Nussenzweig V
1996 Feb-Mar;76(1-2):257-266, Molecular & biochemical parasitology
The malaria circumsporozoite (CS) protein binds to glycosaminoglycan chains from heparan sulfate proteoglycans present on the basolateral surface of hepatocytes and hepatoma cells in vitro. When injected into mice, CS protein is rapidly cleared from the blood circulation by hepatocytes. The binding region for the HSPGs is the evolutionarily conserved region II-plus of the CS protein. Here we have asked whether the presence of glycosaminoglycans on the plasma membrane of target cells is required for sporozoite invasion in vitro. Two types of target cells were used: HepG2 cells, which are permissive for Plasmodium berghei sporozoite development into mature exoerythrocytic forms, and CHO cells, in which the intracellular development of the parasites is arrested early after penetration. The invasion of mutant CHO cells expressing undersulfated glycosaminoglycans or no glycosaminoglycans was only inhibited 41-49% or 24-32%, respectively, in comparison to invasion of CHO-K1 cells. Previous cleavage of HepG2 surface membrane glycosaminoglycans with heparinase or heparitinase had no significant inhibitory effect on subsequent P. berghei sporozoite invasion and EEF development in these cells, although the glycosaminoglycan lyase treatments removed over 80% of CS binding sites from the cell surface. These results suggest that although the presence of glycosaminoglycans on the target cell surface enhances sporozoite invasion, glycosaminoglycans are not required for sporozoite penetration or the development of exoerythrocytic forms in vitro
— id: 10110, year: 1996, vol: 76, page: 257, stat: Journal Article,

Proteasome activity is required for the stage-specific transformation of a protozoan parasite
Gonzalez J; Ramalho-Pinto FJ; Frevert U; Ghiso J; Tomlinson S; Scharfstein J; Corey EJ; Nussenzweig V
1996 Nov 1;184(5):1909-1918, Journal of experimental medicine
A prominent feature of the life cycle of intracellular parasites is the profound morphological changes they undergo during development in the vertebrate and invertebrate hosts. In eukaryotic cells, most cytoplasmic proteins are degraded in proteasomes. Here, we show that the transformation in axenic medium of trypomastigotes of Trypanosoma cruzi into amastigote-like organisms, and the intracellular development of the parasite from amastigotes into trypomastigotes, are prevented by lactacystin, or by a peptide aldehyde that inhibits proteasome function. Clasto-lactacystin, an inactive analogue of lactacystin, and cell-permeant peptide aldehyde inhibitors of T. cruzi cysteine proteinases have no effect. We have also identified the 20S proteasomes from T. cruzi as a target of lactacystin in vivo. Our results document the essential role of proteasomes in the stage-specific transformation of a protozoan
— id: 8375, year: 1996, vol: 184, page: 1909, stat: Journal Article,

Interaction between complement proteins C5b-7 and erythrocyte membrane sialic acid
Marshall P; Hasegawa A; Davidson EA; Nussenzweig V; Whitlow M
1996 Oct 1;184(4):1225-1232, Journal of experimental medicine
The initial phase of membrane attack by complement is the interaction between C5b6, C7, and the cell membrane that leads to the insertion of C5b-7. Here we investigate the role of sialic acid residues in the assembly of C5b-7 intermediates on erythrocyte cell membranes. We find that C5b6 binds to glycophorin, whereas C5 or C6 does not bind, and desialylation of the glycophorin abolishes C5b6 binding. Complement lysis is inhibited by either masking glycophorin sialic acid with F(ab) fragments of an mAb, or by removal of the sialylated region of glycophorin by mild trypsinization. Gangliosides inhibit C5b-7 deposition when added to the aqueous phase. Asialogangliosides and synthetic gangliosides lacking the carboxylic acid residue have no inhibitory activity. We conclude that C5b6 binds to sialylated molecules on the erythrocyte surface. We propose a new model of membrane attack in which C5b6 initially binds to membranes via ionic forces. C7 then binds to C5b6, disrupting the ionic interaction and leading to the exposure of hydrophobic domains. Sialic acid is known to inhibit complement activation. Thus, these findings reveal a paradoxical role for sialic acid in complement attack; the presence of sialic acid inhibits the generation of C5b6, but once the membrane attack pathway is initiated, sialic acid enhances complement lysis
— id: 61953, year: 1996, vol: 184, page: 1225, stat: Journal Article,

Lack of correlation between haptoglobin concentration and trypanolytic activity of normal human serum
Raper J; Nussenzweig V; Tomlinson S
1996 Feb-Mar;76(1-2):337-338, Molecular & biochemical parasitology
— id: 12646, year: 1996, vol: 76, page: 337, stat: Journal Article,

The main lytic factor of Trypanosoma brucei brucei in normal human serum is not high density lipoprotein
Raper J; Nussenzweig V; Tomlinson S
1996 Mar 1;183(3):1023-1029, Journal of experimental medicine
Natural immunity of humans to the cattle pathogen Trypanosoma brucei brucei has been attributed to the presence in normal human serum (NHS) of lytic factors for the parasites. We and others have shown that NHS contains two trypanolytic factors (herein termed TLF1 and TLF2) that can be separated by gel filtration. TLF1 copurifies with a subclass of high density lipoprotein (HDL), whereas TLF2 has a much higher molecular weight and does not appear to be a lipoprotein. We find that the trypanolytic activity of purified TLF1 is totally inhibited by exogenous haptoglobin (Hp) at concentrations (0.1 mg/ml) lower than those present in NHS (0.2-2 mg/ml). In contrast, exogenous Hp (up to 2.5 mg/ml) has no effect on the lytic activity of either NHS or isolated TLF2. Hp-depleted sera from patients with intravascular hemolysis is severalfold more trypanolytic than NHS. These sera contain only TLF1, and their lytic activity is totally abolished upon the addition of Hp (0.1 mg/ml). When NHS containing different Hp allotypes is fractionated by gel filtration, TLF1 activity is either revealed or remains masked, depending on whether it coelutes with Hp. Masked TLF1 activity in the column fractions is revealed if Hp is removed by density gradient ultracentrifugation. We conclude that endogenous Hp inhibits TLF1 activity, and that TLF2 is the main trypanolytic factor in NHS
— id: 6951, year: 1996, vol: 183, page: 1023, stat: Journal Article,

Preventing sporozoite invasion of hepatocytes
Sinnis P; Nussenzweig V
Malaria vaccine development : a multi-immune response approach Washington, D.C. : ASM Press, 1996,
— id: 4242, year: 1996, vol: , page: 15, stat: Chapter,

Remnant lipoproteins inhibit malaria sporozoite invasion of hepatocytes
Sinnis P; Willnow TE; Briones MR; Herz J; Nussenzweig V
1996 Sep 1;184(3):945-954, Journal of experimental medicine
Remnants of lipoproteins, intestinal chylomicrons, and very low density lipoprotein (VLDL), are rapidly cleared from plasma and enter hepatocytes. It has been suggested that remnant lipoproteins are initially captured in the space of Disse by heparan sulfate proteoglycans (HSPGs), and that their subsequent internalization into hepatocytes is mediated by members of the LDL-receptor gene family. Similarly to lipoprotein remnants, malaria sporozoites are removed from the blood circulation by the liver within minutes after injection by Anopheles mosquitoes. The sporozoite's surface is covered by the circumsporozoite protein (CS), and its region II-plus has been implicated in the binding of the parasites to glycosaminoglycan chains of hepatocyte HSPGs. Lactoferrin, a protein with antibacterial properties found in breast milk and neutrophil granules, is also rapidly cleared from the circulation by hepatocytes, and can inhibit the hepatic uptake of lipoprotein remnants. Here we provide evidence that sporozoites, lactoferrin, and remnant lipoproteins are cleared from the blood by similar mechanisms. CS, lactoferrin, and remnant lipoproteins compete in vitro and in vivo for binding sites on liver cells. The relevance of this binding event for sporozoite infectivity is highlighted by our demonstration that apoliprotein E-enriched beta-VLDI and lactoferrin inhibit sporozoite invasion of HepG2 cells. In addition, malaria sporozoites are less infective in LDL-receptor knockout (LDLR -/-) mice maintained on a high fat diet, as compared with littermates maintained on a normal diet. We conclude that the clearance of lipoprotein remnants and sporozoites from the blood is mediated by the same set of highly sulfated HSPGs on the hepatocyte plasma membrane
— id: 8442, year: 1996, vol: 184, page: 945, stat: Journal Article,

Sporozoite ligand and hepatocyte receptors of malaria parasites
Sinnis, P; Frevert, U; Shakibaei, M; Nussenzweig, RS; Nussenzweig, V
1996 DEC ;7(3):1980-1980, Molecular biology of the cell
— id: 53357, year: 1996, vol: 7, page: 1980, stat: Journal Article,

Remnant lipoproteins inhibit malaria sporozoite invasion of hepatocytes
Sinnis, P; Willnow, T; Briones, M; Herz, J; Nussenzweig, V
1996 MAR ;44(3):A200-A200, Journal of investigative medicine
— id: 52936, year: 1996, vol: 44, page: A200, stat: Journal Article,

High-density-lipoprotein-independent killing of Trypanosoma brucei by human serum
Tomlinson S; Jansen AM; Koudinov A; Ghiso JA; Choi-Miura NH; Rifkin MR; Ohtaki S; Nussenzweig V
1995 Mar;70(1-2):131-138, Molecular & biochemical parasitology
The cattle pathogen Trypanosoma brucei brucei is morphologically indistinguishable from the human pathogens T.b. rhodesiense and T.b. gambiense. However, unlike the human pathogens, T.b. brucei is lysed by normal human serum (NHS). The trypanolytic factor in NHS co-purifies with high-density lipoproteins (HDL), but its precise nature is unknown. Using a new fluorescence-based viability assay to assess T.b. brucei killing, we find that the HDL-deficient sera from two patients with Tangier disease are as trypanolytic as NHS. Fractionation of the Tangier sera by density ultracentrifugation revealed that the activity resides only in lipoprotein-depleted fractions. Tangier and NHS were also subjected to molecular sieving chromatography, and the activity profiles were identical. Lytic fractions to T. brucei (but not to T. rhodesiense) appeared under two distinct peaks of 100-600 kDa and > 1000 kDa. Neither peak coincided with the position of the major serum lipoproteins, as determined by cholesterol titrations. The high-molecular-mass peak did not contain the HDL-associated apolipoprotein-A1. Further, we did not find that purified apolipoproteins A1 or J are lytic for the trypanosomes. We conclude that the killing of T. brucei by human serum can be independent of HDL
— id: 56721, year: 1995, vol: 70, page: 131, stat: Journal Article,

The induction of Trypanosoma cruzi trypomastigote to amastigote transformation by low pH
Tomlinson S; Vandekerckhove F; Frevert U; Nussenzweig V
1995 Jun;110(Pt 5):547-554, Parasitology
Following cell invasion, Trypanosoma cruzi trypomastigotes transform into amastigotes, which are the mammalian replicative forms of the parasite. Although amastigotes represent a critical stage in the life-cycle of T. cruzi, little is known of the factors controlling trypomastigote to amastigote transformation. Kanbera et al. (1990) observed that exposure of trypomastigotes to acidic pH induced their transformation into rounded forms resembling amastigotes. We confirm their observation and, using two strains of T. cruzi, establish that these transformants are ultrastructurally and biochemically indistinguishable from natural amastigotes. Incubation of trypomastigotes in medium at pH 5.0 for 2 h was sufficient to trigger their transformation into forms resembling amastigotes. Electron microscopical analysis confirmed that the kinetoplast structure, and general morphological features of the acid-induced, extracellular amastigotes were indistinguishable from those of intracellular-derived amastigotes. The extracellular transformation was accompanied by the acquisition of the stage-specific surface antigen of the naturally transformed amastigotes (Ssp-4), and loss of a stage-specific trypomastigote antigen (Ssp-3). Trypomastigotes incubated at neutral pH did not transform into amastigotes, and did not acquire the Ssp-4 epitope or lose the Ssp-3 epitope. Finally, acid-induced amastigotes subsequently incorporated [3H]thymidine into their DNA, indicating that the important replicative property of intracellular amastigotes is also exhibited by these in vitro transformants. This effect of low pH appears to be of physiological relevance, and acid-induced extracellular transformation appears to represent a valid experimental technique for studies of the molecular mechanisms involved in the differentiation process
— id: 8070, year: 1995, vol: 110, page: 547, stat: Journal Article,

Rapid clearance of malaria circumsporozoite protein (CS) by hepatocytes
Cerami C; Frevert U; Sinnis P; Takacs B; Nussenzweig V
1994 Feb 1;179(2):695-701, Journal of experimental medicine
The circumsporozoite protein (CS) covers uniformly the plasma membrane of malaria sporozoites. In vitro, CS multimers bind specifically to regions of the hepatocyte plasma membrane that are exposed to circulating blood in the Disse space. The ligand is in the region II-plus of CS, an evolutionarily conserved stretch of the protein that has amino acid sequence homology to a cell adhesive motif of thrombospondin. We have now found that intravenously injected CS constructs bind rapidly to the basolateral surface of hepatocytes, provided that the recombinant proteins contain region II-plus, and that they are aggregated. Significant amounts of CS were not retained in any other organ. The striking parallelism between these in vitro and in vivo findings with the target specificity of malaria sporozoites, reinforces the hypothesis that the attachment of the parasites to hepatocytes is via region II-plus of CS
— id: 6331, year: 1994, vol: 179, page: 695, stat: Journal Article,

Meeting on Parasites and the invertebrate vector. John D and Catherine T MacArthur Foundation, November 18-21, 1993
Kaslow DC; Nussenzweig V; Miller L
1994 Apr-Jun;89(2):279-295, Memorias do Instituto Oswaldo Cruz
— id: 61954, year: 1994, vol: 89, page: 279, stat: Journal Article,

Trans-sialidase and sialidase activities discriminate between morphologically indistinguishable trypanosomatids
Medina-Acosta E; Franco AM; Jansen AM; Sampol M; Neves N; Pontes-de-Carvalho L; Grimaldi Junior G; Nussenzweig V
1994 Oct 1;225(1):333-339, European journal of biochemistry
The expression of trans-sialidase and sialidase activities in the kinetoplastid protozoa was explored as a potential marker to discriminate between the morphologically indistinguishable flagellates isolated from human, insects and vertebrate reservoir hosts. By virtue of the differences observed in the ratios of these enzyme activities, a collection of 52 species and strains comprising the major taxa of these parasites could be separated into four expression types. Type-I parasites express comparable levels of both trans-sialidase and sialidase activities (Endotrypanum species and Trypanosoma lewisi). Type-II parasites express predominantly trans-sialidase activity (Trypanosoma cruzi and Trypanosoma conorhini). Type-III parasites express sialidase activity exclusively (Trypanosoma rangeli and Trypanosoma leeuwenhoeki). Type-IV parasites do not express either activity (Leishmania species and Trypanoplasma borreli). The measurement of trans-sialidase and sialidase activities thus permits the differentiation of parasites frequently found in the same insect vectors that are difficult to distinguish, such as T. cruzi and T. rangeli, or in the same sylvatic vertebrate and invertebrate hosts, such as Leishmania and Endotrypanum
— id: 6689, year: 1994, vol: 225, page: 333, stat: Journal Article,

CIGARETTE-SMOKING IN JAPAN
NUSSENZWEIG, V; BIGGS, HM
1994 FEB 5 ;343(8893):365-365, Lancet
— id: 52603, year: 1994, vol: 343, page: 365, stat: Journal Article,

Intrasplenic immunization with infected hepatocytes: a mouse model for studying protective immunity against malaria pre-erythrocytic stage
Renia L; Rodrigues MM; Nussenzweig V
1994 May;82(1):164-168, Immunology
Malaria liver forms are the target of antibody or T-cell-mediated immune mechanisms induced by previous or subsequent developmental stages of the parasite. The potential for vaccine development of antigens expressed exclusively in the liver stages has not been fully explored partly because of the lack of an experimental animal model. Here we show that protective immunity against sporozoite-induced infection with Plasmodium yoelii and P. berghei can be obtained by intrasplenic injection of a small number of liver stages of the parasites. The serum of the protected animals did not contain antibodies against sporozoites, liver or blood stage malaria parasites. Protective immunity was abolished by depletion of either CD4+ or CD8+ T cells from the vaccinated mice before challenge
— id: 12976, year: 1994, vol: 82, page: 164, stat: Journal Article,

Structural and functional properties of Trypanosoma trans-sialidase
Schenkman S; Eichinger D; Pereira ME; Nussenzweig V
1994 ;48:499-523, Annual review of microbiology
Sialic acids and sialidases play important roles in cellular interactions and modulate the recognition of pathogenic microbes by mammalian host cells. Protozoan parasites of the genus Trypanosoma express a unique sialic acid-metabolizing enzyme. This enzyme, named trans-sialidase (TS), catalyzes the transfer of sialic acids from host glycoconjugates to acceptor molecules of the parasite plasma membrane. In African trypanosomes, the agents of sleeping sickness, TS is found only in forms developing within the insect vector, and the enzyme sialylates the major surface protein. In Trypanosoma cruzi, the causative agent of Chagas' disease in Central and South America, TS is expressed both in the insect and mammalian forms of the parasite. The T. cruzi enzyme has been biochemically characterized, and the gene encoding the enzyme has been cloned. The enzyme sialylates abundant mucin-like molecules present on the surface of the parasite. Several lines of evidence suggest that TS and sialic acid acceptors on the surface of T. cruzi participate in host-parasite interactions and mediate the initial stages of the trypanosomes' invasion of host cells
— id: 56524, year: 1994, vol: 48, page: 499, stat: Journal Article,

Structural and functional properties of region II-plus of the malaria circumsporozoite protein
Sinnis P; Clavijo P; Fenyo D; Chait BT; Cerami C; Nussenzweig V
1994 Jul 1;180(1):297-306, Journal of experimental medicine
During feeding, infected mosquitos inject malaria sporozoites into the host circulation. Within minutes, the parasites are found in the liver where they initiate the first stage of malaria infection. All species of malaria sporozoites are uniformly covered by the circumsporozoite protein (CS), which contains a conserved COOH-terminal sequence called region II-plus. We have previously shown that region II-plus is the parasite's hepatocyte-binding ligand and that this ligand binds to heparan sulfate proteoglycans (HSPGs) on the hepatocyte membrane. Using a series of substituted region II-plus peptides, we show here that the downstream basic amino acids as well as the interdispersed hydrophobic residues are required for binding of CS to hepatocyte HSPGs. We also show that this positively charged stretch of amino acids must be aggregated in order to bind to the receptor. On the basis of this information, we have synthesized a multiple antigen peptide that mimics the hepatocyte-binding ligand. This construct inhibits both CS binding to HepG2 cells in vitro as well as CS clearance in mice
— id: 6520, year: 1994, vol: 180, page: 297, stat: Journal Article,

MECHANISM OF ENTRY OF MALARIA PARASITES INTO HEPATOCYTES
SINNIS, P; CERAMI, C; FREVERT, U; NUSSENZWEIG, V
1994 APR ;42(2):A303-A303, Clinical research
— id: 52501, year: 1994, vol: 42, page: A303, stat: Journal Article,

Role of sialic acid in the resistance of Trypanosoma cruzi trypomastigotes to complement
Tomlinson S; Pontes de Carvalho LC; Vandekerckhove F; Nussenzweig V
1994 Oct 1;153(7):3141-3147, Journal of immunology
Trypomastigotes of Trypanosoma cruzi, mammalian infective forms of the parasite, express an unusual cell surface trans-sialidase. This enzyme enables the parasite to rapidly sialylate its surface when supplied with alpha(2,3)-linked sialic acid from glycoconjugates in serum or on cell surfaces. Here we used a novel fluorescence-based, trypomastigote lysis assay to evaluate the role of sialic acid on the parasite's plasma membrane in providing protection against the complement cascade. Trypomastigotes were desialylated, and sialic acid removal was confirmed by a chemical assay and also by flow cytometry with the use of a mAb that recognizes a T. cruzi-sialylated epitope. Compared with sialylated trypomastigotes, which were completely refractory to lysis by human serum, only about 5% of the desialylated trypomastigotes were lysed by complement. However, further analysis revealed that the desialylated parasites had been resialylated during exposure to serum complement. Next we incubated desialylated trypomastigotes with samples of desialylated human serum. Although the sialidase-treated serum retained its full hemolytic activity, lysis of trypomastigotes increased only from 5 to 24%. This increase correlated with an enhanced deposition of complement protein C3 on the parasite surface. The ratio of C3b to lytically inactive iC3b was increased for desialylated, compared with sialylated, parasites. We conclude that although parasite sialic acid promotes C3b cleavage into iC3b, this mechanism alone does not account for the robust resistance of these parasites to complement lysis
— id: 12882, year: 1994, vol: 153, page: 3141, stat: Journal Article,

A synthetic peptide from complement protein C9 binds to CD59 and enhances lysis of human erythrocytes by C5b-9
Tomlinson S; Whitlow MB; Nussenzweig V
1994 Feb 15;152(4):1927-1934, Journal of immunology
The membrane glycoprotein CD59 protects host cells from homologous complement attack by inhibiting the assembly of the membrane attack complex. CD59 binds to C8 and C9 in the nascent membrane attack complex and interferes with C9 membrane insertion and polymerization. We show here that a synthetic peptide from the putative C9 hinge region, postulated to be involved in the rearrangement of C9 globular domains during membrane insertion, binds specifically to CD59 and enhances lysis of human erythrocytes by the terminal complement C5b-9 complex. The peptide, C9H, caused a dose-dependent increase in the sensitivity of human erythrocytes to C5b-9-mediated lysis by interfering with the final C9 binding and/or membrane insertion step. C9H exhibited species-specificity, since it had no activity against guinea pig C8 and C9 or on the putative functional homologues of CD59 in guinea pig erythrocytes. A direct association between CD59 and C9H was suggested by two different binding experiments: C9H inhibited the binding of 125I-labeled CD59 to immobilized C9, and C9H immobilized to microtiter plates bound purified CD59 and selectively recognized CD59 from extracts of detergent-solubilized human erythrocyte membranes. These data indicate that the peptide C9H corresponds to a region of the CD59 binding site of C9
— id: 7888, year: 1994, vol: 152, page: 1927, stat: Journal Article,

Malaria circumsporozoite protein binds to heparan sulfate proteoglycans associated with the surface membrane of hepatocytes
Frevert U; Sinnis P; Cerami C; Shreffler W; Takacs B; Nussenzweig V
1993 May 1;177(5):1287-1298, Journal of experimental medicine
During feeding by infected mosquitoes, malaria sporozoites are injected into the host's bloodstream and enter hepatocytes within minutes. The remarkable target cell specificity of this parasite may be explained by the presence of receptors for the region II-plus of the circumsporozoite protein (CS) on the basolateral domain of the plasma membrane of hepatocytes. We have now identified these receptors as heparan sulfate proteoglycans (HSPG). The binding of CS to the receptors is abolished by heparitinase treatment, indicating that the recognition of region II-plus is via the glycosaminoglycan chains. We have purified and partially characterized the CS-binding HSPGs from HepG2 cells. They have a molecular weight of 400,000-700,000, are tightly associated with the plasma membrane, and are released from the cell surface by very mild trypsinization, a property which the CS receptors share with the syndecan family of proteoglycans
— id: 6374, year: 1993, vol: 177, page: 1287, stat: Journal Article,

Characterization of a novel trans-sialidase of Trypanosoma brucei procyclic trypomastigotes and identification of procyclin as the main sialic acid acceptor
Pontes de Carvalho LC; Tomlinson S; Vandekerckhove F; Bienen EJ; Clarkson AB; Jiang MS; Hart GW; Nussenzweig V
1993 Feb 1;177(2):465-474, Journal of experimental medicine
Here we report the presence of a trans-sialidase on the surface of Trypanosoma brucei culture-derived procyclic trypomastigotes. The enzyme is not detected in lysates of bloodstream trypomastigotes enriched for either stumpy or slender forms. The trans-sialidase catalyzes the transfer of alpha(2-3)-linked sialic acid residues to lactose. beta-galactopyranosyl residues are at least 100 times better acceptors for sialic acid than alpha-galactopyranosyl residues. In the absence of efficient acceptors, the purified enzyme transfers sialic acid to water, i.e., it acts as a sialidase. Although the T. cruzi and T. brucei trans-sialidases have very similar donor and acceptor specificities, they are antigenically distinct. Sodium dodecyl sulfate-polyacramide gel electrophoresis under nonreducing conditions and silver staining of the purified trans-sialidase reveals a single band of 63 kD. When the surface membrane of live procyclic trypomastigotes is trans-sialylated, using radioactive sialyllactose as the donor substrate, it appears that the only sialylated surface molecule is procyclin. Pronase treatment of live parasites removes only part of the surface sialic acid, in agreement with recent data showing that the glycosylphosphatidylinositol anchor of procyclin is sialylated (Ferguson, M. A. J., M. Murray, H. Rutherford, and M. J. McConville. 1993. Biochem. J. In press)
— id: 13271, year: 1993, vol: 177, page: 465, stat: Journal Article,

Trypanosoma rangeli sialidase lacks trans-sialidase activity
Pontes-de-Carvalho LC; Tomlinson S; Nussenzweig V
1993 Nov;62(1):19-25, Molecular & biochemical parasitology
Extracts and tissue culture supernatants of axenic forms of T. rangeli were assayed for the presence of sialidase and trans-sialidase activities. Using sialyl(alpha 2-3)lactose, sialyl(alpha 2-6)lactose, poly(alpha 2-8)N-acetylneuraminic acid, fetuin and 4-methylumbelliferyl-N-acetylneuraminic acid as sialic acid donors, and lactose as a sialic acid acceptor, no trans-sialidase activity was detected. Nevertheless, T. rangeli lysates and culture supernatants contain a sialidase that hydrolyzes sialyl(alpha 2-3)lactose, and much less efficiently sialyl(alpha 2-6)lactose, but not poly(alpha 2-8)N-acetylneuraminic acid. T. cruzi trans-sialidase hydrolyzed only sialyl(alpha 2-3)lactose under the same conditions. The T. rangeli and the T. cruzi enzymes differ antigenically and in their pH optimum for hydrolase activity
— id: 56574, year: 1993, vol: 62, page: 19, stat: Journal Article,

Transgenic mice expressing C-reactive protein are susceptible to infection with Plasmodium yoelii sporozoites
Renia L; Xia D; Samols D; Nussenzweig V
1993 Jan;61(1):348-349, Infection & immunity
Human and rat C-reactive proteins, major acute-phase reactants, bind to sporozoites and inhibit their in vitro development in hepatocytes (A. Nussler, S. Pied, M. Pontet, F. Miltgen, L. Renia, M. Gentilini, and D. Mazier, Exp. Parasitol. 72:1-7, 1991, and S. Pied, A. Nussler, M. Pontet, F. Miltgen, H. Matile, P.-H. Lambert, and D. Mazier, Infect. Immun. 57:278-282, 1989). We show here that rabbit C-reactive protein has identical properties. Nevertheless, infection by Plasmodium yoelii sporozoites was not prevented in transgenic mice engineered to express rabbit C-reactive protein following induction of gluconeogenesis
— id: 13305, year: 1993, vol: 61, page: 348, stat: Journal Article,

Cells lacking glycan phosphatidylinositol-linked proteins have impaired ability to vesiculate
Whitlow M; Iida K; Marshall P; Silber R; Nussenzweig V
1993 Jan 15;81(2):510-516, Blood
Erythrocytes shed membrane vesicles in response to many stimuli. It has been previously demonstrated that glycan phosphatidylinositol-linked (GPI-linked) proteins such as decay accelerating factor and acetylcholinesterase are concentrated in these vesicles relative to the erythrocyte membrane. We have examined the requirement for GPI-linked proteins for the process of vesiculation. Erythrocytes that do not express GPI-linked proteins, obtained from patients with paroxysmal nocturnal hemoglobinuria (PNH), release between 10% and 50% of the quantity of vesicles as normal cells in response to the Ca2+ ionophore A23187. Platelets from the same patients produced 10% to 20% of the amount of vesicles as normal platelets. In addition, a mutant B-lymphoblastoid cell line that lacks GPI-linked molecules produces about half of the number of vesicles as compared with the wild-type cell line in response to the Ca2+ ionophore. Prior findings indicate that vesiculation is one of the mechanisms that the cell uses to remodel the plasma membrane, as well as protect itself from membrane-damaging agents such as the terminal complement components C5b-9. On the basis of the present results, we conclude that GPI-linked proteins play an important role in membrane vesiculation
— id: 61955, year: 1993, vol: 81, page: 510, stat: Journal Article,

Molecular parasitology at Woods Hole
Borst P; Nussenzweig V
1992 Dec 11;71(6):895-899, Cell
— id: 61956, year: 1992, vol: 71, page: 895, stat: Journal Article,

The basolateral domain of the hepatocyte plasma membrane bears receptors for the circumsporozoite protein of Plasmodium falciparum sporozoites
Cerami C; Frevert U; Sinnis P; Takacs B; Clavijo P; Santos MJ; Nussenzweig V
1992 Sep 18;70(6):1021-1033, Cell
Minutes after injection into the circulation, malaria sporozoites enter hepatocytes. The speed and specificity of the invasion process suggest that it is receptor mediated. We show here that recombinant Plasmodium falciparum circumsporozoite protein (CS) binds specifically to regions of the plasma membrane of hepatocytes exposed to circulating blood in the Disse space. No binding has been detected in other organs, or even in other regions of the hepatocyte membrane. The interaction of CS with hepatocytes, as well as sporozoite invasion of HepG2 cells, is inhibited by synthetic peptides representing the evolutionarily conserved region II of CS. We conclude that region II is a sporozoite ligand for hepatocyte receptors localized to the basolateral domain of the plasma membrane. Our findings provide a rational explanation for the target cell specificity of malaria sporozoites
— id: 57534, year: 1992, vol: 70, page: 1021, stat: Journal Article,

Binding of malarial circumsporozoite protein to sulfatides [Gal(3-SO4)beta 1-Cer] and cholesterol-3-sulfate and its dependence on disulfide bond formation between cysteines in region II
Cerami C; Kwakye-Berko F; Nussenzweig V
1992 Aug;54(1):1-12, Molecular & biochemical parasitology
Region II of the malaria circumsporozoite (CS) protein is highly conserved between the CS proteins of different species of malaria. Amino acid sequences homologous to that of region II are found in thrombospondin, properdin, von Willebrand factor and a few other proteins. We show here that the native CS protein from the rodent parasite Plasmodium berghei, and recombinant Plasmodium vivax and Plasmodium falciparum CS proteins containing region II, but not recombinant proteins lacking region II, specifically bind to sulfatides and cholesterol-3-sulfate. The binding is abolished following reduction and alkylation of the proteins. Region II contains 2 cysteines separated by only 3 amino acids, S(N), V, T, and these are the only cysteines present in our recombinant proteins. Therefore, our findings strongly suggest that the region II cysteines are linked by a disulfide bond forming a small peptide loop. We also present evidence that the recognition of sulfatides, cholesterol-3-sulfate, or other cross-reactive sulfated macromolecules by region II may be required during sporozoite invasion of liver cells. Antibodies to a peptide representing region II react with live sporozoites and with sporozoites fixed with glutaraldehyde, indicating that this region is exposed on the surface of the parasites. Furthermore, we have found that the sulfatide and cholesterol-3-sulfate recognition by the CS proteins, and the invasion of hepatocytes by P. berghei sporozoites, are specifically inhibited by dextran sulfate
— id: 13486, year: 1992, vol: 54, page: 1, stat: Journal Article,

An improved polymerase chain reaction assay to detect Trypanosoma cruzi in blood
Diaz C; Nussenzweig V; Gonzalez A
1992 May;46(5):616-623, American journal of tropical medicine & hygiene
Amplification by the polymerase chain reaction of Trypanosoma cruzi satellite DNA was used to enhance sensitivity in the detection of the parasite in blood, with the ultimate goal of improving diagnosis of the chronic phase of Chagas' disease. Two contiguous oligonucleotides were synthesized corresponding to the most conserved region of the 195-basepair repeated sequence and used as primers for the amplification reaction. Nineteen femtograms of parasite DNA that was amplified in the presence of 15 micrograms of human or mouse DNA produced a visible band upon electrophoresis in agarose gels and staining with ethidium bromide. In reconstitution experiments, one parasite in 10 ml of blood could be unambiguously determined when the DNA was isolated from nuclei after the blood was treated with NP40 and centrifuged. Polymerase chain reaction assays were carried out to detect T. cruzi in chronically infected mice. Most mice were parasite-positive when organs or tissues were tested, but all were negative when total blood was tested
— id: 13606, year: 1992, vol: 46, page: 616, stat: Journal Article,

Stage-specific expression and intracellular shedding of the cell surface trans-sialidase of Trypanosoma cruzi
Frevert U; Schenkman S; Nussenzweig V
1992 Jun;60(6):2349-2360, Infection & immunity
We have used antibodies to the Trypanosoma cruzi trans-sialidase and to its product, the host cell invasion-related Ssp-3 epitope, to study the expression of the corresponding antigens during the intracellular development of the parasite and in the extracellular trypomastigotes. As soon as 2 h after host cell invasion, trans-sialidase was no longer detected, whereas the Ssp-3 epitope was still present on intracellular parasites. The amastigotes which subsequently developed remained nonreactive with the antibodies. Expression of enzymatically active T. cruzi trans-sialidase started again only after transformation of the amastigotes into trypomastigotes 72 h after host cell invasion. trans-Sialidase was shed from the trypanosomes into the host cell cytoplasm, where the enzyme accumulated until release of the parasites. All released trypomastigotes expressed trans-sialidase on their surfaces and in the flagellar pockets, but stumpy trypomastigotes were stained more intensely than slender trypomastigotes. Ssp-3, the sialylated reaction product of trans-sialidase, was assembled only after rupture of the host cell membrane and was detected on the plasma membranes and in the flagellar pockets of all trypomastigotes
— id: 13588, year: 1992, vol: 60, page: 2349, stat: Journal Article,

Evidence for the participation of the Ssp-3 antigen in the invasion of nonphagocytic mammalian cells by Trypanosoma cruzi
Schenkman S; Kurosaki T; Ravetch JV; Nussenzweig V
1992 Jun 1;175(6):1635-1641, Journal of experimental medicine
Trypomastigotes of Trypanosoma cruzi have to invade mammalian cells in order to multiply. They bear on their plasma membrane a sialic acid-containing epitope (Ssp-3) defined by a series of monoclonal antibodies (mAbs). Previous investigations have shown that Fab fragments of these mAbs inhibit the attachment of trypomastigotes to 3T3 fibroblasts. To further define the role of Ssp-3 in invasion, here we use, as targets for infection, L cells and CHO cells stably transfected with cDNA coding for the mouse Fc receptors genes. When the trypomastigotes are incubated with small, nonagglutinating amounts of antibodies to Ssp-3, their attachment to the transfected cells is greatly enhanced, without a parallel increase in invasion. The enhancement in attachment is Fc mediated, since it is abolished by treatment of the transfected cells with mAbs to Fc receptors. In contrast, both attachment to, and invasion of, the transfected cells are increased if the parasites are incubated with polyclonal or monoclonal antibodies against T. cruzi surface membrane antigens other than Ssp-3. If, however, antibodies to Ssp-3 are added to the incubation mixtures containing any of the other anti-T. cruzi antibodies, the enhancement of invasion (but not of attachment) is reversed. These results suggest that Ssp-3-bearing molecules participate in the process of parasite internalization
— id: 61958, year: 1992, vol: 175, page: 1635, stat: Journal Article,

Trypanosoma cruzi trans-sialidase and neuraminidase activities can be mediated by the same enzymes
Schenkman S; Pontes de Carvalho L; Nussenzweig V
1992 Feb 1;175(2):567-575, Journal of experimental medicine
Trans-sialidase and neuraminidase activities have been detected on the surface membrane of trypomastigotes of Trypanosoma cruzi, and both have been implicated in the parasite's invasion of host cells. We show here that these enzymes are structurally related. They are recognized by two independently derived monoclonal antibodies, are anchored to the membrane by glycosylphosphatidylinositol, copurify by ion exchange, molecular sieving, and hydrophobic chromatography, have maximal activities between pH 6.5 and 7.5, and are inactivated by heating at 56 degrees C. Furthermore, the neuraminidase and trans-sialidase reactions are coupled. An increase of the concentration of acceptors of the transfer reaction decreases the amount of free sialic acid released through the neuraminidase reaction. We conclude that a single enzyme can catalyze the transfer or the hydrolysis of macromolecular-bound sialic acid. The predominant direction of the reaction will depend on the availability of appropriate oligosaccharide acceptors of sialic acid
— id: 61959, year: 1992, vol: 175, page: 567, stat: Journal Article,

Resialylation of sialidase-treated sheep and human erythrocytes by Trypanosoma cruzi trans-sialidase: restoration of complement resistance of desialylated sheep erythrocytes
Tomlinson S; Pontes de Carvalho L; Vandekerckhove F; Nussenzweig V
1992 Dec;2(6):549-551, Glycobiology
Trypanosoma cruzi trans-sialidase (TS) is a recently described enzyme which transfers alpha(2-3)-linked sialic acid from host-derived sialylated glycoconjugates to parasite surface molecules [Schenkman et al. (1991) Cell, 65, 1117]. We report here on the ability of TS to transfer sialic acid from donor sialyl-alpha(2-3)lactose to sialidase-treated sheep and human erythrocytes. Up to approximately 50% resialylation of both desialylated red cells could be attained. Resialylation of desialylated sheep erythrocytes restores their resistance to lysis by human complement. This ascribes a possible biological role for T. cruzi TS and demonstrates directly that sialic acid is solely responsible for preventing alternative pathway activation of human complement by sheep erythrocytes
— id: 13346, year: 1992, vol: 2, page: 549, stat: Journal Article,

Only some members of a gene family in Trypanosoma cruzi encode proteins that express both trans-sialidase and neuraminidase activities
Uemura H; Schenkman S; Nussenzweig V; Eichinger D
1992 Nov;11(11):3837-3844, EMBO journal
Trypomastigotes, the blood stage form of the human parasite Trypanosoma cruzi, contain an enzyme on their surface, trans-sialidase, which catalyses the transfer of sialic acid from host glycoconjugates to acceptors on its own cell surface. At least a subset of the sialic acid-bearing acceptor molecules are involved in parasite invasion of host cells, an essential step in the life cycle of the parasite. Another trypomastigote surface enzyme that affects host cell invasion is neuraminidase and recent evidence suggests that both trans-sialidase and neuraminidase activities may be expressed by the same proteins on the parasite surface. We describe here the isolation and expression of several members of a trans-sialidase--neuraminidase gene family from T.cruzi. One of the isolated genes does indeed encode a protein with both trans-sialidase and neuraminidase activities, while other members of the gene family encode closely related proteins that express neither enzymatic activity. Chimeric protein constructs combining different portions of active and inactive genes identified a region of the gene necessary for enzymatic activity. Sequence analysis of this portion of the gene revealed a limited number of amino acid differences between the predicted active and inactive gene products
— id: 61957, year: 1992, vol: 11, page: 3837, stat: Journal Article,

Substrate specificity of the Trypanosoma cruzi trans-sialidase
Vandekerckhove F; Schenkman S; Pontes de Carvalho L; Tomlinson S; Kiso M; Yoshida M; Hasegawa A; Nussenzweig V
1992 Dec;2(6):541-548, Glycobiology
Trypanosoma cruzi trypomastigotes acquire sialic acid (SA) from host glycoconjugates by means of a plasma membrane-associated trans-sialidase (TS). Here we study the substrate specificity of TS, which differs from all known sialyltransferases in that it does not require cytidine monophosphate (CMP)-SA as donor. The T. cruzi TS reversibly transfers SA to saccharides with terminal beta-Gal (but not alpha-Gal) residues. Donors are saccharides with SA linked to terminal beta-Gal residues by (alpha 2-3), but not (alpha 2-6) bonds. The type of beta-linkage of the terminal Gal residue is of minor importance (beta 1-4 and beta 1-6 are slightly better than beta 1-3), whereas chain length and the structure of additional vicinal sugar residues are not relevant. SA on the surface of living trypomastigotes of T. cruzi is transferred back and forth between the parasite surface and acceptor molecules with terminal beta-Gal, either in solution or on the surface of neighbouring mammalian cells. Addition of fucose residue on or close to the terminal galactose impairs TS activity. As a consequence, the enzyme acts poorly on the E-selectin ligand sialyl-Lewisx and its precursor Lewisx, and in vitro adhesion of TS-treated neutrophils to L-cells expressing L-selectin is not affected. Modifications in the structure of the (alpha 2-3)-linked N-acetyl-neuraminic acid (Neu5Ac) (deoxy or methoxy) of the donor molecules do not impair transfer if the changes are at C9, whereas changes at C4, C7 and C8 impair the ability to donate the modified SA.(ABSTRACT TRUNCATED AT 250 WORDS)
— id: 13364, year: 1992, vol: 2, page: 541, stat: Journal Article,

CELLS LACKING GLYCAN PHOSPHATIDYLINOSITOL-LINKED PROTEINS HAVE IMPAIRED ABILITY TO VESICULATE
WHITLOW, M; IIDA, K; MARSHALL, P; SILBER, R; ROSSE, W; NUSSENZWEIG, V
1992 APR ;40(2):A242-A242, Clinical research
— id: 51986, year: 1992, vol: 40, page: A242, stat: Journal Article,

Progress toward malaria preerythrocytic vaccines
Hoffman SL; Nussenzweig V; Sadoff JC; Nussenzweig RS
1991 Apr 26;252(5005):520-521, Science
— id: 61960, year: 1991, vol: 252, page: 520, stat: Journal Article,

Membrane vesiculation protects erythrocytes from destruction by complement
Iida K; Whitlow MB; Nussenzweig V
1991 Oct 15;147(8):2638-2642, Journal of immunology
Nucleated cells can resist attack by C by exocytosis or endocytosis of the terminal C components C5b-9 (membrane attack complex) (MAC), but it is generally accepted that formation of a single MAC channel on E leads to lysis (one-hit theory). We find that human and guinea pig E, but not SRBC, can eliminate the MAC from the membrane in the form of microvesicles and escape destruction. When guinea pig or human E are incubated with C5b-9, vesiculation proceeds without a lag and is detected at nonlytic doses of C9. Continuous Ca2+ influx is required for vesiculation. The amount of released vesicles is in direct relation to Ca2+ concentration, and the increase in vesiculation is associated with a parallel decrease in lysis. SRBC, which do not vesiculate when Ca2+ loaded, are lysed by C5b-9 with the same efficiency in the presence or absence of Ca2+. Vesicles released from guinea pig RBC under C5b-9 attack are enriched in C9 by a factor of 10, compared with the unlysed cells, and by a factor of 3 to 4, compared with ghosts. We conclude that E are protected from lysis not only by CD59 and C8bp/HRF, which prevent MAC assembly, but also by selective elimination of the MAC
— id: 8319, year: 1991, vol: 147, page: 2638, stat: Journal Article,

Attachment of Trypanosoma cruzi trypomastigotes to receptors at restricted cell surface domains
Schenkman S; Diaz C; Nussenzweig V
1991 Jan;72(1):76-86, Experimental parasitology
We have used glutaraldehyde-fixed target cells to study the attachment phase of cell invasion by live trypomastigotes of Trypanosoma cruzi, and determined that attachment is polarized and receptor-mediated. T. cruzi trypomastigotes bind much less efficiently to confluent epithelial cells, which are polarized, than to sparse epithelial cells. When the tight junctions of confluent epithelial cells are disrupted by removing Ca2+ from the incubation medium before glutaraldehyde fixation, binding of T. cruzi increases. T. cruzi also shows preference for attachment underneath cells or to the edges of cells. The binding occurs within a few minutes, is saturable, and is influenced by the parasite developmental stage. Fab fragment derived from monoclonal antibodies that immunoprecipitate a 160-kDa molecule present only on the surface of trypomastigotes inhibit adhesion to fixed and live cells. Future characterization of the target cell receptors for this molecule and the use of fixed target cells should facilitate studies of the mechanisms involved in the initial interaction of T. cruzi with its host cells
— id: 14172, year: 1991, vol: 72, page: 76, stat: Journal Article,

A novel cell surface trans-sialidase of Trypanosoma cruzi generates a stage-specific epitope required for invasion of mammalian cells
Schenkman S; Jiang MS; Hart GW; Nussenzweig V
1991 Jun 28;65(7):1117-1125, Cell
When trypomastigotes of T. cruzi emerge from cells of the mammalian host, they contain little or no sialic acids on their surfaces. However, rapidly upon entering the circulation, they express a unique cell surface trans-sialidase activity. This enzyme specifically transfers alpha (2-3)-linked sialic acid from extrinsic host-derived macromolecules to parasite surface molecules, leading to the assembly of Ssp-3, a trypomastigote-specific epitope. The T. cruzi trans-sialidase does not utilize cytidine 5' monophospho-N-acetylneuraminic acid as a donor substrate, but readily transfers sialic acid from exogenously supplied alpha (2-3)-sialyllactose. Monoclonal antibodies that recognize sialic acid residues of Ssp-3 inhibit attachment of trypomastigotes to host cells, suggesting that the unusual trans-sialidase provides Ssp-3 with structural features required for target cell recognition
— id: 13991, year: 1991, vol: 65, page: 1117, stat: Journal Article,

Attachment of Trypanosoma cruzi to mammalian cells requires parasite energy, and invasion can be independent of the target cell cytoskeleton
Schenkman S; Robbins ES; Nussenzweig V
1991 Feb;59(2):645-654, Infection & immunity
We have previously shown that the binding of Trypanosoma cruzi trypomastigotes to glutaraldehyde-fixed mammalian cells has the characteristics of a receptor-mediated process and that it mimics the attachment step of the invasion of live cells by this parasite. In this study we examined the metabolic requirements for the attachment of trypomastigotes to glutaraldehyde-fixed fibroblasts. The attachment of trypomastigotes to fixed cells is prevented when the energy conservation mechanisms are inhibited with the drugs 2-deoxyglucose, sodium azide, antimycin, crystal violet, oligomycin, N,N'-dicyclohexylcarbodiimide, and carbonyl cyanide 3-chlorophenylhydrazone. However, under the same experimental conditions, the movement of parasites is not significantly affected. Several of these drugs totally inhibit the penetration of the parasite into live target cells. We conclude that the attachment of trypomastigotes to mammalian cells is an active process that requires trypomastigote energy. In addition, we present evidence that penetration into nonphagocytic cells can also be an active process. Trypomastigotes can be seen in scanning electron micrographs traversing extended lamellipodia and entering paraformaldehyde-fixed epithelial cells. Cytochalasin D, a drug that disrupts microfilaments and prevents the formation of plasma membrane extensions mediated by actin, had little or no effect on trypomastigote invasion, while it inhibited Salmonella entry into epithelial cells
— id: 14146, year: 1991, vol: 59, page: 645, stat: Journal Article,

HUMAN STUDIES WITH SYNTHETIC PEPTIDE SPOROZOITE VACCINE (NANP)3-TT AND IMMUNIZATION WITH IRRADIATED SPOROZOITES
Herrington, DA; Clyde, DF; Davis, JR; Baqar, S; Murphy, JR; Cortese, JF; Bank, RS; Nardin, E; Dijohn, D; Nussenzweig, RS; Nussenzweig, V; Torres, JR; Murillo, J; Cortesia, M; Sturchler, D; Hollingdale, MR; Levine, MM
1990 Mar;68(1):33-37, Bulletin of the World Health Organization
The synthetic peptide Plasmodium falciparum circumsporozoite (CS) protein conjugate vaccine (NANP)3-TT was safe when given parenterally to 202 volunteers. However, with a few notable exceptions, antibody responses were low and could not be boosted. Vaccinees' lymphocytes did not proliferate when exposed in vitro to (NANP)3. The tetanus toxoid (TT) carrier immunomodulated the response to the CS peptide in that both epitopic suppression and immune enhancement were demonstrated during the course of the clinical trials. During efficacy challenge studies, 1 of 7 vaccinees was protected against sporozoite challenge and in other vaccinees the prepatent period was significantly delayed. P. falciparum-infected mosquitos were irradiated with 20 000 rad (200 Gy). Five volunteers were immunized with 54, 55, 224, 663, and 715 total infective bites of irradiated mosquitos in an attempt to immunize with attenuated sporozoites. Four of these volunteers had significant humoral and cellular immune responses. Two volunteers (who received the largest immunizing doses) were challenge by the bites of infective mosquitos and both developed parasitaemia. In the volunteer with the highest antibody titre there was a marked delay in patency as determined by serial plasmodial cultures. T-cell clones are being obtained and characterized
— id: 32217, year: 1990, vol: 68, page: 33, stat: Journal Article,

The exit of Trypanosoma cruzi from the phagosome is inhibited by raising the pH of acidic compartments
Ley V; Robbins ES; Nussenzweig V; Andrews NW
1990 Feb 1;171(2):401-413, Journal of experimental medicine
The protozoan parasite Trypanosoma cruzi can infect many distinct mammalian cell types. The parasites enter cells through the formation of phagocytic vacuoles, but later are found free in the cytosol, where they multiply as amastigotes. Using transmission electron microscopy we found that within 2 h after infection 70% of the parasites, including examples of both mammalian forms (trypomastigotes and amastigotes), were inside partially disrupted vacuoles or free in the cytosol. We demonstrated that the pH of vacuoles containing recently interiorized parasites is acidic, through immunocytochemical localization of the acidotropic compound DAMP (18) in their interior. Increasing the vacuolar pH with chloroquine, ammonium chloride, methylamine, or monensin significantly inhibited the escape of the parasites into the cytosol. These results are compatible with the hypothesis that an acid-active hemolysin of T. cruzi (15) might be involved in the escape mechanism
— id: 61963, year: 1990, vol: 171, page: 401, stat: Journal Article,

Progress toward a malaria vaccine
Nussenzweig V; Nussenzweig RS
1990 Sep 15;25(9):45-52, 55, Hospital practice (office edition)
In initial human trials, synthetic vaccines have induced humoral immunity sufficient to prevent clinical infection in some cases and delay it in others. Progress in induction of cellular immunity is also noteworthy with identification of determinants recognized by T cells. Antigenic variation and consequent blunting of immunogenicity may not be as troublesome as feared
— id: 61962, year: 1990, vol: 25, page: 45, stat: Journal Article,

Sporozoite malaria vaccine. Where do we stand?
Nussenzweig V; Nussenzweig S
1990 ;65 Suppl 1:49-52, Annales de parasitologie humaine & comparee
A sporozoite malaria vaccine which elicits high levels of antibodies to the circumsporozoite (CS) protein may protect part of the human population in areas of low endemicity. Other possible targets of a sporozoite vaccine are the liver stages, but in this case the effector cells are T-lymphocytes which recognize sporozoite-derived peptides in association with products of the major histocompatibility complex. There is no evidence that the variation observed in the CS protein of P. falciparum is driven by immunological pressure, nor that this variation will be a major impediment to vaccine development
— id: 61964, year: 1990, vol: 65 Suppl 1, page: 49, stat: Journal Article,

Incorporation of T and B epitopes of the circumsporozoite protein in a chemically defined synthetic vaccine against malaria
Tam JP; Clavijo P; Lu YA; Nussenzweig V; Nussenzweig R; Zavala F
1990 Jan 1;171(1):299-306, Journal of experimental medicine
We show here an effective and novel approach to engineer peptide-based vaccines using a chemically defined system, known as multiple peptide antigen systems (MAPs), to protect an inbred mouse strain from infection against rodent malaria. 10 mono- and di-epitope MAP models containing different arrangements and stoichiometry of functional B and/or T helper cell epitopes from the circumsporozoite protein of Plasmodium berghei were used to immunize A/J mice. While these mice did not respond to the mono-epitope MAP bearing only the B or T epitope, very high titers of antibody and protective immunity against sporozoite challenge were elicited by di-epitope MAPs, particularly those with the B and T epitopes in tandem and present in equimolar amounts. These results, obtained in a well-defined rodent malaria model, indicate that MAPs may overcome some of the difficulties in the development of synthetic vaccines, not only for malaria but also for other infectious diseases
— id: 23521, year: 1990, vol: 171, page: 299, stat: Journal Article,

H19, a surface membrane molecule involved in T-cell activation, inhibits channel formation by human complement
Whitlow MB; Iida K; Stefanova I; Bernard A; Nussenzweig V
1990 Mar;126(1):176-184, Cellular immunology
Here we compare the properties of leukocyte antigens H19 and CD59 with those of the PI-linked 18,000-20,000 Mr molecules which inhibit lysis of human cells by the autologous terminal complement components C5b-9. H19, a 19,000 Mr protein found on human erythrocytes, monocytes, neutrophils, T-lymphocytes and other cells, is one of the ligands involved in the spontaneous rosette formation between human T-lymphocytes and erythrocytes. Recent evidence indicates that H19 also participates in T-cell activation. CD59 is a widely distributed 18,000-25,000 Mr protein anchored to the cell membrane by phosphatidylinositol (PI). The function of CD59 is unknown. Affinity-purified H19 incorporates into cell membranes and inhibits channel formation by human C5b-9 on guinea pig erythrocytes. Significant inhibition is achieved with picogram quantities of H19, corresponding to approximately 600 molecules per erythrocyte. H19 is most effective when C9 is limiting but quite active when C5b-7 or C8 are limiting, indicating that it may interact with several of the structurally related terminal complement components. The inhibitory activity is blocked by mAbs to either CD59 or to H19. H19 is PI-anchored: it is released from the cell membrane by treatment with PI-specific phospholipase C, and it is absent from cells from a patient with paroxysmal nocturnal hemoglobinuria (PNH). Analysis of PNH erythrocytes after treatment with terminal complement proteins shows that the H19-negative erythrocytes are more susceptible to C5b-9-mediated lysis. Treatment of normal human erythrocytes with either anti-H19 or anti-CD59 renders them more susceptible to lysis by human C5b-9. We conclude that H19 and CD59 are probably the same molecule and are identical or closely related to the recently described inhibitors of C5b-9 channel formation
— id: 8318, year: 1990, vol: 126, page: 176, stat: Journal Article,

Plasmodium falciparum: restricted polymorphism of T cell epitopes of the circumsporozoite protein in Brazil
Yoshida N; Di Santi SM; Dutra AP; Nussenzweig RS; Nussenzweig V; Enea V
1990 Nov;71(4):386-392, Experimental parasitology
We examined the extent of variation of the 3' region of the circumsporozoite gene among Plasmodium falciparum isolates through amplification of a selected DNA fragment followed by DNA sequencing. A total of 32 isolates were analyzed, of which 24 were from Amazon endemic areas in Brazil and 8 from widely separated geographical regions in the world. Among Brazilian isolates only 2 variants were detected: 19 displayed the same sequence of strain 7G8 whereas the 4 remaining isolates differed from the 7G8 strain at five nucleotide positions which also led to amino acid changes. Variation was restricted to one of the T-helper epitopes while the sequence identified as a cytotoxic T cell epitope was conserved in all Brazilian isolates. P. falciparum samples from other geographical regions in the world showed sequences distinct from those of Brazilian isolates. However, some constancy could be observed within that variation. For instance, the most frequent nucleotide substitutions, from A and C at nucleotide positions 1015 and 1024, were the same in all isolates
— id: 61961, year: 1990, vol: 71, page: 386, stat: Journal Article,

Decay-accelerating factor in the cardiomyocytes of normal individuals and patients with myocardial infarction
Zimmermann A; Gerber H; Nussenzweig V; Isliker H
1990 ;417(4):299-304, Virchows archiv A. Pathological anatomy & histopathology
The presence of decay-accelerating factor (DAF) was clearly demonstrated on the surface of normal cardiomyocytes. In patients who had died of myocardial infarction (MI) cardiomyocytes displayed different appearances: outside the ischaemically damaged region the myocytes showed no significant variations in DAF expression when compared with controls without MI. Within myocardial zones damaged by ischaemia, however, apparently normal myocytes showed large gaps in surface staining of DAF or formed clusters which were entirely devoid of reactivity with anti-DAF antibodies. The number of DAF-deficient myocytes increased with the extent of necrosis and also with the number of days between onset of MI and death. Even though injury to myocytes is to a large extent related to anoxia and to the presence of free oxygen radicals, the complement system also appears to be involved; DAF may have protective functions against complement-mediated injury. We speculate that phospholipase may be involved in the removal of DAF from the cardiomyocyte surface
— id: 61965, year: 1990, vol: 417, page: 299, stat: Journal Article,

Presence of antibodies to the major surface glycoprotein of Trypanosoma cruzi amastigotes in sera from Chagasic patients
Andrews NW; Einstein M; Nussenzweig V
1989 Jan;40(1):46-49, American journal of tropical medicine & hygiene
The surface of amastigote forms of Trypanosoma cruzi is covered by a stage-specific glycoprotein, Ssp-4. We show that Y strain-derived Ssp-4 is recognized by antibodies in sera from Chagasic patients. All 51 sera reacted with the surface of amastigotes by indirect immunofluorescence assays and immunoprecipitated Ssp-4. The human antibodies inhibited the binding of monoclonal antibodies to Ssp-4 in immunoradiometric assays, suggesting that the corresponding region of the molecule may be conserved among distinct strains of the parasite
— id: 10848, year: 1989, vol: 40, page: 46, stat: Journal Article,

Amastigotes of Trypanosoma cruzi escape destruction by the terminal complement components
Iida K; Whitlow MB; Nussenzweig V
1989 Mar 1;169(3):881-891, Journal of experimental medicine
We studied the effect of complement on two life cycle stages of the protozoan parasite Trypanosoma cruzi: epimastigotes, found in the insect vector, and amastigotes, found in the mammalian host. We found that while both stages activate vigorously the alternative pathway, only epimastigotes are destroyed. The amounts of C3 and C5b-7 deposited on the amastigotes were similar to those bound to the much larger epimastigotes. Binding of C9 to amastigotes was four to six times less than binding to epimastigotes, resulting in a lower C9/C5b-7 ratio. Although a fairly large amount of C9 bound stably to amastigotes, no functional channels were formed as measured by release of incorporated 86Rb. The bound C9 had the characteristic properties of poly-C9, that is, it expressed a neo-antigen unique to poly-C9, and migrated in SDS-PAGE with an apparent Mr greater than 10(5). The poly-C9 was removed from the surface of amastigotes by treatment with trypsin, indicating that it was not inserted in the lipid bilayer. Modification of amastigote surface by pronase treatment rendered the parasites susceptible to complement attack. These results suggest that amastigotes have a surface protein that binds to the C5b-9 complex and inhibits membrane insertion, thus protecting the parasites from complement-mediated lysis
— id: 10718, year: 1989, vol: 169, page: 881, stat: Journal Article,

Antisporozoite vaccine for malaria: experimental basis and current status
Nussenzweig RS; Nussenzweig V
1989 May-Jun;11 Suppl 3:S579-S585, Reviews of infectious diseases
A major sporozoite surface antigen, the circumsporozoite protein, has been identified in all four malaria parasites affecting humans and in numerous species causing malaria in rodents and simians. The corresponding genes have been cloned and sequenced, and considerable similarities are apparent. An extensive central region of these proteins consists of tandemly repeated sequences of four to 16 amino acids. The sporozoite protein of Plasmodium falciparum has 37-41 repeats of four amino acids: NANP (asparagine-alanine-asparagine-proline). Most sera from people in endemic areas that react with sporozoites also recognize the dodecamer (NANP)3. Conjugated to a carrier, (NANP)3 is an excellent immunogen for rabbits and mice. NANP has recently served as the basis for two experimental malaria vaccines tested in volunteers. One of these vaccines, (NANP)32 tet32, was genetically engineered in Escherichia coli; the other consisted of the synthetic peptide (NANP)3 conjugated to tetanus toxoid. Most peptide-immunized volunteers developed antipeptide/sporozoite antibodies; however, there was no booster effect, and only one of three individuals was completely protected. For optimal protection, future vaccines must not only contain the B cell epitope but also induce T helper cells and cytotoxic T cells producing interferon-gamma, which has been shown to inhibit the development of liver-stage parasites
— id: 10645, year: 1989, vol: 11 Suppl 3, page: S579, stat: Journal Article,

Circumsporozoite proteins of malaria parasites
Nussenzweig V; Nussenzweig RS
1989 ;144(11):493-504, Bulletin et memoires de l'Academie royale de medecine de Belgique
— id: 61966, year: 1989, vol: 144, page: 493, stat: Journal Article,

Rationale for the development of an engineered sporozoite malaria vaccine
Nussenzweig V; Nussenzweig RS
1989 ;45:283-334, Advances in immunology
— id: 10789, year: 1989, vol: 45, page: 283, stat: Journal Article,

Cloned cytotoxic T cells recognize an epitope in the circumsporozoite protein and protect against malaria
Romero P; Maryanski JL; Corradin G; Nussenzweig RS; Nussenzweig V; Zavala F
1989 Sep 28;341(6240):323-326, Nature
Protective immunity against malaria is induced by vaccination of hosts with irradiation-attenuated sporozoites. This immunity is mediated in part by neutralizing antibodies that are directed mainly against the repeat domain of the circumsporozoite protein. Early experiments showed, however, that B-cell-depleted mice that are immunized with sporozoites can resist challenge, indicating that T-cell effector mechanisms may also have a role in protection. This idea was supported by the recent observation that protective immunity also requires T-cells expressing the CD8 antigen (CD8+ T cells) whose target is probably the developing liver-stage parasites. Moreover, an oral Salmonella vaccine that expresses the circumsporozoite protein is able to protect against murine malaria in the absence of antibodies. Here we report the identification of an epitope contained within amino acids 249-260 of the Plasmodium berghei circumsporozoite protein that is recognized by H-2Kd-restricted cytotoxic T cells. Passive transfer into mice of cytotoxic-T-cell clones that recognize this epitope conferred a high degree of protection against challenge. These results provide the first direct evidence that CD8+ T cells that are specific for a defined epitope can confer protection against a parasitic infection
— id: 10492, year: 1989, vol: 341, page: 323, stat: Journal Article,

The conformational restriction of synthetic peptides, including a malaria peptide, for use as immunogens
Satterthwait AC; Arrhenius T; Hagopian RA; Zavala F; Nussenzweig V; Lerner RA
1989 Jun 12;323(1217):565-572, Philosophical transactions of the Royal Society of London. Series B. Biological sciences
A new strategy is advanced for the conformational restriction of peptidyl immunogens. Our approach is to replace putative amide-amide hydrogen bonds with covalent hydrogen-bond mimics. Because on average every other amino acid in a protein engages in this bond, the syntheses of diversely shaped peptides can be contemplated. Synthetic methods for introducing a potential hydrogen-bond mimic into a peptide with alpha-helical potential is reported and the structural consequences are discussed. The replacement of the hydrogen bond with a chemical link will modify as well as shape the peptide. To explore the consequences of these changes, a potential synthetic vaccine for malaria, the repeating tetrapeptide Asn-Pro-Asn-Ala, was conformationally restricted. Antibodies to the shaped malarial peptide showed a strong cross reaction with Plasmodium falciparum sporozoites
— id: 23523, year: 1989, vol: 323, page: 565, stat: Journal Article,

Stage-specific surface antigens during the morphogenesis of Trypanosoma cruzi: developmentally regulated expression of a glycosyl-phosphatidylinositol anchored glycoprotein of amastigotes
Andrews NW; Robbins E; Ley V; Nussenzweig V
1988 Nov;83 Suppl 1:561-562, Memorias do Instituto Oswaldo Cruz
— id: 10919, year: 1988, vol: 83 Suppl 1, page: 561, stat: Journal Article,

Developmentally regulated, phospholipase C-mediated release of the major surface glycoprotein of amastigotes of Trypanosoma cruzi
Andrews NW; Robbins ES; Ley V; Hong KS; Nussenzweig V
1988 Feb 1;167(2):300-314, Journal of experimental medicine
The surface of amastigotes of Trypanosoma cruzi is covered by Ssp-4, a major stage-specific glycoprotein. Ssp-4 is anchored to the cell membrane by GPI. It can be metabolically labeled with [3H]myristic acid, and is converted into a hydrophilic form by treatment with the glycan-specific phospholipase C of T. brucei, or after lysis of the parasites in non-ionic detergents. The hydrophilic form of Ssp-4 is recognized by antibodies to the cross-reactive determinant of the variant surface glycoprotein of African trypanosomes. Ssp-4 is progressively shed during the intra- or extracellular development of amastigotes preceding their transformation into epi- and trypomastigotes. We show here that T. cruzi contains a phospholipase C and that most shed Ssp-4 is hydrophilic, does not contain myristic acid, and reacts with anti-CRD. These observations provide strong evidence that phospholipase C mediates the release of this glycosyl-phosphatidylinositol-anchored protein under physiological conditions, as the parasite undergoes differentiation
— id: 11194, year: 1988, vol: 167, page: 300, stat: Journal Article,

Trypanosoma cruzi: mechanisms of cell-invasion and intracellular survival
Andrews NW; Schenkman S; Ley V; Whitlow MB; Robbins ES; Nussenzweig V
1988 Nov;83 Suppl 1:452-455, Memorias do Instituto Oswaldo Cruz
— id: 10908, year: 1988, vol: 83 Suppl 1, page: 452, stat: Journal Article,

Amastigotes of Trypanosoma cruzi sustain an infective cycle in mammalian cells
Ley V; Andrews NW; Robbins ES; Nussenzweig V
1988 Aug 1;168(2):649-659, Journal of experimental medicine
The two main stages of development of the protozoan parasite Trypanosoma cruzi found in the vertebrate host are the trypomastigote and the amastigote. It has been generally assumed that only trypomastigotes are capable of entering cells and that amastigotes are the intracellular replicative form of the parasite. We show here that after incubation for 4 h with human monocytes in vitro 90% or more of extracellularly derived (24 h) amastigotes of T. cruzi are taken up by the cells. Within 2 h they escape the phagocytic vacuole and enter the cytoplasm, where they divide and after 4-5 d transform into trypomastigotes. Trypomastigotes also invade cultured human monocytes. However, they show a lag of several hours between invasion and the start of DNA duplication, while amastigotes commence replication without an apparent lag. Amastigotes also infect cultured fibroblasts, albeit with lower efficiency. When injected intraperitoneally into mice, amastigotes are as infective as trypomastigotes. Based on these results, and on prior findings that amastigotes are found free in the circulation of mice during the acute stage of the disease (3), it seems likely that the cellular uptake of amastigotes can initiate an alternative subcycle within the life cycle of this parasite in the mammalian host. Also, because trypomastigotes and amastigotes have diverse surface antigens, they may use different strategies to invade host cells
— id: 11019, year: 1988, vol: 168, page: 649, stat: Journal Article,

AMASTIGOTES OF TRYPANOSOMA-CRUZI SUSTAIN AN INFECTIVE CYCLE IN MAMMALIAN-CELLS
Ley, V; Andrews, NW; Robbins, ES; Nussenzweig, V
1988 Mar 15;2(4):A883-A883, FASEB journal
— id: 31543, year: 1988, vol: 2, page: A883, stat: Journal Article,

Malaria vaccine trials
Nussenzweig RS; Nussenzweig V
1988 Sep 9;241(4871):1278-1278, Science
— id: 61967, year: 1988, vol: 241, page: 1278, stat: Journal Article,

Multiple T helper cell epitopes of the circumsporozoite protein of Plasmodium berghei
Romero PJ; Tam JP; Schlesinger D; Clavijo P; Gibson H; Barr PJ; Nussenzweig RS; Nussenzweig V; Zavala F
1988 Dec;18(12):1951-1957, European journal of immunology
The present findings establish the lack of genetic restriction of the humoral immune response to sporozoites of Plasmodium berghei, corraborating earlier observations that mice of different strains can be protected by immunization with irradiated sporozoites. Most, if not all, anti-sporozoite antibodies are directed against the repetitive B cell epitope of the circumsporozoite (CS) protein. However, neither a peptide containing a dimer of this repeat (17.1), nor a peptide polymer containing multiple repeats induced an antibody response in mice of different H-2 and different genetic backgrounds. A yeast-derived recombinant, containing the repeat domain and part of the surrounding amino and carboxy-terminal regions of the P. berghei CS protein, induces very different levels of antibody in mice of diverse H-2 haplotypes. H-2j mice are high responders and the immunized mice are extensively protected against sporozoite challenge. The lymph node cells of the H-2j mice (but not from other strains) proliferated in the presence of peptide N, contained in the amino terminal region of the CS recombinant. Additional H-2-restricted T cell epitopes have been identified in amino and carboxy-terminal regions of the CS protein, and mice of most of the strains recognized multiple T cell epitopes. Two peptides representing T cell epitopes were synthesized in tandem with a peptide representing the B cell epitope, and were assayed for T helper activity in vivo. The antibody response of mice, primed by a single injection of sporozoites, was boosted very effectively by the administration of peptide N + 17.1 or peptide B-4 + 17.1. The B-4 T cell epitope is located in the carboxy-terminal region of the CS protein and is recognized by mice of at least four different H-2 haplotypes. These observations demonstrate that the immune response to the CS protein of P. berghei is not genetically restricted and that it contains several T cell epitopes, some of which can function as helper epitopes. In addition, they show that a synthetic sporozoite vaccine can boost the immune response to sporozoites
— id: 23526, year: 1988, vol: 18, page: 1951, stat: Journal Article,

Conformational restriction of peptidyl immunogens with covalent replacements for the hydrogen bond
Satterthwait AC; Arrhenius T; Hagopian RA; Zavala F; Nussenzweig V; Lerner RA
1988 Apr;6(2):99-103, Vaccine
A new strategy for designing synthetic vaccines is presented. In this approach synthetic peptides are conformationally restricted by replacing putative hydrogen bonds with covalent mimics. The chemistry for substituting a hydrazone-ethane link (N-N = CH-CH2-CH2) for an (i + 4)----i hydrogen bond in a pentapeptide with alpha-helical potential is reported. Chemically shaping peptides to mimic the three-dimensional surfaces of proteins may enhance their immunogenicity. To test this strategy, a potential synthetic vaccine for malaria, Cys-(Asn-Pro-Asn-Ala)3-NH2, was conformationally restricted by replacing putative hydrogen bonds between asparagine side chains with a covalent replacement, an ethylene bridge, to give first generation chemically shaped immunogens. Antibodies to one of the shaped malarial peptides show a strong reaction with living Plasmodium falciparum sporozoites, a form of malaria which infects hundreds of millions of people yearly
— id: 23528, year: 1988, vol: 6, page: 99, stat: Journal Article,

Trypanosoma cruzi invade a mammalian epithelial cell in a polarized manner
Schenkman S; Andrews NW; Nussenzweig V; Robbins ES
1988 Oct 7;55(1):157-165, Cell
We have determined that parasite entry into host cells can be influenced by cell polarity using a DNA probe to quantitate the infection of cultured Madin-Darby canine kidney (MDCK) epithelial cells by Trypanosoma cruzi, the agent of Chagas' disease. Confluent MDCK cells are polarized, with their plasma membrane separated by tight junctions into two domains, apical and basolateral. We show that T. cruzi forms corresponding to the insect infective stages (metacyclics) and the vertebrate blood stages (trypomastigotes) enter confluent MDCK cells preferentially through their basolateral domains. Sparsely plated MDCK cells are less polarized and are better infected than confluent cells. Scanning electron microscopy showed that 92% +/- 4% of the parasites entered at the edges of cells
— id: 10932, year: 1988, vol: 55, page: 157, stat: Journal Article,

Partial characterization of the cross-reacting determinant, a carbohydrate epitope shared by decay accelerating factor and the variant surface glycoprotein of the African Trypanosoma brucei
Shak S; Davitz MA; Wolinsky ML; Nussenzweig V; Turner MJ; Gurnett A
1988 Mar 15;140(6):2046-2050, Journal of immunology
The variant surface glycoprotein (VSG) of the African trypanosome is anchored in the cell membrane by a complex glycan attached to phosphatidylinositol. The carboxyl terminal portion of VSG contains a cryptic carbohydrate epitope, the cross-reacting determinant (CRD), that is revealed only after removal of the diacylglycerol by phosphatidylinositol-specific phospholipase C (PIPLC) or VSG lipase. Recently, we have shown that after hydrolysis by PIPLC, decay-accelerating factor (DAF)--a mammalian phosphatidylinositol-anchored protein--also contains the CRD epitope. Using a two site immunoradiometric assay in which the capturing antibody is a monoclonal antibody to DAF and the revealing antibody is anti-CRD, we now show that sugar phosphates significantly inhibited the binding of anti-CRD antibody to DAF released by PIPLC. DL-myo-inositol 1,2-cyclic phosphate was the most potent inhibitor of binding (IC50 less than 10(-8) M). Other sugar phosphates, such as alpha-D-glucose-1-phosphate, which also possess adjacent hydroxyl and phosphate moieties in cis also inhibited binding at low concentrations (IC50 = 10(-5) to 10(-4) M). In contrast, sugar phosphates which do not possess adjacent hydroxyl and phosphate moieties in cis and simple sugars weakly inhibited binding (IC50 greater than 10(-3) M). These results suggest that myo-inositol 1,2-cyclic phosphate contributes significantly to the epitope recognized by the anti-CRD antibody and is consistent with analysis of the carboxyl terminus of VSG, which also suggested the presence of the cyclic inositol phosphate. In light of the recent findings that human serum contains a glycan-phosphatidyl-inositol-specific phospholipase D, which converts DAF from a hydrophobic to a hydrophilic form lacking the CRD, the observation that the phosphate is crucial for expression of the epitope may be relevant in understanding the origin of CRD-negative DAF in urine and plasma
— id: 11154, year: 1988, vol: 140, page: 2046, stat: Journal Article,

Decay-accelerating factor in human skin is associated with elastic fibers
Werth VP; Ivanov IE; Nussenzweig V
1988 Nov;91(5):511-516, Journal of investigative dermatology
Recently a complement inhibitor, decay-accelerating factor (DAF), has been found in association with uncharacterized fibers in the extracellular matrix of human dermis. Here we show by immunohistochemistry and immunoelectronmicroscopy that DAF is on the periphery of elastic fibers, and that it appears to be associated with some microfibrillar elements that cover the fibers. That DAF is a component of these microfibrils is also suggested by studies of lesional skin from anetoderma, a disease characterized by destruction of elastic fibers. In two patients we found a network of residual fine fibers in the dermis that stain with antibodies against DAF and fibrillin (one of the proteins known to be present in the microfibrils of elastin), but do not stain with antibodies to elastin. Western blot analysis of dermal extracts with monoclonal antibodies to DAF identified a 67 kDa molecule, slightly smaller than membrane DAF, and similar in size to soluble DAF found in secretions. It is possible that together with vitronectin, an inhibitor of the membrane attack complex recently identified in association with elastin, DAF prevents damage of elastic fibers by complement
— id: 10924, year: 1988, vol: 91, page: 511, stat: Journal Article,

DECAY-ACCELERATING FACTOR IN HUMAN-SKIN IS ASSOCIATED WITH ELASTIC FIBERS AND EPIDERMAL-CELLS
Werth, VP; Ivanov, IE; Nussenzweig, V
1988 Apr;36(3):A703-A703, Clinical research
— id: 31524, year: 1988, vol: 36, page: A703, stat: Journal Article,

DECAY-ACCELERATING FACTOR IN HUMAN-SKIN IS ASSOCIATED WITH ELASTIC FIBERS AND EPIDERMAL-CELLS
Werth, VP; Ivanov, IE; Nussenzweig, V
1988 Apr;90(4):616-616, Journal of investigative dermatology
— id: 31534, year: 1988, vol: 90, page: 616, stat: Journal Article,

EFFICIENCY OF CHANNEL FORMATION BY COMPLEMENT AS MEASURED BY PAROXYSMAL-NOCTURNAL HEMOGLOBINURIA ERYTHROCYTES
Whitlow, MB; Iida, K; Nussenzweig, V
1988 Apr;36(3):A704-A704, Clinical research
— id: 31525, year: 1988, vol: 36, page: A704, stat: Journal Article,

EFFICIENCY OF CHANNEL FORMATION BY COMPLEMENT AS MEASURED ON PAROXYSMAL-NOCTURNAL HEMOGLOBINURIA ERYTHROCYTES
Whitlow, MB; Iida, K; Nussenzweig, V
1988 Apr;90(4):617-617, Journal of investigative dermatology
— id: 31535, year: 1988, vol: 90, page: 617, stat: Journal Article,

EFFICIENCY OF CHANNEL FORMATION BY COMPLEMENT ON PAROXYSMAL- NOCTURNAL HEMOGLOBINURIA ERYTHROCYTES
Whitlow, MB; Iida, K; Nussenzweig, V
1988 Mar 25;2(6):A1643-A1643, FASEB journal
— id: 31527, year: 1988, vol: 2, page: A1643, stat: Journal Article,

Stage-specific surface antigens expressed during the morphogenesis of vertebrate forms of Trypanosoma cruzi
Andrews NW; Hong KS; Robbins ES; Nussenzweig V
1987 Dec;64(3):474-484, Experimental parasitology
The origin of Trypanosoma cruzi slender and broad forms found in the circulation of the mammalian host has remained obscure and, unlike what has been proposed for African trypanosomes, no precise form-function relationship has been ascribed to them. We show here that parasites circulating in the blood of infected animals display a high degree of polymorphism. Around 10% of the forms found circulating in mice during the acute phase of infection were amastigotes, and the other 90% included slender and broad trypomastigotes and intermediate forms between amastigotes and trypomastigotes. Slender trypomastigotes, from blood or cell culture, undergo extracellularly morphological rearrangements in which the parasites become gradually broader and transform into amastigotes. By scanning electron microscopy a progressive internalization of the flagellum and reorganization of the cell shape in a helical fashion were observed in parasites undergoing transformation. After 48 hr of extracellular incubation the parasite population consisted exclusively of amastigotes with a short protruding flagellum. The morphological changes were associated with the expression of different surface antigens defined by monoclonal antibodies: the trypomastigote-specific antigens Ssp-1 (a 100-120-150-Mr glycoprotein), Ssp-2 (a 70-Mr glycoprotein), Ssp-3 (undefined), and Ssp-4, an amastigote-specific surface antigen. Ssp-4 was also detected on intracellular amastigotes (in vitro and in vivo). We conclude that trypomastigotes are programmed to develop into amastigotes whether or not they enter cells, and that the differentiation can occur in the blood of the vertebrate host. These findings raise some questions regarding conventional views on the life cycle of T. cruzi
— id: 11309, year: 1987, vol: 64, page: 474, stat: Journal Article,

Expression in yeast of a Plasmodium vivax antigen of potential use in a human malaria vaccine
Barr PJ; Gibson HL; Enea V; Arnot DE; Hollingdale MR; Nussenzweig V
1987 Apr 1;165(4):1160-1171, Journal of experimental medicine
DNA coding for 234 amino acids of the circumsporozoite (CS) protein of Plasmodium vivax was incorporated into yeast expression vectors. The DNA encoded all the repeat domain and codons for a highly conserved sequence, KLKQP, found in CS proteins from all malaria parasites. Yeast cells transformed with these autonomously replicating plasmids expressed, upon induction, high levels of the CS polypeptide. The malaria antigen was purified in good yields from yeast extracts and was injected into mice using alum as adjuvant. The antibodies recognized the authentic CS protein, and at high dilutions, they inhibited the invasion of hepatocytes by sporozoites in vitro
— id: 61973, year: 1987, vol: 165, page: 1160, stat: Journal Article,

HEMORRHAGIC NECROSIS AND COAGULATION NECROSIS
Bloksma, N; Wallach, D; Pober, JS; Old, LJ; Spriggs, DR; Cerami, A; Schreiber, H; Regenass, U; Nussenzweig, V
1987 Dec 1;131(6):187-191, CIBA Foundation symposium
— id: 31101, year: 1987, vol: 131, page: 187, stat: Journal Article,

USE OF SYNTHETIC AND RECOMBINANT PEPTIDES IN THE STUDY OF HOST-PARASITE INTERACTIONS IN THE MALARIAS
CAMPBELL, GH; ALEY, SB; BALLOU, WR; HALL, T; HOCKMEYER, WT; HOFFMAN, SL; HOLLINGDALE, MR; HOWARD, RJ; LYON, JA; NARDIN, EH; NUSSENZWEIG, RS; NUSSENZWEIG, V; TSANG, VCW; WEBER, JL; WELLEMS, TE; YOUNG, JF; ZAVALA, F
1987 NOV ;37(3):428-444, American journal of tropical medicine & hygiene
— id: 98529, year: 1987, vol: 37, page: 428, stat: Journal Article,

Cloning of decay-accelerating factor suggests novel use of splicing to generate two proteins
Caras IW; Davitz MA; Rhee L; Weddell G; Martin DW Jr; Nussenzweig V
1987 Feb 5-11;325(6104):545-549, Nature
Decay-accelerating factor (DAF), a glycoprotein that is anchored to the cell membrane by phosphatidylinositol, binds activated complement fragments C3b and C4b, thereby inhibiting amplification of the complement cascade on host cell membranes. Here, we report the molecular cloning of human DAF from HeLa cells. Analysis of DAF complementary DNAs revealed two classes of DAF messenger RNA, one apparently derived from the other by a splicing event that causes a coding frameshift near the C terminus. The apparent 'intron' sequence contains an Alu family member and encodes contiguous protein sequence. Two DAF proteins are therefore possible, having divergent C-terminal domains which differ in their hydrophobicity. Both mRNAs are found on polysomes, suggesting that both are translated. We propose that the major (90%) spliced DAF mRNA encodes membrane-bound DAF whereas the minor (10%) unspliced DAF mRNA may encode secreted DAF and we present expression data supporting this. The deduced DAF sequence contains four repeating units homologous to a consensus repeat found in a recently described family of complement proteins
— id: 61977, year: 1987, vol: 325, page: 545, stat: Journal Article,

Signal for attachment of a phospholipid membrane anchor in decay accelerating factor
Caras IW; Weddell GN; Davitz MA; Nussenzweig V; Martin DW Jr
1987 Nov 27;238(4831):1280-1283, Science
Decay accelerating factor (DAF) belongs to a novel group of membrane proteins anchored to the cell surface by a glycophospholipid membrane anchor that is covalently attached to the carboxyl terminus of the protein. The last 37 amino acids of membrane DAF, when fused to the carboxyl terminus of a secreted protein, are sufficient to target the fusion protein to the plasma membrane by means of a glycophospholipid anchor. This approach provides a novel means of targeting proteins to the cell-surface membrane
— id: 61968, year: 1987, vol: 238, page: 1280, stat: Journal Article,

Decay-accelerating factor (DAF) shares a common carbohydrate determinant with the variant surface glycoprotein (VSG) of the African Trypanosoma brucei
Davitz MA; Gurnett AM; Low MG; Turner MJ; Nussenzweig V
1987 Jan 15;138(2):520-523, Journal of immunology
Decay-accelerating factor (DAF) is an integral membrane protein that inhibits amplification of the complement cascade on the cell surface. We and other investigators have shown that DAF is part of a newly characterized family of proteins that are anchored to the cell membrane by phosphatidylinositol (PI). The group includes the variant surface glycoprotein (VSG) of African trypanosomes, the p63 protein of Leishmania, acetylcholinesterase (AChE), alkaline phosphatase, Thy-1, 5'-nucleotidase, and RT6.2--an alloantigen from rat T cells. The structure of the membrane anchor has been best characterized for VSG, but chemical studies of the membrane anchors of AChE and Thy-1 suggest that similar glycolipid moieties anchor these proteins to the cell surface. In the VSG, the membrane anchor consists of an ethanolamine linked covalently to an oligosaccharide and glucosamine; the entire complex is anchored to the cell membrane by PI. Immunologically, this glycolipid defines an epitope, the cross-reacting determinant (CRD), that is only revealed after removal of the diacyl glycerol anchor by a phospholipase C. By Western blotting, we show here that DAF-S (DAF released from the membrane by PI-specific phospholipase C [PIPLC]) also contains CRD. Using a newly developed immunoradiometric assay (IRMA) in which the solid-phase capturing antibody is a monoclonal antibody to DAF and the second antibody is anti-CRD, we have been able to quantitate DAF-S. By IRMA, we show that the reaction between anti-CRD and DAF-S is specific, since the binding is competitively inhibited only by the soluble form of the VSG. These observations further support the concept that the glycolipid anchors of this new family of proteins have similar structures. DAF is also found as a soluble protein in various tissue fluids as well as in Hela cell supernatants. No evidence for the presence of the CRD epitope was found on these proteins, suggesting that these forms of DAF are not released from the surface of cells by endogenous phospholipases
— id: 61978, year: 1987, vol: 138, page: 520, stat: Journal Article,

A glycan-phosphatidylinositol-specific phospholipase D in human serum
Davitz MA; Hereld D; Shak S; Krakow J; Englund PT; Nussenzweig V
1987 Oct 2;238(4823):81-84, Science
A group of proteins anchored to the cell by phosphatidylinositol (PI) has recently been identified. The significance of this new class of membrane anchor is unknown; one possibility is that it facilitates release of the molecule by phospholipases. In fact, phospholipase C enzymes specific for the complex carboxyl-terminal glycolipids of these proteins have been isolated from African trypanosomes and from hepatocyte plasma membranes. This study reports the discovery of a glycan-PI-specific phospholipase D in human serum that cleaves both the membrane form of the variant surface glycoprotein of African trypanosomes and its glycolipid precursor, but not phosphatidylethanolamine, phosphatidylcholine, or phosphatidylinositol. Decay-accelerating factor, another PI-anchored molecule, is also cleaved by the enzyme and converted from a hydrophobic to a soluble protein. The enzyme is Ca2+-dependent, heat labile, and not affected by the inhibitor of serine proteases, phenylmethylsulfonylfluoride. Its function is not known, but the present findings indicate that it participates in the metabolism of glycolipid-anchored membrane proteins
— id: 11346, year: 1987, vol: 238, page: 81, stat: Journal Article,

Isolation of decay accelerating factor (DAF) by a two-step procedure and determination of its N-terminal sequence
Davitz MA; Schlesinger D; Nussenzweig V
1987 Feb 26;97(1):71-76, Journal of immunological methods
Decay-accelerating factor (DAF) from human red cell membranes was purified by a two-step procedure involving anion exchange and immunoaffinity chromatography. The DAF preparations were purified to homogeneity as judged by silver staining. In several experiments, the final product yields were approximately 23% of the total DAF present in the initial membrane extracts. The purified DAF retained its ability to inhibit the classical pathway C3-convertase and to reincorporate into cell membranes. An amino-terminal sequence was obtained by gas-phase sequencing. Rabbit antibodies to a synthetic peptide representing part of this sequence reacted with purified reduced membrane DAF by Western blotting and by a solid-phase immunoradiometric assay
— id: 61975, year: 1987, vol: 97, page: 71, stat: Journal Article,

Use of a DNA probe to measure the neutralization of Plasmodium berghei sporozoites by a monoclonal antibody
Ferreira A; Morimoto T; Altszuler R; Nussenzweig V
1987 Feb 15;138(4):1256-1259, Journal of immunology
A specific DNA probe has been used to quantify the neutralizing effects of monoclonal antibodies (3D11) against the circumsporozoite protein of Plasmodium berghei sporozoites. The amount of parasite DNA was measured in the livers of Norway Brown rats at the peak of proliferation of the exoerythrocytic forms (EEF). In vitro treatment of 1.5 X 10(5) sporozoites with 0.36 microgram/0.5 ml of whole 3D11 IgG neutralized about 90% of the sporozoite infectivity. When the dose was 3.6 micrograms no signal was detected, indicating that less than ten sporozoites developed into EEF in the liver. In contrast, 3.6 micrograms of Fab obtained from 3D11 neutralized sporozoite infectivity by only 60%. Although the neutralizing effect of 3D11 was very marked, the infected rats developed parasitemias after a prolonged delay in patency, suggesting that a small proportion of sporozoites was resistant to the effects of 3D11. The sporozoites were subjected to four cycles of 3D11-mediated selection, each one involving treatment of sporozoites with the antibodies, injection of the mixture into rats, infection of hamsters with blood stage parasites obtained from the rats, feeding of Anopheles stephensi on these hamsters, and obtaining sporozoites from the salivary glands of the infected mosquitoes. After four cycles of selection, the susceptibility of the resulting sporozoites to different concentrations of 3D11 was compared with that of nonselected sporozoites. No differences were detected, indicating that the capacity of a few sporozoites to escape the neutralizing effect of 3D11 antibodies is not inherited
— id: 61976, year: 1987, vol: 138, page: 1256, stat: Journal Article,

SAFETY AND IMMUNOGENICITY IN MAN OF A SYNTHETIC PEPTIDE MALARIA VACCINE AGAINST PLASMODIUM-FALCIPARUM SPOROZOITES
HERRINGTON, DA; CLYDE, DF; LOSONSKY, G; CORTESIA, M; MURPHY, JR; DAVIS, J; BAQAR, S; FELIX, AM; HEIMER, EP; GILLESSEN, D; NARDIN, E; NUSSENZWEIG, RS; NUSSENZWEIG, V; HOLLINGDALE, MR; LEVINE, MM
1987 JUL 16 ;328(6127):257-259, Nature
— id: 98534, year: 1987, vol: 328, page: 257, stat: Journal Article,

A high m.w. form of decay-accelerating factor (DAF-2) exhibits size abnormalities in paroxysmal nocturnal hemoglobinuria erythrocytes
Kinoshita T; Rosenfeld SI; Nussenzweig V
1987 May 1;138(9):2994-2998, Journal of immunology
Decay-accelerating factor (DAF) is a 70,000 Mr membrane protein that inhibits the amplification of the complement cascade on cell surfaces. Monoclonal antibodies against different epitopes of the 70,000 Mr DAF (DAF-1) recognize a second band at the position of 140,000 Mr on a Western blot of total red cell ghost proteins or partially pure DAF subjected to electrophoresis under denaturing conditions. Like DAF-1, this polypeptide (DAF-2) has the ability to accelerate decay of the C3 convertase, C4b2a, and to reincorporate into red cell membranes. A population of erythrocytes from patients with paroxysmal nocturnal hemoglobinuria (PNH) lack DAF-1 and also DAF-2. In addition, in some patients' red cells bearing DAF-1 of normal Mr, DAF-2 is 5,000 to 10,000 Mr smaller than normal. The structural basis for these differences in size of DAF and its PNH variants is unknown
— id: 61972, year: 1987, vol: 138, page: 2994, stat: Journal Article,

Relationship between decay accelerating factor deficiency, diminished acetylcholinesterase activity, and defective terminal complement pathway restriction in paroxysmal nocturnal hemoglobinuria erythrocytes
Medof ME; Gottlieb A; Kinoshita T; Hall S; Silber R; Nussenzweig V; Rosse WF
1987 Jul;80(1):165-174, Journal of clinical investigation
Paroxysmal nocturnal hemoglobinuria (PNH) erythrocytes exhibit abnormalities in decay accelerating factor (DAF), acetylcholinesterase, and resistance to autologous C5b-9 attack. To investigate the nature of the lesion underlying PNH cells, we examined the relationship of these abnormalities to one another. Analyses of DAF in acetylcholinesterase-negative erythrocytes revealed that these two abnormalities involve functionally independent molecules, coincide precisely in the same cell populations, and are similarly expressed in PNH II and more complement-sensitive PNH III erythrocytes. The DAF and acetylcholinesterase deficiencies contrast with the C3b/C4b receptor (CR1) deficit, which is less profound and similarly distributed in complement-insensitive cell populations. Hemolytic studies showed that defective resistance to autologous C5b-9 attack is mediated by another mechanism. Whereas reconstitution of PNH II erythrocytes with DAF completely corrected their complement sensitivity, DAF reconstitution of PNH III erythrocytes restored their ability to circumvent C3b uptake but had no effect on their heightened susceptibility to reactive lysis. Assays of complement-insensitive (PNH I) erythrocytes surviving after reactive lysis disclosed partial DAF and acetylcholinesterase deficits. These findings indicate that the PNH lesion involves multiple membrane components and that PNH I erythrocytes are also abnormal
— id: 61970, year: 1987, vol: 80, page: 165, stat: Journal Article,

Identification of the complement decay-accelerating factor (DAF) on epithelium and glandular cells and in body fluids
Medof ME; Walter EI; Rutgers JL; Knowles DM; Nussenzweig V
1987 Mar 1;165(3):848-864, Journal of experimental medicine
Decay-accelerating factor (DAF) is a 70 kD membrane regulatory protein that prevents the activation of autologous complement on cell surfaces. Using immunohistochemical methods and a radioimmunometric assay based on mAbs to DAF, we found large amounts of membrane-associated DAF antigen on the epithelial surface of cornea, conjunctiva, oral and gastrointestinal mucosa, exocrine glands, renal tubules, ureter and bladder, cervical and uterine mucosa, and pleural, pericardial and synovial serosa. Additionally, we detected soluble DAF antigen in plasma, tears, saliva, and urine, as well as in synovial and cerebrospinal fluids. While plasma, tear, and saliva DAF are larger than erythrocyte (Ehu) membrane DAF by Western blot analysis, urine DAF is slightly smaller (67,000) in Mr. Unlike purified Ehu DAF, however, urine DAF is unable to incorporate into the membrane of red cells. Although its inhibitory activity on the complement enzyme C3-convertase is lower than that of Ehu DAF, it is comparable to that of serum C4 binding protein (C4bp). Biosynthetic studies using cultured foreskin epithelium and Hela cells disclosed DAF levels (approximately 2 X 10(5) molecules/cell) exceeding those on blood cells. In addition, these studies revealed the synthesis of two DAF species, one with apparent Mr corresponding to that of epithelial cell membrane DAF and the other to urine DAF, suggesting that the urine DAF variant arises from adjacent epithelium. The function of DAF in body fluids is unknown, but the observation that urine DAF has C4bp-(or factor H-)like activity shows that it could inhibit the fluid phase activation of the cascade
— id: 61974, year: 1987, vol: 165, page: 848, stat: Journal Article,

Induction of sporozoite-specific memory cells in mice immunized with a recombinant Plasmodium vivax circumsporozoite protein
Nardin EH; Barr PJ; Gibson HL; Collins WE; Nussenzweig RS; Nussenzweig V
1987 Dec;17(12):1763-1767, European journal of immunology
A recombinant Plasmodium vivax circumsporozoite (CS) protein (rPvCS-1) has been investigated as a possible malaria sporozoite vaccine candidate. Experiments were carried out to determine whether sporozoite-specific memory cells develop in Swiss Webster mice immunized with rPvCS-1. Challenge of rPvCS-1-immunized mice with P. vivax sporozoites resulted in a 100-fold increase in the mean serum anti-sporozoite antibody titer. The presence of parasite-specific T helper cells was demonstrated using an in vitro assay. Anti-CS antibodies were detected in the culture supernatants of spleen cells of rPvCS-1-immunized mice following in vitro challenge with P. vivax sporozoite extract. Immune spleen cells depleted of T cells did not produce antibodies when challenged with sporozoite extract in vitro. In conclusion, immunization of mice with the rPvCS-1 protein induced memory T cells which recognized native CS antigen and functioned as T helper cells in the production of anti-sporozoite antibodies both in vivo and in vitro
— id: 11307, year: 1987, vol: 17, page: 1763, stat: Journal Article,

Interferon-gamma inhibits the intrahepatocytic development of malaria parasites in vitro
Schofield L; Ferreira A; Altszuler R; Nussenzweig V; Nussenzweig RS
1987 Sep 15;139(6):2020-2025, Journal of immunology
In this study, we examined the activity of recombinant interferon (IFN)-gamma against Plasmodium berghei exoerythrocytic forms (EEF) grown in vitro within the highly differentiated human hepatoma cell line HEPG2. We assayed the effect of IFN-gamma on parasite growth by DNA hybridization using a P. berghei specific DNA probe. The specific activity of IFN-gamma against EEF is very high, and depends upon the time of lymphokine addition. When IFN-gamma is added to HEPG2 cells containing intracellular EEF, 6 hr after sporozoite invasion, parasite DNA replication is inhibited by approximately 75% at 10(3) U/ml and 50% at 1 U/ml. This treatment can either abolish or greatly reduce the infectivity of EEF for mice. When added earlier, 3 hr after completion of sporozoite invasion, IFN-gamma inhibits parasite replication to an even greater degree. The highest levels of inhibition were obtained when IFN-gamma was added 6 hr prior to sporozoite invasion (100% inhibition at 10(2) U/ml, approximately 55% inhibition at 0.1 U/ml, and 17% inhibition at 0.001 U/ml). We found that HEPG2 cells express approximately 44,000 surface receptors for IFN-gamma. These data are consistent with the view that IFN-gamma exerts its antimalarial activity by binding to surface receptors on hepatocytes and inducing intracellular changes unfavorable for parasite development. Tryptophan starvation does not appear to be involved in this process. These findings also support the idea that IFN-gamma, released from immune T cells upon encountering sporozoite antigen, may be an important effector mechanism in sterile immunity to sporozoite challenge
— id: 61969, year: 1987, vol: 139, page: 2020, stat: Journal Article,

Gamma interferon, CD8+ T cells and antibodies required for immunity to malaria sporozoites
Schofield L; Villaquiran J; Ferreira A; Schellekens H; Nussenzweig R; Nussenzweig V
1987 Dec 17-23;330(6149):664-666, Nature
This study was designed to test the hypothesis that T-cell effector mechanisms are required for protective immunity to malaria sporozoites. Administration of neutralizing monoclonal antibodies against gamma interferon (gamma IFN) to immune hosts, reversed sterile immunity to sporozoite challenge, by allowing the growth of exoerythrocytic forms (EEF) and thus the development of parasitaemia. Immune animals also developed infections when depleted in vivo of their suppressor/cytotoxic T cells expressing the CD8 antigen (CD8+) but not when depleted of helper T cells expressing CD4 antigen (CD4+), before sporozoite challenge. Passive transfer of immune immunoglobin alone, or adoptive transfer of immune T cells alone, conferred partial protection to naive recipients. Transfer of both immune components resulted in significantly greater protection. This transferred immunity was reversed by the in vivo neutralization of gamma IFN. Thus, sterile immunity to sporozoite challenge requires the neutralization of sporozoites by antibodies and the inhibition of EEF development by gamma IFN with the participation of CD8+ cells
— id: 11293, year: 1987, vol: 330, page: 664, stat: Journal Article,

ANTIMALARIAL ACTIVITY OF ALPHA-TUMOR-NECROSIS-FACTOR AND GAMMA- INTERFERON
Schofield, L; Ferreira, A; Nussenzweig, V; Nussenzweig, RS
1987 Mar 1;46(3):760-760, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 31265, year: 1987, vol: 46, page: 760, stat: Journal Article,

DECAY ACCELERATING FACTOR DIFFUSES RAPIDLY ON HELAAE CELL- SURFACES
Thomas, J; Webb, W; Davitz, MA; Nussenzweig, V
1987 Feb;51(2):A522-A522, Biophysical journal
— id: 31414, year: 1987, vol: 51, page: A522, stat: Journal Article,

Mechanism of escape of exoerythrocytic forms (EEF) of malaria parasites from the inhibitory effects of interferon-gamma
Vergara U; Ferreira A; Schellekens H; Nussenzweig V
1987 Jun 15;138(12):4447-4449, Journal of immunology
We have studied the mechanism of inhibition by interferon-gamma (IFN-gamma) of the development of exoerythrocytic forms (EEF) of Plasmodium berghei in the livers of rats. At the time corresponding to the maximum development of EEF (44 hr after injection of sporozoites), the livers of the IFN-gamma-treated rats contained less parasite DNA as compared with controls. Twenty-four to 72 hr later, the livers of both groups of animals were free of parasites; that is, IFN-gamma treatment does not delay the development of the EEF. The decrease in parasite DNA observed in the IFN-gamma-treated rats was due to a diminution in the number, but not the size, of EEF. It appears, therefore, that treatment with the lymphokine either destroys the parasites or does not affect their replication. To study the mechanism of resistance to IFN-gamma of a small population of EEF, we subjected the parasites to four cycles of selection by IFN-gamma. The parasites from the 'selected' and 'nonselected' populations were equally susceptible to inhibition by IFN-gamma, indicating that the escape from IFN-gamma activity is not inherited
— id: 61971, year: 1987, vol: 138, page: 4447, stat: Journal Article,

Synthetic peptide vaccine confers protection against murine malaria
Zavala F; Tam JP; Barr PJ; Romero PJ; Ley V; Nussenzweig RS; Nussenzweig V
1987 Nov 1;166(5):1591-1596, Journal of experimental medicine
A synthetic peptide, (DPPPPNPN)2D, representing a subunit of the repeat domain of the Plasmodium berghei circumsporozoite protein, was conjugated to tetanus toxoid using bisdiazobenzidine. Immunization of mice and rats with the conjugate induced high serum titers of antibodies to the parasite, and most of the animals were completely protected from malaria infection when challenged with sporozoites
— id: 11330, year: 1987, vol: 166, page: 1591, stat: Journal Article,

Decay-accelerating factor is present on cultured human umbilical vein endothelial cells
Asch AS; Kinoshita T; Jaffe EA; Nussenzweig V
1986 Jan 1;163(1):221-226, Journal of experimental medicine
Decay-accelerating factor (DAF) has been previously described only in cells of bone marrow origin where it serves as a negative modulator of complement activation. Using mAb against human DAF, we demonstrated the presence of DAF in human umbilical vein endothelial cells by immunofluorescence microscopy and flow cytometry. By means of an immunoradiometric assay we detected an average of 3.3 X 10(5) molecules of DAF on each cell. When immunoisolates were analyzed in Western blots, endothelial cell DAF comigrated with DAF purified from normal erythrocytes. DAF was synthesized by the endothelial cells since 35S-labeled DAF could be immunoisolated from HUVEC cultured in medium containing [35S]methionine. This is the first evidence for the presence of DAF in cells of extra-marrow origin. DAF may protect endothelial cells from complement-mediated injury
— id: 61988, year: 1986, vol: 163, page: 221, stat: Journal Article,

Release of decay-accelerating factor (DAF) from the cell membrane by phosphatidylinositol-specific phospholipase C (PIPLC). Selective modification of a complement regulatory protein
Davitz MA; Low MG; Nussenzweig V
1986 May 1;163(5):1150-1161, Journal of experimental medicine
Decay-accelerating factor (DAF) is a 70,000 Mr membrane protein that inhibits amplification of the complement cascade on the cell surface, and protects cells from damage. Purified DAF can be reincorporated into the membrane of red cells and is functional. DAF is deficient in paroxysmal nocturnal hemoglobinuria (PNH), a disease characterized by increased sensitivity of erythrocytes to complement lysis. We show here that DAF is part of a newly described family of membrane proteins anchored to the lipid bilayer by means of phosphatidylinositol (PI). Treatment with PI-specific phospholipase C (PIPLC) releases 70-80, 60, and 10% of cell surface DAF from mononuclear cells, neutrophils, and erythrocytes, respectively. The PIPLC-released DAF (DAF-S) is slightly smaller (67,000 Mr) than the membrane form. DAF and DAF-S cannot be distinguished antigenically. Furthermore, DAF-S has lost its ability to significantly inhibit the C3-convertase, as well as its ability to incorporate into cell membranes. Since DAF can only inhibit C3-convertase endogenously, i.e., within the membrane of the same cell, it is likely that the loss of activity of DAF-S is causally related to its inability to reincorporate in the lipid bilayer. As shown by others, the complement-sensitive red cells from PNH patients lack acetylcholinesterase, which is also anchored to the membrane by PI (9). Thus it is possible that the molecular defect in PNH lies in the biosynthetic pathways leading to the attachment of PI to the polypeptide chains, in the transport of these proteins to the surface, or in their release by the action of endogenous phospholipases. From a practical standpoint the specific release of DAF by PIPLC could facilitate killing of tumor cells by amplifying the effects of the complement cascade on the surface of antibody-sensitized cells
— id: 61985, year: 1986, vol: 163, page: 1150, stat: Journal Article,

Circumsporozoite protein of Plasmodium berghei: gene cloning and identification of the immunodominant epitopes
Eichinger DJ; Arnot DE; Tam JP; Nussenzweig V; Enea V
1986 Nov;6(11):3965-3972, Molecular & cellular biology
The gene encoding the circumsporozoite (CS) protein of the rodent malaria parasite Plasmodium berghei was cloned and characterized. A cDNA library made from P. berghei sporozoite RNA was screened with a monoclonal antibody for expression of CS protein epitopes. The resulting cDNA clone was used to isolate the CS protein gene from a lambda library containing parasite blood-stage DNA. The CS protein gene contains a central region encoding two types of tandemly repeated amino acid units, flanked by nonrepeated regions encoding amino- and carboxy-terminal signal and anchorlike sequences, respectively. One of the central repeated amino acid unit types contains the immunodominant epitopes
— id: 61980, year: 1986, vol: 6, page: 3965, stat: Journal Article,

Infectivity of Plasmodium berghei sporozoites measured with a DNA probe
Ferreira A; Enea V; Morimoto T; Nussenzweig V
1986 May;19(2):103-109, Molecular & biochemical parasitology
A 2.3 kb, 32P-labeled repetitive DNA probe of Plasmodium berghei was used to measure the amount of parasite DNA in the liver of Norway Brown rats and mice infected with sporozoites. Standard hybridization curves were obtained by probing different amounts (100 pg to 1 microgram) of P. berghei DNA immobilized on nitrocellulose filters. Host DNA did not interfere with hybridization specificity and sensitivity. A 100-fold increase in hepatic parasite DNA was detected between 25 h post-infection and the peak of parasite proliferation, detected at 44 h. The amount of parasite DNA increased with the number of injected sporozoites. At 5 h post-infection, a large proportion of parasite DNA was found in the spleen. However, this diminished with time and was negligible in amount at 25 h. A significant number of viable sporozoites were probably cleared in the spleen, since considerably more parasite DNA was found in the livers of splenectomized rats than in sham-operated counterparts. Although older rats develop much lower parasitemias upon inoculation of sporozoites, no significant differences were observed in the amount of parasite DNA in rats, 43 and 152 days old, injected with equal numbers of sporozoites. The higher resistance to malaria displayed by older rats is probably controlled by post-hepatic events. The infectivity of sporozoites for A/J mice was calculated to be about 1/20th that of Norway Brown rats
— id: 61984, year: 1986, vol: 19, page: 103, stat: Journal Article,

Inhibition of development of exoerythrocytic forms of malaria parasites by gamma-interferon
Ferreira A; Schofield L; Enea V; Schellekens H; van der Meide P; Collins WE; Nussenzweig RS; Nussenzweig V
1986 May 16;232(4752):881-884, Science
A specific DNA probe was used to study the effect of recombinant rat, mouse, and human gamma-interferon (gamma-IFN) on the course of sporozoite-induced malaria infections. In mice and rats infected with sporozoites of Plasmodium berghei, mouse and rat gamma-IFN's strongly inhibited the development of the exoerythrocytic forms in the liver liver cells of the hosts, but not the development of the erythrocytic stages. The degree of inhibition of the exoerythrocytic forms was proportional to the dose of gamma-IFN administered, but was independent of the number of sporozoites used for challenge. A 30 percent reduction in the development of exoerythrocytic forms in rat liver was achieved when 150 units (about 15 nanograms of protein) of rat gamma-IFN were injected a few hours before sporozoite challenge; the reduction was 90 percent or more with higher doses of gamma-IFN. The effect was less pronounced if the gamma-IFN was administered 18 hours before or a few hours after challenge. Human gamma-IFN also diminished the parasitemia in chimpanzees infected with sporozoites of the human malaria parasite Plasmodium vivax. The target of gamma-IFN activity may be the infected hepatocytes themselves, as shown by in vitro experiments in which small doses of the human lymphokine inhibited the development of exoerythrocytic forms of Plasmodium berghei in a human hepatoma cell line. These results suggest that immunologically induced interferon may be involved in controlling malaria infection under natural conditions
— id: 61983, year: 1986, vol: 232, page: 881, stat: Journal Article,

Membrane-bound C4b interacts endogenously with complement receptor CR1 of human red cells
Kinoshita T; Medof ME; Hong K; Nussenzweig V
1986 Nov 1;164(5):1377-1388, Journal of experimental medicine
Activation of the classical complement pathway on the membrane of autologous cells results in the deposition of C4b on their surface and in the assembly of the C3 convertase C4b2a, one of the amplifying enzymes of the cascade. Here we study the sequence of events leading to irreversible inactivation of the potentially harmful C4b bound to human red cells. We show that deposited C4b interacts endogenously with complement receptor type 1 (CR1) present on the membrane of the same red cell. Complexes containing CR1 and C4b are found in extracts of membranes of C4b-bearing red cells after treatment of the intact cells with a bifunctional crosslinking reagent. The amount of complexed CR1 increases with the number of deposited C4b molecules. Only small amounts of free CR1 are observed on red cells bearing as few as 1,900 molecules of C4b, suggesting that the binding avidity between C4b and endogenous CR1 is high. In agreement with this observation, we find that the deposited C4b inhibits the exogenous cofactor activity of the red cell CR1 for the factor I-mediated cleavage of target-bound clustered C3b. The C4b bound to the human red cells is cleaved by the serum enzyme C3b/C4b inactivator (factor I) and a large fragment (C4c) is released in the incubation medium. The cleavage is totally inhibited by mAbs against CR1, showing that the complement receptor is an essential cofactor for the activity of I. When the number of bound C4b per red cell is relatively small (less than 1,000 molecules) the substrate for the enzymatic activity of factor I is mostly or exclusively the C4b bound endogenously to CR1. Indeed, the kinetics or the extent of cleavage of C4b are not affected by greatly augmenting the concentration of exogenous CR1 or of C4b-bearing red cells in the incubation mixture, thereby increasing the frequency of collisions between CR1 on the surface of one cell with C4b deposited on the membrane of a different cell. On the basis of the present and prior observations, we speculate that both DAF and CR1 act endogenously to inactivate the function of autologous red cell-bound C4b and prevent the progression of the cascade. DAF binding prevents the formation of the C3 convertase, C4b2a. The cleavage and irreversible inactivation of C4b only occurs after the concerted activities of endogenous CR1 and serum factor I.(ABSTRACT TRUNCATED AT 400 WORDS)
— id: 61981, year: 1986, vol: 164, page: 1377, stat: Journal Article,

Endogenous association of decay-accelerating factor (DAF) with C4b and C3b on cell membranes
Kinoshita T; Medof ME; Nussenzweig V
1986 May 1;136(9):3390-3395, Journal of immunology
Decay-accelerating factor (DAF) is a membrane glycoprotein found on various cells that are in contact with complement. It inhibits the formation of the C3 convertases of the complement system, both the classic (C4b2a) and alternative (C3bBb) pathways. In this investigation, we used a homobifunctional cross-linking reagent to search for a DAF ligand on the surface of cells subjected to complement attack. We found that DAF forms complexes with C4b and C3b deposited on the same erythrocytes, but not with the physiologic degradation products of these complement fragments, that is, C4d or C3dg. Taken together with prior observations that DAF action is reversible, and DAF does not affect the structure of C4b or C3b, these findings suggest that DAF functions by competitively inhibiting the uptake of C2 or factor B, and preventing the assembly of the C3 convertases
— id: 61986, year: 1986, vol: 136, page: 3390, stat: Journal Article,

INACTIVATION OF RED CELL-BOUND C4B AND C3B BY ENDOGENOUS ASSOCIATION WITH COMPLEMENT RECEPTOR CR-1
KINOSHITA, T; MEDOF, ME; HONG, K; NUSSENZWEIG, V
1986 MAR 1 ;45(3):247-247, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 41498, year: 1986, vol: 45, page: 247, stat: Journal Article,

Monoclonal anti-gametocyte antibodies identify an antigen present in all blood stages of Plasmodium falciparum
Masuda A; Zavala F; Nussenzweig V; Nussenzweig RS
1986 Jun;19(3):213-222, Molecular & biochemical parasitology
Two polypeptides of 150 and 130 kDa present in all asexual and sexual blood stages of Plasmodium falciparum have been identified with anti-gametocyte monoclonal antibodies. The apparent molecular mass of these antigens is identical in different developmental stages of the parasite and in different isolates. These antigens are released in the culture supernatant during the process of schizogony and are also detected in the sera of patients undergoing a primary P. falciparum infection. Antibodies against these antigens occur in sera of a large percentage of children and most adults living in malaria-endemic areas, suggesting that they are highly immunogenic. The anti-gametocyte monoclonal antibodies react with a synthetic peptide (Glu-Glu-Asn-Val)4, present in antigen Pf155 [Perlmann, H. et al. (1984) J. Exp. Med. 159, 1686-1704] and in the ring-infected erythrocyte surface antigen [Coppel, R.L. et al. (1984) Nature 310, 789-792], indicating that these polypeptides are closely related. In contrast, two glycophorin-binding proteins of similar molecular mass [Perkins, M.E. (1984) J. Exp. Med. 160, 788-798] appear to be entirely distinct from the presently described antigens. We failed to observe any in vitro inhibitory activity of the monoclonal antibodies on merozoite invasion and on gametocyte infectivity
— id: 23537, year: 1986, vol: 19, page: 213, stat: Journal Article,

Research toward malaria vaccines
Miller LH; Howard RJ; Carter R; Good MF; Nussenzweig V; Nussenzweig RS
1986 Dec 12;234(4782):1349-1356, Science
Malaria exacts a toll of disease to people in the Tropics that seems incomprehensible to those only familiar with medicine and human health in the developed world. The methods of molecular biology, immunology, and cell biology are now being used to develop an antimalarial vaccine. The Plasmodium parasites that cause malaria have many stages in their life cycle. Each stage is antigenically distinct and potentially could be interrupted by different vaccines. However, achieving complete protection by vaccination may require a better understanding of the complexities of B- and T-cell priming in natural infections and the development of an appropriate adjuvant for use in humans
— id: 61979, year: 1986, vol: 234, page: 1349, stat: Journal Article,

Experimental basis for the development of a synthetic vaccine against Plasmodium falciparum malaria sporozoites
Nussenzweig V; Nussenzweig R
1986 ;119:150-163, CIBA Foundation symposium
Malaria continues to cause extensive morbidity and mortality in man. The exact number of individuals affected is not known. Estimates vary from 200 to 400 million, and more than one million die each year. Protective immunity against malaria can be obtained by vaccination with irradiated sporozoites. The protective antigens are polypeptides (circumsporozoite [CS] proteins) which cover the surface membrane of the parasite. CS proteins contain species-specific immunodominant epitopes, formed by tandem repeated sequences of amino acids. The dominant epitope of Plasmodium falciparum is represented in the synthetic peptide asparagine-alanine-asparagine-proline repeated in tandem three times; that is, (NANP)3. Monoclonal antibodies and most or all polyclonal human antibodies to P. falciparum sporozoites react with (NANP)3. Polyclonal antibodies raised against the synthetic peptide (NANP)3 react with the surface of the parasite and neutralize its infectivity. Since (NANP)3 repeats are present worldwide in CS proteins from P. falciparum, this epitope is a logical target for vaccine development
— id: 61987, year: 1986, vol: 119, page: 150, stat: Journal Article,

Development of a sporozoite malaria vaccine
Nussenzweig V; Nussenzweig RS
1986 Jul;35(4):678-688, American journal of tropical medicine & hygiene
— id: 61982, year: 1986, vol: 35, page: 678, stat: Journal Article,

Circumsporozoite protein of Plasmodium vivax: gene cloning and characterization of the immunodominant epitope
Arnot DE; Barnwell JW; Tam JP; Nussenzweig V; Nussenzweig RS; Enea V
1985 Nov 15;230(4727):815-818, Science
The gene encoding the circumsporozoite (CS) protein of the human malaria parasite Plasmodium vivax has been cloned. The deduced sequence of the protein consists of 373 amino acids with a central region of 19 tandem repeats of the nonapeptide Asp-Arg-Ala-Asp/Ala-Gly-Gln-Pro-Ala-Gly. A synthetic 18-amino acid peptide containing two tandem repeats binds to a monoclonal antibody directed to the CS protein of Plasmodium vivax and inhibits the interaction of this antibody with the native protein in sporozoite extracts. The portions of the CS gene that do not contain repeats are closely related to the corresponding regions of the CS genes of two simian malarias, Plasmodium cynomolgi and Plasmodium knowlesi. In contrast, the homology between the CS genes of Plasmodium vivax and Plasmodium falciparum, another malaria parasite of humans, is very limited
— id: 61990, year: 1985, vol: 230, page: 815, stat: Journal Article,

Antigenic diversity of the circumsporozoite proteins in the Plasmodium cynomolgi complex
Cochrane AH; Gwadz RW; Ojo-Amaize E; Hii J; Nussenzweig V; Nussenzweig RS
1985 Jan;14(1):111-124, Molecular & biochemical parasitology
Antigenic diversity was observed in the circumsporozoite (CS) proteins of five of the six Plasmodium cynomolgi isolates (NIH, Mulligan, London, Gombak, Ceylon, RO) that we examined. Monoclonal antibodies were produced against salivary gland sporozoites of three of the isolates. Interaction of these monoclonal antibodies with the sporozoites was isolate specific, the exception being the anti-NIH monoclonals which also reacted with Mulligan strain sporozoites. Inhibition of binding between the different monoclonal antibodies indicated that for each of the NIH, London, and Gombak strains, the homologous monoclonals were recognizing the same or a topographically close immunodominant epitope on the respective CS protein. Also the binding of a polyvalent anti-NIH rhesus serum to the homologous antigen could only be inhibited by anti-NIH monoclonal antibody. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analysis of sporozoite extracts demonstrated clear differences in the apparent molecular weights of the CS proteins of four of the six isolates. This is the first study which provides evidence of antigenic diversity in the CS proteins of different isolates of a primate plasmodial species
— id: 61998, year: 1985, vol: 14, page: 111, stat: Journal Article,

MALARIA SPOROZOITE INFECTIVITY EVALUATED BY QUANTITATION OF THE EXOERYTHROCYTIC FORMS (EEF) IN THE HOSTS LIVER WITH A DNA PROBE
Ferreira, A; Morimoto, T; Enea, V; Nussenzweig, V
1985 ;44(3):654-654, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 30974, year: 1985, vol: 44, page: 654, stat: Journal Article,

Regulatory proteins for the activated third and fourth components of complement (C3b and C4b) in mice. II. Identification and properties of complement receptor type 1 (CR1)
Kinoshita T; Lavoie S; Nussenzweig V
1985 Apr;134(4):2564-2570, Journal of immunology
We identified on the membrane of mouse spleen cells a polypeptide of Mr 190,000 (S190), with binding affinity for the mouse third component of the complement system (C3). S190, purified by affinity chromatography on C3-Sepharose, has properties resembling those of the human C3 receptor type 1 (CR1). Thus, S190, like CR1, served as a cofactor for the C3b inactivator (I)-mediated cleavage of fluid-phase C3b into iC3b, and had cofactor activity comparable to that of serum factor H (H). S190 also acted as a cofactor for the cleavages of membrane-bound C3b or membrane-bound iC3b into C3c (Mr 140,000) and C3dg (Mr 40,000) by serum factor I. As is the case with CR1, the specific activity of S190 for the cleavages leading to C3c-C3dg formation was approximately 100-fold greater than that of H. We therefore conclude that S190 and CR1 are analogous proteins
— id: 61996, year: 1985, vol: 134, page: 2564, stat: Journal Article,

Distribution of decay-accelerating factor in the peripheral blood of normal individuals and patients with paroxysmal nocturnal hemoglobinuria
Kinoshita T; Medof ME; Silber R; Nussenzweig V
1985 Jul 1;162(1):75-92, Journal of experimental medicine
Decay-accelerating factor (DAF) is a 70,000 Mr protein that has been isolated from the membrane of red cells. The function of DAF is to inhibit the assembly of amplifying enzymes of the complement cascade on the cell surface, thereby protecting them from damage by autologous complement. We raised monoclonal antibodies to DAF and used them to study its distribution in cells from the peripheral blood of normal individuals and of patients with paroxysmal nocturnal hemoglobinuria (PNH), a disease characterized by the unusual susceptibility of red cells to the hemolytic activity of complement. The results of immunoradiometric assays and of fluorescence-activated cell sorter analysis showed that DAF was present not only on red cells but was widely distributed on the surface membrane of platelets, neutrophils, monocytes, and B and T lymphocytes. By Western blotting, we observed small but consistent differences in the Mr of DAF from the membranes of various cell types. Quantitative studies showed that phagocytes and B lymphocytes, which presumably enter more frequently in contact with immune complexes and other potential activators of complement, had the highest DAF levels. As previously reported by others, the red cells from PNH patients were DAF deficient. When the patients' red cells were incubated in acidified serum (Ham test), only the DAF-deficient cells were lysed. In addition, we detected defects in DAF expression on platelets and all types of leukocytes. The observed patterns of DAF deficiency in these patients were consistent with the concept that the PNH cells were of monoclonal origin. In one patient, abnormal and normal cells were found only in the erythroid, myeloid, and megakaryocytic lineages. In two other patients, the lymphocytes were also DAF deficient, suggesting that a mutation occurred in a totipotent stem cell. It appears, therefore, that the lesion leading to PNH can occur at various stages in the differentiation of hematopoietic cells
— id: 61993, year: 1985, vol: 162, page: 75, stat: Journal Article,

MONOCLONAL-ANTIBODIES RECOGNIZE A 150 KDA ANTIGEN IN SEXUAL AND ASEXUAL STAGES OF PLASMODIUM-FALCIPARUM
Masuda, A; Zavala, F; Nussenzweig, V; Nussenzweig, RS
1985 ;44(4):982-982, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 30962, year: 1985, vol: 44, page: 982, stat: Journal Article,

Amelioration of lytic abnormalities of paroxysmal nocturnal hemoglobinuria with decay-accelerating factor
Medof ME; Kinoshita T; Silber R; Nussenzweig V
1985 May;82(9):2980-2984, Proceedings of the National Academy of Sciences of the United States of America
Purified decay-accelerating factor (DAF), from the stroma of normal human erythrocytes, was incorporated into the membranes of erythrocytes of patients with paroxysmal nocturnal hemoglobinuria (PNH), and its effect on the complement sensitivity of the cells was investigated. Reconstitution with exogenous DAF restored the ability of the affected PNH cells to resist assembly of the homologous C3 convertase, C4b2a, on their surfaces, and decreased the susceptibility of the cells to lysis in acidified serum. Conversely, treatment of normal erythrocytes with monoclonal or polyclonal anti-DAF antibodies abrogated the capacity of the normal cells to circumvent C4b2a assembly and rendered the cells sensitive to acid lysis. These findings show that the previously reported association of DAF deficiency with PNH is causally related to the lytic abnormalities of the cells and clarify the molecular basis for restriction of autologous convertase formation on normal human erythrocytes
— id: 61994, year: 1985, vol: 82, page: 2980, stat: Journal Article,

DIMINISHED EXPRESSION OF THE C3B/C4B RECEPTOR (CR-1) IN HLA DR3 PATIENTS WITH INSULIN DEPENDENT DIABETES-MELLITUS
Medof, ME; Decordoba, SR; Rubinstein, P; Nussenzweig, V
1985 ;33(2):A438-A438, Clinical research
— id: 30924, year: 1985, vol: 33, page: A438, stat: Journal Article,

PARTIAL CORRECTION OF THE PAROXYSMAL-NOCTURNAL HEMOGLOBINURIA (PNH) HEMOLYTIC DEFECTS WITH DECAY ACCELERATING FACTOR (DAF)
Medof, ME; Rosse, WF; Kinoshita, T; Silber, R; Nussenzweig, V
1985 ;33(2):A548-A548, Clinical research
— id: 30929, year: 1985, vol: 33, page: A548, stat: Journal Article,

Development of a sporozoite vaccine
Nussenzweig RS; Nussenzweig V
1985 Dec;1(6):150-152, Parasitology today
— id: 61989, year: 1985, vol: 1, page: 150, stat: Journal Article,

Circumsporozoite proteins of malaria parasites
Nussenzweig V; Nussenzweig RS
1985 Sep;42(2):401-403, Cell
— id: 61992, year: 1985, vol: 42, page: 401, stat: Journal Article,

Malaria vaccine against sporozoites?
Nussenzweig V; Nussenzweig RS
1985 Nov-Dec;136D(3):301-312, Annales de l'Insitut Pasteur. Immunologie
Malaria kills over one million people a year. A promising candidate suitable for either a synthetic or a genetically engineered malaria vaccine has been synthesized. The molecule, a string of 4 amino acids repeated 3 times, is modeled on a surface component of sporozoites apparent when they are injected by a mosquito into a human. An immune response to the peptide might neutralize sporozoites before they are sequestered in host liver cells. The peptide reacted with antibodies in serum of randomly selected individuals living where malaria is endemic and with serum from a volunteer protected from infection by immunization with irradiated parasites. It induced antibodies in animals; the antibodies prevented the parasite from entering human cells growing in culture
— id: 61991, year: 1985, vol: 136D, page: 301, stat: Journal Article,

Progressos no desenvolvimento de vacina esporozoitica para a malaria
Nussenzweig, Ruth S; Nussenzweig, Victor
1985 ;37(Suppl):135-139, Revista brasileira de malariologia e doencas tropicais
— id: 90049, year: 1985, vol: 37, page: 135, stat: Journal Article,

RATIONALE AND EXPERIMENTAL BASIS FOR THE DEVELOPMENT OF A SYNTHETIC VACCINE AGAINST P-FALCIPARUM MALARIA
Nussenzweig, V; Nussenzweig, RS
1985 ;190(SEP):26-, Abstracts of papers (American Chemical Society)
— id: 30850, year: 1985, vol: 190, page: 26, stat: Journal Article,

Multiple non-repeated epitopes on the circumsporozoite protein of Plasmodium knowlesi
Vergara U; Gwadz R; Schlesinger D; Nussenzweig V; Ferreira A
1985 Mar;14(3):283-292, Molecular & biochemical parasitology
The Plasmodium knowlesi circumsporozoite (CS) protein contains a repetitive immunodominant epitope. Here we show that the serum of rabbits repeatedly immunized with P. knowlesi sporozoites contains antibodies which bind to immobilized synthetic peptides ('C2', 'N2', and 'charged') representing two different polar regions of the CS polypeptide. These reactions are specific since the binding is inhibited only by the homologous peptides. Antisporozoite antibodies were isolated from the rabbit serum by affinity chromatography on Sepharose beads coupled to two synthetic peptides, 'C2' and 'charged'. Both purified antibodies recognized the CS protein and the intracellular precursors as shown by Western blotting analysis using sporozoite extracts. These results demonstrate that the corresponding areas of the native CS molecule are immunogenic, accessible to interaction with antibody, and therefore constitute potential targets for vaccine development. In addition, the present findings confirm the published amino acid sequence of a large portion of the CS protein which has been deduced from the nucleotide sequence of the corresponding gene
— id: 61997, year: 1985, vol: 14, page: 283, stat: Journal Article,

Conserved group-specific epitopes of the circumsporozoite proteins revealed by antibodies to synthetic peptides
Vergara U; Ruiz A; Ferreira A; Nussenzweig RS; Nussenzweig V
1985 May;134(5):3445-3448, Journal of immunology
The immunogenic properties of sporozoites are associated mainly with the circumsporozoite (CS) protein that covers the surface of mature sporozoites. This stage-specific protein has an immunodominant region with repetitive epitopes. Rabbits that are repeatedly immunized with sporozoites of Plasmodium knowlesi, a monkey malaria parasite, also recognize two synthetic peptides (N2 and C2) representing other polar domains of the CS protein. We show in this report that antibodies to the N2 and C2 synthetic peptides react not only with P. knowlesi but also with conserved regions of the surface membrane of other human, monkey, and rodent (but not avian) malaria sporozoites. Moreover, antibodies to N2 partially neutralize the infectivity of sporozoites of P. berghei, a rodent malaria parasite. In contrast, antibodies to synthetic peptides representing the repetitive epitope of P. knowlesi were strictly species specific
— id: 61995, year: 1985, vol: 134, page: 3445, stat: Journal Article,

"PRESENCE OF MULTIPLE, CONSERVED AND NON-REPEATED EPITOPES IN DIFFERENT SPECIES OF MALARIA PARASITES"
Vergara, U; Ferreira, A; Schlesinger, D; Nussenzweig, RS; Nussenzweig, V
1985 ;44(4):1172-1172, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 30965, year: 1985, vol: 44, page: 1172, stat: Journal Article,

Immunoradiometric assay to measure the in vitro penetration of sporozoites of malaria parasites into hepatoma cells
Zavala F; Hollingdale MR; Schwartz AL; Nussenzweig RS; Nussenzweig V
1985 Feb;134(2):1202-1205, Journal of immunology
We describe here an immunoradiometric assay to quantitate the in vitro invasion of hepatoma cells by sporozoites. The assay measures levels of circumsporozoite (CS) antigen that remain associated with the hepatoma cells after their incubation with the parasites. Several observations show that these measurements reflect internalized rather than extracellular antigen. For example, when incubations were performed with nonviable parasites (sonicated or heated), or in the presence of metabolic inhibitors, such as sodium azide and deoxyglucose, the amounts of CS antigen found in hepatoma cell extracts were greatly diminished. Moreover, Western blotting experiments revealed a striking difference in the pattern of CS proteins of infected cell extracts as compared with those of free parasites. The assay was used to measure the amounts of intracellular CS antigen for several days after infection of the hepatoma cells. The results confirmed previous microscopic observations, made by using immunofluorescence techniques, showing that the CS antigen in the host's liver cells diminishes progressively while the parasite develops into the exoerythrocytic stage. The immunoradiometric assay should facilitate the evaluation of the effects of drugs on sporozoites and also on studies aimed at the identification of a sporozoite receptor on the hepatocyte
— id: 23542, year: 1985, vol: 134, page: 1202, stat: Journal Article,

Ubiquity of the repetitive epitope of the CS protein in different isolates of human malaria parasites
Zavala F; Masuda A; Graves PM; Nussenzweig V; Nussenzweig RS
1985 Oct;135(4):2790-2793, Journal of immunology
Sporozoites of the human malaria Plasmodium falciparum and Plasmodium vivax obtained from a large number of endemic areas were screened with species-specific monoclonal antibodies that recognize the repeated epitopes of the respective circumsporozoite (CS) proteins. By using a two-site immunoradiometric assay, it was determined that all the parasite isolates of a given species react with a single monoclonal antibody, indicating the presence of a common repeated epitope. Polyacrylamide gel electrophoresis, followed by Western blot, showed that the CS proteins of the various isolates differed in their apparent m.w
— id: 23539, year: 1985, vol: 135, page: 2790, stat: Journal Article,

Rationale for development of a synthetic vaccine against Plasmodium falciparum malaria
Zavala F; Tam JP; Hollingdale MR; Cochrane AH; Quakyi I; Nussenzweig RS; Nussenzweig V
1985 Jun 21;228(4706):1436-1440, Science
Protective immunity against malaria can be obtained by vaccination with irradiated sporozoites. The protective antigens known as circumsporozoite (CS) proteins, are polypeptides that cover the surface membrane of the parasite. The CS proteins contain species-specific immunodominant epitopes formed by tandem repeated sequences of amino acids. Here it is shown that the dominant epitope of Plasmodium falciparum is contained in the synthetic dodecapeptide Asn-Ala-Asn-Pro-Asn-Ala-Asn-Pro-Asn-Ala-Pro or (NANP)3. Monoclonal antibodies and most or all polyclonal human antibodies to the sporozoites react with (NANP)3, and polyclonal antibodies raised against the synthetic peptide (NANP)3 react with the surface of the parasite and neutralize its infectivity. Since (NANP)3 repeats are present in CS proteins of P. falciparum from many parts of the world, this epitope is a logical target for vaccine development
— id: 23540, year: 1985, vol: 228, page: 1436, stat: Journal Article,

THE EPITOPE SPECIFICITY OF ANTI-P-FALCIPARUM SPOROZOITE ANTIBODIES PRESENT IN HUMAN-SERA FROM ENDEMIC AREAS
Zavala, F; Tamm, J; Nussenzweig, RS; Nussenzweig, V
1985 ;44(4):980-980, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 30961, year: 1985, vol: 44, page: 980, stat: Journal Article,

Deficiency in C3b receptors on neutrophils of patients with chronic granulomatous disease and hyperimmunoglobulin-E recurrent infection (Job's) syndrome
Gaither TA; Gallin JI; Iida K; Nussenzweig V; Frank MM
1984 Dec;8(4):429-444, Inflammation
C3b receptor (CR1) expression by neutrophils (PMNs) and erythrocytes (Es) from patients with chronic granulomatous disease (CGD) or with hyper-IgE, frequent infection (Job's) syndrome was compared with that of control subjects. The control subjects consisted of one group of patients with infections and a second group of normal, healthy individuals. Three quantitative assays were used: rosette formation with C3b-coated cellular intermediates (EAC43b), binding of radiolabeled monoclonal anti-CR1 ([125I]anti-CR1) to PMN surfaces, and binding of the antibody to nonidet P-40 (NP-40) extracts of PMNs and Es in an immunoradiometric assay. Rosette formation by the PMNs of five male CGD patients was about 50% of that of paired normal control subjects, whereas the rosette formation of three female CGD patients was similar to that of the control subjects. Surface binding of [125I]anti-CR1 to PMNs of 10 CGD patients was about half that of the normal subjects (mean percent binding was 2.33% for the CGD patients vs. 3.86% for the normal subjects, giving a difference of -1.53 +/- 0.22%, P less than 0.001 by the paired-sample t test). The degree of PMN binding was similarly low for both the male and the female CGD patients. Conversely, the binding of anti-CR1 to the PMNs of 11 infected control patients appeared to be similar to that of the normal subjects (4.51% for the patient vs. 4.21% for the paired normal subjects). The infected control group originally included four Job's syndrome patients, and when this subgroup was analyzed separately, their PMNs were shown to bind significantly less anti-CR1 than did the PMNs of the normal subjects (P less than 0.01 by the paired-sample t test). In contrast, the other infected control patients showed higher-than-normal levels of anti-CR1 binding (P less than 0.05). When compared to that of the normal subjects, the total CR1 quantitated in PMN extracts was also lower than normal in CGD patients (P less than 0.01 and in the PMN extracts of eight Job's syndrome patients tested (P less than 0.01). The PMNs of the other infected control subjects were not significantly different from those of the normal subjects in total CR1 expression. Extracts of Es from Job's syndrome patients also had fewer than normal CR1 (P less than 0.02). On the other hand, CR1 levels in E extracts from the CGD patients and the other control patients were similar to those in the normal control subjects. Quantitations of C3, C4, and factor B were normal in CGD.(ABSTRACT TRUNCATED AT 400 WORDS)
— id: 62000, year: 1984, vol: 8, page: 429, stat: Journal Article,

Neutralization of the infectivity of sporozoites of Plasmodium knowlesi by antibodies to a synthetic peptide
Gysin J; Barnwell J; Schlesinger DH; Nussenzweig V; Nussenzweig RS
1984 Sep 1;160(3):935-940, Journal of experimental medicine
Antibodies against a synthetic peptide representing the repetitive epitope of the circumsporozoite protein (CS) of Plasmodium knowlesi have properties similar to those of antibodies against the native protein. Either antibody reacts with the synthetic peptide, cross-links the CS protein on the membrane of the parasite giving the CSP reaction, and neutralizes the infectivity of sporozoites. The synthetic peptide and sporozoite extracts were equally effective when used in an immunoradiometric assay as antigens to detect antibodies to CS proteins. It is likely that the corresponding synthetic repeats from the human malaria parasites could be used to measure levels of anti-sporozoite antibodies in endemic areas, or to evaluate the humoral response to anti-sporozoite vaccines. The authors are grateful to Dr. Robert Gwadz, NIH, for supplying Anopheles mosquitoes and P. knowlesi sporozoites used in this study
— id: 62003, year: 1984, vol: 160, page: 935, stat: Journal Article,

Regulatory proteins for the activated third and fourth components of complement (C3b and C4b) in mice. I. Isolation and characterization of factor H: the serum cofactor for the C3b/C4b inactivator (factor I)
Kinoshita T; Nussenzweig V
1984 Jul 6;71(2):247-257, Journal of immunological methods
Factor H, purified from mouse EDTA-plasma using a 4-step procedure, consists of a single polypeptide chain of Mr 150,000 on SDS-PAGE. Mouse H (Hmo) was required for the cleavage of fluid-phase mouse C3b by mouse I (Imo). The final product of degradation of fluid-phase mouse C3b was iC3b, consisting of fragments of the alpha'-chain (alpha'-70, alpha'-43) linked by disulfide bonds to an intact beta-chain. Imo alone was capable of cleavage of membrane-bound mouse C3b and of generating iC3b. The addition of Hmo nevertheless had an enhancing effect on Imo activity, but cleavage did not proceed beyond iC3b. These observations suggest that one important function of Hmo is to permit the inactivation of fluid-phase C3b, and to inhibit irreversibly its activity. The concentration of H in the plasma of male and female BALB/c mice was not significantly different. Among different inbred strains of mice, large differences were observed in the plasma levels of H, and plasma H levels were positively correlated with the plasma levels of C3. This observation, taken together with the well known role of H in the control of the activation of the alternative pathway, suggests that the turnover of C3 is controlled to some extent by H
— id: 62004, year: 1984, vol: 71, page: 247, stat: Journal Article,

Inhibition of complement activation on the surface of cells after incorporation of decay-accelerating factor (DAF) into their membranes
Medof ME; Kinoshita T; Nussenzweig V
1984 Nov 1;160(5):1558-1578, Journal of experimental medicine
Decay-accelerating factor (DAF), extracted from the stroma of human erythrocytes, was purified to homogeneity and incorporated into the membrane of sheep red cell complement intermediates, where its functional properties were analyzed. Incorporation of DAF into the cell membranes was temperature dependent, took place on pronase- or trypsin-treated erythrocytes, and did not depend on prior deposition of antibody, C1 or C4. Serum lipoproteins (high and low density) effectively inhibited DAF incorporation, but had no effect on the activity of DAF after its association with the cell membrane. The incorporated DAF could not be removed from the red cell surface by repeated washings in the presence of high salt concentration but was solubilized when the stroma were extracted with 0.1% Nonidet P-40. The presence of DAF in the membrane of EA did not affect the deposition of C1 and C4, but as few as 10(2) DAF molecules per cell profoundly inhibited the assembly of C3 and C5 convertases of both the classical and alternative pathways. The DAF inhibitory effect on EAC14 or EAC43 was not overcome by supplying an excess of C2 or factor B, but the alternative pathway C3 convertase could be assembled in the presence of Ni++, or nonphysiological concentrations of Mg++, which enhances the binding affinity of factor B for C3b. The DAF effect on EAC14 or EAC143 was entirely reversed by treating the cells with specific anti-DAF antibodies, showing that DAF did not alter the structure of C4b or C3b. Taken together, the experimental evidence suggests that DAF interacts directly with membrane-bound C3b or C4b and prevents subsequent uptake of C2 and factor B. DAF can function only within the cell membrane. Indeed, the decay dissociation of the C4b2a enzyme on DAF-containing sheep intermediates was not changed by varying the cell concentration. DAF-treated EA had no influence on the decay of nontreated EAC142 present in the same mixture. Moreover, the inhibitory activity of intact human erythrocytes on C4b2a was not blocked by antibodies to DAF, but was abolished by antibodies to the C3b/C4b receptor (CR1). When incorporated into the membrane of rabbit erythrocytes, human DAF inhibited their lysis by human complement. In conclusion, on the basis of these and previous results, it appears that DAF plays a central role in preventing the amplification of the complement cascade on host cell surfaces.(ABSTRACT TRUNCATED AT 400 WORDS)
— id: 62002, year: 1984, vol: 160, page: 1558, stat: Journal Article,

Control of the function of substrate-bound C4b-C3b by the complement receptor Cr1
Medof ME; Nussenzweig V
1984 Jun 1;159(6):1669-1685, Journal of experimental medicine
The complement fragments C3b and C4b are the main ligands for the membrane receptor CR1. We showed elsewhere that CR1 functions as an essential cofactor for the factor I-mediated enzymatic breakdown of membrane-bound C3b (*C3b) into C3c and * C3dg . One of the main findings of the present paper is that CR1 also promotes the degradation of bound C4b (*C4b) into C4c and *C4d. On a weight basis, the cofactor activity of CR1 in the cleavage of *C4b present on the cell intermediate EAC14 is 10(3)-fold greater than that of the serum cofactor C4-binding protein ( C4bp ). An additional finding is that the effect of CR1 on either *C3b or *C4b is modulated by the presence of the other ligand in its vicinity; that is, *C4b degradation by CR1 plus I is enhanced by neighboring *C3b and vice versa. For example, upon uptake of optimal amounts of *C3b onto EAC142 and the assembly of the C3-convertase EAC1423 , the activity of CR1 in generating C4c is enhanced 5-10 times further. Conversely, when the number of *C3b molecules on EAC1423 is relatively small (or when EAC1423 has been converted by I plus H into EAC1423i ), the presence of neighboring *C4b enhances the conversion of *C3b (or *iC3b) into C3c plus * C3dg . The enhancing effect of *C3b on the cleavage of *C4b by I is observed only if the cofactor of this reaction is CR1. Indeed, the activity of I or I plus C4bp on *C4b is significantly inhibited when *C3b is fixed and the main product of the reaction is * iC4b . Taken together, these findings suggest that degradation of *C4b will be more effective when enough C3b molecules are fixed nearby, thus facilitating the interaction of *C4b*3b clusters with CR1-bearing cells, and that under physiological conditions, *C4b activity can be efficiently controlled by CR1
— id: 62005, year: 1984, vol: 159, page: 1669, stat: Journal Article,

Development of sporozoite vaccines
Nussenzweig RS; Nussenzweig V
1984 Nov 13;307(1131):117-128, Philosophical transactions of the Royal Society of London. Series B. Biological sciences
Protective immunity against malaria has been achieved in hosts ranging from birds to man by repeated inoculation of irradiated sporozoites. The main antigens involved in protective immunity to sporozoites are the circumsporozoite (CS) proteins, which are part of a family of proteins, covering the whole surface membrane of the parasite, and which have similar physico-chemical and antigenic properties. Monovalent fragments of monoclonal antibodies to CS proteins neutralize sporozoite infectivity. All monoclonal antibodies recognize a single immunodominant region within the various CS proteins, and this region contains repetitive epitopes. The recurrent immunodominant epitope of the CS protein of P. knowlesi has been identified, and shown to consist of 12 tandemly repeated subunits of 12 amino acids. The dimer of the dodecapeptide was coupled to protein carriers, emulsified in Freund's complete adjuvant, and injected into rodents and monkeys. All animals made anti-peptide antibodies, and most of the antisera reacted with P. knowlesi CS protein
— id: 62001, year: 1984, vol: 307, page: 117, stat: Journal Article,

Synthetic peptides and malaria surface antigens
Nussenzweig V
1984 ;1(2):187-189, Annali Sclavo. Collana monografica
— id: 62006, year: 1984, vol: 1, page: 187, stat: Journal Article,

Recent advances in the development of a sporozoite vaccine for malaria
Nussenzweig V; Nussenzweig RS
1984 Dec;2(2):289-292, Asian Pacific journal of allergy & immunology
— id: 61999, year: 1984, vol: 2, page: 289, stat: Journal Article,

Structure of an immunodominant epitope of the circumsporozoite surface protein of Plasmodium knowlesi
Schlesinger DH; Cochrane AH; Gwadz RW; Godson GN; Melton R; Nussenzweig RS; Nussenzweig V
1984 Nov 6;23(23):5665-5670, Biochemistry
Previous studies have shown that the immunodominant region of the circumsporozoite surface (CS) protein of Plasmodium knowlesi is contained within a tandemly repeated dodecapeptide: Gln-Ala-Gln-Gly-Asp-Gly-Ala-Asn-Ala-Gly-Gln-Pro. We show here that the CS protein epitopes reacting with six monoclonal antibodies raised against the intact parasite are represented in a synthetic tandem repeat of this dodecapeptide. The specificity of four of these antibodies was studied further by preparing synthetic peptides corresponding to overlapping regions of the repeats and measuring their ability to inhibit the specific interaction between the antibodies and CS proteins. We find that three antibodies have very similar patterns of reactivity with this series of peptides and that they define an epitope of eight amino acids (Gly-Asp-Gly-Ala-Asn-Ala-Gly-Gln) within the dodecapeptide. The remaining antibody probably recognizes a configurational epitope formed by a tandem repeat of the dodecapeptide
— id: 17320, year: 1984, vol: 23, page: 5665, stat: Journal Article,

Plasmodium knowlesi sporozoite antigen: expression by infectious recombinant vaccinia virus
Smith GL; Godson GN; Nussenzweig V; Nussenzweig RS; Barnwell J; Moss B
1984 Apr 27;224(4647):397-399, Science
The gene coding for the circumsporozoite antigen of the malaria parasite Plasmodium knowlesi was inserted into the vaccinia virus genome under the control of a defined vaccinia virus promoter. Cells infected with the recombinant virus synthesized polypeptides of 53,000 to 56,000 daltons that reacted with monoclonal antibody against the repeating epitope of the malaria protein. Furthermore, rabbits vaccinated with the recombinant virus produced antibodies that bound specifically to sporozoites. These data provide evidence for expression of a cloned malaria gene in mammalian cells and illustrate the potential of vaccinia virus recombinants as live malaria vaccines
— id: 17323, year: 1984, vol: 224, page: 397, stat: Journal Article,

FACTORS INFLUENCING THE HOST RESPONSE TO LEISHMANIA-MEXICANA - DISCUSSION
CHANG; PEREZ; HUDSON; PFEFFERKORN; SHARMA; ODALY; SHER; WARREN; WYLER; ANDRADE; MARTINEZPALOMO; HERNANDEZ; MIRELMAN; NUSSENZWEIG
1983 ;99(4):167-173, CIBA Foundation symposium
— id: 50788, year: 1983, vol: 99, page: 167, stat: Journal Article,

Genetic polymorphism of human C4-binding protein
de Cordoba SR; Ferreira A; Nussenzweig V; Rubinstein P
1983 Sep;131(3):1565-1569, Journal of immunology
Two different forms of human C4-bp, C4-bp A and C4-bp B, have been identified by isoelectric focusing (IEF) of neuraminidase-treated EDTA-plasma samples. Family studies demonstrate Mendelian segregation of these forms, indicating that they are under gentic control. This conclusion is supported by IEF analysis of the two variants purified by affinity chromatography. Under completely denaturing conditions, C4-bp B was found to be composed of two subunits that focused at different pH, whereas C4-bp A contains only the more basic one. These results suggest that a single autosomal locus with at least two codominant alleles coding for the subunits controls the IEF variation of C4-bp in humans. The allele designated C4BP*1 codes for a subunit that, after neuraminidase treatment, focuses at pH = 6.65. The allele C4BP*2 codes for a different subunit that focuses at pH = 6.60. The C4-bp A phenotype corresponds to the genotype C4BP*1,C4BP*1 and the phenotype C4-bp B to the genotype C4BP*1,C4BP*2. The phenotype corresponding to the C4BP*2,C4BP*2 homozygous genotype has not been encountered thus far. Initial linkage data indicate that the C4BP locus is not closely linked to either the HLA or to the C3 loci
— id: 62008, year: 1983, vol: 131, page: 1565, stat: Journal Article,

HUMAN POLYMORPHISM OF C4-BINDING PROTEIN
DECORDOBA, SR; FERREIRA, A; NUSSENZWEIG, V; RUBINSTEIN, P
1983 ;42(5):1232-1232, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 40706, year: 1983, vol: 42, page: 1232, stat: Journal Article,

Cloning and expression in E. coli of the malarial sporozoite surface antigen gene from Plasmodium knowlesi
Ellis J; Ozaki LS; Gwadz RW; Cochrane AH; Nussenzweig V; Nussenzweig RS; Godson GN
1983 Apr 7;302(5908):536-538, Nature
The malarial sporozoite, the infective stage found in the salivary gland of the insect vector, bears highly immunogenic surface antigen(s). Repeated exposure to irradiated sporozoites induces protection against malaria in several host species, including man. Further, monoclonal antibodies that confer passive immunity react with the immunogenic surface determinants of different sporozoite species. One approach to prevent malaria, therefore, would be to produce a vaccine that induces high titres of circulating antibodies against the sporozoite surface determinant(s). However, production of such a vaccine has not been possible since sporozoites cannot be cultivated in vitro and, therefore, only limited amounts of surface antigen may be obtained. To overcome this problem, we have prepared mRNA from Plasmodium knowlesi-infected mosquitoes to construct a cDNA library. From this library we have isolated a clone that expresses the sporozoite surface antigen as a beta-lactamase fusion protein in the plasmid pBR322. This is the first potentially protective malarial antigen to be cloned by recombinant DNA technology
— id: 17328, year: 1983, vol: 302, page: 536, stat: Journal Article,

Monoclonal antibodies to human complement receptor (CR1) detect defects in glomerular diseases
Emancipator SN; Iida K; Nussenzweig V; Gallo GR
1983 May;27(2):170-175, Clinical immunology & immunopathology
The complement receptor for C3b of the epithelial cells of human glomeruli is structurally and functionally very similar or identical to CR1, the complement receptor for C3b and C4b present on the membrane of red cells and leukocytes. Four monoclonal antibodies directed against separate epitopes of CR1 react with an antigen in the glomeruli, which appears to be present on the epithelial podocytes. Moreover, the monoclonal antibodies very effectively inhibit the binding of C3b-bearing red cells to the glomeruli. The pattern of immunofluorescence of the receptor was normal or slightly altered in patients with minimal change disease, mesangial proliferative glomerulonephritis (GN), or idiopathic membranous GN. Glomeruli with endocapillary proliferation showed some attenuation of staining. Glomeruli in which the capillary tuft architecture was altered, or of patients with systemic lupus erythematosus, or of patients with diffuse diabetic nephropathy tended to have few foci or no staining for the receptor. No correlation was found between the intensities of staining of the C3b receptor and of C3 antigen deposited in the glomeruli
— id: 59961, year: 1983, vol: 27, page: 170, stat: Journal Article,

Murine sex-limited protein (Slp) antigenic sites in human complement component C4
Ferreira A; Nussenzweig V
1983 ;18(4):335-341, Immunogenetics
Human complement component C4 is encoded by two HLA-linked loci, A and B. In the mouse, the H-2 region contains structural genes for two serum proteins that react with antibodies to human C4, but one of these proteins (Slp) has no C4 hemolytic activity. Because the product of C4-A locus in man has low hemolytic activity, a previous report suggests it may be the homologue of murine Slp. We show here that Slp antigenic determinants are found in human C4. However, they are expressed in the products of both loci A and B, that is, C4A and C4B, since both proteins were specifically immunoprecipitated by the IgG fraction of alloantisera to mouse Slp. Therefore, Slp-associated structural features are preserved in evolution, although they do not seem to be relevant to the hemolytic properties of C4
— id: 62012, year: 1983, vol: 18, page: 335, stat: Journal Article,

DECREASED C3B-RECEPTORS (CR-1) ON CHRONIC GRANULOMATOUS-DISEASE (CGD) NEUTROPHILS (PMN)
GAITHER, TA; GALLIN, J; IIDA, K; NUSSENZWEIG, V; FRANK, MM
1983 ;164(3-4):244-245, Immunobiology
— id: 40674, year: 1983, vol: 164, page: 244, stat: Journal Article,

Identification and chemical synthesis of a tandemly repeated immunogenic region of Plasmodium knowlesi circumsporozoite protein
Godson GN; Ellis J; Svec P; Schlesinger DH; Nussenzweig V
1983 Sep 1-7;305(5929):29-33, Nature
Complementary DNA clones that code for the immunogenic region of the Plasmodium knowlesi circumsporozoite protein were shown to contain a tandemly repeating 36-base pair unit. A synthetic dodecapeptide corresponding to the predicted reading frame of the repeating nucleotide unit behaved, in an immunoradiometric assay, identically with the native P. knowlesi circumsporozoite protein. The repeating 36-base pair unit occurred 12 times within the gene and accounts for at least one-third of the amino acid sequence of the surface antigen protein
— id: 17326, year: 1983, vol: 305, page: 29, stat: Journal Article,

Identification of the membrane receptor for the complement fragment C3d by means of a monoclonal antibody
Iida K; Nadler L; Nussenzweig V
1983 Oct 1;158(4):1021-1033, Journal of experimental medicine
The B2 antigen characterized by means of a monoclonal antibody (14) is a 140,000 Mr protein expressed only in certain stages of the differentiation of lymphocytes of the B lineage. Here we examine the relationship between B2 and the membrane complement receptor type 2 (CR2) for the complement fragment C3d (11, 12), which is also associated only with B cells. Both phenotypic markers are distributed in a similar manner among B cell malignancies and, as shown here, among established cell lines. A polypeptide with binding affinity for C3d was isolated from the membrane of B2-positive cells, i.e., tonsil lymphocytes and Raji cells. We found that this C3d-binding protein not only had the same Mr and isoelectric point (pI) as the B2 antigen, but that it was recognized by the monoclonal antibody to B2. However, anti-B2 does not mask the ligand-binding site of CR2 since it does not prevent the interaction of the purified 140,000 Mr polypeptide with immobilized C3d. Rosette formation between tonsil lymphocytes and erythrocyte intermediates bearing C3d was specifically inhibited by anti-B2. In the case of Raji cells, rosette formation was strongly inhibited only when the lymphocytes were sequentially treated with anti-B2 and with a polyclonal antibody against mouse Ig. In short, B2 and CR2 have a similar distribution among normal and malignant cells, have the same Mr and pI under denaturing conditions, and react with a single monoclonal antibody. We conclude that B2 is identical to CR2
— id: 62007, year: 1983, vol: 158, page: 1021, stat: Journal Article,

Functional properties of membrane-associated complement receptor CR1
Iida K; Nussenzweig V
1983 Apr;130(4):1876-1880, Journal of immunology
It was previously shown that membrane receptors for C3b (CR1) purified from human erythrocytes were powerful inhibitors of the complement cascade and that they encompass the regulatory functions of the serum proteins beta 1H (H) and C4-binding protein (C4bp). In the present report we study the functional properties of membrane-associated CR1. When tonsil lymphocytes, which contain between 30 and 60% of CR1-bearing B cells, are incubated with the red cell complement intermediate EAC14oxy2lim or EAC14oxy23lim, they inhibit both C42 and C423 in a dose-dependent manner. These effects are mediated by membrane-associated molecules. Indeed, mild trypsinization of the lymphocytes abolishes their activity, and formaldehyde-fixed cells are as effective as viable cells. The inhibitory effects are in part mediated by CR1. The lymphocyte activities are reversed about 60% if monoclonal antibodies to CR1 or fluid phase C3b are present in the incubation medium. Moreover, upon addition of C3b-inactivator (l), lymphocytes release C3c fragments from EAC14oxy23b. The release of C3c was also abolished by antibodies to CR1. These results support the idea that CR1, as well as other molecules from the lymphocyte membrane, can function as inhibitor(s) of complement activation in their vicinity
— id: 62009, year: 1983, vol: 130, page: 1876, stat: Journal Article,

Role of the complement receptor CR1 in the processing of substrate-bound C3
Medof ME; Iida K; Nussenzweig V
1983 ;421:299-306, Annals of the New York Academy of Sciences
— id: 62011, year: 1983, vol: 421, page: 299, stat: Journal Article,

FUNCTIONAL-PROPERTIES OF DIFFERENT CR-1 PHENOTYPES
MEDOF, ME; IIDA, K; NUSSENZWEIG, V; DYKMAN, T; DIXIT, R; ATKINSON, J
1983 ;31(4):A733-A733, Clinical research
— id: 40614, year: 1983, vol: 31, page: A733, stat: Journal Article,

DIFFERENTIAL ACTIVITIES OF CR-1 AND H IN REGULATION OF THE FUNCTION OF SUBSTRATE-BOUND AND FLUID-PHASE C3B
MEDOF, ME; NUSSENZWEIG, V
1983 ;164(3-4):275-276, Immunobiology
— id: 40675, year: 1983, vol: 164, page: 275, stat: Journal Article,

MONOCLONAL-ANTIBODIES IDENTIFY PROTECTIVE ANTIGENS IN MALARIA PARASITES
NUSSENZWEIG, V
1983 JAN 20 ;2(2):241-241, Hybridoma
— id: 98610, year: 1983, vol: 2, page: 241, stat: Journal Article,

Structure of the plasmodium knowlesi gene coding for the circumsporozoite protein
Ozaki LS; Svec P; Nussenzweig RS; Nussenzweig V; Godson GN
1983 Oct;34(3):815-822, Cell
The gene that codes for the surface antigen of Plasmodium knowlesi sporozoites (CS protein) is unsplit and present in the genome in only one copy. The CS protein, as deduced from DNA sequence analysis of the structural gene, has an unusual structure with the central 40% of the polypeptide chain present as 12 tandemly repeated amino acid peptide units flanked by regions of highly charged amino acids. The protein has an amino-terminal hydrophobic amino acid signal sequence and a hydrophobic carboxy-terminal anchor sequence. The coding sequence of the gene has an AT content of 53%, compared with 70% AT in the 5' and 3' flanking sequences, and is contained entirely within an 11 kb Eco RI genomic DNA fragment. This genomic fragment expresses the CS protein in E. coli, indicating that the parasite promoter and ribosome binding site signals can be recognized in E. coli
— id: 17325, year: 1983, vol: 34, page: 815, stat: Journal Article,

Structural similarities among the protective antigens of sporozoites from different species of malaria parasites
Santoro F; Cochrane AH; Nussenzweig V; Nardin EH; Nussenzweig RS; Gwadz RW; Ferreira A
1983 Mar 10;258(5):3341-3345, Journal of biological chemistry
— id: 62010, year: 1983, vol: 258, page: 3341, stat: Journal Article,

Circumsporozoite proteins of malaria parasites contain a single immunodominant region with two or more identical epitopes
Zavala F; Cochrane AH; Nardin EH; Nussenzweig RS; Nussenzweig V
1983 Jun 1;157(6):1947-1957, Journal of experimental medicine
We have used panels of monoclonal antibodies to circumsporozoite (CS) proteins of Plasmodium falciparium, P. vivax, and P. knowlesi to determine the number of topographically independent epitopes of these antigens. The results of competition binding assays indicated that single regions of the CS molecules were recognized by the homologous monoclonal antibodies. Competition binding assays were also used to study the specificity of antibodies contained in the sera of humans and monkeys that had developed sterile immunity after immunization with irradiated, intact sporozoites. We found that single monoclonal antibodies inhibited 70-95% of the specific binding of the polyclonal antibodies to crude extracts of sporozoites. It appears, therefore, that CS proteins are among the most immunogenic constituents of sporozoites, and that a single region of these molecules contains most of the immunogenic activity. An additional finding was that the immunodominant region of CS molecules is multivalent with regard to the expression of a single epitope. This was demonstrated by the ability of monomers of CS proteins to bind simultaneously two or more molecules of the same monoclonal antibody
— id: 23547, year: 1983, vol: 157, page: 1947, stat: Journal Article,

Monoclonal antibodies identify the protective antigens of sporozoites of Plasmodium knowlesi
Cochrane AH; Santoro F; Nussenzweig V; Gwadz RW; Nussenzweig RS
1982 Sep;79(18):5651-5655, Proceedings of the National Academy of Sciences of the United States of America
Nine monoclonal antibodies against surface antigens of sporozoites of the simian malaria parasite Plasmodium knowlesi were produced by fusion of plasmacytoma cells with spleen cells of a mouse immunized with the parasites. Immunoprecipitation of extracts of [35S]methionine-labeled sporozoites with seven of the monoclonals identified the same three polypeptides with apparent molecular weights of 52,000 (Pk52), 50,000 (Pk50) and 42,000 (Pk42). These antigens also were recognized by serum of a rhesus monkey immunized with and protected against P. knowlesi sporozoites. Pulse--chase experiments indicated that the higher molecular weight proteins are precursors of Pk42. As shown by trypsin treatment of viable sporozoites, Pk42 is a surface antigen whereas Pk52 and Pk50 appear to be intracellular. Three of the monoclonal antibodies also reacted with a membrane antigen of sporozoites of another simian malaria, P. cynomolgi, and one monoclonal antibody reacted with sporozoites of human malaria, P. falciparum. When assayed for sporozoite neutralizing activity, most of the antibodies and their Fab fragments, which recognize Pk52, Pk50, and Pk42, abolished parasite infectivity
— id: 62015, year: 1982, vol: 79, page: 5651, stat: Journal Article,

The murine sex-limited protein (Slp): reassessment of its sex limitation
Ferreira A; Eichinger D; Nussenzweig V
1982 Oct;129(4):1506-1508, Journal of immunology
Previous studies in which an alloantiserum was used to measure Slp levels indicated that in certain inbred strains of mice (Slpa), this protein was sex-limited, that is, present only in males. We raised several monoclonal antibodies directed against different epitopes of Slp and used them to develop a sensitive two-site immunoradiometric assay. Using this assay we detected Slp in serum of all Slpa females previously thought to be phenotypically negative. The levels of Slp in these females are about 0.2 to 4% of that of the males of the same inbred strain. The molecule found in serum of females was isolated by affinity chromatography and was found to have the characteristic three-chain structure of male Slp. These findings establish that the presence of Slp in Slpa females is the rule rather than the exception. Quantitative differences similar in magnitude to those found between males and females were also detected among Slpa males; i.e., Sd males have about 100 times more Slp than Sp males. The mechanisms by which androgens determine the extensive quantitative male-female differences, and by which the S region determines large variations among Slpa males, are unknown
— id: 62014, year: 1982, vol: 129, page: 1506, stat: Journal Article,

DECREASED C3B RECEPTOR ACTIVITY ON CHRONIC GRANULOMATOUS-DISEASE (CGD) NEUTROPHILS (PMN)
Gaither, TA; Gallin, JI; Iida, K; Nussenzweig, V; Frank, MM
1982 ;30(2):A348-A348, Clinical research
— id: 30423, year: 1982, vol: 30, page: A348, stat: Journal Article,

Antibodies to the protective antigen of Plasmodium berghei sporozoites prevent entry into cultured cells
Hollingdale MR; Zavala F; Nussenzweig RS; Nussenzweig V
1982 Apr;128(4):1929-1930, Journal of immunology
— id: 23549, year: 1982, vol: 128, page: 1929, stat: Journal Article,

Complement receptor (CR1) deficiency in erythrocytes from patients with systemic lupus erythematosus
Iida K; Mornaghi R; Nussenzweig V
1982 May 1;155(5):1427-1438, Journal of experimental medicine
This study reports quantitative information on the concentration of complement receptor for C3b and C4b (CR1) on erythrocytes from normal individuals and patients with immune complex disease. The measurements were performed by an immunoradiometric assay using monoclonal antibodies against CR1. The antibody specificity was confirmed by immunoprecipitation of CR1 from extracts of surface-labeled cells, by inhibition of rosette formation between B lymphocytes and the erythrocytes intermediate EAC14oxy23b, and by the characteristic distribution of the antigen among cells of human peripheral blood. The number of CR1 molecules in erythrocytes from 52 normal individuals was estimated as 1,410 +/- 620. No significant differences in CR1 levels were observed when individuals were grouped by sex, age, or blood groups. In patients with SLE and rheumatoid arthritis, the number of CR1 molecules per RBC was significantly lower, i.e., 600 +/- 307 and 903 +/- 417, respectively. CR1 levels were normal in asthmatics undergoing long-term treatment with prednisone. In SLE patients, significant correlations were found between CR1 levels, C4 hemolytic titers, and levels of circulating immune complexes. In two out of four patients with SLE, CR1 levels increased significantly during remission, showing that the deficiency is, at least in part, reversible. The deficiency in CR1 could be genetically controlled or could represent an epiphenomenon caused by the interaction of the receptor with a ligand present in the circulation of patients
— id: 62017, year: 1982, vol: 155, page: 1427, stat: Journal Article,

HUMAN LYMPHOCYTE-B-ASSOCIATED COMPLEMENT RECEPTOR (CR-1) INHIBITS C-3 AND C5-CONVERTASES
Iida, K; Nussenzweig, V
1982 ;19(11):1377-1377, Molecular immunology
— id: 30512, year: 1982, vol: 19, page: 1377, stat: Journal Article,

Unique role of the complement receptor CR1 in the degradation of C3b associated with immune complexes
Medof ME; Iida K; Mold C; Nussenzweig V
1982 Dec 1;156(6):1739-1754, Journal of experimental medicine
The main finding of this paper is that CR1, the membrane receptor for C3b and C4b, together with C3b/C4b-inactivator (I), degrades C3b bound to immune complexes (C3b*). Two fragments are generated: C3c, which is released from the immune complexes, and C3d*. The C3c fragment released from the cell intermediate EAC1423b prepared with 125I-C3 was analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and radioautography. It has a 135,000 mol wt and contains disulfide bonded labeled polypeptide chains of 75,000 and 31,000 mol wt, which presumably represent the beta and a fragment of the alpha-chain of C3b*. Silver staining of the SDS-PAGE gels revealed other C3-derived bands with 39-42,000 mol wt. Human erythrocytes + I also cleave C3b* into C3c and C3d*. The activity of the erythrocytes is CR1 mediated because it can be totally inhibited by monoclonal antibodies to CR1. In contrast with these results, I together with the serum protein beta 1H (H) transform EAC1423b into hemolytically inactive EAC1423bi and cleave the alpha' chain of C3b* into fragments of 70,000 and 40,000 mol wt. Small amounts of C3c are also released at relatively high concentrations of H. On a molar basis, the efficiency of CR1 in the generation of C3c and C3d is 10(4)-10(5) greater than H. An additional observation was that C3c could be released by treating EAC1423bi with CR1 + I and that this reaction was also inhibited by monoclonal antibodies to CR1. Therefore, it is likely that CR1 has binding affinity for iC3b and that the degradation of C3b* proceeds as follows: C3b (formula, see text) C3c + C3d*. Taken together, our findings argue that the processing of C3b* in vivo occurs in solid phase, that is, on the surface of cells bearing CR1
— id: 62013, year: 1982, vol: 156, page: 1739, stat: Journal Article,

Circumsporozoite proteins of human malaria parasites Plasmodium falciparum and Plasmodium vivax
Nardin EH; Nussenzweig V; Nussenzweig RS; Collins WE; Harinasuta KT; Tapchaisri P; Chomcharn Y
1982 Jul 1;156(1):20-30, Journal of experimental medicine
Monoclonal antibodies were raised against sporozoites of two species of malaria parasites, Plasmodium falciparum and Plasmodium vivax. The antibodies reacted with polypeptides (circumsporozoite proteins) that are uniformly distributed over the entire surface of sporozoites, as shown by indirect immunofluorescence and by the circumsporozoite precipitin reaction. The epitopes recognized by the monoclonal antibodies were expressed on sporozoites from different geographical isolates of the homologous species but were not detected on sporozoites of heterologous species nor on blood forms of the parasite. The monoclonal antibody to P. falciparum specifically immunoprecipitated two polypeptides of apparent 67,000 mol wt (Pf67) and 58,000 mol wt (Pf58) from extracts of [35S]methionine-labeled P. falciparum sporozoites. Similarly, the anti-P. vivax monoclonal immunoprecipitated two proteins of 51,000 mol wt (Pv51) and 45,000 mol wt (Pv45) from extracts of metabolically labeled P. vivax sporozoites. The extracts were also reacted with the serum of human volunteers successfully vaccinated with sporozoites of either P. vivax or P. falciparum. The patterns of immunoprecipitation were almost identical to those obtained with the corresponding monoclonal antibodies. The circumsporozoite proteins of P. falciparum and P. vivax play a role in immune protection. Incubation of the appropriate monoclonal antibody with viable sporozoites of the homologous species significantly reduced parasite infectivity, as determined by sporozoite neutralization assays carried out in splenectomized chimpanzees
— id: 62016, year: 1982, vol: 156, page: 20, stat: Journal Article,

Immunoprophylaxis of malaria: characterization of a protective surface antigen
Nussenzweig RS; Nussenzweig V
1982 83;78:59-85, Harvey lectures
— id: 62018, year: 1982, vol: 78, page: 59, stat: Journal Article,

CIRCUMSPOROZOITE (CS) PROTEINS - A FAMILY OF PROTECTIVE MALARIA ANTIGENS
Nussenzweig, V
1982 ;41(3):483-483, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 30580, year: 1982, vol: 41, page: 483, stat: Journal Article,

Inhibition of idiotype--anti-idiotype interaction for detection of a parasite antigen: a new immunoassay
Potocnjak P; Zavala F; Nussenzweig R; Nussenzweig V
1982 Mar 26;215(4540):1637-1639, Science
Described in this report is an immunoradiometric assay of general applicability that is based on a new principle: the inhibition of the interaction between monoclonal antibodies by an antigen. The advantages of this assay are that it measures concentrations of single epitopes, purified antigen is not required, and the reagents can be obtained in unlimited amounts and are homogeneous. Its features are particularly attractive when the antigen has not been purified and is a minor component of a complex mixture of molecule
— id: 23550, year: 1982, vol: 215, page: 1637, stat: Journal Article,

Monoclonal antibodies to circumsporozoite proteins identify the species of malaria parasite in infected mosquitoes
Zavala F; Gwadz RW; Collins FH; Nussenzweig RS; Nussenzweig V
1982 Oct 21;299(5885):737-738, Nature
— id: 23548, year: 1982, vol: 299, page: 737, stat: Journal Article,

The protective antigen of malarial sporozoites (Plasmodium berghei) is a differentiation antigen
Aikawa M; Yoshida N; Nussenzweig RS; Nussenzweig V
1981 Jun;126(6):2494-2495, Journal of immunology
Pb44, the protective antigen of rodent malaria sporozoite (Plasmodium berghei) covers the entire surface of mature, salivary gland sporozoites. This antigen is undetectable in approximately 50% of the immature, i.e., oocyst sporozoites. On the surface of the remaining oocyst sporozoites, Pb44 is found in patches. Pb44 is present in early exoerythrocytic liver stages of P. berghei but is present in early exoerythrocytic liver stages of P. berghei but becomes undetectable after 30 hr of intrahepatocytic development. It seems likely that Pb44 is a differentiation antigen associated with an unique function of the sporozoites, perhaps penetration in the target host cells
— id: 62020, year: 1981, vol: 126, page: 2494, stat: Journal Article,

MONOCLONAL-ANTIBODIES AGAINST A SURFACE-ANTIGEN OF SPOROZOITES OF SIMIAN MALARIA ABOLISH PARASITE INFECTIVITY
COCHRANE, AH; GWADZ, R; NUSSENZWEIG, V; NUSSENZWEIG, RS
1981 ;40(3):1011-1011, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 40258, year: 1981, vol: 40, page: 1011, stat: Journal Article,

Complement receptor is an inhibitor of the complement cascade
Iida K; Nussenzweig V
1981 May 1;153(5):1138-1150, Journal of experimental medicine
A glycoprotein from the membrane of human erythrocytes has been identified as a receptor for C3b (CR1). It promotes the dissociation of the alternative pathway C3 convertase C3b,Bb and the cleavage of C3b by C3b/C4b inactivator. We find that CR1 also inactivates the C3 and C5 convertases of the classical pathway. CR1 inhibits the consumption of C3 by C3 convertase EAC142 and enhances the decay of C4b,2a sites. On a weight basis, CR1 is approximately 5-10 times more active than C4 binding protein, a serum inhibitor of C4b,2a. The binding of 125I-CR1 to EAC14 cells is inhibited by C2. Therefore, it is likely that CR1 and C2 compete for a site on C4b. CR1 inhibited C5 convertase even more effectively, but had no effect on the assembly of the late complement components. At high concentrations, CR1 alone has no irreversible effects on cell-bound C4b. In the fluid phase, CR1 can function as a cofactor for the cleavage of the alpha' chain of C4b by C3b/C4b inactivator. A well-known function of CR1 is to promote adherence of microbes or immune complexes bearing C3b and C4b to cells. This interaction could result in a microenvironment damaging to the plasma membrane of the responding cell because the extrinsic C3b and C4b fragments can serve as additional sites of assembly of enzymes of the cascade. We therefore wish to propose that CR1 on the surface of cells supplies an increased local concentration of a strong inhibitor of the amplifying enzymes of the complement system and provides cells with a mechanism for circumventing damage when they bind C3b- and C4b-bearing substrates
— id: 62021, year: 1981, vol: 153, page: 1138, stat: Journal Article,

cis-Interacting genes in the S region of the murine major histocompatibility complex
Michaelson J; Ferreira A; Nussenzweig V
1981 Jan 22;289(5795):306-308, Nature
Insight into the control of gene expression may be gained by analysing genetic systems marked by both regulatory and structural variants. In such systems one can determine whether a regulatory element controls structural genes on both chromosomes or only on the chromosome to which it is linked. The latter may be detected in individuals heterozygous at both the regulatory and structural loci, in which case the effect of each regulatory allele is seen to be exerted only on the cis-located structural allele. In prokaryotic organisms, the identification of cis interaction of this sort has allowed elucidation of many features of genetic regulation, first for the lac operon and subsequently for a variety of other systems. In higher organisms, however, there have been few opportunities to observe cis-interacting genes. The most thoroughly characterized mammalian system in this regard is the murine beta-glucuronidase locus described by Paigen and his colleagues, in which cis interaction has been shown to occur between two closely linked genetic elements-the beta-glucuronidase structural gene itself and an androgen-activated regulatory gene which controls the quantity of beta-glucuronidase expressed. We report here that cis-interacting genetic elements are also found in the S region of the mouse major histocompatibility complex H-2
— id: 62022, year: 1981, vol: 289, page: 306, stat: Journal Article,

COMPLEMENT-RECEPTOR INHIBITS THE COMPLEMENT CASCADE
Nussenzweig, V; Iida, K
1981 ;40(3):1013-1013, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 30281, year: 1981, vol: 40, page: 1013, stat: Journal Article,

HUMAN C4-BINDING PROTEIN (C4-BP)
NUSSENZWEIG, V; MELTON, R
1981 ;80(1):124-133, Methods in enzymology
— id: 40437, year: 1981, vol: 80, page: 124, stat: Journal Article,

Complement-mediated defect in clearance and sequestration of sensitized, autologous erythrocytes in rodent malaria
Pappas MG; Nussenzweig RS; Nussenzweig V; Shear HL
1981 Jan;67(1):183-192, Journal of clinical investigation
— id: 62023, year: 1981, vol: 67, page: 183, stat: Journal Article,

INHIBITION OF IDIOTYPE-ANTI-IDIOTYPE REACTION - AN ASSAY TO DETECT ANTIGENS
Potocnjak, P; Zavala, F; Nussenzweig, V
1981 ;14(3):287-287, Archivos de biologia y medicina experimentalis
— id: 30506, year: 1981, vol: 14, page: 287, stat: Journal Article,

Biosynthesis of Pb44, the protective antigen of sporozoites of Plasmodium berghei
Yoshida N; Potocnjak P; Nussenzweig V; Nussenzweig RS
1981 Oct 1;154(4):1225-1236, Journal of experimental medicine
In a previous paper (2) we identified a protective antigen (Pb44) of the surface membrane of sporozoites of Plasmodium berghei by means of a monoclonal antibody. Immunoprecipitation of extracts of mature salivary gland sporozoites, metabolically labeled with L[35S]methionine using the same monoclonal antibody, revealed three specific polypeptides: *Pb44, *Pb52, and *Pb54. Metabolically labeled *Pb44 is probably identical to the protective antigen previously identified by surface labeling. Both proteins have the same molecular weights and isoelectric points under denaturing conditions, and they share an epitope. Moreover, *Pb44 also seems to be located on the cell membrane. The results of pulse-chase experiments strongly suggest that *Pb52 is the precursor of *Pb44. The relationship between *Pb54 and the protective antigen is unknown. The three polypeptides seem to be strictly associated with only one of the developmental stage of the parasite. They were not detected in blood forms and were found in minute amounts in sporozoites from the midgut of mosquitoes. In contrast, in mature salivary gland sporozoites they constitute main products of protein synthesis
— id: 62019, year: 1981, vol: 154, page: 1225, stat: Journal Article,

The murine H-2.7 specificity is an antigenic determinant of C4d, a fragment of the fourth component of the complement system
Ferreira A; David CS; Nussenzweig V
1980 Jun 1;151(6):1424-1435, Journal of experimental medicine
The S region of H-2 controls a polymorphism of the gamma-chain of C4 (gamma 1, gamma 2, and gamma 3) as shown by differences in their isoelectric points. The G region of H-2 was defined by the presence of an alloantigen (H-2.7) on erythrocytes and serum. We found that antisera to H-2.7 immunoprecipitated C4 and no other protein from mouse EDTA-plasma. Furthermore, all H-2.7-positive strains bear C4-gamma 1, and conversely, H-2.7-negative mice bear C4-gamma 2 or gamma 3 (with one exception; see below). The H-2.7 specificity resides on C4d, a 45,000-mol wt fragment generated from the cleavage of the alpha'-chain of C4b by serum control proteins. Because the C4d fragment bears the labile binding site of C4 for cell membranes, it is likely that the erythrocyte alloantigen is acquired from serum as a result of the activation of C4. On the basis of these findings, the existence of a separate G locus is unlikely. Our results also show that C4-gamma 1 and C4-gamma 2 differ from each other at least in their alpha- and gamma-chains, and may represent complex allotypes. No trans effects were observed in F1 hybrids between H-2.7-positive and -negative mice. Mice that bear the k allele in the S region are exceptional in two respects: they are C4-deficient and their C4 molecules bear gamma 2 chains and the H-2.7 alloantigen. Perhaps the low levels of C4 are a consequence of the genetic event leading to this unusual alpha-gamma-chain combination
— id: 62027, year: 1980, vol: 151, page: 1424, stat: Journal Article,

A polymorphism of the gamma-chain of mouse C4 controlled by the S region of the major histocompatibility complex
Ferreira A; Michaelson J; Nussenzweig V
1980 Sep;125(3):1178-1182, Journal of immunology
Three phenotypes of the gamma-chain of mouse C4 have been detected by a modification of the two-dimensional O'Farrell technique. Strains carrying the H-2s, H-2p, H-2f and H-2ja haplotypes had chains with pI 7.4 (gamma 1). Strains with H-2k, H-2q, H-2d, H-2r, H-2b, H-2u, and H-2w7 had gamma-chains with pI 6.9 (gamma 2), and strains carrying a wild-derived haplotype had gamma chains with pI 6.5 (gamma 3). The genes controlling this polymorphism were mapped in the S region of the H-2 complex by using congenic strains
— id: 62025, year: 1980, vol: 125, page: 1178, stat: Journal Article,

H-2-controlled polymorphism of the gamma chain of Slp (sex-limited protein)
Ferreira A; Michaelson J; Nussenzweig V
1980 ;11(5):491-497, Immunogenetics
A genetic polymorphism detected by the O'Farrell two-dimensional technique (isoelectric focusing and SDS-PAGE) of the murine sex-limited protein (Slp) is described and shown to map to the H-2 complex. The Slp charge variation was found to be in the gamma chains. Inbred strains carrying the H-2w7 and H-2wr7 haplotypes, which are derived from a wild mouse, had Slp-gamma chains with pI = 6.55 (Slp-1b). All other inbred strains, bearing H-2j,H-2s,H-2p,H-2d,H-2u, as well as three additional Slp-constitutive wild females captured in Chile, had Slp-gamma chain with pI = 6.71 (Slp-1a)
— id: 11454, year: 1980, vol: 11, page: 491, stat: Journal Article,

Polymorphism of the gamma chain of murine Ss (C4) and Slp proteins
Ferreira A; Michaelson J; Nussenzweig V
1980 ;158(1-2):3-4, Immunobiology
— id: 62029, year: 1980, vol: 158, page: 3, stat: Journal Article,

IDENTIFICATION OF THE H-2.7 SPECIFICITY AS AN ANTIGENIC DETERMINANT OF C-4
Ferreira, A; Michaelson, J; David, C; Nussenzweig, V
1980 ;39(3):808-808, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 28039, year: 1980, vol: 39, page: 808, stat: Journal Article,

IDENTIFICATION OF THE H-2.7(G) SPECIFICITY AS AN ANTIGENIC DETERMINANT OF C-4
Ferreira, A; Michaelson, J; David, C; Nussenzweig, V
1980 ;124(3):1520-1520, Journal of immunology
— id: 28021, year: 1980, vol: 124, page: 1520, stat: Journal Article,

ISOLATION AND CHARACTERIZATION OF MOUSE C4B INACTIVATOR
Fujita, T; Kai, S; Gigli, I; Nussenzweig, V
1980 ;124(3):1520-1520, Journal of immunology
— id: 28022, year: 1980, vol: 124, page: 1520, stat: Journal Article,

MODULATION OF THE CLASSICAL PATHWAY C-3 CONVERTASE BY THE PLASMA-PROTEINS C4-BP AND C3-BINA
Gigli, I; Fujita, T; Nussenzweig, V
1980 ;124(3):1521-1521, Journal of immunology
— id: 28023, year: 1980, vol: 124, page: 1521, stat: Journal Article,

Mouse C3b/C4b inactivator: purification and properties
Kai S; Fujita T; Gigli I; Nussenzweig V
1980 Dec;125(6):2409-2415, Journal of immunology
Mouse C3b/C4b inactivator (C3b/C4bINA) was purified approximately 400 times from mouse serum. It is a beta-globulin and consists of 2 disulfide bonded chains of m.w. 60,000 and 35,000. Under nonreducing conditions, its m.w. is 95,000. It cleaves the alpha'-chain of cell-bound C4b into 3 fragments: alpha 2, alpha 3, alpha 4. The alpha 2 fragments remain bound to the cell surface (C4d), and the rest of the molecule (C4c) is released into the fluid phase. In fluid phase, C3b/C4bINA cleaves the alpha'-chain of C4b in a similar manner but only in the presence of mouse or human C4-binding protein (C4-bp). Mouse C4-bp and human C3b/C4bINA do not cleave human C4b, although mouse C4-bp binds to human C4b. This incompatibility suggests that C4-bp and C3b/C4bINA must interact to cleave fluid phase C4b. Mouse C3b/C4bINA also cleaves the alpha'-chain of human C3b in solution into 2 fragments in the presence of human beta 1H. Therefore, it is likely that mouse and human C3b/C4bINA are homologous proteins. A monospecific antiserum to mouse C3b/C4bINA has been prepared in rabbits. By crossed immunoelectrophoresis, this antiserum detects, in addition to the protein described above, a fast beta-globulin with a m.w. of approximately 200,000 and antigenically identical to C3b/C4bINA but enzymatically inactive. This protein could represent a precursor of C3b/C4bINA
— id: 62024, year: 1980, vol: 125, page: 2409, stat: Journal Article,

HYBRIDOMA PRODUCES PROTECTIVE ANTIBODIES DIRECTED AGAINST A SURFACE-ANTIGEN (PB44) OF THE SPOROZOITE STAGE OF MALARIA PARASITE
Nussenzweig, RS; Yoshida, N; Potocnjak, P; Nussenzweig, V
1980 ;39(3):805-805, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 28144, year: 1980, vol: 39, page: 805, stat: Journal Article,

Monovalent fragments (Fab) of monoclonal antibodies to a sporozoite surface antigen (Pb44) protect mice against malarial infection
Potocnjak P; Yoshida N; Nussenzweig RS; Nussenzweig V
1980 Jun 1;151(6):1504-1513, Journal of experimental medicine
Monoclonal antibodies (IG1, k) directed against a surface component of Plasmodium berghei sporozoites (Pb-44) confer complete protection to mice against a lethal inoculum of parasites. The degree of protection is a function of the number of parasites used in the challenge and of the antibody concentration in serum. Passive transfer of 10 micrograms of antibody per mouse abolished or profoundly diminished the infectivity of 10(3) sporozoites, but much higher amounts of antibody were required for complete protection against challenge with 10(4) parasites. Fab fragments of the monoclonal antibodies were as effective as the intact antibodies in mediating protection as determined by the neutralizing assay. This observation suggests that the antibodies interfere with a parasite function necessary for its infectivity, such as, for example, the ability to penetrate into the target cell or to multiply in the hepatocytes. When sporozoites are incubated with the intact monoclonal antibodies at 37 degrees C, a long filament appears at its posterior end (circumsporzoite precipitation [CSP] reaction). Fab fragments are ineffective at high concentrations. However, if after treatment with Fab, the sporozoites are incubated with rabbit antibodies to mouse k-chains, a strong CSP reaction is observed. We conclude that the CSP reaction can result from the cross-linking of Pb44 and that it has the characteristics of a capping reaction followed by the shedding of the immune complexes
— id: 62026, year: 1980, vol: 151, page: 1504, stat: Journal Article,

Hybridoma produces protective antibodies directed against the sporozoite stage of malaria parasite
Yoshida N; Nussenzweig RS; Potocnjak P; Nussenzweig V; Aikawa M
1980 Jan 4;207(4426):71-73, Science
Hybrid cells secreting antibodies against sporozoites of Plasmodium berghei were obtained by fusion of plasmacytoma cells with immune murine spleen cells. The monoclonal antibodies bound to a protein with an apparent molecular weight of 44,000 (Pb44), which envelopes the surface membrane of sporozoites. Incubation of sporozoites in vitro with antibodies to Pb44 abolished their infectivity
— id: 62028, year: 1980, vol: 207, page: 71, stat: Journal Article,

Mouse C4 (Ss): three-step purification of its C4c fragment and production of a monospecific antiserum
Ferreira A; Nussenzweig V
1979 Feb;122(2):490-493, Journal of immunology
We report here that a large fragment of mouse C4 (C4c) can be easily purified from serum with good recoveries, and used to produce a monospecific antiserum. The method of isolation of C4c is based on the observation that C4 is easily activated and fragmented in mouse serum. The fragments bind to the C4-binding protein (C4-bp), a newly described macromolecular component of the complement system. The high m.w. complexes were precipitated by dialysis of the serum against 0.1 M acetate buffer, pH 5.0, and purified by passage of the dissolved precipitate through a Sephadex G-200 column. The complexes were dissociated at high salt concentration, and the C4 fragments were isolated by passage of the mixture through a second Sephadex G-200 column. One of the C4 fragments (C4c) was used to immunize rabbits, and a monospecific antiserum was obtained, which showed a reaction of identity between C4 and Slp. Therefore the C4c fragment of C4 and the Slp protein are structurally related
— id: 62034, year: 1979, vol: 122, page: 490, stat: Journal Article,

The role of C4-binding protein and beta 1H in proteolysis of C4b and C3b
Fujita T; Nussenzweig V
1979 Aug 1;150(2):267-276, Journal of experimental medicine
— id: 62032, year: 1979, vol: 150, page: 267, stat: Journal Article,

ROLE OF C4-BINDING PROTEIN (C4-BP) AND BETA-1H IN PROTEOLYSIS OF C4B AND C3B
Fujita, T; Nussenzweig, V
1979 ;38(3):1011-1011, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 30035, year: 1979, vol: 38, page: 1011, stat: Journal Article,

Modulation of the classical pathway C3 convertase by plasma proteins C4 binding protein and C3b inactivator
Gigli I; Fujita T; Nussenzweig V
1979 Dec;76(12):6596-6600, Proceedings of the National Academy of Sciences of the United States of America
We recently described the isolation from human serum of a serum protein (C4 binding protein) that functions as an essential cofactor for C3b inactivator in the proteolysis of fluid-phase C4b and to a much lesser extent, C3b. We show here the role of C4 binding protein in the formation and function of the classical pathway C3 convertase (C42). C4 binding protein interferes with the assembly of the membrane-bound C3 convertase of the classical pathway and accelerates the decay of C42 in a dose-dependent fashion. Its removal from serum by means of specific immune absorption promotes the vigorous consumption of C3 after addition of C1; this effect is abolished by reconstitution with purified C4 binding protein. Although C4 binding protein inhibits the hemolytic function of cell-bound C4b, we did not detect any change in the structure of C4b even after prolonged incubations of EAC14 with C4 binding protein. For this reason, and on the basis of studies of the time required for maximal reactivity (Tmax) of cellular intermediates generated in the presence of C4 binding protein and limited amounts of C2, we conclude that the effects of C4 binding protein are probably mediated by displacing C2a from specific binding sites on C4b. In addition, C4 binding protein enhances the cleavage by C3b inactivator of the alpha' chain of cell-bound C4b. When EAC14 cells were incubated with both control proteins, the Tmax of the cells was prolonged and the lysis was markedly diminished. We conclude that C4 binding protein and C3b inactivator control the C3 convertase of the classical pathway in a fashion similar to that described for beta 1H and C3b inactivator in the alternative pathway
— id: 62031, year: 1979, vol: 76, page: 6596, stat: Journal Article,

Preliminary studies on vaccination of rhesus monkeys with irradiated sporozoites of Plasmodium knowlesi and characterization of surface antigens of these parasites
Gwadz RW; Cochrane AH; Nussenzweig V; Nussenzweig RS
1979 ;57 Suppl 1:165-173, Bulletin of the World Health Organization
— id: 62035, year: 1979, vol: 57 Suppl 1, page: 165, stat: Journal Article,

Danazol's failure to suppress autoimmunity in NZB/NZW F1 mice
Roubinian JR; Talal N; Greenspan JS; Goodman JR; Nussenzweig V
1979 Dec;22(12):1399-1402, Arthritis & rheumatism
— id: 62030, year: 1979, vol: 22, page: 1399, stat: Journal Article,

Human C4-binding protein. Association with immune complexes in vitro and in vivo
Scharfstein J; Correa EB; Gallo GR; Nussenzweig V
1979 Mar;63(3):437-442, Journal of clinical investigation
C4-binding protein (bp), a glycoprotein with specific binding affinity for the activated form of C4 (C4b), has recently been isolated from human serum and partially characterized. This report demonstrates that C4-bp is incorporated into soluble immune complexes after complement activation in vitro. The reaction requires Ca++ ions and the presence of C4 in serum. Immunopathological studies of various forms of glomerulonephritis revealed intense C4-bp deposition in glomeruli from patients with immune-complex type of pathogenesis. C4-bp deposition was in close correlation with that of C4. These observations, together with the in vitro association of C4-bp to immune complexes, support the notion that the deposits in glomeruli represent the local accumulation of immune complexes
— id: 59975, year: 1979, vol: 63, page: 437, stat: Journal Article,

Cross-species contamination of commercial serum proteins
Scharfstein J; Nussenzweig V
1979 May;122(5):2135-2135, Journal of immunology
— id: 62033, year: 1979, vol: 122, page: 2135, stat: Journal Article,

ROLE OF COMPLEMENT-SYSTEM ON CONCOMITANT IMMUNITY OF SCHISTOSOMIASIS-MANSONI
DIASDASILVA, W; GAZZINELLI, G; MOTASANTOS, TA; TAVARES, CAP; NUSSENZWEIG, V
1978 ;120(5):1798-1799, Journal of immunology
— id: 98681, year: 1978, vol: 120, page: 1798, stat: Journal Article,

Structural and functional differences between the H-2 controlled Ss and Slp proteins
Ferreira A; Nussenzweig V; Gigli I
1978 Nov 1;148(5):1186-1197, Journal of experimental medicine
Based on functional and structural data, it is concluded that the Ss protein in the mouse expresses the activity of the fourth component of complement. Removal of the Ss, but not of Slp, antigen correlates with a high degree of significance (P less than 0.001) with decrease of C4 hemolytic activity. In phenotypically Slp negative mice the plasma/serum levels of Ss correlate with the C4 activity (P less than 0.001). Structurally, Ss is a 209,000-mol wt protein, consisting of three covalently linked polypeptide chains (alpha,beta,gamma). Treatment of Ss with C1 cleaves a 7,000-8,000-mol wt fragment from the alpha-chain. Slp is also a three chain covalently linked protein of 209,000 daltons, however its three chains differ in size from those of the Ss protein. Slp does not express hemolytic activity and its alpha-chain is not cleaved by C1
— id: 62036, year: 1978, vol: 148, page: 1186, stat: Journal Article,

Testosterone control of serum levels of C4-binding protein in mice
Ferreira A; Weisz-Carrington P; Nussenzweig V
1978 Sep;121(3):1213-1215, Journal of immunology
— id: 62038, year: 1978, vol: 121, page: 1213, stat: Journal Article,

PURIFICATION AND CHARACTERIZATION OF A MOUSE SERUM-PROTEIN WITH SPECIFIC BINDING AFFINITY FOR C4 (SS PROTEIN)
Ferreira, A; Weiszcarrington, P; Gigli, I; Nussenzweig, V
1978 ;120(5):1772-1773, Journal of immunology
— id: 29934, year: 1978, vol: 120, page: 1772, stat: Journal Article,

Human C4-binding protein. II. Role in proteolysis of C4b by C3b-inactivator
Fujita T; Gigli I; Nussenzweig V
1978 Oct 1;148(4):1044-1051, Journal of experimental medicine
We recently described the isolation from human serum of a high molecular weight protein with specific binding affinity for fluid-phase activated C4. We show here that the C4-binding protein (C4-Bp) functions as an essential cofactor in the proteolysis of C4b in the presence of C3b-inactivator (C3bINA). C4-bp, together with C3bINA, cleave the alpha'-chain of C4b into three fragments called alpha2, alpha3, and alpha4, with mol wt of 47,000, 25,000, and 17,000 daltons, respectively. The alpha2 fragment was dissociated from C4b without reduction, whereas the alpha3 and alpha4 fragments were disulfide bonded the other chains of C4b. The reaction did not occur when either C4-bp or C3bINA were omitted, nor in the presence of either protein in combination with beta1H. Native C4 was not affected by C3bINA aand C4-bp. C4b was not cleaved when incubated in serum of a patient with genetic deficiency of C3bINA. However, when purified C3bINA was added, the alpha'-chain of C4b was cleaved and fragments with the same molecular weight as alpha2, alpha3, and alpha4 were generated
— id: 62037, year: 1978, vol: 148, page: 1044, stat: Journal Article,

Human C4-binding protein. I. Isolation and characterization
Scharfstein J; Ferreira A; Gigli I; Nussenzweig V
1978 Jul 1;148(1):207-222, Journal of experimental medicine
— id: 62040, year: 1978, vol: 148, page: 207, stat: Journal Article,

PRESENCE OF A C4-BINDING PROTEIN (C4-BP) IN HUMAN-SERUM
Scharfstein, J; Ferreira, A; Gigli, I; Nussenzweig, V
1978 ;120(5):1795-1795, Journal of immunology
— id: 29820, year: 1978, vol: 120, page: 1795, stat: Journal Article,

Requirements for the solubilization of immune aggregates by complement. The role of the classical pathway
Takahashi M; Takahashi S; Brade V; Nussenzweig V
1978 Aug;62(2):349-358, Journal of clinical investigation
In this paper we examine the role of the classical pathway in the complement-mediated solubilization of immune precipitates (CRA). Serum reagents were depleted of the alternative pathway components properdin and factor D. Both depleted reagents lack CRA although they have almost intact hemolytic activity. Also, immune complexes were not solubilized when incubated with high concentrations of the classical pathway components (C1, C4, C2, and C3. We conclude that CRA is not mediated by the classical pathway alone. Activation of the classical pathway by the immune aggregates greatly enhances CRA. The effect of the classical pathway is to deposit C3b on the antigen-antibody lattice and promote the assembly of a lattice-associated, properdin-dependent C3-convertase. Although C3, C4, and properdin were detected on complexes solubilized by serum in the presence of Ca++ and Mg++, only C3 and properdin were found on the complexes when Ca++ had been chelated by ethylene glycol-bis-(beta-aminoethyl ether), N,N'-tetraacetic acid. In both situations the aggregates were capable of converting C5 in the fluid phase. However, no C5 was found on the solubilized complexes. These findings suggest that in contrast to nascent C3b and C4b, nascent C5-9 lacks binding affinity for immune aggregates
— id: 62039, year: 1978, vol: 62, page: 349, stat: Journal Article,

Complement receptors
Bianco C; Nussenzweig V
1977 ;6:145-176, Contemporary topics in molecular immunology
— id: 62045, year: 1977, vol: 6, page: 145, stat: Journal Article,

The role of membrane receptors for C3b and C3d in phagocytosis
Ehlenberger AG; Nussenzweig V
1977 Feb 1;145(2):357-371, Journal of experimental medicine
In this paper we re-examine the roles of particle-bound IgG and C3 in phagocytosis of sheep erythrocytes (E) by monolayers of purified human monocytes and polymorphonuclear leukocytes (PMN). We conclude that two fragments of the C3 molecule, that is, C3b and C3d, can function as opsonins if the phagocyte has the appropriate membrane receptors. Monocytes, that bind both C3b and C3d, respond to both as opsonins. PMN, which do not bind C3d, respond only to particles opsonized with C3b. C3 and IgG have separate roles in phagocytosis. IgG, through its Fc fragment, directly stimulates particle ingestion, but is relatively inefficient at inducing particle binding. On the other hand, C3 primarily mediates the binding of the particle via complement receptors. A marked synergy exists between C3 and IgG in inducing phagocytosis. Thus, opsonization of the particle with C3 can be a necessary condition for particle ingestion, although by itself C3 does not trigger phagocytosis. The opsonic effect of C3 can be mimicked by a variety of nonimmunologic agents which enhance binding of the particle to the phagocyte without directly stimulating ingestion. The contact-inducing agents used include centrifugation of particle and phagocyte, high molecular weight dextran, protamine, and treatment of E with neuraminidase. These results suggest that the role of C3 in opsonization is mainly or exclusively one of establishing contact between particle and phagocyte
— id: 62043, year: 1977, vol: 145, page: 357, stat: Journal Article,

Purificaiton and characterization of mouse serum protein with specific binding affinity for C4 (Ss protein)
Ferreira A; Takahashi M; Nussenzweig V
1977 Oct 1;146(4):1001-1008, Journal of experimental medicine
— id: 62041, year: 1977, vol: 146, page: 1001, stat: Journal Article,

Erythrocyte membrane-associated immunoglobulins during malaria infection of mice
Lustig HJ; Nussenzweig V; Nussenzweig RS
1977 Jul;119(1):210-216, Journal of immunology
Immunoglobulin (Ig) is associated with erythrocyte membranes during infection of A/J mice with Plasmodium berghei. It was detected by agglutination of the cells with rabbit antibodies to mouse IgG and by a radioimmunoassay with 125I-labelled rabbit antibodies to mouse IgG. As shown by the degree of agglutination and of binding of radiolabeled antibodies to the erythrocyte membranes, the amount of Ig increased with time after infection and paralleled parasitemia and reticulocytosis. The erythrocyte-associated immunoglobulins are mainly IgG but IgM was also present on the cells of some mice. A large proportion of the Ig could be eluted at 37 degrees C and was analyzed by immunoprecipitation and acrylamide gel electrophoresis. A radioautographic study with 125I-labeled anti-mouse IgG revealed that both parasitized and nonparasitized reticulocytes of infected mice had much larger amounts of membrane-bound immunoglobulin than did mature, nonparasitized erythrocytes. The nature of the bonds between the Ig and the surface membrane of the reticulocytes is not known. The Ig could be part of immune complexes nonspecifically bound to the cell surface. However, since we have not detected Fc or C3d receptors on reticulocytes, it is possible that the Ig constitutes autoantibodies against reticulocytes or antibodies against parasitic antigens present on the cell membrane
— id: 62042, year: 1977, vol: 119, page: 210, stat: Journal Article,

COMPLEMENT-INDUCED DISAGGREGATION OF IMMUNE COMPLEXES
NUSSENZWEIG, V
1977 ;10(3):212-213, Revista brasileira de pesquisas medicas e biologicas = Brazilian journal of medical & biological research
— id: 98696, year: 1977, vol: 10, page: 212, stat: Journal Article,

Requirements for the solubilization of immune aggregates by complement: assembly of a factor B-dependent C3-convertase on the immune complexes
Takahashi M; Tack BF; Nussenzweig V
1977 Jan 1;145(1):86-100, Journal of experimental medicine
During the solubilization of immune precipitates BSA-rabbit antibodies to BSA by human complement, at least three stages can be distinguished. (A) Generation of alternative pathway C3-convertase sites associated with the immune complexes. During the first minutes of interaction between the immune aggregates and serum, before any solubilization has taken place, properdin (P), factor B, and C3 moieties are incorporated into the lattice. The washed precipitates have C3-convertase activity, which can be completely inhibited by antibodies to factor B, but not to C2. The assembly of the convertase is temperature-dependent, and does not take place in the absence of Mg++. The immune complex-associated C3-convertase activity decays rapidly at 37 degrees C, but it can be restored by addition of purified factor B and properdin. (B) Amplification. When the aggregates bearing C3-convertase are incubated with purified C3, solubilization takes place. It appears that solubilization is caused by the accumulation of a large number of C3 fragments on the Ag-Ab lattice. In solubilized complexes, the molar ratios of Ab/C3 are close to one. (C) Spontaneous release. The final step in the solubilization process is a secondary reaction, during which some rearrangement of the lattice takes place. It occurs in medium devoid of serum and does not require divalent cations
— id: 62044, year: 1977, vol: 145, page: 86, stat: Journal Article,

Studies on the mechanism of solubilization of immune precipitates by serum
Czop J; Nussenzweig V
1976 Mar 1;143(3):615-630, Journal of experimental medicine
Antigen (Ag)-antibody (Ab) aggregates prepared with several different antigens are solubilized by fresh serum at 37 degrees C (complex-release activity of serum or CRA). The rate of solubilization varies in different systems and is strongly influenced by the affinity of Ab for the Ag in the immune precipitate. With a given Ag-Ab precipitate, the maximum amount of complex that can be solubilized by individual sera is independent of the initial concentration of complexes and cannot be increased by prolonged incubation. CRA occurs in the absence of C2 and C4, but not in the absence of C3 and factor B of the properdin pathway. Addition of C2 to C2-deficient serum or C4 to C4-deficient serum enhances CRA. Solubilization does not involve extensive degradation of the complexed antibody, as might be detected by acrylamide gel electrophoresis of released antibody after reduction and alkylation to separate H and L chains. Immune precipitates can also be solubilized by incubation with monovalent fragments (Fab or Fab') of antibodies against determinants of the Ab molecules in the immune precipitate. In contrast, F(ab')2 fragments decrease the solubility of the immune precipitates. In view of these findings, we propose that CRA is mediated by the binding of functionally monovalent C fragments (C3 and C4) onto Ab molecules in the precipitates
— id: 62048, year: 1976, vol: 143, page: 615, stat: Journal Article,

Immunoglobulin-bearing and complement-receptor lymphocytes constitute the same population in human peripheral blood
Ehlenberger AG; McWilliams M; Phillips-Quagliata JM; Lamm ME; Nussenzweig V
1976 Jan;57(1):53-56, Journal of clinical investigation
Complement-receptor lymphocytes have generally been considered to be a subpopulation of bone-marrow derived (B) lymphocytes. However, the present studies show that essentially all cells with integral surface immunoglobulin from normal human peripheral blood bear receptors for the third component of complement. Moreover, after removal of phagocytes, all cells with complement receptors bear surface Ig. Thus, circulating B cells and complement-receptor lymphocytes are the same population
— id: 28811, year: 1976, vol: 57, page: 53, stat: Journal Article,

Relationship between 4a and 4b HLA-determined specificities and C3 receptors of leukocyte membrane
Ferreira A; Fotino M; Nussenzweig V
1976 Nov;6(11):832-833, European journal of immunology
— id: 62046, year: 1976, vol: 6, page: 832, stat: Journal Article,

Influence of H-2 on the ontogenesis of a spleen cell population which lacks C3 receptors and Thy-1 antigen
Ferreira A; Nussenzweig V
1976 Sep;117(3):771-773, Journal of immunology
During ontogeny there are marked differences in the cellularity of the spleen of mice from different inbred strains. Data from segregation analysis demonstrate that one of the genes involved in the control of the size of the spleen at 15 days lies in the H-2 region. In contrast to previous reports, we find that the cell population under H-2 influence lacks complement receptors
— id: 62047, year: 1976, vol: 117, page: 771, stat: Journal Article,

CONTROL OF C3 LEVELS IN MICE DURING ONTOGENY BY A GENE IN CENTRAL REGION OF H-2 COMPLEX
Ferreira, A; Nussenzweig, V
1976 ;260(5552):613-615, Nature
— id: 28707, year: 1976, vol: 260, page: 613, stat: Journal Article,

GENETIC-CONTROL OF C3 LEVELS IN MICE
Ferreira, A; Nussenzweig, V
1976 ;116(6):1732-1732, Journal of immunology
— id: 29470, year: 1976, vol: 116, page: 1732, stat: Journal Article,

Complement alterations in rodent malaria
Krettli AU; Nussenzweig V; Nussenzweig RS
1976 Jan;25(1):34-41, American journal of tropical medicine & hygiene
In the course of rodent malaria, the ability of mouse serum to release immune complexes from lymphocytes (complex-release, or CRA), a complement dependent function, becomes profoundly altered. These alterations occur in parallel with changes in the serum levels of the third complement component (C3). A transitory but significant increase in CRA and C3 was noticed during the first 3 days after blood-induced Plasmodium berghei infection. This was followed by a progressive decrease in CRA, which was extremely low in the 2nd week after injection. At this time, C3 levels were about 25% of those found in normal mouse serum. Incubation of blood cells of malaria-infected animals with normal serum 'in vitro' resulted in a significant inhibition of the CRA of the normal serum. This inhibition was shown to operate through the alternate complement pathway. In addition, a considerable proportion of hypocomplementemic malarious sera also had an inhibitory effect on the CRA of normal sera
— id: 62049, year: 1976, vol: 25, page: 34, stat: Journal Article,

Mechanism of solubilization of immune aggregates by complement. Implications for immunopathology
Takahashi M; Czop J; Ferreira A; Nussenzweig V
1976 ;32:121-139, Transplantation reviews
— id: 62050, year: 1976, vol: 32, page: 121, stat: Journal Article,

SOLUBILIZATION OF IMMUNE-COMPLEXES BY COMPLEMENT ACTIVATED BY ALTERNATIVE PATHWAY BUT NOT BY CLASSICAL PATHWAY
Takahashi, M; Brade, V; Nussenzweig, V
1976 ;35(3):254-254, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 29492, year: 1976, vol: 35, page: 254, stat: Journal Article,

SYNERGY BETWEEN RECEPTORS FOR FC AND C3 IN INDUCTION OF PHAGOCYTOSIS BY HUMAN MONOCYTES AND NEUTROPHILS
Ehlenberger, AG; Nussenzweig, V
1975 ;34(3):854-854, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 28677, year: 1975, vol: 34, page: 854, stat: Journal Article,

Genetic linkage between serum levels of the third component of complement and the H-2 complex
Ferreira A; Nussenzweig V
1975 Feb 1;141(2):513-517, Journal of experimental medicine
AKR/J (H-2kk) mice have higher serum C3 levels than DBA/2J (H-2dd). The F1 hybrids have intermediate levels. Analysis of the progeny of backcrosses at 21 days of age shows that C3 levels in mice of H-2dk type are significantly higher than those with H-2dd type and lower than those with H-2kk type. In addition, mice of H-2kk, H-2dk, and H-2dd types have C3 levels not significantly different from those of AKR/J, AKD2F1, and DBA/2J respectively. These findings demonstrate linkage between a gene controlling C3 levels and the H-2 complex
— id: 62053, year: 1975, vol: 141, page: 513, stat: Journal Article,

GENETIC-CONTROL OF COMPLEMENT (C3) LEVELS AND OF DEVELOPMENT OF LYMPHOID SYSTEM
Ferreira, A; Nussenzweig, V
1975 ;34(3):979-979, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 28679, year: 1975, vol: 34, page: 979, stat: Journal Article,

A new complement function: solubilization of antigen-antibody aggregates
Miller GW; Nussenzweig V
1975 Feb;72(2):418-422, Proceedings of the National Academy of Sciences of the United States of America
Antigen-antibody aggregates are solubilized when incubated with fresh serum at 37 degrees, yielding immune-complexes of relatively small molecular weight which contain antigen, antibody, and complement (C3)determinants. Solubilization is complement-dependent,requires free Mg++ but not Ca++, and proceeds in sera from C4- or C5-deficient animals. It is accelerated in the presence of Ca++ in normal or C4-deficient guinea pig serum, suggesting involvement of the Cl-bypass activation of the properdin system. Immune precipitates can also be solubilized by monovalent fragments (Fab) of antibodies directed against determinants of the antibody molecules included in the antigen-antibody lattice. Similarly, it is suggested that complement-mediated solubilization might be induced by the combination of a complement fragment with the antibody in the immune-aggregate
— id: 62054, year: 1975, vol: 72, page: 418, stat: Journal Article,

Complement-dependent alterations in the handling of immune complexes by NZB/W mice
Miller GW; Steinberg AD; Green I; Nussenzweig V
1975 Apr;114(4):1166-1170, Journal of immunology
Serum of normal mammals contains factors which can release antigen-antibody complexes from the surfaces of leukocytes and platelets. This 'complex release activity' (CRA) is mediated by the alternative pathway of complement activation, and is measured by a kinetic assay of the release of lymphocyte-bound soluble immune complexes. CRA activity was measured in the sera of NZB/W mice, which develop an autoimmune disease with aging. CRA in these mice declined rapidly after 16 weeks of age, and by 32 weeks was barely detectable. Serum C3 levels also declined in these mice. An association test correlating CRA and C3 concentration was highly significant. The decreased complement levels in the older mice led to profound changes in their handling of injected soluble immune complexes, as demonstrated in studies of the kinetics of distribution of the complexes between plasma and circulating cells. These abnormalities may be related to the diseases which occurs spontaneously in NZB/W mice, as well as in human immune complex diseases
— id: 62052, year: 1975, vol: 114, page: 1166, stat: Journal Article,

Selective phagocytic paralysis induced by immobilized immune complexes
Rabinovitch M; Manejias RE; Nussenzweig V
1975 Oct 1;142(4):827-838, Journal of experimental medicine
The phagocytic recognition by peritoneal macrophages plated on glass- or plastic-bound immune complexes of bovine plasma albumin (BSA) and anti-BSA was examined. Ingestion but not the attachment of erythrocytes opsonized with an IgG rich antiserum (EA) was markedly inhibited. In contrast, macrophage interactions with complement-coated (EAC) red cells, or ingestion of latex particles, yeast cell walls or glutaraldehyde-treated erythrocytes was not inhibited. Complexes prepared with pepsin-treated anti-BSA IgG were ineffective indicating a requirement for the Fc region. Inhibition of ingestion of EA was not a consequence of macrophage spreading and did not appear to be mediated by solubilized complexes or by cell-derived inhibitors of phagocytosis. Significant restoration of the ability to ingest EA was obtained when macrophages on complex-coated substrates were incubated for 4-8 h in medium enriched with mouse or fetal bovine serum. Restoration was also attained by removing macrophages from complex-coated dishes and replating onto uncoated dishes. The selective inhibition of ingestion of EA may be due to blocking of Fc receptors by the complexes but depletion of receptors by endocytosis of complexes cannot be ruled out. Alternatively, the complexes may have induced selective failure of the interiorization mechanism
— id: 62051, year: 1975, vol: 142, page: 827, stat: Journal Article,

Complement as a regulator of interactions between immune complexes and cell membranes
Miller GW; Nussenzweig V
1974 Aug;113(2):464-469, Journal of immunology
— id: 62055, year: 1974, vol: 113, page: 464, stat: Journal Article,

COMPLEMENT AS A REGULATOR OF INTERACTIONS BETWEEN IMMUNE- COMPLEXES AND CELL-MEMBRANES
Miller, GW; Nussenzw[...], V
1974 ;33(3):760-760, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 28381, year: 1974, vol: 33, page: 760, stat: Journal Article,

Receptors for immune complexes on lymphocytes
Nussenzweig V
1974 ;19(0):217-258, Advances in immunology
— id: 62056, year: 1974, vol: 19, page: 217, stat: Journal Article,

Leukemic cells with membrane properties of thymus-derived (T) lymphocytes in a case of Sezary's syndrome: morphologic and immunologic studies
Broome JD; Zucker-Franklin D; Weiner MS; Bianco C; Nussenzweig V
1973 Apr;1(3):319-329, Clinical immunology & immunopathology
— id: 61803, year: 1973, vol: 1, page: 319, stat: Journal Article,

Interaction and release of soulble immune complexes from mouse B luymphocytes
Eden A; Bianco C; Bogart B; Nussenzweig V
1973 Jun;7(3):474-483, Cellular immunology
— id: 18044, year: 1973, vol: 7, page: 474, stat: Journal Article,

C3 split products inhibit the binding of antigen-antibody-complement complexes to B lymphocytes
Eden A; Bianco C; Nussenzweig V; Mayer MM
1973 May;110(5):1452-1453, Journal of immunology
— id: 62060, year: 1973, vol: 110, page: 1452, stat: Journal Article,

Human lymphocytes bear membrane receptors for C3b and C3d
Eden A; Miller GW; Nussenzweig V
1973 Dec;52(12):3239-3242, Journal of clinical investigation
— id: 62057, year: 1973, vol: 52, page: 3239, stat: Journal Article,

BINDING OF SOLUBLE IMMUNE COMPLEXES BY B LYMPHOCYTES
EDEN, A; BIANCO, C; NUSSENZW.V
1973 ;32(MAR):873-&, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 39873, year: 1973, vol: 32, page: 873, stat: Journal Article,

MECHANISM OF BINDING OF SOLUBLE IMMUNE COMPLEXES TO LYMPHOCYTES
EDEN, A; BIANCO, C; NUSSENZW.V
1973 ;7(3):459-473, Cellular immunology
— id: 39794, year: 1973, vol: 7, page: 459, stat: Journal Article,

Complement-dependent release of immune complexes from the lymphocyte membrane
Miller GW; Saluk PH; Nussenzweig V
1973 Sep 1;138(3):495-507, Journal of experimental medicine
— id: 62059, year: 1973, vol: 138, page: 495, stat: Journal Article,

C-MEDIATED RELEASE OF MEMBRANE-BOUND IMMUNE COMPLEXES
MILLER, G; NUSSENZW.V
1973 ;111(1):299-300, Journal of immunology
— id: 39859, year: 1973, vol: 111, page: 299, stat: Journal Article,

Enhancement of an anti-hapten antibody response by an antiserum to the carrier protein
Pincus C; Miller G; Nussenzweig V
1973 Jan;110(1):301-304, Journal of immunology
— id: 62061, year: 1973, vol: 110, page: 301, stat: Journal Article,

Enhanced binding of neuraminidase-treated sheep erythrocytes to human T lymphocytes
Weiner MS; Bianco C; Nussenzweig V
1973 Dec;42(6):939-946, Blood
— id: 62058, year: 1973, vol: 42, page: 939, stat: Journal Article,

Electron microscopic study of the lymphocytes capable of binding antigen-antibody-complement complexes
Chen LT; Eden A; Nussenzweig V; Weiss L
1972 Jul;4(3):279-288, Cellular immunology
— id: 62064, year: 1972, vol: 4, page: 279, stat: Journal Article,

Complementarity of H and L chains from antihapten antibodies of different classes
Eden A; Lamm ME; Nussenzweig V
1972 Jun;108(6):1605-1608, Journal of immunology
— id: 62065, year: 1972, vol: 108, page: 1605, stat: Journal Article,

Phagocytosis of immune complexes by macrophages. Different roles of the macrophage receptor sites for complement (C3) and for immunoglobulin (IgG)
Mantovani B; Rabinovitch M; Nussenzweig V
1972 Apr 1;135(4):780-792, Journal of experimental medicine
— id: 62066, year: 1972, vol: 135, page: 780, stat: Journal Article,

Increased proportion of complement-receptor lymphocytes in the peripheral blood of patients with chronic lymphocytic leukemia
Pincus S; Bianco C; Nussenzweig V
1972 Sep;40(3):303-310, Blood
— id: 62062, year: 1972, vol: 40, page: 303, stat: Journal Article,

Cell surface immunoglobulin. IV. Distribution among thymocytes, bone mrrow cells, and their derived populations
Vitetta ES; Bianco C; Nussenzweig V; Uhr JW
1972 Jul 1;136(1):81-93, Journal of experimental medicine
— id: 62063, year: 1972, vol: 136, page: 81, stat: Journal Article,

Theta-bearing and complement-receptor lymphocytes are distinct populations of cells
Bianco, C; Nussenzweig, V
1971 Jul 9;173(992):154-156, Science
— id: 62069, year: 1971, vol: 173, page: 154, stat: Journal Article,

Bone marrow origin of complement-receptor lymphocytes
Dukor, P; Bianco, C; Nussenzweig, V
1971 Dec;1(6):491-494, European journal of immunology
— id: 62068, year: 1971, vol: 1, page: 491, stat: Journal Article,

A population of lymphocytes bearing a membrane receptor antigen-antibody-complement complexes. II. Specific isolation
Eden, A; Bianco, C; Nussenzweig, V
1971 Dec;2(6):658-669, Cellular immunology
— id: 62067, year: 1971, vol: 2, page: 658, stat: Journal Article,

Binding of sheep red blood cells to a large population of human lymphocytes
Lay, W H; Mendes, N F; Bianco, C; Nussenzweig, V
1971 Apr 23;230(5295):531-532, Nature
— id: 62071, year: 1971, vol: 230, page: 531, stat: Journal Article,

Lack of correlation between the net charge of antigen and antibodies in guinea pigs immunized with some charged antigens
Nussenzweig, V; Green, I
1971 Apr;106(4):1089-1094, Journal of immunology
— id: 62072, year: 1971, vol: 106, page: 1089, stat: Journal Article,

Regulation of the immune response: suppressive and enhancing effects of passively administered antibody
Pincus, C S; Lamm, M E; Nussenzweig, V
1971 May 1;133(5):987-1003, Journal of experimental medicine
— id: 62070, year: 1971, vol: 133, page: 987, stat: Journal Article,

A population of lymphocytes bearing a membrane receptor for antigen-antibody-complement complexes. I. Separation and characterization
Bianco C; Patrick R; Nussenzweig V
1970 Oct 1;132(4):702-720, Journal of experimental medicine
— id: 62074, year: 1970, vol: 132, page: 702, stat: Journal Article,

Tissue localization of lymphocytes bearing a membrane receptor for antigen-antibody-complement complexes
Dukor P; Bianco C; Nussenzweig V
1970 Oct;67(2):991-997, Proceedings of the National Academy of Sciences of the United States of America
— id: 62073, year: 1970, vol: 67, page: 991, stat: Journal Article,

Relationship between the net electrical charge of antigens and specific antibodies. An example of selection by antigen of cells producing highest affinity antibody
Benacerraf B; Nussenzweig V; Maurer PH; Stylos W
1969 Mar-Apr;5(2):171-176, Israel journal of medical sciences
— id: 62077, year: 1969, vol: 5, page: 171, stat: Journal Article,

Ca++-dependent binding of antigen-19 S antibody complexes to macrophages
Lay WH; Nussenzweig V
1969 May;102(5):1172-1178, Journal of immunology
— id: 62076, year: 1969, vol: 102, page: 1172, stat: Journal Article,

Further evidence of the role of gamma 1 guinea pig antibodies in mediating passive cutaneous anaphylaxis (PCA)
Nussenzweig V; Benacerraf B; Ovary Z
1969 Nov;103(5):1152-1154, Journal of immunology
— id: 58339, year: 1969, vol: 103, page: 1152, stat: Journal Article,

Passive antibody may simultaneously suppress and stimulate antibody formation against different portions of a protein molecule
Pincus CS; Nussenzweig V
1969 May 10;222(193):594-596, Nature
— id: 62075, year: 1969, vol: 222, page: 594, stat: Journal Article,

Studies on chemotaxis. 8. The role of 7S-gamma-1 and 7S-gamma-2 guinea-pig antibodies for chemotaxis in granulocytes
Keller HU; Nussenzweig V; Sorkin E
1968 May;5(3):293-295, Immunochemistry
— id: 62079, year: 1968, vol: 5, page: 293, stat: Journal Article,

Receptors for complement of leukocytes
Lay WH; Nussenzweig V
1968 Nov 1;128(5):991-1009, Journal of experimental medicine
— id: 62078, year: 1968, vol: 128, page: 991, stat: Journal Article,

Changes in the proportion of guinea-pig gamma-1 and gamma-2 antibodies during immunization and the cellular localization of these immunoglobulins
Nussenzweig V; Green I; Vassalli P; Benacerraf B
1968 May;14(5):601-609, Immunology
— id: 62080, year: 1968, vol: 14, page: 601, stat: Journal Article,

Specificity of the antibodies produced by single cells following immunization with antigens bearing two types of antigenic determinants
Green I; Vassalli P; Nussenzweig V; Benacerraf B
1967 Mar 1;125(3):511-526, Journal of experimental medicine
— id: 62083, year: 1967, vol: 125, page: 511, stat: Journal Article,

Comparison of guinea pig gamma 1-and gamma 2-immunoglobulins by peptide mapping
Lamm ME; Lisowska-Bernstein B; Nussenzweig V
1967 Sep;6(9):2819-2828, Biochemistry
— id: 62082, year: 1967, vol: 6, page: 2819, stat: Journal Article,

Antihapten antibody specificity and L chain type
Nussenzweig V; Benacerraf B
1967 Oct 1;126(4):727-743, Journal of experimental medicine
— id: 62081, year: 1967, vol: 126, page: 727, stat: Journal Article,

Isolation of purified H and L polypeptide chains from guinea-pig gamma-2-immunoglobulin after mild reduction
Lamm ME; Nussenzweig V; Benacerraf B
1966 Apr;10(4):309-319, Immunology
— id: 62087, year: 1966, vol: 10, page: 309, stat: Journal Article,

Presence of identical antigenic determinants in the Fd fragments of gamma-1- and gamma-2-guinea pig immunoglobulins
Nussenzweig V; Benacerraf B
1966 Aug;97(2):171-176, Journal of immunology
— id: 62086, year: 1966, vol: 97, page: 171, stat: Journal Article,

Quantitative variations in L chain types in guinea pig antihapten antibodies
Nussenzweig V; Benacerraf B
1966 Nov 1;124(5):805-818, Journal of experimental medicine
— id: 62085, year: 1966, vol: 124, page: 805, stat: Journal Article,

Presence of two types of L polypeptide chains in guinea pig 7S immunoglobulins
Nussenzweig V; Lamm ME; Benacerraf B
1966 Nov 1;124(5):787-803, Journal of experimental medicine
— id: 62084, year: 1966, vol: 124, page: 787, stat: Journal Article,

ELECTROPHORETIC PATTERNS AT ACID AND ALKALINE PH OF REDUCED GUINEA-PIG 7 S GAMMA GLOBULIN AND ANTI-HAPTEN ANTIBODIES OF DIFFERENT SPECIFICITIES
NUSSENZWEIG V; BENACERRAF B
1965 ;27:193-198, International archives of allergy & applied immunology
— id: 62088, year: 1965, vol: 27, page: 193, stat: Journal Article,

Heterogeneity of rat immunoglobulins
Nussenzweig V; Binaghi RA
1965 ;27(6):355-360, International archives of allergy & applied immunology
— id: 62089, year: 1965, vol: 27, page: 355, stat: Journal Article,

DIFFERENCES IN THE ELECTROPHORETIC MOBILITIES OF GUINEA PIG 7S ANTIBODIES OF DIFFERENT SPECIFICITIES
NUSSENZWEIG V; BENACERRAF B
1964 Mar 1;119:409-423, Journal of experimental medicine
— id: 62091, year: 1964, vol: 119, page: 409, stat: Journal Article,

STUDIES ON THE PROPERTIES OF FRAGMENTS OF GUINEA PIG GAMMA-1 AND GAMMA-2 ANTIBODIES OBTAINED BY PAPAIN DIGESTION AND MILD REDUCTION
NUSSENZWEIG V; BENACERRAF B
1964 Dec;93:1008-1014, Journal of immunology
— id: 62090, year: 1964, vol: 93, page: 1008, stat: Journal Article,

DIFFERENCES IN ANTIGENIC CONSTITUTION OF STRAINS OF TRYPANOSOMA CRUZI
NUSSENZWEIG V; DEANE LM; KLOETZEL J
1963 Oct;14:221-232, Experimental parasitology
— id: 62094, year: 1963, vol: 14, page: 221, stat: Journal Article,

ACQUIRED IMMUNITY IN MICE INFECTED WITH STRAINS OF IMMUNOLOGICAL TYPES A AND B OF TRYPANOSOMA CRUZI
NUSSENZWEIG V; KLOETZEL J; DEANE LM
1963 Oct;14:233-239, Experimental parasitology
— id: 62093, year: 1963, vol: 14, page: 233, stat: Journal Article,

EFFECT OF THE AMINONUCLEOSIDE OF STYLOMYCIN AND PRIMAQUINE ON THE SYNTHESIS OF ANTI EGG ALBUMIN BY RABBITS
WARMBRAND M; NUSSENZWEIG V; FERNANDES JF
1963 Nov-Dec;10:294-296, Revista do Instituto de Medicina Tropical de Sao Paulo
— id: 62092, year: 1963, vol: 10, page: 294, stat: Journal Article,

Cross reaction studies in a protein-antiprotein system. The immunochemical relationship between two isolated components of digested human fibrinogen with bovine fibrinogen
NUSSENZWEIG V; DE SOUZA EA
1962 ;21:294-304, International archives of allergy & applied immunology
— id: 62096, year: 1962, vol: 21, page: 294, stat: Journal Article,

[Difference in the antigenic composition of Trypanosoma cruzi strains isolated from man and opossums. (Preliminary note)]
NUSSENZWEIG V; DEANE LM; KLOETZEL J
1962 Nov-Dec;4:409-410, Revista do Instituto de Medicina Tropical de Sao Paulo
— id: 62095, year: 1962, vol: 4, page: 409, stat: Journal Article,

[The degradation products of human fibrinogen by plasmin. II. Immunological study: existence of native anti-fibrinogen antibodies possessing different specificities.]
NUSSENZWEIG V; SELIGMANN M; GRABAR P
1961 Apr;100:490-508, Annales de l'Institut Pasteur
— id: 62097, year: 1961, vol: 100, page: 490, stat: Journal Article,

[The products of degradation of human fibrinogen by plasmin. I. Separation and physicochemical properties.]
NUSSENZWEIG V; SELIGMANN M; PELMONT J; GRABAR P
1961 Mar;100:377-389, Annales de l'Institut Pasteur
— id: 62098, year: 1961, vol: 100, page: 377, stat: Journal Article,

[Analysis, by immuno-chemical methods, of the degradation by plasmin of human fibrinogen and fibrin, at different stages.]
NUSSENZWEIG V; SELIGMANN M
1960 Nov-Dec;15:451-466, Nouvelle revue francaise d'hematologie
— id: 62099, year: 1960, vol: 15, page: 451, stat: Journal Article,

[Recent data on the use of gentian violet in prevention of the transmission of Chagas'disease by blood transfusion.]
NUSSENZWEIG V; AMATO NETO V; MELLONE O
1959 Feb;55(2):183-188, Hospital (Rio De Janeiro O Hospital)
— id: 62100, year: 1959, vol: 55, page: 183, stat: Journal Article,

Contribuicao para o estudo de reacao de fixacao do complemento na leishmaniose visceral, com antigeno extraido de bacilos de tuberculose
Nussenzweig, Victor
Rio de Janeiro : [Servico Nacional de Educacao Sanitaria], 1958,
— id: 1533, year: 1958, vol: , page: , stat: ,

[Effects of physical and chemical agents of Trypanosoma cruzi in vitro.]
NUSSENZWEIG V; NUSSENZWEIG RS; DE FREITAS JL; AMATO NETO V; BIANCALANA A; KLOETZEL J
1954 May;45(5):589-599, Hospital (Rio De Janeiro O Hospital)
— id: 62101, year: 1954, vol: 45, page: 589, stat: Journal Article,

[Blood tests for Chagas disease in prospective donors in blood banks in the states of Sao Paulo and Minas Gerais.]
BIANCALANA A; DE FREITAS JL; AMATO NETO V; NUSSENZWEIG V; SONNTAG R
1953 Dec;44(6):745-749, Hospital (Rio De Janeiro O Hospital)
— id: 62102, year: 1953, vol: 44, page: 745, stat: Journal Article,

[Effect of gentian violet on Trypanosoma cruzi in vitro; importance in the sterilization of blood for transfusion.]
NUSSENZWEIG V; BIANCALANA A; AMATO NETO V; SONNTAG R; DE FREITAS JP; KLOETZEL J
1953 Jan;42(1):57-58, Revista paulista de medicina
— id: 62104, year: 1953, vol: 42, page: 57, stat: Journal Article,

[Effect of triphenylmethane dyes on Trypanosoma cruzi in vitro; use of gentian violet in prevention of transmission of Chagas disease by blood transfusion.]
NUSSENZWEIG V; SONNTAG R; BIANCALANA A; DE FREITAS JL; AMATO NETO V; KLOETZEL J
1953 Dec;44(6):731-744, Hospital (Rio De Janeiro O Hospital)
— id: 62103, year: 1953, vol: 44, page: 731, stat: Journal Article,

[Chagas' disease in blood banks in the capital of Sao Paulo.]
DE FREITAS JP; BIANCALANA A; AMATO NETO V; NUSSENZWEIG V; SONNTAG R; BARRETTO JG
1952 Feb;41(2):229-236, Hospital (Rio De Janeiro O Hospital)
— id: 62105, year: 1952, vol: 41, page: 229, stat: Journal Article,