Ruth S Nussenzweig, Ph.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,

Breakthroughs towards a malaria vaccine
Nussenzweig, Ruth Sonntag
2011 Jun 1;18(2):559-564, Historia, ciencias, saude--Manguinhos
— id: 135579, year: 2011, vol: 18, page: 559, 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,

Immunogenicity and protective efficacy of a recombinant yellow fever vaccine against the murine malarial parasite Plasmodium yoelii
Stoyanov, Cristina T; Boscardin, Silvia B; Deroubaix, Stephanie; Barba-Spaeth, Giovanna; Franco, David; Nussenzweig, Ruth S; Nussenzweig, Michel; Rice, Charles M
2010 Jun 23;28(29):4644-4652, Vaccine
The live-attenuated yellow fever vaccine (YF17D) is one of the safest and most effective vaccines available today. Here, YF17D was genetically altered to express the circumsporozoite protein (CSP) from the murine malarial parasite Plasmodium yoelii. Reconstituted recombinant virus was viable and exhibited robust CSP expression. Immunization of naive mice resulted in extensive proliferation of adoptively transferred CSP-specific transgenic CD8(+) T-cells. A single immunization of naive mice with recombinant YF17D resulted in robust production of IFN-gamma by CD8(+) T-cells and IFN-gamma and IL-2 by CD4(+) T-cells. A prime-boost regimen consisting of recombinant virus followed by a low-dose of irradiated sporozoites conferred protection against challenge with P. yoelii. Taken together, these results show that recombinant YF17D can efficiently express CSP in culture, and prime a protective immune response in vivo
— id: 133512, year: 2010, vol: 28, page: 4644, 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,

Antigen targeting to dendritic cells elicits long-lived T cell help for antibody responses
Boscardin, Silvia B; Hafalla, Julius C R; Masilamani, Revati F; Kamphorst, Alice O; Zebroski, Henry A; Rai, Urvashi; Morrot, Alexandre; Zavala, Fidel; Steinman, Ralph M; Nussenzweig, Ruth S; Nussenzweig, Michel C
2006 Mar 20;203(3):599-606, Journal of experimental medicine
Resistance to several prevalent infectious diseases requires both cellular and humoral immune responses. T cell immunity is initiated by mature dendritic cells (DCs) in lymphoid organs, whereas humoral responses to most antigens require further collaboration between primed, antigen-specific helper T cells and naive or memory B cells. To determine whether antigens delivered to DCs in lymphoid organs induce T cell help for antibody responses, we targeted a carrier protein, ovalbumin (OVA), to DCs in the presence of a maturation stimulus and assayed for antibodies to a hapten, (4-hydroxy-3-nitrophenyl) acetyl (NP), after boosting with OVA-NP. A single DC-targeted immunization elicited long-lived T cell helper responses to the carrier protein, leading to large numbers of antibody-secreting cells and high titers of high-affinity antihapten immunoglobulin Gs. Small doses of DC-targeted OVA induced higher titers and a broader spectrum of anti-NP antibody isotypes than large doses of OVA in alum adjuvant. Similar results were obtained when the circumsporozoite protein of Plasmodium yoelii was delivered to DCs. We conclude that antigen targeting to DCs combined with a maturation stimulus produces broad-based and long-lived T cell help for humoral immune responses
— id: 78870, year: 2006, vol: 203, page: 599, 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,

Safety and enhanced immunogenicity of a hepatitis B core particle Plasmodium falciparum malaria vaccine formulated in adjuvant Montanide ISA 720 in a phase I trial
Oliveira, Giane A; Wetzel, Kristiane; Calvo-Calle, J Mauricio; Nussenzweig, Ruth; Schmidt, Annette; Birkett, Ashley; Dubovsky, Filip; Tierney, Eveline; Gleiter, Christoph H; Boehmer, Gabriele; Luty, Adrian J F; Ramharter, Michael; Thornton, George B; Kremsner, Peter G; Nardin, Elizabeth H
2005 Jun;73(6):3587-3597, Infection & immunity
Highly purified subunit vaccines require potent adjuvants in order to elicit optimal immune responses. In a previous phase I trial, an alum formulation of ICC-1132, a malaria vaccine candidate comprising hepatitis B core (HBc) virus-like particle containing Plasmodium falciparum circumsporozoite (CS) protein epitopes, was shown to elicit Plasmodium falciparum-specific antibody and cellular responses. The present study was designed as a single-blind, escalating-dose phase I trial to evaluate the safety and immunogenicity of single intramuscular doses of ICC-1132 formulated in the more potent water-in-oil adjuvant Montanide ISA 720 (ICC-1132/ISA 720). The vaccine was safe and well tolerated, with transient injection site pain as the most frequent complaint. All vaccinees that received either 20 mug or 50 mug of ICC-1132/ISA 720 developed antiimmunogen and anti-HBc antibodies. The majority of volunteers in these two groups developed sporozoite-specific antibodies, predominantly of opsonizing immunoglobulin G subtypes. Peak titers and persistence of parasite-specific antibody following a single injection of the ISA 720 formulated vaccine were comparable to those obtained following two to three immunizations with alum-adsorbed ICC-1132. Peripheral blood mononuclear cells of ICC-1132/ISA 720 vaccinees proliferated and released cytokines (interleukin 2 and gamma interferon) when stimulated with recombinant P. falciparum CS protein, and CS-specific CD4(+) T-cell lines were established from volunteers with high levels of antibodies to the repeat region. The promising results obtained with a single dose of ICC-1132 formulated in Montanide ISA 720 encourage further clinical development of this malaria vaccine candidate
— id: 55915, year: 2005, vol: 73, page: 3587, 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,

Induction of protective immunity against malaria by priming-boosting immunization with recombinant cold-adapted influenza and modified vaccinia Ankara viruses expressing a CD8+-T-cell epitope derived from the circumsporozoite protein of Plasmodium yoelii
Gonzalez-Aseguinolaza, Gloria; Nakaya, Yurie; Molano, Alberto; Dy, Edward; Esteban, Mariano; Rodriguez, Dolores; Rodriguez, Juan Ramon; Palese, Peter; Garcia-Sastre, Adolfo; Nussenzweig, Ruth S
2003 Nov;77(21):11859-11866, Journal of virology
We immunized mice with an attenuated (cold-adapted) influenza virus followed by an attenuated vaccinia virus (modified vaccinia virus Ankara), both expressing a CD8(+)-T-cell epitope derived from malaria sporozoites. This vaccination regimen elicited high levels of protection against malaria. This is the first time that the vaccine efficacy of a recombinant cold-adapted influenza virus vector expressing a foreign antigen has been evaluated
— id: 42653, year: 2003, vol: 77, page: 11859, stat: Journal Article,

A modified hepatitis B virus core particle containing multiple epitopes of the Plasmodium falciparum circumsporozoite protein provides a highly immunogenic malaria vaccine in preclinical analyses in rodent and primate hosts
Birkett, A; Lyons, K; Schmidt, A; Boyd, D; Oliveira, GA; Siddique, A; Nussenzweig, R; Calvo-Calle, JM; Nardin, E
2002 DEC ;70(12):6860-6870, Infection & immunity
Despite extensive public health efforts, there are presently 200 to 400 million malaria infections and I to 2 million deaths each year due to the Plasmodium parasite. A prime target for malaria vaccine development is the circumsporozoite (CS) protein, which is expressed on the extracellular sporozoite and the intracellular hepatic stages of the parasite. Previous studies in rodent malaria models have shown that CS repeat B- cell epitopes expressed in a recombinant hepatitis B virus core (HBc) protein can elicit protective immunity. To design a vaccine for human use, a series of recombinant HBc proteins containing epitopes of Plasmodium falciparum CS protein were assayed for immunogenicity in mice [A. Birkett, B. Thornton, D. Millich, G. A. Oliveira, A. Siddique, R. Nussenzweig, J. M. Calvo-Calle, and E. H. Nardin, abstract from the 50th Annual Meeting of the American Society of Tropical Medicine and Hygiene 2001, Am. J. Trop. Med. Hyg. 65(Suppl. 3):258, 2001; D. R. Milich, J. Hughes, J. Jones, M. Sallberg, and T. R. Phillips, Vaccine 20:771-788, 2001]. The present paper summarizes preclinical analyses of the optimal P. falciparum HBc vaccine candidate, termed ICC-1132, which contains T- and B-cell epitopes from the repeat region and a universal T-cell epitope from the C terminus of the CS protein. The vaccine was highly immunogenic in mice and in Macaca fascicularis (cynomolgus) monkeys. When formulated in adjuvants suitable for human use, the vaccine elicited antisporozoite antibody titers that were logs higher than those obtained in previous studies. Human malaria-specific CD4(+)-T-cell clones and T cells of ICC- 1132-immunized mice specifically recognized malaria T-cell epitopes contained in the vaccine. In addition to inducing strong mallaria-specific immune responses in naive hosts, ICC- 1132 elicited potent anamnestic antibody responses in mice primed with P. falciparum sporozoites, suggesting potential efficacy in enhancing the sporozoite-primed immune responses of individuals living in areas where malaria is endemic
— id: 33041, year: 2002, vol: 70, page: 6860, stat: Journal Article,

Surface expression of an immunodominant malaria protein B cell epitope by yellow fever virus
Bonaldo, Myrna C; Garratt, Richard C; Caufour, Philippe S; Freire, Marcos S; Rodrigues, Mauricio M; Nussenzweig, Ruth S; Galler, Ricardo
2002 Jan 25;315(4):873-885, Journal of molecular biology
The yellow fever 17D virus (YF17D) has several characteristics that are desirable for the development of new, live attenuated vaccines. We approached its development as a vector for heterologous antigens by studying the expression of a humoral epitope at the surface of the E protein based on the results of modelling its three-dimensional structure. This model indicated that the most promising insertion site is between beta-strands f and g, a site that is exposed at the external surface of the virus. The large deletion of six residues from the fg loop of the E protein from yellow fever virus, compared to tick-born encephalitis virus, leaves space at the dimer interface for a large insertion without creating steric hindrance. We have tested this hypothesis by inserting a model humoral epitope from the circumsporozoite protein of Plasmodium falciparum consisting of triple NANP repeats. Recombinant virus (17D/8) expressing this insertion flanked by two glycine residues at each end, is specifically neutralized by a monoclonal antibody to the model epitope. Furthermore, mouse antibodies raised to the recombinant virus recognize the parasite protein in an ELISA assay. Serial passage analysis confirmed the genetic stability of the insertion made in the viral genome and the resulting 17D/8 virus is significantly more attenuated in mouse neurovirulence tests than the 17DD vaccine. The fg loop belongs to the dimerization domain of the E protein and lies at the interface between monomers. This domain undergoes a low pH transition, which is related to the fusion of the viral envelope to the endosome membrane. It is conceivable that a slower rate of fusion, resulting from the insertion close to the dimer interface, may delay the onset of virus production and thereby lead to a milder infection of the host. This would account for the more attenuated phenotype of the recombinant virus in the mouse model and lower extent of replication in cultured cells. The vectorial capacity of the yellow fever virus is being further explored for the expression and presentation of other epitopes, including those mediating T-cell responses
— id: 29331, year: 2002, vol: 315, page: 873, stat: Journal Article,

Delayed-type hypersensitivity in volunteers immunized with a synthetic multi-antigen peptide vaccine (PfCS-MAP1NYU) against Plasmodium falciparum sporozoites
Kublin, James G; Lowitt, Mark H; Hamilton, Robert G; Oliveira, Giane A; Nardin, Elizabeth H; Nussenzweig, Ruth S; Schmeckpeper, Barbara J; Diggs, Carter L; Bodison, Sacared A; Edelman, Robert
2002 Mar 15;20(13):1853-1861, Vaccine
During the testing of the safety and immunogenicity of an adjuvanted, synthetic Plasmodium falciparum CS multiple antigen peptide (MAP) vaccine, we investigated the potential for using cutaneous delayed-type hypersensitivity (DTH) reactions as a correlate of immune response. We evaluated 27 of our volunteers for DTH reactions to intradermal inoculation (0.02ml) of several concentrations of the MAP vaccine and adjuvant control solutions. Induration was measured 2 days after skin tests were applied. Nine of 14 vaccinees (64%) with serum, high-titered anti-MAP antibody developed positive DTH (>/=5mm induration), that first appeared by 29 days after immunization and persisted for at least 3-6 months after 1-2 more immunizations. In contrast, DTH responses were negative in eight of eight vaccinees with no or low antibody titers, and in five of five non-immunized volunteers. Biopsies of positive DTH skin test sites were histologically compatible with a DTH reaction. We conclude that the presence of T cell functional activity reflected by a positive DTH skin test response to the MAP antigen serves as another marker for vaccine immunogenicity
— id: 29330, year: 2002, vol: 20, page: 1853, 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,

Complete, long-lasting protection against malaria of mice primed and boosted with two distinct viral vectors expressing the same plasmodial antigen
Bruna-Romero O; Gonzalez-Aseguinolaza G; Hafalla JC; Tsuji M; Nussenzweig RS
2001 Sep 25;98(20):11491-11496, Proceedings of the National Academy of Sciences of the United States of America
We report that complete protection against malaria and total inhibition of liver stage development and parasitemia was obtained in 100% of BALB/c mice primed with a replication-defective recombinant adenovirus expressing the circumsporozoite (CS) protein of Plasmodium yoelii (AdPyCS), followed by a booster with an attenuated recombinant vaccinia virus, expressing the same malaria antigen, VacPyCS. We found increased levels of activated CS-specific CD8(+) and CD4(+) T cells, higher anti-sporozoite antibody titers, and greater protection in these mice, when the time between priming and boosting with these two viral vectors was extended from 2 to 8 or more weeks. Most importantly, by using this immunization regimen, the protection of the immunized mice was found to be long-lasting, namely complete resistance to infection of all animals 3 1/2 months after priming. These results indicate that immunization with AdPyCS generates highly effective memory T and B cells that can be recalled long after priming by boosting with VacPyCS
— id: 23956, year: 2001, vol: 98, page: 11491, 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,

A totally synthetic polyoxime malaria vaccine containing Plasmodium falciparum B cell and universal T cell epitopes elicits immune responses in volunteers of diverse HLA types
Nardin EH; Calvo-Calle JM; Oliveira GA; Nussenzweig RS; Schneider M; Tiercy JM; Loutan L; Hochstrasser D; Rose K
2001 Jan 1;166(1):481-489, Journal of immunology
This open-labeled phase I study provides the first demonstration of the immunogenicity of a precisely defined synthetic polyoxime malaria vaccine in volunteers of diverse HLA types. The polyoxime, designated (T1BT(*))(4)-P3C, was constructed by chemoselective ligation, via oxime bonds, of a tetrabranched core with a peptide module containing B cell epitopes and a universal T cell epitope of the Plasmodium falciparum circumsporozoite protein. The triepitope polyoxime malaria vaccine was immunogenic in the absence of any exogenous adjuvant, using instead a core modified with the lipopeptide P3C as an endogenous adjuvant. This totally synthetic vaccine formulation can be characterized by mass spectroscopy, thus enabling the reproducible production of precisely defined vaccines for human use. The majority of the polyoxime-immunized volunteers (7/10) developed high levels of anti-repeat Abs that reacted with the native circumsporozoite on P. falciparum sporozoites. In addition, these seven volunteers all developed T cells specific for the universal epitope, termed T(*), which was originally defined using CD4(+) T cells from protected volunteers immunized with irradiated P. falciparum sporozoites. The excellent correlation of T(*)-specific cellular responses with high anti-repeat Ab titers suggests that the T(*) epitope functioned as a universal Th cell epitope, as predicted by previous peptide/HLA binding assays and by immunogenicity studies in mice of diverse H-2 haplotypes. The current phase I trial suggests that polyoximes may prove useful for the development of highly immunogenic, multicomponent synthetic vaccines for malaria, as well as for other pathogens
— id: 26830, year: 2001, vol: 166, page: 481, stat: Journal Article,

A striking property of recombinant poxviruses: efficient inducers of in vivo expansion of primed CD8(+) T cells
Zavala F; Rodrigues M; Rodriguez D; Rodriguez JR; Nussenzweig RS; Esteban M
2001 Feb 15;280(2):155-159, Virology
— id: 23507, year: 2001, vol: 280, page: 155, stat: Journal Article,

Synthetic malaria peptide vaccine elicits high levels of antibodies in vaccinees of defined HLA genotypes
Nardin EH; Oliveira GA; Calvo-Calle JM; Castro ZR; Nussenzweig RS; Schmeckpeper B; Hall BF; Diggs C; Bodison S; Edelman R
2000 Nov;182(5):1486-1496, Journal of infectious diseases
A multiple antigen peptide (MAP) malaria vaccine containing minimal Plasmodium falciparum circumsporozoite protein repeat epitopes was assessed for safety and immunogenicity in volunteers of known class II genotypes. The MAP/alum/QS-21 vaccine formulation elicited high levels of parasite-specific antibodies in 10 of 12 volunteers expressing DQB1*0603, DRB1*0401, or DRB1*1101 class II molecules. In contrast, volunteers of other HLA genotypes were low responders or nonresponders. A second study of 7 volunteers confirmed the correlation of class II genotype and high responder phenotype. This is the first demonstration in humans that a peptide vaccine containing minimal T and B cell epitopes composed of only 5 amino acids (N, A, V, D, and P) can elicit antibody titers comparable to multiple exposures to irradiated P. falciparum-infected mosquitoes. Moreover, the high-responder phenotypes were predicted by analysis of peptide/HLA interactions in vitro, thus facilitating the rational design of epitope-based peptide vaccines for malaria, as well as for other pathogens
— id: 29332, year: 2000, vol: 182, page: 1486, stat: Journal Article,

A totally synthetic polyoxime malaria vaccine containing Plasmodium falciparum B cell and universal T cell epitopes elicits immune responses in volunteers of diverse HLA types
Nardin, E H; Calvo-Calle, J M; Oliveira, G A; Nussenzweig, R; Schneider, M; Loutan, L; Tiercy, J-M; Hochstrasser, D; Rose, K
2000 Oct 29-Nov 02;62(3 Supplement):200-200, American journal of tropical medicine & hygiene
— id: 15773, year: 2000, vol: 62, page: 200, stat: Journal Article,

Immunogenicity of Ty-VLP bearing a CD8(+) T cell epitope of the CS protein of P. yoelii: enhanced memory response by boosting with recombinant vaccinia virus
Oliveira-Ferreira J; Miyahira Y; Layton GT; Savage N; Esteban M; Rodriguez D; Rodriguez JR; Nussenzweig RS; Zavala F; Myahira Y
2000 Mar 6;18(17):1863-1869, Vaccine
We characterized the immunogenicity of the hybrid Ty-virus-like carrying the CD8(+) T cell epitope (SYVPSAEQI) of the circumsporozoite (CS) protein of Plasmodium yoelii (TyCS-VLP), a rodent malaria parasite. Balb/c mice were immunized with hybrid TyCS-VLP, and their CS-specific CD8(+) T cell response was quantitatively evaluated with the ELISPOT assay, based on the enumeration of epitope specific gamma-interferon secreting CD8(+) T cell. A single immunization with the TyCS-VLP by a variety of routes and doses indicated that the maximal response occurred in mice, which were immunized with 50 micrograms of these particles, administered via intramuscular. Combined immunization of mice with this TyCS-VLP followed by recombinant vaccinia virus expressing the entire P. yoelii CS protein (VacPyCS) or irradiated sporozoites, induced high levels of IFN-gamma-producing cells. The immunization regime, priming with TyCS-VLP and boosting with VacPyCS generated a potent protective immune response, which strongly inhibited P. yoelii liver stages development and protected 62% of the mice against a subsequent live P. yoelii sporozoite challenge
— id: 23508, year: 2000, vol: 18, page: 1863, stat: Journal Article,

Immunogenicity of Ty-VLP bearing a CD8(+) T cell epitope of the CS protein of P. yoelii: enhanced memory response by boosting with recombinant vaccinia virus
Oliveira-Ferreira J; Myahira Y; Layton GT; Savage N; Esteban M; Rodriguez D; Rodriguez JR; Nussenzweig RS; Zavala F
2000 Jun 15;18(25):2923-2923, Vaccine
— id: 29333, year: 2000, vol: 18, page: 2923, stat: Journal Article,

Interferon-gamma-independent CD8+ T cell-mediated protective anti-malaria immunity elicited by recombinant adenovirus
Rodrigues EG; Claassen J; Lee S; Wilson JM; Nussenzweig RS; Tsuji M
2000 Mar;22(3):157-160, Parasite immunology
Recombinant adenovirus, expressing the CS protein of Plasmodium yoelii, AdPyCS, was shown to induce a comparable degree of T cell-mediated protection against malaria as a single dose of irradiated P. yoelii sporozoites, causing inhibition of liver stage development. We now report that differently from sporozoite-induced immunity, interferon (IFN)-gamma does not mediate the protective immunity induced by AdPyCS, since a similar degree of protection was observed in AdPyCS immunized mice lacking IFN-gamma-/- and the IFN-gamma receptor (IFN-gammaR-/-) compared to that in wild-type mice. Depletion of CD8+ T cells from these immunized mice almost completely abolished the AdPyCS-induced immunity, indicating that the immunization with AdPyCS induces CD8+ T cell-mediated protective anti-malaria immunity, which is independent of IFN-gamma
— id: 8533, year: 2000, vol: 22, page: 157, stat: Journal Article,

Protective role of NKT cells against liver stages of malaria infection in mice
Gonzalez-Aseguinolaza, G; de Oliveira, C; Koezuka, Y; Nussenzweig, RS; Van Kaer, L; Bendelac, A; Tsuji, M
1999 Nov 28-Dec 2;61(3 SUPPL.):341-342, American journal of tropical medicine & hygiene
— id: 15883, year: 1999, vol: 61, page: 341, stat: Journal Article,

Interferon-gamma responses are associated with resistance to reinfection with Plasmodium falciparum in young African children
Luty, AJF; Lell, B; Schmidt-Ott, R; Lehman, LG; Luckner, D; Greve, B; Matousek, P; Herbich, K; Schmid, D; Migot-Nabias, F; Deloron, P; Nussenzweig, RS; Kremsner, PG
1999 APR ;179(4):980-988, Journal of infectious diseases
The contribution of T cell-mediated responses was studied with regard to resistance to reinfection in groups of Gabonese children participating In a prospective study of severe and mild malaria due to infection with Plasmodium falciparum. In those admitted with mild malaria, but not in those with severe malaria, production of IFN-gamma by peripheral blood mononuclear cells (PBMC) in response to either liver-stage or merozoite antigen peptides was associated with significantly delayed first reinfections and with significantly lower rates of reinfection. Proliferative or tumor necrosis factor responses to the same peptides showed no such associations. Production of interferon-gamma by PBMC in response to sporozoite and merozoite antigen peptides was observed in a higher proportion of those presenting with mild malaria. Differences in the Th1/Th2 cytokine balance may be linked. to the ability to control parasite multiplication in these young children, helping to explain the marked differences observed in both susceptibility to infection as well as in clinical presentation
— id: 54100, year: 1999, vol: 179, page: 980, stat: Journal Article,

Preclinical evaluation of a synthetic Plasmodium falciparum MAP malaria vaccine in Aotus monkeys and mice
Moreno CA; Rodriguez R; Oliveira GA; Ferreira V; Nussenzweig RS; Moya Castro ZR; Calvo-Calle JM; Nardin E
1999 Aug 20;18(1-2):89-99, Vaccine
Multiple antigen peptides (MAPs) containing epitopes of the major surface protein of the malaria sporozoite, the circumsporozoite (CS) protein, have been shown in previous studies to elicit antibody-mediated protection against sporozoite challenge in experimental murine and simian hosts. For the preparation for a phase I trial of a P. falciparum (T1B)4 MAP, which contains T and B cell epitopes from the CS repeat region, pre-clinical immunogenicity and adjuvant formulation studies were carried out in mice and Aotus monkeys. The (T1B)4 MAP was found to be immunogenic in three different species of owl monkeys, Aotus nancymae, A. vociferans and A. nigriceps. Optimal antibody responses were obtained in A. nancymae immunized s.c. with (T1B)4 MAP emulsified in Freund's, in which peak titers of over 10(6) were obtained in individual monkeys. MAP immunized A. vociferans also developed high levels of anti-sporozoite antibodies, although the kinetics and the magnitude of the response differed from A. nancymae. (T1B)4 MAP adsorbed to alum (aluminum hydroxide), a formulation that is acceptable for human use, was less immunogenic in naive A. nancymae, as well as A. nigriceps. The injection of MAPs/alum, however, significantly enhanced antibody responses in sporozoite-primed monkeys, suggesting that the administration of the MAP vaccine may be an effective means to increase the low levels of antibody present in individuals living in malaria endemic areas. The addition of a co-adjuvant QS-21, a purified saponin, significantly increased the immunogenicity of the alum-adsorbed MAP in both mice and monkeys, providing a vaccine formulation suitable for phase I trials in human volunteers
— id: 8477, year: 1999, vol: 18, page: 89, 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,

Subtle mutagenesis by ends-in recombination in malaria parasites
Nunes A; Thathy V; Bruderer T; Sultan AA; Nussenzweig RS; Menard R
1999 Apr;19(4):2895-2902, Molecular & cellular biology
The recent advent of gene-targeting techniques in malaria (Plasmodium) parasites provides the means for introducing subtle mutations into their genome. Here, we used the TRAP gene of Plasmodium berghei as a target to test whether an ends-in strategy, i.e., targeting plasmids of the insertion type, may be suitable for subtle mutagenesis. We analyzed the recombinant loci generated by insertion of linear plasmids containing either base-pair substitutions, insertions, or deletions in their targeting sequence. We show that plasmid integration occurs via a double-strand gap repair mechanism. Although sequence heterologies located close (less than 450 bp) to the initial double-strand break (DSB) were often lost during plasmid integration, mutations located 600 bp and farther from the DSB were frequently maintained in the recombinant loci. The short lengths of gene conversion tracts associated with plasmid integration into TRAP suggests that an ends-in strategy may be widely applicable to modify plasmodial genes and perform structure-function analyses of their important products
— id: 6059, year: 1999, vol: 19, page: 2895, stat: Journal Article,

Genetic restriction of the serological and cellular responses in volunteers immunized with a Plasmodium falciparum synthetic peptide vaccine
Oliveira, G A; Calvo-Calle, J M; Nussenzweig, R S; Kublin, J; Edelman, R; Nardin, E
1999 Nov 28-Dec 2;61(3 SUPPL.):306-306, American journal of tropical medicine & hygiene
— id: 15882, year: 1999, vol: 61, page: 306, stat: Journal Article,

Recombinant viruses expressing a human malaria antigen can elicit potentially protective immune CD8+ responses in mice
Miyahira Y; Garcia-Sastre A; Rodriguez D; Rodriguez JR; Murata K; Tsuji M; Palese P; Esteban M; Zavala F; Nussenzweig RS
1998 Mar 31;95(7):3954-3959, Proceedings of the National Academy of Sciences of the United States of America
Extensive studies on protective immunity to rodent malaria provided the basis for the current experiments in which mice were immunized with recombinant (re) influenza and vaccinia viruses expressing selected sequences of the circumsporozoite (CS) protein of the human malaria parasite Plasmodium falciparum. Mice of different H-2 haplotypes immunized with re influenza viruses expressing the immunodominant B cell epitope of this CS protein produced high titers of antibodies to the parasite. A cytotoxic T lymphocyte epitope of the CS protein of P. falciparum, PF3, recognized by CD8+ T cells of H-2(k) mice, was expressed in a re vaccinia virus (VacPf) and a re influenza virus (FluPf). Immunization of mice with either FluPf or VacPf elicited a modest CS-specific CD8+ T cell response detected by interferon gamma secretion of individual immune cells. Priming of mice with FluPf, followed by a booster with VacPf, resulted in a striking enhancement of this T cell response. The reverse protocol, i.e., priming with VacPf followed by a booster with FluPf, failed to enhance the primary response. VacPf also greatly enhanced the primary response of mice injected with P. falciparum sporozoites or with a lipopeptide containing PF3. A booster with FluPf also amplified the response of lipopeptide- or sporozoite-primed mice but less than a VacPf booster did. Although mice are not susceptible to infection by P. falciparum sporozoites, we demonstrated that administration of two distinct immunogens expressing PF3 elicited activated, extravasating CS-specific T cells that protected against an intracerebral VacPf challenge
— id: 7689, year: 1998, vol: 95, page: 3954, stat: Journal Article,

Plasmodium falciparum polyoximes: highly immunogenic synthetic vaccines constructed by chemoselective ligation of repeat B-cell epitopes and a universal T-cell epitope of CS protein
Nardin EH; Calvo-Calle JM; Oliveira GA; Clavijo P; Nussenzweig R; Simon R; Zeng W; Rose K
1998 Apr;16(6):590-600, Vaccine
Effective immunoprophylaxis directed against the pre-erythrocytic stages of the malaria parasite requires a vaccine that can elicit humoral and cell mediated immunity in individuals of diverse genetic background. In order for a synthetic peptide malaria vaccine to meet these requirements, problems associated with genetic restriction, peptide chemistry, adjuvant formulation and physiochemical characterization of the final synthetic vaccine product must first be overcome. To address these issues, five polyoxime vaccine candidates have been constructed by ligating purified peptide epitopes of the P. falciparum CS protein to a branched template via oxime bonds. All five constructs, including two based on templates containing the synthetic adjuvant tripalmitoyl-S-glyceryl cysteine (Pam3Cys), were of sufficient purity for characterization by mass spectrometry. The immunogenicity of the malaria polyoximes in different murine strains was compared to that of multiple antigen peptide (MAP) constructs synthesized by standard step-wise synthesis. A tri-epitope polyoxime-Pam3Cys construct, based on the repeats and a universal T-cell epitope that contains both helper and CTL epitopes of the CS protein, was shown to be a precisely-defined synthetic malaria vaccine candidate that was highly immunogenic in murine strains of diverse H-2 haplotypes
— id: 8229, year: 1998, vol: 16, page: 590, stat: Journal Article,

Efficient induction of protective anti-malaria immunity by recombinant adenovirus
Rodrigues EG; Zavala F; Nussenzweig RS; Wilson JM; Tsuji M
1998 Nov;16(19):1812-1817, Vaccine
The immunogenicity of a previously constructed replication-defective recombinant adenovirus expressing the CS protein of Plasmodium yoelii was compared with that of irradiated sporozoites. We found that immunization of BALB/c mice with a single dose of this recombinant adenovirus induced a much greater CS-specific T-cell response compared with immunization with irradiated sporozoites. More importantly, we found that this recombinant adenovirus induces similar or higher levels of protective immunity than those induced by irradiated sporozoites, eliciting an appreciable resistance to malaria infection
— id: 12061, year: 1998, vol: 16, page: 1812, stat: Journal Article,

Recombinant Sindbis viruses expressing a cytotoxic T-lymphocyte epitope of a malaria parasite or of influenza virus elicit protection against the corresponding pathogen in mice
Tsuji M; Bergmann CC; Takita-Sonoda Y; Murata K; Rodrigues EG; Nussenzweig RS; Zavala F
1998 Aug;72(8):6907-6910, Journal of virology
Subcutaneous administration in mice of recombinant Sindbis viruses expressing a class I major histocompatibility complex-restricted 9-mer epitope of the Plasmodium yoelii circumsporozoite protein or the nucleoprotein of influenza virus induces a large epitope-specific CD8(+) T-cell response. This immunization also elicits a high degree of protection against infection with malaria or influenza A virus
— id: 8241, year: 1998, vol: 72, page: 6907, 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,

A malaria vaccine based on a sporozoite antigen
Nussenzweig RS; Zavala F
1997 Jan 9;336(2):128-130, New England journal of medicine
— id: 23511, year: 1997, vol: 336, page: 128, stat: Journal Article,

Development of novel influenza virus vaccines and vectors
Palese P; Zavala F; Muster T; Nussenzweig RS; Garcia-Sastre A
1997 Aug;176 Suppl 1(11):S45-S49, Journal of infectious diseases
Approaches to improve the efficacy of the current (killed) influenza virus vaccines include the generation of cold-adapted and genetically engineered influenza viruses containing specific attenuating mutations. It is hoped that these genetically altered viruses, in which the hemagglutinin and neuraminidase genes from circulating strains have been incorporated by reassortment, can be used as safe live influenza virus vaccines to induce a long-lasting protective immune response in humans. In addition, genetically engineered influenza viruses may provide a means for expressing foreign antigens. Immunization of mice with recombinant influenza and vaccinia viruses expressing specific antigens of Plasmodium yoelii resulted in a dramatic protective immune response against malaria in this model. Mice immunized with recombinant influenza viruses expressing human immunodeficiency virus (HIV) epitopes generated long-lasting HIV-specific serum antibodies and secretory IgA in the secretory nasal, vaginal, and intestinal mucosa. These results suggest that genetically engineered influenza viruses may be developed for use as live virus vaccines against influenza as well as other diseases
— id: 23510, year: 1997, vol: 176 Suppl 1, page: S45, 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,

Characterization of in vivo primary and secondary CD8+ T cell responses induced by recombinant influenza and vaccinia viruses
Murata K; Garcia-Sastre A; Tsuji M; Rodrigues M; Rodriguez D; Rodriguez JR; Nussenzweig RS; Palese P; Esteban M; Zavala F
1996 Oct 10;173(1):96-107, Cellular immunology
We characterized the in vivo primary and secondary murine CD8+ T cell responses induced by immunization with influenza and vaccinia viruses, which were engineered to express the same H-2K(k)- and H-2K(d)-restricted epitopes. Our results show that the induction and magnitude of the primary CD8+ T cell response closely depends on the viral dose used for immunization, while it is not affected by the route of immunization. The induction of secondary CD8+ T cell responses appears to be highly restricted, as suggested by the lack of in vivo expansion of antigen-specific CD8+ T cells after repeated immunization with the same virus. In contrast, a 20- to 30-fold increase in the frequency of antigen-specific CD8+ T cells could be induced after combined immunization with recombinant influenza and vaccinia viruses. These findings may provide the basis for the development of new prophylactic and therapeutic strategies to prevent or control intracellular infections and certain malignancies
— id: 12517, year: 1996, vol: 173, page: 96, 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,

Plasmodium yoelii: peptide immunization induces protective CD4+ T cells against a previously unrecognized cryptic epitope of the circumsporozoite protein
Takita-Sonoda Y; Tsuji M; Kamboj K; Nussenzweig RS; Clavijo P; Zavala F
1996 Nov;84(2):223-230, Experimental parasitology
In this study we characterized the CD4+ T cell response directed against two distinct epitopes located in the circumsporozoite (CS) protein of Plasmodium yoelii. The immunization of mice with P. yoelii sporozoites induced CD4+ T cells which were mostly directed against one of these peptides, Py-1, previously reported to contain a CD4+ epitope. The CD4+ T cells directed against this immunodominant epitope were mostly of the Th-1 type. Another newly identified peptide, AS44, induced a specific CD4+ T cell response, which was mainly detectable after immunization with the corresponding peptide. Several CD4+ T cell clones, recognizing this epitope, were generated and their lymphokine expression was characterized, as well as their surface markers and their anti-parasite activity in vivo. It was noteworthy that some of these CD4+ T cell clones, which recognize this cryptic epitope and were of different Th subtypes, were shown to have a strong inhibitory effect on the development of liver stages of malaria parasites
— id: 7093, year: 1996, vol: 84, page: 223, stat: Journal Article,

Phenotypic and functional properties of murine gamma delta T cell clones derived from malaria immunized, alpha beta T cell-deficient mice
Tsuji M; Eyster CL; O'Brien RL; Born WK; Bapna M; Reichel M; Nussenzweig RS; Zavala F
1996 Mar;8(3):359-366, International immunology
Six murine T cell clones expressing gamma delta TCR were generated from malaria immunized, alpha beta T cell-deficient mice. Phenotypic characterization of these clones has revealed that, in contrast to conventional alpha beta T cells, there is a considerable degree of heterogeneity among these gamma delta clones with regard to their surface markers and their lymphokine profile. One clone was found to display significant anti-parasite activity in vivo upon adoptive transfer. We attempted to determine whether the protective clone differs in one or more key characteristics from the non-protective clones. Although no obvious pattern peculiar to the protective gamma delta clone was observed, it appears that more than one parameter may, in combination, define a distinct protective phenotype, and thus explain the functional difference between the protective and non-protective gamma delta clones
— id: 8088, year: 1996, vol: 8, page: 359, stat: Journal Article,

Detection of anti-Plasmodium falciparum antibodies directed against a repetitive peptide of the gametocyte antigen Pfs2400 in malaria patients in Brazil
Marrelli, MT; Nussenzweig, RS; Collins, WE; Kloetzel, JK
1995 DEC ;89(6):593-599, Annals of tropical medicine & parasitology
Sera collected from 164 individuals who had clinical Plasmodium falciparum malaria and came from several areas of Brazil where malaria is endemic were tested for the presence of anti-gametocyte antibodies. Antibodies directed against P. falciparum gametocytes were detected, by IFAT, in the sera of 67.1% of these patients. The prevalence of these antibodies was significantly higher in patients who had undergone multiple attacks of malaria than in those who were experiencing their first attack at the time of serum collection. Although circulating gametocytes mere detected in 22% of the patients at this time, there was no difference in the percentages of IFAT positivity between apparent gametocyte 'carriers' and 'non-carriers'. All sera were also tested by ELISA, using a dimer of the nonamer peptide [PEE(L/V)VEEV(I/V)](2), which represents a tandem consensus repeat of the P. falciparum gametocyte antigen, Pfs2400, a target of transmission-blocking antibodies. ELISA demonstrated that 32.9% of the patients had antibodies that reacted with this peptide. Positive ELISA reactions were significantly more frequent amongst the sera of patients who had had multiple malaria attacks than in those undergoing their first malaria episode; positivity was lower in the gametocyte 'carriers' than in their 'non-carriers'. These results demonstrate that anti-gametocyte antibodies, which have already been shown to have potential transmission-blocking activity, are naturally elicited in Brazilian patients, the highest rates of seropositivity occurring alter multiple malaria attacks
— id: 53102, year: 1995, vol: 89, page: 593, stat: Journal Article,

The use of multiple antigen peptides in the analysis and induction of protective immune responses against infectious diseases
Nardin EH; Oliveira GA; Calvo-Calle JM; Nussenzweig RS
1995 ;60:105-149, Advances in immunology
— id: 7025, year: 1995, vol: 60, page: 105, stat: Journal Article,

Development of antimalaria immunity in mice lacking IFN-gamma receptor
Tsuji M; Miyahira Y; Nussenzweig RS; Aguet M; Reichel M; Zavala F
1995 May 15;154(10):5338-5344, Journal of immunology
IFN-gamma receptor deficient (IFN-gamma R-/-) mice, immunized with different developmental stages of malaria parasites, were used to define the mechanisms of protection against the various stages of this infection. IFN-gamma R-/- mice failed to develop protective immunity against Plasmodium yoelii sporozoites or liver stages, upon immunization with a single dose of irradiated sporozoites, whereas in immunized wild-type mice, parasite development was strongly inhibited. Immunized wild-type mice expressed high levels of inducible nitric oxide synthase (iNOS) mRNA in their liver, upon challenge with viable sporozoites, whereas only background levels of iNOS were detected in immunized IFN-gamma R-/- mice. In contrast, after immunization with multiple doses of irradiated sporozoites, both IFN-gamma R-/- and wild-type mice mounted an immune response, which strongly inhibited the development of liver stage parasites. In both types of mice, protection occurred in the absence of appreciable expression of liver iNOS mRNA. As for the course of the erythrocytic phase of infection by nonlethal malaria species, P. yoelii yoelii and P. chabaudi adami, we observed only a moderately prolonged parasitemia in IFN-gamma R-/- mice compared with wild-type mice, indicating that IFN-gamma may only play a modest role in immunity against erythrocytic stages. These results indicate that IFN-gamma is the main mediator of the protective mechanism that develops first upon immunization with sporozoites. However, the nature of the anti-parasite mechanism(s) changes in the course of immunization, so that multiple immunizing doses elicit additional protective mechanisms, which are independent of IFN-gamma and its receptor
— id: 12771, year: 1995, vol: 154, page: 5338, stat: Journal Article,

Immunogenicity of an alum-adsorbed synthetic multiple-antigen peptide based on B- and T-cell epitopes of the Plasmodium falciparum CS protein: possible vaccine application
de Oliveira GA; Clavijo P; Nussenzweig RS; Nardin EH
1994 Aug;12(11):1012-1017, Vaccine
Multiple-antigen peptides (MAPs), containing B- and T-cell epitopes of the Plasmodium falciparum circumsporozoite (CS) protein, have been designed to overcome the limitations of first-generation peptide vaccines caused by low epitope density, carrier toxicity and the lack of parasite-derived T-cell epitopes. The immunogenicity of a P. falciparum MAP construct (T1B4), containing four copies of the 5' repeat cell T epitope (T1) combined with the 3' repeat epitope (NANP)3, has been examined using different adjuvant formulations. Mice immunized intraperitoneally or subcutaneously with (T1B)4 in alum, a formulation suitable for human vaccines, developed high anti-peptide and anti-sporozoite antibody titres, comparable with those obtained with Freund's adjuvant. The MAP/alum formulation also elicited a strong anamnestic antibody response in sporozoite-primed mice, raising the possibility of using a MAP/alum vaccine to increase the low anti-sporozoite antibody levels of people living in malaria-endemic areas
— id: 12940, year: 1994, vol: 12, page: 1012, stat: Journal Article,

Malaria vaccines: multiple targets
Nussenzweig RS; Long CA
1994 Sep 2;265(5177):1381-1383, Science
— id: 12892, year: 1994, vol: 265, page: 1381, stat: Journal Article,

AN OVERVIEW
NUSSENZWEIG, R
1994 JAN 15 ;145(6):491-491, Research in immunology
— id: 87466, year: 1994, vol: 145, page: 491, stat: Journal Article,

Influenza and vaccinia viruses expressing malaria CD8+ T and B cell epitopes. Comparison of their immunogenicity and capacity to induce protective immunity
Rodrigues M; Li S; Murata K; Rodriguez D; Rodriguez JR; Bacik I; Bennink JR; Yewdell JW; Garcia-Sastre A; Nussenzweig RS; et al
1994 Nov 15;153(10):4636-4648, Journal of immunology
We compared the effectiveness of several recombinant influenza and vaccinia viruses to induce a malaria-specific immune response. The CD8+ T cell epitope of the circumsporozoite (CS) protein of Plasmodium yoelii, a rodent malaria parasite, was expressed in two distinct influenza virus proteins, the hemagglutinin and the neuraminidase. These recombinant viruses were found to be equally efficient at inducing CS-specific CD8+ T cells in mice. A third recombinant virus, which expresses a B cell epitope of the CS protein, induced neutralizing anti-sporozoite Abs. Expression in the same recombinant virus of the CD8+ T cell epitope and of the B cell epitope did not impair the capacity of this recombinant virus to induce malaria-specific CD8+ T cells and neutralizing Abs. The immunogenicity of a vaccinia virus, expressing the entire CS protein, was compared with that of a highly attenuated vaccinia strain expressing the same protein and with that of another vaccinia virus expressing only the CD8+ T cell epitope. All three vaccinia virus recombinants elicited CS-specific CD8+ cells and a potent inhibitory response against pre-erythrocytic stages of malaria parasites. Optimal levels of anti-sporozoite Abs, inhibition of liver stage development, and protection against malaria infection resulted from repeatedly immunizing the animals with recombinant influenza viruses followed by boosters with a recombinant vaccinia virus. These findings support the concept that live viral vectors expressing the appropriate proteins and/or epitopes can be used as promising vaccine candidates
— id: 12863, year: 1994, vol: 153, page: 4636, stat: Journal Article,

Demonstration of heat-shock protein 70 in the sporozoite stage of malaria parasites
Tsuji M; Mattei D; Nussenzweig RS; Eichinger D; Zavala F
1994 ;80(1):16-21, Parasitology research
Three monoclonal antibodies generated by immunization of mice with Plasmodium berghei-infected red blood cells were found to react with the 75-kDa heat-shock protein (HSP70) present in liver stages and erythrocytic forms of the parasites. These antibodies were shown to react with a recombinant protein encoding the carboxyl terminal half of PfHSP70 (aa 365-681). Differently from earlier results, we clearly demonstrated that HSP70 was also expressed in the sporozoite stage, using these monoclonal antibodies in an immunofluorescence and Western immunoblot assay. These monoclonal antibodies react not only with sporozoites of P. berghei, the parasites originally used for the immunization, but also with sporozoites of several other rodent and human plasmodial species. Passive transfer of these monoclonal antibodies into naive mice, simultaneously injected with sporozoites, failed to neutralize the infectivity of P. berghei sporozoites and to inhibit the development of liver stages of P. yoelii
— id: 13020, year: 1994, vol: 80, page: 16, stat: Journal Article,

Gamma delta T cells contribute to immunity against the liver stages of malaria in alpha beta T-cell-deficient mice
Tsuji M; Mombaerts P; Lefrancois L; Nussenzweig RS; Zavala F; Tonegawa S
1994 Jan 4;91(1):345-349, Proceedings of the National Academy of Sciences of the United States of America
The functional role of gamma delta T cells (expressing the gamma delta heterodimeric T-cell receptor for antigen) in infectious diseases remains largely unknown. We have therefore attempted to define the possible role of these T cells in the immune response against the various developmental stages of malaria parasites. For this purpose, we monitored the immune response and the development of liver and blood stages of Plasmodium yoelii, a rodent malaria parasite, in immunized and nonimmunized alpha beta T-cell-deficient and gamma delta T-cell-deficient mice. Immunization of alpha beta T-cell-deficient mice with irradiated sporozoites induced an immune response that significantly inhibited the development of the parasite's liver stages. This inhibitory immune response was abolished by an antibody-mediated transient in vivo depletion of gamma delta T cells. Two gamma delta T-cell clones were derived from malaria-immunized alpha beta T-cell-deficient mice. The adoptive transfer of one of these gamma delta T-cell clones to normal mice inhibited the development of liver stages, following sporozoite inoculation. These results provide evidence for gamma delta T-cell-mediated protective immunity against parasites, in the absence of alpha beta T cells. As for the blood phase of the infection, both normal mice and gamma delta T-cell-deficient mice cleared the blood stages of the nonlethal strain of P. yoelii, while alpha beta T-cell-deficient mice failed to control the parasitemia
— id: 13004, year: 1994, vol: 91, page: 345, stat: Journal Article,

ANOPHELINES IN THE STATE OF ACRE, BRAZIL, INFECTED WITH PLASMODIUM-FALCIPARUM, PLASMODIUM-VIVAX, THE VARIANT PLASMODIUM-VIVAX VK247 AND P-MALARIAE
BRANQUINHO, MS; LAGOS, CBT; ROCHA, RM; NATAL, D; BARATA, JMS; COCHRANE, AH; NARDIN, E; NUSSENZWEIG, RS; KLOETZEL, JK
1993 JUL-AUG ;87(4):391-394, Transactions of the Royal Society of Tropical Medicine & Hygiene
Anophelines collected indoors and in the peri-domiciliary area in 3 localities in the Amazon region, state of Acre, Brazil, from August 1990 to January 1991 were examined by enzyme-linked immunosorbent assay (ELISA) using specific monoclonal antibodies directed against the repeats of the circumsporozoite proteins of Plasmodium falciparum, P. vivax, P. vivax V247, and P. malariae. Of the 3056 specimens collected, 2610 were Anopheles oswaldoi, 362 A. deaneorum, 60 A. triannulatus and 24 were A. darlingi. The infection rates of A. oswaldoi were 3-41% for P. falciparum, 2.26% for P. vivax, 1.22 for P. vivax VK247, and 0-42% for P. malariae. For A. deaneorum, the infection rates were 2.76% for P. falciparum, 0.55% for P. vivax, and 0-82% for P. vivax VK247. All samples of the other 2 species collected (A. triannulatus and A. darlingi) were negative in the ELISA. There were certain differences in the anopheline distribution and infection rates between these localities, and in one only A . oswaldoi was found to be infected. These results strongly point to A. oswaldoi as the main malaria vector in the region. No difference was found between the potential vectors of P. vivax and P. vivax VK247. The significance of these findings for malaria control is discussed
— id: 52230, year: 1993, vol: 87, page: 391, stat: Journal Article,

Immunogenicity of multiple antigen peptides containing B and non-repeat T cell epitopes of the circumsporozoite protein of Plasmodium falciparum
Calvo-Calle JM; de Oliveira GA; Clavijo P; Maracic M; Tam JP; Lu YA; Nardin EH; Nussenzweig RS; Cochrane AH
1993 Feb 15;150(4):1403-1412, Journal of immunology
We have characterized the immune response of mice to multiple Ag peptide systems (MAP) containing the immunodominant B cell epitope (NANP)3 and one of three distinct Th epitopes, Th2R, Th3R, and CS.T3, of the C terminal region of the circumsporozoite protein of Plasmodium falciparum, a human malaria parasite. Mice of three different MHC haplotypes (H-2k, H-2d, and H-2a) were immunized with the various MAP constructs. Mice of all three strains produced antibodies, but their anti-sporozoite titers were considerably lower than their anti-peptide titers as detected by ELISA. These antibodies reacted at high titers not only with the repeat polymer (NANP)50, but also with MAP that contained only the respective Th sequence. The antibody binding site within each of the Th sequences was mapped, using truncated peptides, in an inhibition assay. A primary antibody response, induced by a single i.v. inoculation of sporozoites, was greatly enhanced by the injection of MAP
— id: 13249, year: 1993, vol: 150, page: 1403, stat: Journal Article,

Pfs2400 can mediate antibody-dependent malaria transmission inhibition and may be the Plasmodium falciparum 11.1 gene product
Feng Z; Hoffmann RN; Nussenzweig RS; Tsuji M; Fujioka H; Aikawa M; Lensen TH; Ponnudurai T; Pologe LG
1993 Feb 1;177(2):273-281, Journal of experimental medicine
Monoclonal antibodies (mAb) have been raised against Plasmodium falciparum gametocyte stage protein extracts, in an effort to identify novel parasite antigens that might mediate malaria transmission-blocking immunity. mAb 1A1 identified Pfs2400, a sexual stage-specific antigen of greater than 2 megadaltons, that is associated with the outer leaflet of the parasitophorous vacuole membrane in mature circulating gametocyte-infected red blood cells. Upon induction of gametogenesis, Pfs2400 partitions between the gamete plasmalemma and the degenerating erythrocyte membrane. The antigen is no longer detectable in the fully emerged gamete. mAb 1A1 dramatically reduces the number of oocysts formed in P. falciparum gametocyte-fed mosquitoes. The cognate antigen is probably the product of the Pf11.1 gene (Scherf et al. 1988. EMBO [Eur. Mol. Biol. Organ.]J. 7:1129) on the basis that a peptide composed of two copies of the degenerate nine amino acid repeat sequence in the Pf11.1 protein, can inhibit binding of mAb1A1 to the native antigen. The mechanism of transmission inhibition mediated by the Pfs2400 is discussed
— id: 13272, year: 1993, vol: 177, page: 273, stat: Journal Article,

Priming with recombinant influenza virus followed by administration of recombinant vaccinia virus induces CD8+ T-cell-mediated protective immunity against malaria
Li S; Rodrigues M; Rodriguez D; Rodriguez JR; Esteban M; Palese P; Nussenzweig RS; Zavala F
1993 Jun 1;90(11):5214-5218, Proceedings of the National Academy of Sciences of the United States of America
Live vectors expressing foreign antigens have been used to induce immunity against several pathogens. However, for the virulent rodent malaria parasite Plasmodium yoelii, the use of recombinant vaccinia virus, pseudorabies virus, or Salmonella, expressing the circumsporozoite protein of this parasite, failed to induce protection. We generated a recombinant influenza virus expressing an epitope from the circumsporozoite protein of P. yoelii known to be recognized by CD8+ T cells and demonstrated that this vector induced class I major histocompatibility complex-restricted cytotoxic T cells against this foreign epitope. Immunization of mice with this recombinant influenza virus, followed by a recombinant vaccinia virus expressing the entire circumsporozoite protein, induced protective immunity against sporozoite-induced malaria. The sequence of immunization appears to be crucial, since a primer injection with recombinant vaccinia virus, followed by a booster injection with recombinant influenza virus, failed to induce protection. The protection induced by immunization with these recombinant viruses is mostly mediated by CD8+ T cells, as treatment of mice with anti-CD8 monoclonal antibody abolishes the anti-malarial immunity. The use of different live vectors for primer and booster injections has a synergistic effect on the immune response and might represent an effective general strategy for eliciting protective immune responses to key antigens of microbial pathogens
— id: 23515, year: 1993, vol: 90, page: 5214, stat: Journal Article,

T cell responses to pre-erythrocytic stages of malaria: role in protection and vaccine development against pre-erythrocytic stages
Nardin EH; Nussenzweig RS
1993 ;11:687-727, Annual review of immunology
Malaria remains a leading cause of human morbidity and mortality due to the inability of insecticides and chemotherapy/chemoprophylaxis to eliminate the vectors or disease caused by this protozoan parasite. In an effort to develop new methods of control, vaccines targeted to the various stages of the complex life cycle of Plasmodium have been developed. This review describes recent advances in the elucidation of cell-mediated immune mechanisms directed against sporozoites and liver stages of malaria parasites, their role in protection, and their relation to vaccine development. Recent data on the molecular basis of sporozoite-liver cell interaction are presented, and these may provide new approaches for chemoprophylaxis and immunoprophylaxis. We describe the role of the circumsporozoite protein, the major sporozoite surface antigen, in sporozoite movement and as a target of humoral immunity. The recognition of the circumsporozoite protein by human T cells is reviewed with emphasis on cytotoxic T cells and immune resistance against the exo-erythrocytic stage of the parasite. Earlier concepts regarding the polymorphisms of the circumsporozoite protein, the immunological relevance of this polymorphism, and predictions regarding vaccine development are reevaluated on the basis of recent data from different malaria endemic areas. Non-CS sporozoite antigens and liver stage antigens are discussed as potential targets for immune intervention. Recent experimental approaches such as multiple antigen peptides, recombinant live vectors, and new more potent adjuvants are considered for the development of more effective malaria vaccine formulations
— id: 8410, year: 1993, vol: 11, page: 687, stat: Journal Article,

The relative contribution of antibodies, CD4+ and CD8+ T cells to sporozoite-induced protection against malaria
Rodrigues M; Nussenzweig RS; Zavala F
1993 Sep;80(1):1-5, Immunology
Protective immunity against Plasmodium yoelii, induced by sporozoite immunization, was investigated using a quantitative method based on the measurement of plasmodial ribosomal RNA in the liver of sporozoite-challenged mice. The relative importance of the different immune mechanisms induced by sporozoite immunization was determined by evaluating quantitatively the anti-parasite activity of antibodies, CD4+ and CD8+ T cells. The role of antibodies was determined by passive transfer of immune sera to naive mice. The transfer to mice of sera obtained after a single immunizing dose reduced the liver stages by 47%. The respective contribution of CD4+ and CD8+ T-cell subsets was determined in B10 (H-2b) mice, treated with a monoclonal antibody (mAb) which inhibits B-cell maturation, and subsequently immunized once with irradiated sporozoites. These mice produced low levels of anti-sporozoite antibodies, but were capable of inhibiting the development of liver stages as efficiently as non-manipulated immunized mice. Administration of either anti-CD4 or anti-CD8 mAb to these mice, did not significantly decrease their capacity to inhibit the development of liver stages. We only observed a significant loss of immunity when the mice were depleted in vivo of both CD4+ and CD8+ T cells. In contrast to earlier studies, we found that the induction of protective immunity is not a phenomenon restricted to a few strains of mice having a particular genetic make-up. The apparent non-responsiveness observed in some strains of mice can be overcome by using larger immunizing doses
— id: 13087, year: 1993, vol: 80, page: 1, stat: Journal Article,

Recognition of different domains of the Plasmodium falciparum CS protein by the sera of naturally infected individuals compared with those of sporozoite-immunized volunteers
Calle JM; Nardin EH; Clavijo P; Boudin C; Stuber D; Takacs B; Nussenzweig RS; Cochrane AH
1992 Oct 15;149(8):2695-2701, Journal of immunology
The fine specificities of antibodies to the circumsporozoite (CS) protein of Plasmodium falciparum, present in the sera of volunteers immunized with irradiated P. falciparum sporozoites, were defined and compared to those of sera from persons living in a malaria-endemic area in West Africa. The specificity of these anti-CS antibodies was determined by ELISA, using recombinant proteins and synthetic peptides containing repeat and nonrepeat sequences of this CS protein. All 10 serum samples of the five sporozoite-immunized volunteers displayed very high antibody titers to the immunodominant repeat (NANP)n of the CS protein. However, only three of the serum samples of these vaccinees reacted with a single nonrepeat region and only at low titers. In contrast, a high percentage of sera from adults living in the malaria-endemic area who had been exposed to sporozoites, as well as liver and blood stages of P. falciparum, had high antibody levels, not only to the repeats but also to several nonrepeat regions of the CS protein. Furthermore, a number of sera from children living in this endemic area displayed appreciable levels of antibodies to the nonrepeat regions, in the absence of any antirepeat reactivity. Sera of Saimiri monkeys, which had undergone multiple blood-induced P. falciparum infections, consistently contained high titers of antibodies to several nonrepeat sequences of the CS protein, whereas only a few of these sera had low titers of antirepeat antibodies. Antibody binding sites, in nonrepeat regions, were mapped using synthetic polymers containing multiple copies of selected C-terminal sequences of the P. falciparum CS protein. The binding to sporozoites of antibodies to nonrepeat regions of the CS protein was determined. The basis for the differences in antibody binding sites of sera from persons immunized with irradiated sporozoites, compared to those from an endemic area, is discussed
— id: 13395, year: 1992, vol: 149, page: 2695, stat: Journal Article,

PREVALENCE AND LEVEL OF ANTIBODIES TO THE CIRCUMSPOROZOITE PROTEINS OF HUMAN MALARIA PARASITES, INCLUDING A VARIANT OF PLASMODIUM-VIVAX, IN THE POPULATION OF 2 EPIDEMIOLOGICALLY DISTINCT AREAS IN THE STATE OF ACRE, BRAZIL
KREMSNER, PG; NEIFER, S; ZOTTER, GM; BIENZLE, U; ROCHA, RM; MARACIC, M; CLAVIJO, P; NUSSENZWEIG, RS; COCHRANE, AH
1992 JAN-FEB ;86(1):23-27, Transactions of the Royal Society of Tropical Medicine & Hygiene
A seroepidemiological study of the prevalence of antibodies against the repeating epitopes of circumsporozoite (CS) proteins of human malaria parasites was conducted in 2 different areas in the state of Acre, Brazil in 1987 and 1990. In 1987 antibodies against the CS protein of the VK 247 variant Plasmodium vivax as well as antibodies against the CS proteins of P. falciparum and the classic P. vivax were found at relatively high rates in the 2 areas, but significant microepidemiological differences were observed. In 1990, when large scale migration in Amazonia had ceased and control measures were applied in the study areas, the malaria endemicity decreased, as determined by the declining prevalence of anti-sporozoite antibodies against all Plasmodium species, and the small number of individuals with positive blood smears. Antibodies against sporozoites of the variant P. vivax did not cross-react with the CS proteins of the classic P. vivax, nor with antibodies against sporozoites of P. falciparum and P. malariae. Sera containing antibodies against the CS protein of P. malariae were found at a very low frequency, and only in 1987. The anti-CS protein antibody response to all Plasmodium species was age-related
— id: 52072, year: 1992, vol: 86, page: 23, stat: Journal Article,

T cell responses to repeat and non-repeat regions of the circumsporozoite protein detected in volunteers immunized with Plasmodium falciparum sporozoites
Nardin E; Munesinghe YD; Moreno A; Clavijo P; Calle MC; Edelman R; Davis J; Herrington D; Nussenzweig RS
1992 ;87 Suppl 3:223-227, Memorias do Instituto Oswaldo Cruz
The design of a malarial vaccine based on the circumsporozoite (CS) protein, a major surface antigen of the sporozoite stage of the malaria parasite, requires the identification of T and B cell epitopes for inclusion in recombinant or synthetic vaccine candidates. We have investigated the specificity and function of a series of T cell clones, derived from volunteers immunized with Plasmodium falciparum sporozoites, in an effort to identify relevant epitopes in the immune response to the pre-erythrocytic stages of the parasite. CD4+ T cell clones were obtained which specifically recognized a repetitive epitope located in the 5' repeat region of the CS protein. This epitope, when conjugated to the 3' repeat region in a synthetic MAPs construct, induced high titers of antisporozoite antibodies in C57BL mice. A second T cell epitope, which mapped to aa 326-345 of the carboxy terminal, was recognized by lytic, as well as non-lytic, CD4+ T cells derived from the sporozoite-immunized volunteers. The demonstration of CD4+ CTL in the human volunteers, and the recent studies in the rodent model (Renia et al., 1991; Tsuji et al., 1990), suggest that CS-specific CD4+ T cells, in addition to their indirect role as helper cells in the induction of antibody and CD8+ effector cells, may also play a direct role in protection against sporozoite challenge by targeting EEF within the liver
— id: 6465, year: 1992, vol: 87 Suppl 3, page: 223, stat: Journal Article,

The in vivo cytotoxic activity of CD8+ T cell clones correlates with their levels of expression of adhesion molecules
Rodrigues M; Nussenzweig RS; Romero P; Zavala F
1992 Apr 1;175(4):895-905, Journal of experimental medicine
CD8+ T cell clones specific for a defined epitope present in the circumsporozoite protein of Plasmodium yoelii display striking differences in their in vivo antiplasmodial activity. The adoptive transfer of certain clones (YA23 and YA26) into naive mice inhibits by 90% or more the development of liver stages of malaria parasites and protects against malaria infection. The adoptive transfer of two other T cell clones (YB8 and YA15) results, respectively, in partial or no inhibitory activity on parasite development. We found that 'protective' and 'nonprotective' cytotoxic T lymphocyte (CTL) clones do not differ in their fine epitope specificity and display similar levels of lysis and DNA degradation of target cells in vitro. Their pattern of production of lymphokines and granule-associated proteins also failed to correlate with their in vivo antiplasmodial activity. Histological studies combined with autoradiography showed that, upon adoptive transfer, only T cells from the protective CTL clones are capable of 'associating' with a significant percentage of parasitized hepatocytes. Fluorescence-activated cell sorter analysis of surface molecules revealed pronounced differences in the levels of CD44 and VLA-4 expression by the different clones, correlating closely with their in vivo protective activity. The correlation between in vivo antiparasite activity and the expression of CD44 was further corroborated by the results of sorting, from the partially protective YB8 clone, two sub-populations expressing high and low levels of CD44. These were protective and nonprotective, respectively. The clones also differed in their adhesive properties. Cross-linking of CD44, using specific antibodies, induced LFA-1-mediated homotypic aggregation of protective clones, while nonprotective cells failed to aggregate
— id: 13651, year: 1992, vol: 175, page: 895, stat: Journal Article,

ROLE OF ANOPHELES-CULICIFACIES SIBLING SPECIES IN MALARIA TRANSMISSION IN MADHYA-PRADESH STATE, INDIA
SUBBARAO, SK; VASANTHA, K; JOSHI, H; RAGHAVENDRA, K; DEVI, CU; SATHYANARAYAN, TS; COCHRANE, AH; NUSSENZWEIG, RS; SHARMA, VP
1992 NOV-DEC ;86(6):613-614, Transactions of the Royal Society of Tropical Medicine & Hygiene
— id: 54402, year: 1992, vol: 86, page: 613, stat: Journal Article,

SUCCESSFUL IMMUNIZATION OF HUMANS WITH IRRADIATED MALARIA SPOROZOITES - HUMORAL AND CELLULAR-RESPONSES OF THE PROTECTED INDIVIDUALS
Herrington, D; Davis, J; Nardin, E; Beier, M; Cortese, J; Eddy, H; Losonsky, G; Hollingdale, M; Sztein, M; Levine, M; Nussenzweig, RS; Clyde, D; Edelman, R
1991 Nov;45(5):539-547, American journal of tropical medicine & hygiene
Two groups of volunteers were vaccinated by repeated exposure to the bites of Plasmodium falciparum-infected, x-irradiated mosquitoes in order to characterize the humoral and cellular immune responses of sporozoite-immunized, protected individuals. One of the two volunteers in the first immunization trial, when challenged by the bile of P. falciparum-infected mosquitoes, developed an infection only after a prolonged prepatent period. A second group of three volunteers who were exposed more frequently to larger numbers of infected mosquitoes irradiated with a lower x-ray dose was completely protected against sporozoite challenge. These individuals and the volunteer with delayed infection had high levels of antibodies to sporozoites and to the repeat region of the circumsporozoite (CS) protein. The CS-specific cellular immune responses of these volunteers were also stimulated by sporozoite immunization, as determined by proliferation of peripheral blood mononuclear cells (PBMC) and mitogen or antigen-expanded PBMC, in response to in vitro challenge with a recombinant P. falciparum CS protein. Based upon the assays used in this study, it is not possible to reach conclusions regarding specific immunologic responses and protection from sporozoite challenge
— id: 32204, year: 1991, vol: 45, page: 539, 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,

INHIBITORY ACTIVITY AGAINST PLASMODIUM-VIVAX SPOROZOITES INDUCED BY PLASMA FROM SAIMIRI MONKEYS IMMUNIZED WITH CIRCUMSPOROZOITE RECOMBINANT PROTEINS OR IRRADIATED SPOROZOITES
Millet, P; Collins, WE; Broderson, JR; Bathurst, I; Nardin, EH; Nussenzweig, RS
1991 Jul;45(1):44-48, American journal of tropical medicine & hygiene
Two Saimiri monkey vaccine trials have been conducted comparing four recombinant Plasmodium vivax circumsporozoite proteins and irradiated sporozoites. Only a small number of animals immunized with certain recombinants or irradiated sporozoites became fully protected against sporozoite challenge. Preimmunization and postimmunization plasma samples obtained from 30 monkeys on the day of challenge were tested in an in vitro assay based on sporozoite development into exoerythrocytic stages in primary cultures of Saimiri monkey hepatocytes. The percentage of inhibition was determined by comparison of the number of exoerythrocytic stages developing from sporozoites preincubated with a preimmunization and a postimmunization plasma sample of each animal. The plasma samples of the day of challenge of nearly all the immunized animals had a variable, but significant inhibitory effect, when compared with the corresponding preimmunization sample. We found no correlation between the degree of in vitro inhibition of liver stage development, and the in vivo protection against sporozoite challenge of individual animals. The variable results of the incubation of sporozoites with 'normal' plasma of different animals indicates that the in vitro results were affected by plasma factors unrelated to anti-sporozoite antibodies
— id: 32208, year: 1991, vol: 45, page: 44, stat: Journal Article,

Immunogenicity of multiple antigen peptides (MAP) containing T and B cell epitopes of the repeat region of the P. falciparum circumsporozoite protein
Munesinghe DY; Clavijo P; Calle MC; Nussenzweig RS; Nardin E
1991 Dec;21(12):3015-3020, European journal of immunology
The immunogenicity of multiple antigen peptides (MAP) constructs containing T and B cell epitopes of the repeat region of the P. falciparum circumsporozoite (CS) protein was examined in vitro, using a human T cell clone, and in vivo, using four different strains of mice. All the MAP constructs that contained the T cell epitope, (DPNANPNVDPNANPNV), stimulated proliferation and interferon-gamma production by a human T cell clone specific for this epitope which is located in the 5' end of the repeat region of the P. falciparum CS protein. These human T cells did not recognize MAP that contained only the B cell epitope, (NANP)3, which is located in the 3' repeat region. Optimal antibody responses were obtained in mice immunized with MAP containing four copies of tandemly arranged T and B cell epitopes, (TB)4. The murine immune response to the MAP constructs was genetically restricted. Mice of a high responder strain, C57BL, recognized both the 5' and 3' repeat sequences in the MAP as T, as well as B, cell epitopes and developed very high anti-MAP and anti-sporozoite antibody titers. A/J and C3H mice, which were intermediate responders, developed lower antibody titers which varied according to the orientation of the T vs. the B cell epitopes within the MAP constructs. BALB/c mice were nonresponders and did not develop antibodies following immunization with any of the MAP constructs containing the 5' and 3' repeats of the P. falciparum CS protein
— id: 65750, year: 1991, vol: 21, page: 3015, stat: Journal Article,

T cell epitopes of the circumsporozoite protein of Plasmodium vivax. Recognition by lymphocytes of a sporozoite-immunized chimpanzee
Nardin E; Clavijo P; Mons B; van Belkum A; Ponnudurai T; Nussenzweig RS
1991 Mar 1;146(5):1674-1678, Journal of immunology
The humoral and cellular antisporozoite immune responses of a laboratory-born chimpanzee were measured following multiple exposures to the bites of Plasmodium vivax-infected mosquitoes. T cell lines and clones derived from the chimpanzee's PBL were used to identify T cell epitopes of the P. vivax circumsporozoite (CS) protein. Two independently obtained cell lines, established by culturing the PBL with either a recombinant P. vivax circumsporozoite (rPvCS) protein or a pool of synthetic peptides spanning the rPvCS sequence, recognized a 20-mer peptide from a nonpolymorphic region of the carboxyl terminus of the CS protein. This peptide overlaps a sequence homologous to region II of the Plasmodium falciparum CS protein. A third T cell line recognized an epitope within the central repeat domain, which has recently been found to be a polymorphic region of the P. vivax CS protein. The CD4+ clones derived from this third T cell line secreted IFN-gamma and IL-2 when stimulated with either the P. vivax repeat peptide (DRAAGQPAG)2 or the rPvCS protein
— id: 14126, year: 1991, vol: 146, page: 1674, stat: Journal Article,

CD8+ cytolytic T cell clones derived against the Plasmodium yoelii circumsporozoite protein protect against malaria
Rodrigues MM; Cordey AS; Arreaza G; Corradin G; Romero P; Maryanski JL; Nussenzweig RS; Zavala F
1991 Jun;3(6):579-585, International immunology
Immunization of BALB/c mice with radiation-attenuated Plasmodium yoelii sporozoites induces cytotoxic T lymphocytes (CTL) specific for an epitope located within the amino acid sequence 277-288 of the P. yoelii circumsporozoite (CS) protein. Several CD8+ CTL clones were derived from the spleen cells of sporozoite-immunized mice, all displaying an apparently identical epitope specificity. All the clones induced high levels of cytolysis in vitro upon exposure to peptide-incubated MHC-compatible target cells. The adoptive transfer of two of these clones conferred complete protection against sporozoite challenge to naive mice. This protection is species and stage specific. Using P. yoelii specific ribosomal RNA probes to monitor the in vivo effects of the CTL clones, we found that their target was the intrahepatocytic stage of the parasite. The protective clones completely inhibited the development of the liver stages of P. yoelii. Some CTL clones were only partially inhibitory in vivo, while others failed completely to alter liver stage development and to confer any detectable degree of protection. The elucidation of the effector mechanism of this CTL mediated protection against rodent malaria should facilitate the design of an effective malaria vaccine. From a broader perspective this model may provide further insight into the mechanism(s) of CTL mediated killing of intracellular non-viral pathogens in general
— id: 14014, year: 1991, vol: 3, page: 579, stat: Journal Article,

Widespread reactivity of human sera with a variant repeat of the circumsporozoite protein of Plasmodium vivax
Cochrane AH; Nardin EH; de Arruda M; Maracic M; Clavijo P; Collins WE; Nussenzweig RS
1990 Nov;43(5):446-451, American journal of tropical medicine & hygiene
A panel of Brazilian and Indian sera was screened for reactivity with a variant strain of Plasmodium vivax recently isolated in Thailand. This strain has been shown to have a unique repeat region which differs from the previously described P. vivax CS proteins. A total of 21/343 human sera were found to react with a synthetic peptide representing the variant P. vivax repeat. All of the sera that reacted with the variant repeat peptide, (ANGAGNQPG)4, also reacted with variant P. vivax sporozoites. Both the anti-peptide and the antisporozoite reactivity were totally abolished by adsorption with the variant peptide. Some of the human sera contained variant antibodies that were species specific and could only be adsorbed with the specific variant peptide. These findings suggest that the variant strain of P. vivax might have a worldwide distribution. We also found that some of the variant positive sera reacted with P. brasilianum sporozoites and with the P. brasilianum/P. malariae CS repeat. The adsorption of these sera with the P. brasilianum/P. malariae repeat peptide, (NAAG)4, significantly reduced the reactivity of these sera with the P. vivax variant. In addition, polyclonal and monoclonal antibodies of mice immunized with P. brasilianum sporozoites cross-reacted with the variant P. vivax CS. These findings suggest that exposure to P. brasilianum or P. malariae may give rise to sporozoite antibodies which cross-react with the P. vivax variant CS
— id: 14301, year: 1990, vol: 43, page: 446, stat: Journal Article,

PRESENCE OF A CIRCUMSPOROZOITE-LIKE PROTEIN IN MICRONEMES OF BLOOD-STAGE MEROZOITES OF MALARIA PARASITES
Cochrane, AH; Uni, S; Maracic, M; Digiovanni, L; Aikawa, M; Nussenzweig, RS
1990 Mar;68(1):181-183, Bulletin of the World Health Organization
We demonstrate for the first time the presence of a circumsporozoite (CS)-like protein in invasive blood stages of malaria parasites. Immunogold electron microscopy using antisporozoite monoclonal antibodies localized these antigens in the micronemes of merozoites. Western immunoblot and two- dimensional gel electrophoresis of mature blood-stage extracts of Plasmodium falciparum, P. berghei, P. cynomolgi, and P. brasilianum identified polypeptides having the same apparent molecular mass and isoelectric points as the corresponding sporozoite (CS) proteins. The CS-like protein of merozoites is present in relatively minor amounts, compared to the CS protein of sporozoites. Mice with long-term P. berghei blood-induced infections develop antibodies which react with sporozoites
— id: 32219, year: 1990, vol: 68, page: 181, stat: Journal Article,

FURTHER-STUDIES ON THE IMMUNIZATION OF SAIMIRI-SCIUREUS- BOLIVIENSIS WITH RECOMBINANT VACCINES BASED ON THE CIRCUMSPOROZOITE PROTEIN OF PLASMODIUM-VIVAX
Collins, WE; Nussenzweig, RS; Ruebush, TK; Bathurst, IC; Nardin, EH; Gibson, HL; Campbell, GH; Barr, PJ; Broderson, JR; Skinner, JC; Filipski, VK; Stanfill, PS; Roberts, JM; Wilson, CL
1990 Dec;43(6):576-583, American journal of tropical medicine & hygiene
Reported are the results of a trial in squirrel monkeys of 2 Plasmodium vivax malaria vaccine candidates based on the circumsporozoite (CS) protein, namely, rPvCs-2 and rPvCS-3. Compared with an earlier recombinant P. vivax CS construct, rPvCS-1 rPvCS-2 has an additional 24 amino acids at the C- terminal, which includes the thrombospondin region of homology and a putative T cell epitope. The rPvCS-3 was generated from a chemically synthesized gene that contained an additional 54 amino acids at the amino terminus and terminates at the same carboxy-terminal amino acid as rPvCS-2. In addition, rPvCS-3 contained only 1 each of the repeat sequences DRADGQPAG and DRAAGQPAG. Both antigens were administered with alum as adjuvant. Neither formulation caused toxic side effects and both recombinant molecules induced high antibody titers. Two monkeys were protected against sporozoite challenge by immunization with rPvCS-2 antigen, while none of the rPvCS-3 immunized animals displayed any degree of protection. While there was no correlation between protection and antibody titer or the in vitro proliferation of lymphocytes in response to the antigens, this is further evidence to support the role of the repeating epitopes in generating protective immunity
— id: 32197, year: 1990, vol: 43, page: 576, 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,

CELLULAR AND HUMORAL IMMUNE-RESPONSES TO A RECOMBINANT PLASMODIUM-FALCIPARUM CS PROTEIN IN SPOROZOITE-IMMUNIZED RODENTS AND HUMAN VOLUNTEERS
Nardin, EH; Nussenzweig, RS; Altszuler, R; Herrington, D; Levine, M; Murphy, J; Davis, J; Bathurst, I; Barr, P; Romero, P; Zavala, F
1990 Mar;68(1):85-87, Bulletin of the World Health Organization
The immune responses of sporozoite-immunized rodents and of human volunteers exposed to multiple bites of irradiated Plasmodium falciparum infected mosquitos have been investigated using a yeast-derived recombinant P. falciparum circumsporozoite (rPfCS) protein. The murine immune response to immunization with rPfCS was not genetically restricted. Nine different murine haplotypes, when immunized with rPfCS, developed high levels of antisporozoite antibodies detectable by IFA and RIA. In addition, injection of rPfCS induced a secondary antibody response in P falciparum sporozoite-primed mice. Murine T-cell epitopes were mapped in the C terminus of the rPfCS protein using overlapping synthetic peptides. The human T-cell response was investigated using T-cell clones derived from peripheral blood lymphocytes (PBL) of a P. falciparum sporozoite-immunized volunteer. A total of 40 CD4+ T-cell clones were obtained. Stimulation indices ranged from 2.5 to 103.4 following challenge with rPfCS in the presence, but not in the absence, of antigen-presenting cells. The clones were specific for rPfCs and did not proliferate or secrete lymphokines when challenged with yeast-derived recombinant P. vivax or P. berghei CS protein or with a yeast- extract control. The clones also recognized the native CS protein in extracts of P. falciparum, but not P. berghei or P. cynomolgi, sporozoites
— id: 32218, year: 1990, vol: 68, page: 85, stat: Journal Article,

Recombinant proteins and synthetic peptides as malaria vaccine candidates
Nussenzweig RS
1990 Nov;36(11):817-820, Canadian journal of microbiology
— id: 14281, year: 1990, vol: 36, page: 817, 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,

IMMUNOLOGY AND CHEMOTHERAPY OF PLASMODIUM
Nussenzweig, R
1990 Mar;7(3):125-12?, Zoological science
— id: 32061, year: 1990, vol: 7, page: 125, stat: Journal Article,

VARIATION OF T-CELL EPITOPES OF THE PLASMODIUM-FALCIPARUM CS PROTEIN - ITS OCCURRENCE, EXTENT AND RELEVANCE
NUSSENZWEIG, RS; YOSHIDA, N
1990 AUG ;25(1-3):21-22, Immunology letters
— id: 98500, year: 1990, vol: 25, page: 21, stat: Journal Article,

Isolation and characterization of protective cytolytic T cells in a rodent malaria model system
Romero P; Maryanski JL; Cordey AS; Corradin G; Nussenzweig RS; Zavala F
1990 Aug;25(1-3):27-31, Immunology letters
Protective immunity against malaria is induced by immunization with irradiation-attenuated sporozoites. Here we report the isolation of cytolytic T-cell (CTL) clones from BALB/c (H-2d) mice immunized with either Plasmodium berghei or Plasmodium yoelii sporozoites. The epitopes recognized by these CTL can be mimicked by synthetic peptides corresponding to a homologous region in the CS proteins of both rodent malaria species. Both peptides are recognized by the CTL in the context of the same MHC class I molecule, H-2 Kd. In vivo adoptive transfer of the CTL clones into non-immune syngeneic mice protected them from a lethal challenge of infectious sporozoites
— id: 23519, year: 1990, vol: 25, page: 27, 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,

CD4+ cytolytic T cell clone confers protection against murine malaria
Tsuji M; Romero P; Nussenzweig RS; Zavala F
1990 Nov 1;172(5):1353-1357, Journal of experimental medicine
A CD4+ T cell clone (A1.6) was derived from spleen cells of mice immunized with irradiated sporozoites. This T cell clone recognizes an antigen that is shared by sporozoites and blood forms of Plasmodium berghei and differs from the circumsporozoite protein. Clone A1.6 displays cytotoxic activity, produces IFN-gamma and IL-2 in vitro, and recognizes the plasmodial antigen in the context of the class II I-Ed molecule. Passive transfer of this CD4+ clone into naive mice resulted in a high degree of protection against sporozoite challenge
— id: 14299, year: 1990, vol: 172, page: 1353, 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,

A circumsporozoite-like protein is present in micronemes of mature blood stages of malaria parasites
Cochrane AH; Uni S; Maracic M; Di Giovanni L; Aikawa M; Nussenzweig RS
1989 Nov;69(4):351-356, Experimental parasitology
We demonstrate for the first time the presence of a circumsporozoite (CS)-like protein in invasive blood stages of malaria parasites. Immunogold electron microscopy using antisporozoite monoclonal antibodies localized these antigens in the micronemes of merozoites. Western immunoblot and two-dimensional gel electrophoresis of mature blood stage extracts of Plasmodium falciparum, P. berghei, P. cynomolgi, and P. brasilianum identified polypeptides having the same apparent molecular mass and isoelectric points as the corresponding sporozoite (CS) proteins. The CS-like protein of merozoites is present in relatively minor amounts, compared to the CS protein of sporozoites. Mice with long-term P. berghei blood-induced infections develop antibodies which react with sporozoites
— id: 10452, year: 1989, vol: 69, page: 351, stat: Journal Article,

IMMUNIZATION OF SAIMIRI-SCIUREUS-BOLIVIENSIS WITH RECOMBINANT VACCINES BASED ON THE CIRCUMSPOROZOITE PROTEIN OF PLASMODIUM- VIVAX
Collins, WE; Nussenzweig, RS; Ballou, WR; Ruebush, TK; Nardin, EH; Chulay, JD; Majarian, WR; Young, JF; Wasserman, GF; Bathurst, I; Gibson, HL; Barr, PJ; Hoffman, SL; Wasserman, SS; Broderson, JR; Skinner, JC; Procell, PM; Filipski, VK; Wilson, CL
1989 May;40(5):455-464, American journal of tropical medicine & hygiene
— id: 31634, year: 1989, vol: 40, page: 455, stat: Journal Article,

Estimate of Plasmodium falciparum sporozoite content of Anopheles stephensi used to challenge human volunteers
Davis JR; Murphy JR; Clyde DF; Baqar S; Cochrane AH; Zavala F; Nussenzweig RS
1989 Feb;40(2):128-130, American journal of tropical medicine & hygiene
Plasmodium falciparum infected Anopheles stephensi, taken from a group of mosquitoes which had been used to challenge recipients of (NANP)3-TT vaccine, were tested for P. falciparum sporozoite content by an immunoradiometric assay. Seventy-six percent were infected with mean and median sporozoite equivalents per mosquito of 220,994 and 217,398, respectively (SD = 54,911). This sporozoite density is greater than that usually found in the field. These data suggest that this challenge for evaluating P. falciparum sporozoite vaccines is a demanding test of immunity
— id: 23524, year: 1989, vol: 40, page: 128, stat: Journal Article,

SERO-EPIDEMIOLOGICAL STUDIES OF MALARIA IN INDIAN TRIBES AND MONKEYS OF THE AMAZON BASIN OF BRAZIL
DEARRUDA, M; NARDIN, EH; NUSSENZWEIG, RS; COCHRANE, AH
1989 OCT ;41(4):379-385, American journal of tropical medicine & hygiene
— id: 51408, year: 1989, vol: 41, page: 379, 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,

ASSOCIATION OF MICRONEME ANTIGENS OF PLASMODIUM-BRASILIANUM MEROZOITES WITH KNOBS AND OTHER PARASITE-INDUCED STRUCTURES IN HOST ERYTHROCYTES
Torii, M; Matsumoto, Y; Kamboj, KK; Maracic, M; Guo, SQ; Nussenzweig, RS; Aikawa, M; Cochrane, AH
1989 Feb;57(2):596-601, Infection & immunity
— id: 31777, year: 1989, vol: 57, page: 596, stat: Journal Article,

Membrane-associated antigens of blood stages of Plasmodium, brasilianum, a quartan malaria parasite
Cochrane AH; Matsumoto Y; Kamboj KK; Maracic M; Nussenzweig RS; Aikawa M
1988 Aug;56(8):2080-2088, Infection & immunity
The localization of Plasmodium brasilianum-derived antigens in short and long clefts within the cytoplasm of infected erythrocytes and in association with knobs of the host cell membrane was demonstrated by immunoelectron microscopy with monoclonal antibodies. Our results document that malaria-induced short and long clefts, previously distinguishable only by morphology, differ also in antigenic composition. Another parasite-derived antigen was found to be associated with the parasitophorous vacuole space in schizonts. In segmenters, this antigen was present in large amounts between merozoites and in the cytoplasm of infected cells. These antigens were characterized by biosynthetic labeling and gel electrophoresis
— id: 10999, year: 1988, vol: 56, page: 2080, stat: Journal Article,

Prevalence and levels of antibodies to the circumsporozoite protein of Plasmodium falciparum in an endemic area and their relationship to resistance against malaria infection
Esposito F; Lombardi S; Modiano D; Zavala F; Reeme J; Lamizana L; Coluzzi M; Nussenzweig RS
1988 ;82(6):827-832, Transactions of the Royal Society of Tropical Medicine & Hygiene
A study on malaria transmission, prevalence of infection and anti-sporozoite antibodies was carried out in Burkina Faso (West Africa). The prevalence and the levels of antibodies to (NANP)3 were found to be related to the entomological sporozoite inoculation rates measured at the same time in a defined area. The major inducer of anti-(NANP)3 antibody production under field conditions is sporozoite inoculation by infected mosquitoes. Levels of antibodies to (NANP)3 vary considerably with age and transmission season. High levels of anti-(NANP)3 antibodies raised under field conditions might offer protection against small inocula of sporozoites
— id: 23529, year: 1988, vol: 82, page: 827, stat: Journal Article,

Characterization of cross-reactive blood-stage antigens of the Plasmodium cynomolgi complex using anti-Plasmodium vivax monoclonal antibodies
Kamboj KK; Barnwell JW; Nussenzweig RS; Cochrane AH
1988 Jun;74(3):403-408, Journal of parasitology
Five out of 18 monoclonal antibodies (moAB's) produced against blood stages of a Brazilian (Belem) strain of Plasmodium vivax were shown to cross-react with all of the 11 strains of the P. cynomolgi complex that were assayed. The 5 moAB's produced 3 different patterns of immunofluorescence, identical for both P. vivax and P. cynomolgi. Three of these moAB's appeared to react with antigens associated with the cytoplasm or membranes of infected erythrocytes. By Western blot analysis, 2 of these 3 moAB's identified an antigen with an apparent molecular weight of 31 kDa in extracts of parasitized erythrocytes of both species; the third of these moAB's reacted with an antigen with an apparent molecular weight of 95 kDa. By immunofluorescence, the 2 other moAB's reacted only with parasites at all developmental stages. The target antigen of these 2 moAB's was not identified. Immunoradiometric assays indicated that the moAB's are directed against 3 or possibly 4 distinct nonrepetitive epitopes. None of the moAB's inhibited merozoite invasion or growth of the parasites in an in vitro culture system of the Berok strain of P. cynomolgi
— id: 11088, year: 1988, vol: 74, page: 403, stat: Journal Article,

CIRCUMSPOROZOITE PROTEIN OF PLASMODIUM-GALLINACEUM CHARACTERIZED BY MONOCLONAL-ANTIBODIES
Krettli, AU; Rocha, EMM; Lopes, JD; Carneiro, CRW; Kamboj, KK; Cochrane, AH; Nussenzweig, RS
1988 Sep;10(5):523-533, Parasite immunology
— id: 31587, year: 1988, vol: 10, page: 523, 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,

Susceptibility of Anopheles culicifacies species A and B to Plasmodium vivax and Plasmodium falciparum as determined by immunoradiometric assay
Subbarao SK; Adak T; Vasantha K; Joshi H; Raghvendra K; Cochrane AH; Nussenzweig RS; Sharma VP
1988 ;82(3):394-397, Transactions of the Royal Society of Tropical Medicine & Hygiene
We have used a two-site immunoradiometric assay and species-specific antisporozoite monoclonal antibodies to determine the relative roles that sibling species A and B of the Anopheles culicifacies complex play in malaria transmission in western Uttar Pradesh, India. The results unequivocally establish species A as the primary vector of both Plasmodium vivax and P. falciparum in this area. Our results indicate active transmission of P. vivax from May to October and of P. falciparum from August to December. The identification of species A as the primary malaria vector in northern India will now allow suitable malaria control strategies to be designed
— id: 63212, year: 1988, vol: 82, page: 394, 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,

Circumsporozoite gene of a Plasmodium falciparum strain from Thailand
del Portillo, H A; Nussenzweig, R S; Enea, V
1987 Jul;24(3):289-294, Molecular & biochemical parasitology
The nucleotide and deduced amino acid sequences of the CS gene of a Plasmodium falciparum strain from Thailand (T4) are presented. Comparison with the nucleotide sequences of two other P. falciparum CS genes, 7G8 from Brazil and Wellcome from West Africa, shows that: the coding regions outside the repeats of T4 and 7G8 are co-extensive and lack 30 nucleotides present in the Wellcome strain 5' to the repeats; in this region, T4 also differs at 3 nucleotide positions from the 7G8 and the Wellcome strains; in the region 3' to the repeats, T4 differs at two positions from 7G8 and at two other positions from the Wellcome strain--remarkably, all of these differences result in amino acid substitutions; the structure of the tandem repeats in the CS gene of T4 is, 5' to 3', [NANP-NVDP] X 3, [NANP] X 38, which is different from that of the two other strains. Due to the use of synonymous codons, the repetition of the sequence is more precise at the amino acid level than at the nucleotide level. These features contrast with those observed in the CS genes of other plasmodial species
— id: 127215, year: 1987, vol: 24, page: 289, stat: Journal Article,

The circumsporozoite gene of the Plasmodium cynomolgi complex
Galinski, M R; Arnot, D E; Cochrane, A H; Barnwell, J W; Nussenzweig, R S; Enea, V
1987 Jan 30;48(2):311-319, Cell
An analysis of the circumsporozoite (CS) genes of six closely related plasmodia is presented. Like other plasmodial antigens, the CS protein contains tandem repeats flanked by conventional nonrepeated sequences. Our analysis shows that the repeats, which encode the immunodominant epitope of the CS protein, diverge more rapidly than the remainder of the gene, and that the maintenance and evolution of the repeats cannot be explained as the result of selection at the protein level. We argue that a mechanism acts directly on the DNA sequence to constrain the internal divergence of the repeats, and as a result promotes their rapid divergence between taxa
— id: 127216, year: 1987, vol: 48, page: 311, 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,

Detection and anatomical localization of Plasmodium falciparum circumsporozoite protein and sporozoites in the afrotropical malaria vector Anopheles gambiae s.l
Lombardi S; Esposito F; Zavala F; Lamizana L; Rossi P; Sabatinelli G; Nussenzweig RS; Coluzzi M
1987 Nov;37(3):491-494, American journal of tropical medicine & hygiene
Salivary glands from Anopheles gambiae s.l. collected in Burkina Faso, West Africa, were analyzed by both microscopic examination and immunoradiometric assay to determine the Plasmodium falciparum sporozoite rates. Using the same mosquito samples, the immunoassay revealed positive salivary glands with low sporozoite loads, which were frequently missed by microscopy. A closer agreement between both techniques was found using salivary glands with high sporozoite loads. We also found a number of mosquitoes with uninfected salivary glands which harbored the circumsporozoite antigen in their thoraces. In a particular village these mosquitoes represented 43.5% of all sporozoite antigen carrying specimens
— id: 23531, year: 1987, vol: 37, page: 491, 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,

HUMAN TRIALS OF MALARIA VACCINE
Nussenzweig, RS
1987 May 15;236(4803):763-763, Science
— id: 31184, year: 1987, vol: 236, page: 763, stat: Journal Article,

Antigenic analysis of the repeat domain of the circumsporozoite protein of Plasmodium vivax
Romero P; Heimer EP; Herrera S; Felix AM; Nussenzweig RS; Zavala F
1987 Sep 1;139(5):1679-1682, Journal of immunology
In the present study we analyzed the fine specificity of mouse monoclonal and human polyclonal antibodies directed against the repeat domain of the circumsporozoite (CS) protein of the human malaria parasite, Plasmodium vivax. Five synthetic peptides, representing monomeric and dimeric repeats of this malarial antigen, were assayed for their capacity to inhibit the binding of these antibodies to a yeast-derived recombinant CS protein. The results revealed the existence of at least two distinct repeated overlapping epitopes in the CS protein of P. vivax. Furthermore, polyclonal sera contain antibodies which recognize additional determinants not represented by the synthetic repeat peptides. Some of these sera contain antibodies recognizing a region flanking the repeat domain (region I). The present findings are in contrast with the antibody response in rodents and humans to the Plasmodium falciparum CS protein, which is directed against a single repeated immunodominant epitope
— id: 23532, year: 1987, vol: 139, page: 1679, 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,

ULTRASTRUCTURAL-LOCALIZATION OF THE 150/130 KD ANTIGENS IN SEXUAL AND ASEXUAL BLOOD STAGES OF PLASMODIUM-FALCIPARUM- INFECTED HUMAN-ERYTHROCYTES
Uni, S; Masuda, A; Stewart, MJ; Igarashi, I; Nussenzweig, R; Aikawa, M
1987 May;36(3):481-488, American journal of tropical medicine & hygiene
— id: 31326, year: 1987, vol: 36, page: 481, stat: Journal Article,

Plasmodium falciparum: epidemiological studies on the circumsporozoite gene
Yoshida N; del Portillo HA; di Santi SM; Nussenzweig RS; Enea V
1987 Dec;64(3):510-513, Experimental parasitology
— id: 11308, year: 1987, vol: 64, page: 510, 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,

FURTHER-STUDIES ON THE ANTIGENIC DIVERSITY OF THE CIRCUMSPOROZOITE PROTEINS OF THE PLASMODIUM-CYNOMOLGI COMPLEX
COCHRANE, AH; GWADZ, RW; BARNWELL, JW; KAMBOJ, KK; NUSSENZWEIG, RS
1986 MAY ;35(3):479-487, American journal of tropical medicine & hygiene
— id: 41294, year: 1986, vol: 35, page: 479, stat: Journal Article,

POTENTIAL VECTORS OF MALARIA AND THEIR DIFFERENT SUSCEPTIBILITY TO PLASMODIUM-FALCIPARUM AND PLASMODIUM-VIVAX IN NORTHERN BRAZIL IDENTIFIED BY IMMUNOASSAY
DEARRUDA, M; CARVALHO, MB; NUSSENZWEIG, RS; MARACIC, M; FERREIRA, AW; COCHRANE, AH
1986 SEP ;35(5):873-881, American journal of tropical medicine & hygiene
— id: 41282, year: 1986, vol: 35, page: 873, stat: Journal Article,

Evolutionary profile of the circumsporozoite gene of the Plasmodium cynomolgi complex
Enea, V; Galinski, M; Schmidt, E; Gwadz, R; Nussenzweig, R S
1986 Apr 20;188(4):721-726, Journal of molecular biology
The circumsporozoite genes and flanking sequences of the Ceylon, Gombak, London, NIH and Mulligan strains of the Plasmodium cynomolgi complex were isolated by molecular cloning and compared. About 11,000 bases of the Gombak clone were mapped in detail and found to have their exact counterparts in all the other strains. In contrast the epitope-encoding region, a 600-base sequence consisting of short tandem repeats, exhibited no homology with any of the other clones. These findings show that different regions of the circumsporozoite gene evolve in sharply different modes
— id: 127217, year: 1986, vol: 188, page: 721, stat: Journal Article,

Immunity to Plasmodium sporozoites: recent advances and applications to field research
Esposito F; Lombardi S; Modiano D; Zavala F; Reeme J; Lamizana L; Coluzzi M; Nussenzweig RS
1986 Aug-Dec;28(2-3):101-105, Parassitologia
The presence of antibodies against Plasmodium falciparum sporozoites in humans living in malaria endemic areas was measured using as antigen the synthetic peptide (NANP)3, which represents the immunodominant region of the circumsporozoite (CS) protein. The results indicate that: i) the production of anti-CS antibodies is unrelated to the presence in the circulation of blood-stage parasites; ii) anti-CS antibodies, raised by natural inoculation, could exert a protective role against natural malaria infection; iii) anti-CS antibodies can be used as indicators of the intensity of malaria transmission
— id: 23536, year: 1986, vol: 28, page: 101, 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,

CS antigen localization in malaria vectors: hypothetical refractoriness to transmission observed in the field
Lombardi S; Esposito F; Zavala F; Lamizana L; Rossi P; Sabatinelli G; Nussenzweig RS; Coluzzi M
1986 Aug-Dec;28(2-3):113-116, Parassitologia
Indoor resting Anopheles gambiae s.l. were collected in two villages near Ouagadougou, Burkina Faso, and processed to investigate the presence and distribution of Plasmodium sporozoites. Salivary glands were dissected, examined by phase contrast microscopy and further processed by IRMA in order to reveal the presence of the circumsporozoite (CS) antigen of P. falciparum. The corresponding thoraces were homogenized and processed by IRMA. In the village characterized by the higher inoculation rate more than 40% of the infected mosquitoes were not found infective since CS antigen was detected in the thorax in absence of sporozoites and CS antigen in the corresponding salivary glands
— id: 23535, year: 1986, vol: 28, page: 113, 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,

MONOCLONAL-ANTIBODIES PRODUCED AGAINST SPOROZOITES OF THE HUMAN PARASITE PLASMODIUM-MALARIAE ABOLISH INFECTIVITY OF SPOROZOITES OF THE SIMIAN PARASITE PLASMODIUM-BRASILIANUM
COCHRANE, AH; BARNWELL, JW; COLLINS, WE; NUSSENZWEIG, RS
1985 JAN 20 ;50(1):58-61, Infection & immunity
— id: 98569, year: 1985, vol: 50, page: 58, stat: Journal Article,

Laboratory assessment of a species-specific radioimmunoassay for the detection of malaria sporozoites in mosquitoes (Diptera: Culicidae)
Collins FH; Gwadz RW; Koontz LC; Zavala F; Nussenzweig RS
1985 Mar 22;22(2):121-129, Journal of medical entomology
— id: 23541, year: 1985, vol: 22, page: 121, stat: Journal Article,

PROGRESS ON THEILERIA VACCINE
Doherty, PC; Nussenzweig, R
1985 ;316(6028):484-485, Nature
— id: 30730, year: 1985, vol: 316, page: 484, 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,

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,

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,

ULTRASTRUCTURE OF INVITRO CULTURED EXOERYTHROCYTIC STAGE OF PLASMODIUM-BERGHEI IN A HEPATOMA-CELL LINE
AIKAWA, M; SCHWARTZ, A; UNI, S; NUSSENZWEIG, R; HOLLINGDALE, M
1984 ;33(5):792-799, American journal of tropical medicine & hygiene
— id: 41047, year: 1984, vol: 33, page: 792, stat: Journal Article,

Identification of malaria-infected mosquitoes by a two-site enzyme-linked immunosorbent assay
Burkot TR; Zavala F; Gwadz RW; Collins FH; Nussenzweig RS; Roberts DR
1984 Mar;33(2):227-231, American journal of tropical medicine & hygiene
A micro enzyme-linked immunosorbent assay (ELISA) for identifying malaria sporozoites in mosquitoes is described. Using an extract of dried infected mosquitoes as antigen, a two-site ELISA was sensitive enough to detect one infected mosquito in a pool of 20. The species specificity, sensitivity and ease of performance of this assay, as well as the stability of the reagent, should make it a useful epidemiological tool
— id: 23546, year: 1984, vol: 33, page: 227, stat: Journal Article,

MONOCLONAL-ANTIBODY IDENTIFIES CIRCUMSPOROZOITE PROTEIN OF PLASMODIUM-MALARIAE AND DETECTS A COMMON EPITOPE ON PLASMODIUM-BRASILIANUM SPOROZOITES
COCHRANE, AH; COLLINS, WE; NUSSENZWEIG, RS
1984 ;45(3):592-595, Infection & immunity
— id: 40784, year: 1984, vol: 45, page: 592, stat: Journal Article,

IDENTIFICATION OF CIRCUMSPOROZOITE PROTEINS IN INDIVIDUAL MALARIA-INFECTED MOSQUITOS BY WESTERN BLOT ANALYSIS
COCHRANE, AH; OCKENHOUSE, CF; NUSSENZWEIG, RS
1984 ;71(2):241-245, Journal of immunological methods
— id: 40792, year: 1984, vol: 71, page: 241, stat: Journal Article,

First field trial of an immunoradiometric assay for the detection of malaria sporozoites in mosquitoes
Collins FH; Zavala F; Graves PM; Cochrane AH; Gwadz RW; Akoh J; Nussenzweig RS
1984 Jul;33(4):538-543, American journal of tropical medicine & hygiene
An immunoradiometric assay (IRMA) using a monoclonal antibody to the major surface protein of Plasmodium falciparum sporozoites was used to assess the P. falciparum sporozoite rate in a West African population of Anopheles gambiae (s.1.). Unlike current dissection techniques, the IRMA could detect sporozoite antigen in dried as well as fresh mosquitoes. In a controlled comparison, the sensitivity of the IRMA was comparable that of the dissection technique. Additionally, the IRMA was species specific and quantitative. Sensitivity of the assay was sufficient to detect sporozoite infections resulting from the development of a single oocyst
— id: 23545, year: 1984, vol: 33, page: 538, stat: Journal Article,

DNA cloning of Plasmodium falciparum circumsporozoite gene: amino acid sequence of repetitive epitope
Enea V; Ellis J; Zavala F; Arnot DE; Asavanich A; Masuda A; Quakyi I; Nussenzweig RS
1984 Aug 10;225(4662):628-630, Science
A clone of complementary DNA encoding the circumsporozoite (CS) protein of the human malaria parasite Plasmodium falciparum has been isolated by screening an Escherichia coli complementary DNA library with a monoclonal antibody to the CS protein. The DNA sequence of the complementary DNA insert encodes a four-amino acid sequence: proline-asparagine-alanine-asparagine, tandemly repeated 23 times. The CS beta-lactamase fusion protein specifically binds monoclonal antibodies to the CS protein and inhibits the binding of these antibodies to native Plasmodium falciparum CS protein. These findings provide a basis for the development of a vaccine against Plasmodium falciparum malaria
— id: 23544, year: 1984, vol: 225, page: 628, stat: Journal Article,

Circumsporozoite gene of plasmodium cynomolgi (Gombak):cDNA cloning and expression of the repetitive circumsporozoite epitope
Enea, V; Arnot, D; Schmidt, E C; Cochrane, A; Gwadz, R; Nussenzweig, R S
1984 Dec;81(23):7520-7524, Proceedings of the National Academy of Sciences of the United States of America
We report the identification, sequence, and expression in Escherichia coli of the immunodominant epitope of the circumsporozoite (CS) gene of Plasmodium cynomolgi (Gombak), a simian malaria parasite. This epitope is encoded by a DNA sequence that is tandemly repeated 10 times in the cDNA clone. Subclones that contain and express only repeats and in variable number have been constructed. We show that the binding of a specific anti-CS protein monoclonal antibody correlates positively with the number of repeats in each subclone. The CS gene of another strain of P. cynomolgi (NIH) encodes an immunodominant epitope that is immunologically distinct from that of the Gombak strain. We present evidence that these two CS genes share extensive overall homology, although the nucleotide sequences that encode the epitopes appear to be unrelated
— id: 127218, year: 1984, vol: 81, page: 7520, stat: Journal Article,

IMMUNO-ELECTRON MICROSCOPIC OBSERVATIONS ON PLASMODIUM-KNOWLESI SPOROZOITES - LOCALIZATION OF PROTECTIVE ANTIGEN AND ITS PRECURSORS
FINE, E; AIKAWA, M; COCHRANE, AH; NUSSENZWEIG, RS
1984 ;33(2):220-226, American journal of tropical medicine & hygiene
— id: 41090, year: 1984, vol: 33, page: 220, 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,

INHIBITION OF ENTRY OF PLASMODIUM-FALCIPARUM AND PLASMODIUM-VIVAX SPOROZOITES INTO CULTURED-CELLS - AN INVITRO ASSAY OF PROTECTIVE ANTIBODIES
HOLLINGDALE, MR; NARDIN, EH; THARAVANIJ, S; SCHWARTZ, AL; NUSSENZWEIG, RS
1984 ;132(2):909-913, Journal of immunology
— id: 41120, year: 1984, vol: 132, page: 909, 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,

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,

Plasmodium berghei sporozoites are mitogenic for murine T cells, induce interferon, and activate natural killer cells
Ojo-Amaize EA; Vilcek J; Cochrane AH; Nussenzweig RS
1984 Aug;133(2):1005-1009, Journal of immunology
Enhanced natural killer (NK) activity was detected in the spleens of mice as early as 24 hr after single i.v. inoculation with gamma-irradiated Plasmodium berghei sporozoites. The activity peaked at 48 hr post-injection, and declined below baseline level by day 8. Reinoculation of mice with irradiated sporozoites produced an increased NK activity significantly smaller than the original activity. Spleen cells sensitized in vivo as well as nonsensitized spleen cells stimulated in vitro with sporozoites produced high levels of interferon (IFN) and displayed enhanced NK activity. Characterization of the IFN through the use of specific antibodies revealed that it was mainly IFN-gamma. The cellular basis for IFN-gamma induction was linked to the mitogenicity of P. berghei sporozoites for T cells. The possibility exists that IFN-gamma may have a regulatory effect on antibody production against P. berghei sporozoites
— id: 15573, year: 1984, vol: 133, page: 1005, 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,

MONOCLONAL-ANTIBODIES TO TRYPANOSOMA-CRUZI INHIBIT MOTILITY AND NUCLEIC-ACID SYNTHESIS OF CULTURE FORMS
Alves, MJM; Aikawa, M; Nussenzweig, RS
1983 ;39(1):377-382, Infection & immunity
— id: 30693, year: 1983, vol: 39, page: 377, 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,

PROTECTIVE ANTI-MALARIAL ANTIBODIES REACT WITH AN IMMUNODOMINANT REPETITIVE EPITOPE OF THE SPOROZOITE SURFACE-ANTIGEN
NUSSENZWEIG, RS
1983 ;42(4):964-964, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 40715, year: 1983, vol: 42, page: 964, 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,

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,

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 PROTEINS - A FAMILY OF PROTECTIVE MALARIAL ANTIGENS
Nussenzweig, RS
1982 ;4(4):273-273, International journal of immunopharmacology
— id: 30532, year: 1982, vol: 4, page: 273, stat: Journal Article,

PARASITIC DISEASE AS A CAUSE OF IMMUNOSUPPRESSION
Nussenzweig, RS
1982 ;306(7):423-424, New England journal of medicine
— id: 30584, year: 1982, vol: 306, page: 423, stat: Journal Article,

PROGRESS IN MALARIA VACCINE DEVELOPMENT - CHARACTERIZATION OF PROTECTIVE ANTIGENS
Nussenzweig, RS
1982 ;1(3):40-45, Scandinavian journal of infectious diseases
— id: 30664, year: 1982, vol: 1, page: 40, stat: Journal Article,

COMPARATIVE STUDIES ON THE IMMUNOGENICITY OF INFECTIVE AND ATTENUATED SPOROZOITES OF PLASMODIUM-BERGHEI
ORJIH, AU; COCHRANE, AH; NUSSENZWEIG, RS
1982 ;76(1):57-61, Transactions of the Royal Society of Tropical Medicine & Hygiene
— id: 40412, year: 1982, vol: 76, page: 57, 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,

CONGENITAL TRANSFER OF ANTIBODIES AGAINST MALARIAL SPOROZOITES DETECTED IN GAMBIAN INFANTS
NARDIN, EH; NUSSENZWEIG, RS; BRYAN, JH; MCGREGOR, IA
1981 ;30(6):1159-1163, American journal of tropical medicine & hygiene
— id: 40297, year: 1981, vol: 30, page: 1159, stat: Journal Article,

ACTIVE IMMUNIZATION AND PASSIVE TRANSFER OF RESISTANCE AGAINST SPOROZOITE-INDUCED MALARIA IN INFANT MICE
Orjih, AU; Cochrane, AH; Nussenzweig, RS
1981 ;291(5813):331-332, Nature
— id: 30212, year: 1981, vol: 291, page: 331, 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,

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,

SPOROZOITES OF MAMMALIAN MALARIA - ATTACHMENT TO, INTERIORIZATION AND FATE WITHIN MACROPHAGES
Danforth, HD; Aikawa, M; Cochrane, AH; Nussenzweig, RS
1980 ;27(2):193-202, Journal of protozoology
— id: 27903, year: 1980, vol: 27, page: 193, stat: Journal Article,

USE OF RADIATION-ATTENUATED SPOROZOITES IN THE IMMUNOPROPHYLAXIS OF MALARIA
Nussenzweig, R
1980 ;7(2):89-96, International journal of nuclear medicine & biology
— id: 28066, year: 1980, vol: 7, page: 89, 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,

IMMUNIZATION AGAINST RODENT MALARIA WITH CRYOPRESERVED IRRADIATED SPOROZOITES OF PLASMODIUM-BERGHEI
Orjih, AU; Nussenzweig, RS
1980 ;29(3):343-347, American journal of tropical medicine & hygiene
— id: 28072, year: 1980, vol: 29, page: 343, 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,

FREEZE-FRACTURE STUDY OF MALARIA SPOROZOITES - ANTIBODY-INDUCED CHANGES OF THE PELLICULAR MEMBRANE
Aikawa, M; Cochrane, AH; Nussenzweig, RS; Rabbege, J
1979 ;26(2):273-279, Journal of protozoology
— id: 29985, year: 1979, vol: 26, page: 273, stat: Journal Article,

ENHANCEMENT OF A SIMIAN MALARIAL INFECTION (PLASMODIUM- CYNOMOLGI) IN MOSQUITOS FED ON RHESUS (MACACA-MULATTA) PREVIOUSLY INFECTED WITH AN UNRELATED MALARIA (PLASMODIUM- KNOWLESI)
Arrudamayr, MD; Cochrane, AH; Nussenzweig, RS
1979 ;28(4):627-633, American journal of tropical medicine & hygiene
— id: 29981, year: 1979, vol: 28, page: 627, 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,

Membrane-bound antibodies to bloodstream Trypanosoma cruzi in mice: strain differences in susceptibility to complement-mediated lysis
Krettli, A U; Weisz-Carrington, P; Nussenzweig, R S
1979 Sep;37(3):416-423, Clinical & experimental immunology
The Y, CL and other strains of Trypanosoma cruzi display different morphological and immunological characteristics. Such observations are here extended to the interaction of bloodstream forms of different strains of T. cruzi with components of the complement system. We demonstrate that the bloodstream forms of the Y and B strains, but not those of the CL strain, are lysed by normal human serum. Lysis is mediated by combined activities of the alternative and classical complement pathways. These activities are triggered by antibodies on the surface of the parasites as shown by: (a) binding of fluorescein or radiolabelled anti-mouse immunoglobulin to the parasite's membrane and (b) the finding that bloodstream forms from lethally irradiated mice can be sensitized and rendered susceptible to complement-mediated lysis by incubation with sera from acutely infected animals. Bloodstream forms of the CL strain also bear surface immunoglobulin and sensitizing antibodies are present in the sera of mice infected with this strain. However, CL trypomastigotes from acutely infected mice fail to be lysed by human or mouse complement unless the parasites are pre-incubated with sera from chronically infected animals. The basis of the different interactions between CL and Y trypomastigotes with antibodies and the complement system, and their biological significance are discussed
— id: 124734, year: 1979, vol: 37, page: 416, stat: Journal Article,

ANTIBODIES TO SPOROZOITES - THEIR FREQUENT OCCURRENCE IN INDIVIDUALS LIVING IN AN AREA OF HYPER-ENDEMIC MALARIA
Nardin, EH; Nussenzweig, RS; Mcgregor, IA; Bryan, JH
1979 ;206(4418):597-599, Science
— id: 29710, year: 1979, vol: 206, page: 597, stat: Journal Article,

PLASMODIUM-BERGHEI - SUPPRESSION OF ANTIBODY-RESPONSE TO SPOROZOITE STAGE BY ACUTE BLOOD STAGE INFECTION
Orjih, AU; Nussenzweig, RS
1979 ;38(1):1-8, Clinical & experimental immunology
— id: 29975, year: 1979, vol: 38, page: 1, stat: Journal Article,

IMMUNE PHAGOCYTOSIS IN MURINE MALARIA
Shear, HL; Nussenzweig, RS; Bianco, C
1979 ;149(6):1288-1298, Journal of experimental medicine
— id: 29986, year: 1979, vol: 149, page: 1288, stat: Journal Article,

IMMUNE PHAGOCYTOSIS IN MURINE MALARIA
Shear, HL; Nussenzweig, RS; Bianco, C
1979 ;38(3):1275-1275, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 30146, year: 1979, vol: 38, page: 1275, stat: Journal Article,

IMMUNOFLUORESCENT STAINING OF EXOERYTHROCYTIC SCHIZONTS OF PLASMODIUM-BERGHEI IN FIXED LIVER-TISSUE WITH STAGE-SPECIFIC IMMUNE SERUM
Danforth, HD; Orjih, AU; Nussenzweig, RS
1978 ;64(6):1123-1125, Journal of parasitology
— id: 30049, year: 1978, vol: 64, page: 1123, stat: Journal Article,

Sporozoites of rodent and simian malaria, purified by anion exchangers, retain their immunogenicity and infectivity
Moser, G; Brohn, F H; Danforth, H D; Nussenzweig, R S
1978 Feb;25(1):119-124, Journal of protozoology
Sporozoites of rodent malaria, Plasmodium berghei, and simian malaria, Plasmodium knowlesi and Plasmodium cynomolgi, were partially separated from mosquito debris and microbial contaminants by passage of Anopheles material through a DEAE-cellulose column. In addition to eliminating most of the contaminants (80-90%), this simple technic has made it possible to recover rapidly large numbers of viable sporozoites (55-75% yield), which have retained their infectivity, immunogenicity, and capacity to react with known antisera. Mice injected with varying doses of column-purified sporozoites (CS) of P. berghei produced infections which paralleled those seen in the controls. Total protection against challenge with a potentially lethal dose of viable sporozoites was acquired by mice inoculated twice with irradiated CS of P. berghei CS of P. berghei and P. cynomolgi gave positive circumsporozoite precipitation (CSP) reactions, upon inoculation with the respective immune sera. The preservation of the surface antigens of CS was documented by immunofluorescence. It was shown that differences in elution behavior exist among sporozoites of certain species of Plasmodium as well as among sporozoiters of the same species derived from different organs of the mosquito. These results may be attributed to differences in the surface charge of the sporozoites or conditions in sample media. Purified sporozoites obtained by the method described in this report provide an adequate source of parasites for a variety of in vitro studies
— id: 150534, year: 1978, vol: 25, page: 119, stat: Journal Article,

INFECTIVITY AND IMMUNOGENICITY OF SPOROZOITES OF MAMMALIAN MALARIA PURIFIED BY ANION-EXCHANGE CHROMATOGRAPHY
Moser, G; Brohn, FH; Danforth, HD; Nussenzweig, RS
1978 ;37(6):1847-1847, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 29913, year: 1978, vol: 37, page: 1847, stat: Journal Article,

STAGE-SPECIFIC ANTIGENS ON SURFACE-MEMBRANE OF SPOROZOITES OF MALARIA PARASITES
NARDIN, EH; NUSSENZWEIG, RS
1978 ;274(5666):55-57, Nature
— id: 40040, year: 1978, vol: 274, page: 55, 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,

PLASMODIUM-BERGHEI - T CELL DEPENDENCE OF SPOROZOITE-INDUCED IMMUNITY IN RODENTS
Spitalny, GL; Verhave, JP; Meuwissen, JHET; Nussenzweig, RS
1977 ;42(1):73-81, Experimental parasitology
— id: 29542, year: 1977, vol: 42, page: 73, stat: Journal Article,

SPECIFICITY OF CIRCUM-SPOROZOITE PRECIPITATION ANTIGEN(S) OF HUMAN AND SIMIAN MALARIAS
Chen, DH; Nussenzweig, RS; Collins, WE
1976 ;62(4):636-637, Journal of parasitology
— id: 28734, year: 1976, vol: 62, page: 636, stat: Journal Article,

ANTIBODY-INDUCED ULTRASTRUCTURAL CHANGES OF MALARIAL SPOROZOITES
COCHRANE, AH; AIKAWA, M; JENG, M; NUSSENZWEIG, RS
1976 ;116(3):859-867, Journal of immunology
— id: 98726, year: 1976, vol: 116, page: 859, 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,

TRICHINELLA-SPIRALIS - ANAPHYLACTIC ANTIBODY-FORMATION AND SUSCEPTIBILITY IN STRAINS OF INBRED MICE
Riveraortiz, CI; Nussenzweig, R
1976 ;39(1):7-17, Experimental parasitology
— id: 28709, year: 1976, vol: 39, page: 7, stat: Journal Article,

PLASMODIUM-BERGHEI - SPLEEN IN SPOROZOITE-INDUCED IMMUNITY TO MOUSE MALARIA
Spitalny, GL; Riveraortiz, CI; Nussenzweig, RS
1976 ;40(2):179-188, Experimental parasitology
— id: 29415, year: 1976, vol: 40, page: 179, stat: Journal Article,

Immunological studies in rodent malaria. I: Protective immunity induced in mice by mild strains of Plasmodium berghei yoelii against a virulent and fatal line of this plasmodium
Hargreaves, J; Yoeli, M; Nussenzweig, R S
1975 Sep;69(3):289-299, Annals of tropical medicine & parasitology
Mild and virulent lines of Plasmodium berghei yoelii are readily distinguished both by their course of infection and by the preference of the virulent line for mature red blood cells. Mice given either mild line were fully protected against the virulent P.b. yoelii one week after they had become negative. Mice given the mild line of P.b. yoelii 17X were fully protected against a challenge by the virulent line on the third day of infection (D+3). Mice given the mild and virulent lines of P.b. yoelii 17X concomitantly showed only slight protection, all eventually succumbing. Mice given the virulent P.b. yoelii 17X and challenged with P.b. yoelii 17X mild on D+1 showed 2/6 with virulent-like infections and 4/6 infections which resembled the mild controls. Five out of eleven animals challenged with P.b. berghei after immunization with mild P.b. yoelii had infections which resembled the P.b. berghei control group and were dead by D+23. The other six mice became negative, but all of them relapsed and three of them subsequently died. In mice challenged four weeks after their mild P.b. yoelii 17X infections had become negative, 5/6 succumbed to a P.b. berghei infection. Mice immunized with P.b. yoelii 17X mild and challenged with P.v. vinckei one week after becoming negative had a survival rate of 2/10
— id: 117433, year: 1975, vol: 69, page: 289, stat: Journal Article,

EVALUATION OF A METHOD FOR INVITRO OOKINETE DEVELOPMENT OF RODENT MALARIAL PARASITE, PLASMODIUM-BERGHEI
SHAPIRO, M; ESPINALTEJADA, C; NUSSENZWEIG, RS
1975 ;61(6):1105-1106, Journal of parasitology
— id: 98730, year: 1975, vol: 61, page: 1105, stat: Journal Article,

DEPLETION OF T AND B LYMPHOCYTES IN MALARIA
KRETTLI, AU; NUSSENZW.RS
1974 ;33(3):619-619, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 39890, year: 1974, vol: 33, page: 619, stat: Journal Article,

DEPLETION OF T AND B LYMPHOCYTES DURING MALARIAL INFECTIONS
Krettli, AU; Nussenzw[...], R
1974 ;13(3):440-446, Cellular immunology
— id: 28332, year: 1974, vol: 13, page: 440, stat: Journal Article,

ANTIBODY-RESPONSE TO SPOROZOITES OF SIMIAN AND HUMAN MALARIA PARASITES - ITS STAGE AND SPECIES SPECIFICITY AND STRAIN CROSS-REACTIVITY
NUSSENZW.RS; CHEN, D
1974 ;50(3-4):293-297, Bulletin of the World Health Organization
— id: 39887, year: 1974, vol: 50, page: 293, stat: Journal Article,

SOME CHARACTERISTICS OF IMMUNE-RESPONSE TO SPOROZOITES OF SIMIAN AND HUMAN MALARIA
Nussenzweig, RS; Chen, D
1974 ;77(6):469-477, Boletin de la Oficina Sanitaria Panamericana
— id: 28614, year: 1974, vol: 77, page: 469, stat: Journal Article,

IMMUNOGENICITY AND INFECTIVITY OF SPOROZOITES OF MAMMALIAN MALARIA ISOLATED BY DENSITY-GRADIENT CENTRIFUGATION
KRETTLI, A; CHEN, DH; NUSSENZW.RS
1973 ;20(5):662-665, Journal of protozoology
— id: 39766, year: 1973, vol: 20, page: 662, stat: Journal Article,

ANTIBODIES AGAINST SPOROZOITES OF HUMAN AND SIMIAN MALARIA PRODUCED IN RATS
NUSSENZW.RS; MONTUORI, W; SPITALNY, GL; CHEN, D
1973 ;110(2):600-601, Journal of immunology
— id: 39819, year: 1973, vol: 110, page: 600, stat: Journal Article,

PLASMODIUM-BERGHEI - RELATIONSHIP BETWEEN PROTECTIVE IMMUNITY AND ANTI-SPOROZOITE (CSP) ANTIBODY IN MICE
SPITALNY, GL; NUSSENZW.RS
1973 ;33(1):168-178, Experimental parasitology
— id: 39814, year: 1973, vol: 33, page: 168, stat: Journal Article,

Plasmodium berghei: accelerated clearance of sporozoites from blood as part of immune-mechanism in mice
Nussenzweig RS; Vanderberg JP; Sanabria Y; Most H
1972 Feb;31(1):88-97, Experimental parasitology
— id: 29400, year: 1972, vol: 31, page: 88, stat: Journal Article,

Sporozoite-induced immunity in mammalian malaria. A review
Nussenzweig, R S; Vanderberg, J; Spitalny, G L; Rivera, C I; Orton, C; Most, H
1972 Sep;21(5):722-728, American journal of tropical medicine & hygiene
— id: 71632, year: 1972, vol: 21, page: 722, stat: Journal Article,

INCREASED PHAGOCYTIC ACTIVITY OF RETICULOENDOTHELIAL SYSTEM DURING IMMUNIZATION WITH X-IRRADIATED SPOROZOITES OF PLASMODIUM-BERGHEI IN MICE
RIVERAOR.C; NUSSENZW.RS
1972 ;39(NOV):497-506, Proceedings of the Helminthological Society of Washington
— id: 39885, year: 1972, vol: 39, page: 497, stat: Journal Article,

EFFECT OF VARIOUS ROUTES OF IMMUNIZATION AND METHODS OF PARASITE ATTENUATION ON DEVELOPMENT OF PROTECTION AGAINST SPOROZOITE-INDUCED RODENT MALARIA
SPITALNY, GL; NUSSENZW.RS
1972 ;39(NOV):506-514, Proceedings of the Helminthological Society of Washington
— id: 39886, year: 1972, vol: 39, page: 506, stat: Journal Article,

MORPHOLOGICAL DIVERGENCE IN A MAMMALIAN MALARIAL PARASITE - FINE-STRUCTURE OF PLASMODIUM-BRASILIANUM
STERLING, CR; AIKAWA, M; NUSSENZW.RS
1972 ;39(NOV):109-129, Proceedings of the Helminthological Society of Washington
— id: 39827, year: 1972, vol: 39, page: 109, stat: Journal Article,

STAGE SPECIFICITY OF ANTI-SPOROZOITE ANTIBODIES IN RODENT MALARIA AND ITS RELATIONSHIP TO PROTECTIVE IMMUNITY
Vanderbe[...], JP; Nussenzw[...], RS; Sanabria, Y; Nawrot, R; Most, H
1972 ;39(NOV):514-525, Proceedings of the Helminthological Society of Washington
— id: 28320, year: 1972, vol: 39, page: 514, stat: Journal Article,

Exogenous interferon protects mice against Plasmodium berghei malaria
Jahiel RI; Vilcek J; Nussenzweig RS
1970 Sep 26;227(265):1350-1351, Nature
— id: 15658, year: 1970, vol: 227, page: 1350, stat: Journal Article,

The clearance rate of sporozoites of Plasmodium berghei from the blood of immune and normal mice
Nussenzweig R; Vanderberg JP; Most H
1970 ;56(Sect II):251-252, Journal of parasitology
— id: 71826, year: 1970, vol: 56, page: 251, stat: Journal Article,

Immunity in simian malaria induced by irraditated sporozoites
Nussenzweig R; Vanderberg JP; Most H; Orton C
1970 ;56(Sect II):252-252, Journal of parasitology
— id: 71827, year: 1970, vol: 56, page: 252, stat: Journal Article,

Protective immunity produced by the bite of X-irradiated mosquitoes infected with Plasmodium berghei
Vanderberg JP; Nussenzweig R; Most H
1970 ;56(Sect II):350-351, Journal of parasitology
— id: 71828, year: 1970, vol: 56, page: 350, stat: Journal Article,

Protective effect of interferon inducers on Plasmodium berghei malaria
Jahiel RI; Nussenzweig RS; Vilcek J; Vanderberg J
1969 Nov;18(6):823-835, American journal of tropical medicine & hygiene
— id: 15662, year: 1969, vol: 18, page: 823, stat: Journal Article,

Specificity of protective immunity produced by x-irradiated Plasmodium berghei sporozoites
Nussenzweig RS; Vanderberg JP; Most H; Orton C
1969 May 3;222(192):488-489, Nature
— id: 29401, year: 1969, vol: 222, page: 488, stat: Journal Article,

Protective immunity produced by the injection of x-irradiated sporozoites of Plasmodium berghei. IV. Dose response, specificity and humoral immunity
Nussenzweig, R; Vanderberg, J; Most, H
1969 Sep;134(10):1176-1182, Military medicine
— id: 71818, year: 1969, vol: 134, page: 1176, stat: Journal Article,

Protective immunity produced by the injection of x-irradiated sporozoites of Plasmodium berghei. V. In vitro effects of immune serum on sporozoites
Vanderberg, J; Nussenzweig, R; Most, H
1969 Sep;134(10):1183-1190, Military medicine
— id: 71819, year: 1969, vol: 134, page: 1183, stat: Journal Article,

Anti-malarial effect of interferon inducers at different stages of development of Plasmodium berghei in the mouse
Jahiel RI; Nussenzweig RS; Vanderberg J; Vilcek J
1968 Nov 16;220(168):710-711, Nature
— id: 15665, year: 1968, vol: 220, page: 710, stat: Journal Article,

Interferon inducers protect mice against plasmodium berghei malaria
Jahiel RI; Vilcek J; Nussenzweig R; Vanderberg J
1968 Aug 23;161(843):802-804, Science
— id: 15666, year: 1968, vol: 161, page: 802, stat: Journal Article,

Protection obtained by vaccination with X-irradiated sporozoites of Plasmodium berghei
Nussenzweig R; Vanderberg JP; Most H; Orton C
Proceeding of the VIIIth International Congress of Tropical Medicine and Malariology [S.l. : s.n.], 1968,
'Teheran, 1968'
— id: 4253, year: 1968, vol: , page: 1271, stat: Chapter,

Further studies on the Plasmodium berghei-Anopheles stephensi--rodent system of mammalian malaria
Vanderberg JP; Nussenzweig RS; Most H
1968 Oct;54(5):1009-1016, Journal of parasitology
— id: 29403, year: 1968, vol: 54, page: 1009, stat: Journal Article,

Protective immunity produced by the injection of x-irradiated sporozoites of Plasmodium berghei. II. Effects of radiation on sporozoites
Vanderberg JP; Nussenzweig RS; Most H; Orton CG
1968 Dec;54(6):1175-1180, Journal of parasitology
— id: 29402, year: 1968, vol: 54, page: 1175, stat: Journal Article,

Protective immunity produced by the injection of x-irradiated sporozoites of plasmodium berghei
Nussenzweig, R S; Vanderberg, J; Most, H; Orton, C
1967 Oct 14;216(5111):160-162, Nature
— id: 71824, year: 1967, vol: 216, page: 160, stat: Journal Article,

Susceptibility of genetically standardized (JAX) mouse strains to sporozoite- and blood-induced Plasmodium berghei infections
Most, H; Nussenzweig, R S; Vanderberg, J; Herman, R; Yoeli, M
1966 Sep;131(9):Suppl:915-Suppl:918, Military medicine
— id: 71817, year: 1966, vol: 131, page: Suppl:915, stat: Journal Article,

Studies on the protective effect of Plasmodium chabaudi infection in mice upon a subsequent infection with another rodent malaria species, plasmodium vinckei
Nussenzweig, R S; Yoeli, M; Most, H
1966 Sep;131(9):Suppl:1237-Suppl:1242, Military medicine
— id: 89964, year: 1966, vol: 131, page: Suppl:1237, stat: Journal Article,

Studies on sporozoite-induced infections of rodent malaria. 3. The course of sporozoite-induced Plasmodium berghei in different hosts
Nussenzweig, R; Herman, R; Vanderberg, J; Yoeli, M; Most, H
1966 Sep;15(5):684-689, American journal of tropical medicine & hygiene
— id: 71822, year: 1966, vol: 15, page: 684, stat: Journal Article,

[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,