Ross S Basch, M.D.

Stem cell markers in amniotic fluid derived cells
Jadhav A.; Basch R.; Chan M.; Strelchenko N.; Chen Z.; Young B.
2012 ;206(1 SUPPL 1):S186-S187, American journal of obstetrics & gynecology
OBJECTIVE: We sought to characterize markers of pluripotency in amniotic fluid derived cells as a non-controversial and readily available source of potentially therapeutic stem cells. STUDY DESIGN: Amniotic fluid stem cells (AFSC) express stem cell surface markers as well as transcription factors. Isolation and enrichment of the stem cell population is essential to their therapeutic potential. We studied expression of stem cell surface markers CD 117, CD 133, SSEA3, SSEA4, TRA 160, TRA 181 and CD90; as well as transcription factors OCT4, SOX2, NANOG and REX 1 by magnetic bead separation, flow cytometry analysis and PCR for transcription factors. Samples were obtained after cytogenetic analysis following routine amniocentesis for age or maternal anxiety in 10 normal patients. Cells were cultured for up to seven passages with analysis after confluence. RESULTS: There was great variation in different samples ability to express the different markers. The most prevalent marker was CD90, a mesenchymal stem cell factor; followed by SSEA4 and TRA160, both embryonic stem cell markers. The other markers were significantly present as well (SSEA3, TRA 160, TRA 181,CD90,OCT4, SOX2, NANOG and REX 1), however CD 117 and CD 133 were often undetectable or present in small amounts. CONCLUSION: There was considerable variation among samples, possibly gestational age related. In Amniotic fluid derived cells, stem cell markers CD90, SSEA4 and TRA160 are expressed in the largest amount with CD90 being the most abundantly expressed marker. Therefore these markers might be used for identification, isolation and enrichment of amniotic fluid stem cells for potential clinical use, since amniotic fluid is widely available and non-controversial as a source of multipotent stem cells.(Table persented)
— id: 149828, year: 2012, vol: 206, page: S186, stat: Journal Article,

Identification and Isolation of Putative Stem Cells from Mouse Placenta
Proudfit, Christine L.; Chan, Michael K.; Basch, Ross S.; Young, Bruce K.
2011 MAR ;18(3):261A-261A, Reproductive sciences (Thousand Oaks, Calif.)
— id: 134893, year: 2011, vol: 18, page: 261A, stat: Journal Article,

Novel Technique for Injection of Fetal and Neonatal Murine Kidneys Using Ultrasound Biomicroscopy
Proudfit, Christine L.; Chan, Michael K.; Basch, Ross S.; Young, Bruce K.
2011 MAR ;18(3):367A-368A, Reproductive sciences (Thousand Oaks, Calif.)
— id: 134894, year: 2011, vol: 18, page: 367A, stat: Journal Article,

Temporal Expression of Renal Markers in Mouse Placenta
Proudfit, Christine L.; Chan, Michael K.; Basch, Ross S.; Young, Bruce K.
2011 MAR ;18(3):187A-187A, Reproductive sciences (Thousand Oaks, Calif.)
— id: 134892, year: 2011, vol: 18, page: 187A, stat: Journal Article,

Levels of elevated circulating endothelial cell decline after tumor resection in patients with pancreatic ductal adenocarcinoma
Sabbaghian, M Shirin; Rothberger, Gary; Alongi, Alexandra P; Gagner, Jean-Pierre; Goldberg, Judith D; Rolnitzky, Linda; Chiriboga, Luis; Hajdu, Cristina H; Zagzag, David; Basch, Ross; Shamamian, Peter
2010 Jul;30(7):2911-2917, Anticancer research
AIM: To evaluate circulating endothelial lineage cells (ELCs) as biomarkers of tumor neovascularization in patients with pancreatic ductal adenocarcinoma (PDAC). MATERIALS AND METHODS: ELCs were isolated from the peripheral blood of patients with PDAC (n=14) or controls (n=17) before and after tumor resection/surgery and quantified using flow cytometry. Vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) were detected in tumor using immunohistochemistry and in plasma using an ELISA technique. RESULTS: Circulating ELC levels were increased in patients with PDAC compared to controls. After PDAC resection, ELC levels declined. ELC level increases were associated with cancer recurrence. VEGF and PlGF were identified in cancer cells and exocrine pancreas cells. Only PlGF was detected in tumor-associated inflammatory cells. Plasma levels of PlGF were higher in patients with PDAC compared to controls. CONCLUSION: Circulating ELCs are a potential biomarker of PDAC neovascularization, and PlGF may be an important target in treatment of PDAC
— id: 111825, year: 2010, vol: 30, page: 2911, stat: Journal Article,

Increased expression of histone deacetylaces (HDACs) and inhibition of prostate cancer growth and invasion by HDAC inhibitor SAHA
Wang, Longgui; Zou, Xuanyi; Berger, Aaron D; Twiss, Christian; Peng, Yi; Li, Yirong; Chiu, Jason; Guo, Hongfeng; Satagopan, Jaya; Wilton, Andrew; Gerald, William; Basch, Ross; Wang, Zhengxin; Osman, Iman; Lee, Peng
2009 ;1(1):62-71, American Journal of Translational Research
Histone deacetetylases (HDACs) are a group of corepressors of transcriptional activators and their levels of expression are potentially dysregulated in prostate cancer. Certain inhibitors of histone deacetylases show anti-tumor activity in prostate cancer cell lines. Here, we systemically studied the expression of HDACs in human prostate cancer and the suppression of prostate cancer growth and invasion by HDAC inhibitor SAHA. HDAC1-5 showed increased expression using a combination of DNA microarray, in-situ hybridization, and immunohistochemistry in benign and malignant human prostate tissue as well as RT-PCR and Western blot analysis on various PCa cell lines. Importantly, HDAC inhibitor SAHA suppressed, in particular, prostate cancer cell growth and invasion determined using cell proliferation and Matrigel invasion assays. The findings of this study show that the expression of HDACs and their associated corepressors are increased in prostate cancer in humans and HDAC inhibitor SAHA could serve as a potential therapeutic agent in prostate cancer in addition to anti-androgens
— id: 115887, year: 2009, vol: 1, page: 62, stat: Journal Article,

Up-regulation of nuclear hormone receptor cofactor TBLRI expression in breast adenocarcinoma
Gellert, LL; Zhang, XM; Wei, JH; Singh, B; Wieczorek, R; Gerald, W; Xu, RL; Lee, P; Basch, R
2008 OCT ;130(4):661-661, American journal of clinical pathology
— id: 86668, year: 2008, vol: 130, page: 661, stat: Journal Article,

Hematopoiesis and stem cell renewal in long-term bone marrow cultures containing catalase
Gupta, Rashmi; Karpatkin, Simon; Basch, Ross S
2006 Mar 1;107(5):1837-1846, Blood
Culturing mouse bone marrow in the presence of catalase dramatically alters hematopoiesis. Granulocyte output is initially increased 4-5 fold. This increase is transient and granulocyte production declines as immature (Sca-1+/LIN-) cells accumulate. One-third of these immature cells have a phenotype (Sca-1+/c-Kit +) characteristic of hematopoietic stem cells. At 2-3 weeks there are >200 fold more Sca-1+/c-Kit+/LIN- cells in treated cultures than in controls. This population contains functional stem cells with both short-term and long-term bone marrow repopulating activity. In addition to myeloid progenitors, this Sca-1+/LIN- population contain a large number of cells that express CD31, CD34, and have an active Tie-2 promoter, indicating that they are in the endothelial lineage. After 3-4 weeks hematopoiesis in treated cultures wanes but if catalase is removed, hematopoiesis resumes. After 7-10 days the cultures are indistinguishable from untreated controls. Thus, protected from H2O2, hematopoietic progenitors multiply and become quiescent. This sequence resembles in vivo development in normal marrow. These results make it clear that peroxide-sensitive regulatory mechanisms play an important role in controlling hematopoiesis ex vivo and presumably in vivo as well. They also indicate that manipulation of the peroxide levels can be used to enhance the growth of hematopoietic stem cells in culture
— id: 61868, year: 2006, vol: 107, page: 1837, stat: Journal Article,

TBLR1 regulates the expression of nuclear hormone receptor co-repressors
Zhang, Xin-Min; Chang, Qing; Zeng, Lin; Gu, Judy; Brown, Stuart; Basch, Ross S
2006 ;7:31-31, BMC Cell Biology
BACKGROUND: Transcription is regulated by a complex interaction of activators and repressors. The effectors of repression are large multimeric complexes which contain both the repressor proteins that bind to transcription factors and a number of co-repressors that actually mediate transcriptional silencing either by inhibiting the basal transcription machinery or by recruiting chromatin-modifying enzymes. RESULTS: TBLR1 [GenBank: NM024665] is a co-repressor of nuclear hormone transcription factors. A single highly conserved gene encodes a small family of protein molecules. Different isoforms are produced by differential exon utilization. Although the ORF of the predominant form contains only 1545 bp, the human gene occupies approximately 200 kb of genomic DNA on chromosome 3q and contains 16 exons. The genomic sequence overlaps with the putative DC42 [GenBank: NM030921] locus. The murine homologue is structurally similar and is also located on Chromosome 3. TBLR1 is closely related (79% homology at the mRNA level) to TBL1X and TBL1Y, which are located on Chromosomes X and Y. The expression of TBLR1 overlaps but is distinct from that of TBL1. An alternatively spliced form of TBLR1 has been demonstrated in human material and it too has an unique pattern of expression. TBLR1 and the homologous genes interact with proteins that regulate the nuclear hormone receptor family of transcription factors. In resting cells TBLR1 is primarily cytoplasmic but after perturbation the protein translocates to the nucleus. TBLR1 co-precipitates with SMRT, a co-repressor of nuclear hormone receptors, and co-precipitates in complexes immunoprecipitated by antiserum to HDAC3. Cells engineered to over express either TBLR1 or N- and C-terminal deletion variants, have elevated levels of endogenous N-CoR. Co-transfection of TBLR1 and SMRT results in increased expression of SMRT. This co-repressor undergoes ubiquitin-mediated degradation and we suggest that the stabilization of the co-repressors by TBLR1 occurs because of a novel mechanism that protects them from degradation. Transient over expression of TBLR1 produces growth arrest. CONCLUSION: TBLR1 is a multifunctional co-repressor of transcription. The structure of this family of molecules is highly conserved and closely related co-repressors have been found in all eukaryotic organisms. Regulation of co-repressor expression and the consequent alterations in transcriptional silencing play an important role in the regulation of differentiation
— id: 68630, year: 2006, vol: 7, page: 31, stat: Journal Article,

The growth arrest-specific gene product Gas6 promotes the survival of human oligodendrocytes via a phosphatidylinositol 3-kinase-dependent pathway
Shankar, Sai Latha; O'Guin, Kathleen; Cammer, Michael; McMorris, F Arthur; Stitt, Trevor N; Basch, Ross S; Varnum, Brian; Shafit-Zagardo, Bridget
2003 May 15;23(10):4208-4218, Journal of neuroscience
Microarray analysis revealed that transcripts for the Axl and Mer receptor tyrosine kinases are expressed at high levels in O4+-immunopanned oligodendrocytes isolated from second trimester human fetal spinal cord. In humans the sole known ligand for the Axl/Rse/Mer kinases is growth arrest-specific gene 6 (Gas6), which in the CNS is secreted by neurons and endothelial cells. We hypothesized that Gas6 is a survival factor for oligodendrocytes and receptor activation signals downstream to the phosphatidylinositol 3 (PI3)-kinase/Akt pathway to increase cell survival in the absence of cell proliferation. To test this hypothesis, we grew enriched human oligodendrocytes for 6 d on a monolayer of NIH3T3 cells stably expressing Gas6. CNP+ oligodendrocytes on Gas6-secreting 3T3 cells had more primary processes and arborizations than those plated solely on 3T3 cells. Also, a twofold increase in CNP+ and MBP+ oligodendrocytes was observed when they were plated on the Gas6-secreting cells. The effect was abolished in the presence of Axl-Fc but remained unchanged in the presence of the irrelevant receptor fusion molecule TrkA-Fc. A significant decrease in CNP+/TUNEL+ oligodendrocytes was observed when recombinant human Gas6 (rhGas6) was administered to oligodendrocytes plated on poly-L-lysine, supporting a role for Gas6 signaling in oligodendrocyte survival during a period of active myelination in human fetal spinal cord development. PI3-kinase inhibitors blocked the anti-apoptotic effect of rhGas6, whereas a MEK/ERK inhibitor had no effect. Thus Gas6 sustains human fetal oligodendrocyte viability by receptor activation and downstream signaling via the PI3-kinase/Akt pathway
— id: 81319, year: 2003, vol: 23, page: 4208, stat: Journal Article,

Gas6 enhances human oligodendrocyte viability and maturation
Shafit-Zagardo, B; Shankar, SL; O'Guin, K; McMorris, FA; Stitt, T; Varnum, B; Basch, RS
2002 Jun;81(7):47-47, Journal of neurochemistry
— id: 32367, year: 2002, vol: 81, page: 47, stat: Journal Article,

The growth arrest specific gene product Gas6 promotes the survival of human oligodendrocytes through a PI3-kinase-dependent pathway
Shankar, SL; O'Guin, K; McMorris, FA; Stitt, TN; Basch, RS; Varnum, B; Shafit-Zagardo, B
2002 NOV ;13(4):289A-290A, Molecular biology of the cell
— id: 37189, year: 2002, vol: 13, page: 289A, stat: Journal Article,

Immortalized multipotential mesenchymal cells and the hematopoietic microenvironment
Dormady SP; Bashayan O; Dougherty R; Zhang XM; Basch RS
2001 Feb;10(1):125-140, Journal of hematotherapy & stem cell research
In an attempt to analyze the cellular and molecular basis of the capacity of bone marrow stromal cells to support hematopoiesis in culture, we developed a series of murine stromal cell lines from a single long-term bone marrow culture (BMC). The cytokines produced by these cells were analyzed using immunohistochemical techniques, ribonuclease protection assays (RPA) and RT-PCR. We examined the capacity of these cloned cell lines to replace primary bone marrow-derived stromal cells in long-term bone marrow cultures (LT-BMC) and sought correlations between the capacity to support hematopoiesis in culture with the production of known cytokines. These immortalized lines replicate many of the functions of the hematopoietic microenvironment. They express cytokines known to play a role in hematopoiesis. All of the lines constitutively express mRNA for PBSF (SDF-1), macrophage colony-stimulating factor (M-CSF), stem cell factor (SCF), FLT-3, thrombopoietin (TPO), interleukin 7 (IL-7), leukemia inhibitory factor (LIF), tumor necrosis factor-beta (TNF-beta), and interferon-gamma (IFN-gamma). Most lines also express granulocyte-macrophage colony-stimulating factor (GM-CSF) and G-CSF. They vary in their expression of IL-6, tumor growth factor-beta1 (TGF-beta1), TGF-beta2, and TNF-alpha. Growing these lines in the presence of cytokines that influence hematopoiesis alters the levels of cytokine message. The most striking effects were produced by TNF-alpha. In addition to the cytokine mRNAs, the cell lines express factors associated with bone formation such as osteoblast-specific factor-2 (OSF-2) and bone morphogenetic protein-1 (BMP-1). They also express the neural cell-adhesion molecule neuropilin and neurotrophic factors including nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF). Several of the lines can maintain hematopoiesis in culture, as measured by the continuous production of myeloid colony-forming cells (CFU-c), for months. This capacity to support hematopoiesis does not correlate with any pattern of cytokine expression. Several of these lines also support the growth of human hematopoietic cells, and human CFU-c can be detected in the cultures in which CD34(+) bone marrow cells (BMC) are cultured on murine stromal cells. No correlation between the production of any of the known cytokines and the ability to support murine hematopoiesis was detected. In addition, there was no correlation between the capacity to support murine hematopoiesis and the capacity to maintain human HSC. Despite repeated cloning, the lines remain heterogeneous and are capable of producing cells with the properties of fibroblasts, osteoblasts, adipocytes, and myoblasts. In addition to the cytokine mRNAs, the cell lines express factors associated with bone formation such as OSF-2 and BMP-1. They also express the neural cell-adhesion molecule neuropilin and neurotrophic factors including NGF and BDNF
— id: 26759, year: 2001, vol: 10, page: 125, stat: Journal Article,

Thrombin induces the release of angiopoietin-1 from platelets
Li JJ; Huang YQ; Basch R; Karpatkin S
2001 Feb;85(2):204-206, Thrombosis & haemostasis
Blood platelets contain angiopoietin-1, a growth factor essential for blood vessel development via stabilization of proliferating endothelial cells. It has recently been reported that angiopoietin-1 can act as a vascular stability factor (Nature Medicine 6:460, 2000). In investigating the normal tissue distribution of angiopoietin-1 from surgically-removed frozen specimens by RT-PCR, we found it consistently present in platelets and megakaryocytes, usually absent in relatively non-vascular tissue: breast, colon, lung, skin, kidney, thyroid, testicle, cervix and occasionally present in tissue enriched with vasculature: prostate, endometrium, ovary, under conditions in which mRNA stability was verified by the positive detection of internal control, actin mRNA. The consistent distribution in platelets and relatively absent distribution in non-vascular normal tissue suggested that the well-known role of platelets in maintaining vascular stability, may in part be due to platelet release of angiopoietin-1 following platelet activation. In this communication we report the incidence of Ang-1 in various normal tissues and demonstrate that thrombin-treated human platelets release angiopoietin-1 in vitro
— id: 21237, year: 2001, vol: 85, page: 204, stat: Journal Article,

Hematopoietic progenitor cells grow on 3T3 fibroblast monolayers that overexpress growth arrest-specific gene-6 (GAS6) [In Process Citation]
Dormady SP; Zhang XM; Basch RS
2000 Oct 24;97(22):12260-12265, Proceedings of the National Academy of Sciences of the United States of America
Pluripotential hematopoietic stem cells grow in close association with bone marrow stromal cells, which play a critical role in sustaining hematopoiesis in long-term bone marrow cultures. The mechanisms through which stromal cells act to support pluripotential hematopoietic stem cells are largely unknown. This study demonstrates that growth arrest-specific gene-6 (GAS6) plays an important role in this process. GAS6 is a ligand for the Axl (Ufo/Ark), Sky (Dtk/Tyro3/Rse/Brt/Tif), and Mer (Eyk) family of tyrosine kinase receptors and binds to these receptors via tandem G domains at its C terminus. After translation, GAS6 moves to the lumen of the endoplasmic reticulum, where it is extensively gamma-carboxylated. The carboxylation process is vitamin K dependent, and current evidence suggests that GAS6 must be gamma-carboxylated to bind and activate any of the cognate tyrosine kinase receptors. Here, we show that expression of GAS6 is highly correlated with the capacity of bone marrow stromal cells to support hematopoiesis in culture. Nonsupportive stromal cell lines express little to no GAS6, whereas supportive cell lines express high levels of GAS6. Transfection of the cDNA encoding GAS6 into 3T3 fibroblasts is sufficient to render this previously nonsupportive cell line capable of supporting long-term hematopoietic cultures. 3T3 cells, genetically engineered to stably express GAS6 (GAS6-3T3), produce a stromal layer that supports the generation of colony-forming units in culture (CFU-c) for up to 6 wk. Hematopoietic support by genetically engineered 3T3 is not vitamin K dependent, and soluble recombinant GAS6 does not substitute for coculturing the hematopoietic progenitors with genetically modified 3T3 cells
— id: 14362, year: 2000, vol: 97, page: 12260, stat: Journal Article,

Compensation by fibroblast growth factor 1 (FGF1) does not account for the mild phenotypic defects observed in FGF2 null mice [published erratum appears in Mol Cell Biol 2000 May;20(10):3752]
Miller DL; Ortega S; Bashayan O; Basch R; Basilico C
2000 Mar;20(6):2260-2268, Molecular & cellular biology
Fibroblast growth factor 1 (FGF1) and FGF2, the prototypic members of the FGF family of growth factors, have been implicated in a variety of physiological and pathological processes. Unlike most other FGFs, FGF1 and FGF2 are ubiquitously expressed and are not efficiently secreted. Gene knockouts in mice have previously demonstrated a role for FGF2 in brain development, blood pressure regulation, and wound healing. The relatively mild phenotypic defects associated with FGF2 deletion led to the hypothesis that the continued expression of other FGFs partially compensated for the absence of FGF2 in these mice. We now report our generation of mice lacking FGF1 and their use, in combination with our previously described FGF2 null mice, to produce mice lacking both FGF1 and FGF2. FGF1-FGF2 double-knockout mice are viable and fertile and do not display any gross phenotypic defects. In the double-knockout mice we observed defects that were similar in extent to those previously described for the FGF2 null mice. Differences in the organization of neurons of the frontal motor cortex and in the rates of wound healing were observed. We also observed in FGF2(-/-) mice and in FGF1-FGF2 double-knockout mice novel impairments in hematopoiesis that were similar in severity. Essentially no abnormalities were found in mice lacking only FGF1. Our results suggest that the relatively mild defects in FGF2 knockout animals are not a consequence of compensation by FGF1 and suggest highly restricted roles for both factors under normal developmental and physiological conditions
— id: 11824, year: 2000, vol: 20, page: 2260, stat: Journal Article,

Compensation by fibroblast growth factor 1 (FGF1) does not account for the mild phenotypic defects observed in FGF2 null mice (vol 20, pg 2260, 2000)
Miller, DL; Ortega, S; Bashayan, O; Basch, R; Basilico, C
2000 MAY ;20(10):3752-3752, Molecular & cellular biology
— id: 54696, year: 2000, vol: 20, page: 3752, stat: Journal Article,

Identification of four human cDNAs that are differentially expressed by early hematopoietic progenitors [In Process Citation]
Zhang X; Dormady SP; Basch RS
2000 Nov;28(11):1286-1296, Experimental hematology
The molecular processes that maintain the stem cell pool are largely unknown. Using polymerase chain reaction-driven subtraction, we examined genes that are differentially expressed by early hematopoietic progenitors. We expected that identifying genes that are uniquely expressed by the earliest precursors would provide insight into the mechanism(s) through which stem cell number is maintained and differentiation is regulated.Using CD34(+)CD38(-) cells as starting material, we identified four mRNAs, expressed by these cells, that are either absent or present in reduced amounts in more mature CD34(+)CD38(+) cells. One of these cDNAs (C40) encodes a known member of the subfamily of protein phosphatases (CL100) that exhibits dual substrate specificity for phosphotyrosine- and phosphoserine/threonine-containing substrates and specifically inactivates MAP kinases. This phosphatase has been shown to play a role in regulating the differentiation of several cell types. The second cDNA (C23) is identical to LR11 (gp250), a member of the low-density lipoprotein receptor family. LR11 is unusual in that, in addition to 11 ligand-binding repeats, it contains a series of fibronectin type III repeats near its carboxyl terminal end that are similar to those found in cytokine receptors. It is highly expressed in developing brain, but hematopoietic expression has not been reported. The 178-bp fragment that we originally cloned is part of a 4,145-bp 3' untranslated region (UTR) that had not been previously sequenced and is among the largest human 3' UTRs ever reported. The other isolates (C21 and C12) do not correspond to known protein sequences. They are homologous to EST sequences from a fetal brain library. C21 encodes a previously unknown gene that is a member of the WD-40 family. An open reading frame encoding a 515 amino acid protein has been identified.Four mRNAs, differentially expressed by CD34(+)CD38(-) human bone marrow cells, have been identified. Although this population is highly enriched for early hematopoietic progenitors, none of these genes encodes a message whose expression is limited to the hematopoietic system. They all are expressed in a variety of tissues, suggesting that they are involved in processes that are fundamental to the development of many cell types. All of these cDNAs possess atypically long 3' UTRs, and one of them is among the longest ever described. Their differential expression by immature hematopoietic cells, in contrast to more mature cells, suggest that long 3' UTRs may be characteristic of genes that play a regulatory role during development
— id: 14361, year: 2000, vol: 28, page: 1286, stat: Journal Article,

mVH1, a dual-specificity phosphatase whose expression is cell cycle regulated.[In Process Citation]
Zhang XM; Dormady SP; Chaung W; Basch RS
2000 Dec;11(12):1154-1156, Mammalian genome
— id: 14360, year: 2000, vol: 11, page: 1154, stat: Journal Article,

Expression of CD41 and c-mpl does not indicate commitment to the megakaryocyte lineage during haemopoietic development
Basch RS; Zhang XM; Dolzhanskiy A; Karpatkin S
1999 Jun;105(4):1044-1054, British journal of haematology
Haemopoietic progenitors with the phenotype expected of early megakaryocyte precursors (CD34+ CD41+) were isolated from normal human bone marrow or induced in culture from CD34+ CD41- bone marrow cells by treatment with thrombopoietin (TPO) or IL-3. We found that although this population included the majority of cells that can form CFU-MK in culture, it also contained both erythroid and myeloid progenitors. The clonogenic potential of the CD34+ CD41+-induced cells was greater than that of isolated CD34+ CD41+ cells in that the isolated cells only formed CFU-MK and BFU-e, whereas the induced cells formed myeloid colonies as well. Glycophorin was found on isolated CD34+ CD41+ cells, not on induced cells. Its presence distinguished between MK and erythroid progenitors. Separation of a CD34+ CD41+ glycophorin A+ population resulted in the isolation of a highly purified population of BFU-e. A major portion of the cells that expressed CD34+ CD41+, in either cohort, were of the erythroid lineage. True MK progenitors were present in the CD34+ population in greater proportion than in whole marrow and were further enriched amongst CD34+ populations that expressed CD41. The presence of the thrombopoietin (TPO) receptor, c-mpl, did not correlate with inducibility of the gpIIbIIIa complex since essentially all CD34+ progenitors, including the earliest identifiable human haemopoietic progenitors (CD34+ CD38- cells), expressed c-mpl mRNA detectable by PCR regardless of their ultimate fate. Thus neither the expression of CD41 nor the expression of c-mpl was predictive of commitment to the MK lineage
— id: 6230, year: 1999, vol: 105, page: 1044, stat: Journal Article,

Complementary and antagonistic effects of IL-3 in the early development of human megakaryocytes in culture
Dolzhanskiy A; Hirst J; Basch RS; Karpatkin S
1998 Feb;100(2):415-426, British journal of haematology
The effect of IL-3 on the early steps in the growth and development of megakaryocytes (MK) in culture has been studied. Although thrombopoietin (TPO) by itself could support the development of mature CD41+ MK from pre-MK, the number of cells produced was greatly augmented by the addition of IL-3 and SCF. IL-3 was also able to support the growth of MK colonies in semi-solid media (CFU-MK). The CD41+ cells that developed in suspension cultures containing IL-3 differed phenotypically from those that developed without this agent. Cells grown in the presence of IL-3 lost CD34 expression more rapidly, expressed lower levels of the platelet glycoproteins gpIIb-IIIa and Ib and achieved lower degrees of polyploidy than in the absence of IL-3. The inhibitory effects of IL-3 were not a consequence of the dilution of the mature cells by increased numbers of immature cells since it was observed under conditions in which IL-3 did not stimulate MK growth. The results obtained in these cultures suggest that IL-3 plays an important role in early MK development, but inhibits further maturation after endoreduplication begins. Thus, prolonged contact with IL-3 results in the appearance of cells that do not mature normally
— id: 7552, year: 1998, vol: 100, page: 415, stat: Journal Article,

Growth of human hematopoietic cells in immunodeficient mice conditioned with cyclophosphamide and busulfan
Basch RS; Quito FL; Beh J; Hirst JA
1997 ;15(4):314-323, Stem cells
Human hematopoietic cells survive and proliferate for at least 10 weeks in severe combined immunodeficient mice prepared with the cytotoxic drugs busulfan and cyclophosphamide. The human cells growing in the mice can be detected by in situ hybridization using a probe detecting human repetitive DNA or by staining the cells with antihuman antibodies (anti-CD45 and anti-HLA I). Busulfan/cyclophosphamide-treated mice were injected with a wide range of cell doses, ranging from 5 to 50 million unfractionated bone marrow cells and 2 to 40 million low density bone marrow cells. Animals were killed at 1, 3, 5, 7 and 10 weeks after transplantation. Human cells were found in many animals and could be detected as early as one week after transplantation. The peak of repopulation was at two to five weeks, but in some animals human cells could be detected for as long as 10 weeks. Many of the human cells expressed high levels of glycophorin, but mature human erythrocytes were not found. The human cells were not uniformly distributed throughout the marrow. They grew in small clusters in the subepiphyseal region. The extent of human hematopoietic repopulation in the mouse was extremely variable. At no time and at no dose was repopulation achieved in all of the animals. Treatment with human growth factors is not necessary for the survival of the human hematopoietic cells but, in their absence, normal hematopoiesis does not occur
— id: 7109, year: 1997, vol: 15, page: 314, stat: Journal Article,

The development of human megakaryocytes: III. Development of mature megakaryocytes from highly purified committed progenitors in synthetic culture media and inhibition of thrombopoietin-induced polyploidization by interleukin-3
Dolzhanskiy A; Basch RS; Karpatkin S
1997 Jan 15;89(2):426-434, Blood
Megakaryocyte (MK) progenitors, CD34+CD41+ cells, were isolated from human bone marrow with a purity greater than 98% and a viability of 95%, using affinity techniques with magnetic beads followed by fluorescence-activated cell sorting. These cells were incubated in synthetic media containing the cytokines thrombopoietin (TPO), interleukin-3 (IL-3), stem cell factor (SCF), and IL-6, obviating the confounding effects of serum growth factors or cytokine secretions of non-MK cells on MK maturation. MK number, MK colony-forming units (CFU-MK), and MK ploidy and phenotype were examined during 7 days in culture. TPO in serum-free cultures without any other exogenously added cytokine supported MK growth and maturation. SCF synergized with TPO to augment MK production and maturation and could partially replace it under some conditions. Both TPO and IL-3 alone increased MK number (12- and 5-fold, respectively) and CFU-MK (approximately 15-fold each). SCF alone had no effect on MK proliferation in the absence of TPO, but increased both MK number and CFU-MK by 1.5- to 2.0-fold in the presence of TPO. When combined with IL-3, SCF increased both MK number and CFU-MK by 15- to 20-fold in the absence of TPO. In the presence of TPO, the combination of IL-3 and SCF produced only modest increases (1.5- to 2.0-fold) in both MK number and CFU-MK. The proportion of polyploid MK increased greater than fivefold in the presence of TPO. SCF had little effect on MK ploidy in the presence of TPO, but enhanced ploidy twofold to threefold in the absence of TPO. IL-3 alone never increased the level of polyploidization. Rather, it consistently inhibited TPO- and SCF-induced polyploidization of MK. This inhibition was observed in cultures with or without SCF or IL-6. Although IL-3 also supported the proliferation of CD41+ cells and CFU-MK production, the cells that developed under the influence of IL-3 were phenotypically unusual (CD41dim, CD42dim) and of relatively low ploidy. Mature MK were not produced. When added with TPO, IL-3 suppressed polyploidization. Therefore, TPO stimulates MK growth and maturation, whereas IL-3 stimulates growth without maturation and may serve to conserve the immature MK compartment
— id: 8333, year: 1997, vol: 89, page: 426, stat: Journal Article,

The development of human megakaryocytes. II. CD4 expression occurs during haemopoietic differentiation and is an early step in megakaryocyte maturation
Basch RS; Dolzhanskiy A; Zhang XM; Karpatkin S
1996 Sep;94(3):433-442, British journal of haematology
CD4 expression is not limited to T cells and monocytes. In both mouse and man the antigen has been detected on some early haemopoietic progenitors and we have shown that some mature megakaryocytes (MK) express CD4, the surface molecule that serves as the high-affinity receptor for human immunodeficiency virus type-1 (HIV-1). Using a serum-free culture system in which sorted CD34+ haemopoietic progenitors are cultured with thrombopoietin (TPO), IL-3, IL-6 and SCF, we now show that CD4 expression is induced in virtually all developing haemopoietic cells. This phenomenon was particularly striking in the MK lineage, where CD4 expression began whilst the cells were still CD34+ but after they expressed CD41 (GPIIb/IIIa). CD4 expression and endomitotic polyploidization occur at the same time in MK development. In culture, maximum CD4 expression occurred 4-6 d after CD41 expression and lasted for a few days. Expression of CD4 declined gradually thereafter and most MK were CD4- by the end of the culture period. The amount of CD4 on the surface of some MK, as measured by intensity of fluorescence staining, exceeded that of normal monocytes and approached the brightness of T cells. Appearance of the surface antigen correlated with the presence of mRNA for CD4, as measured by RT-PCR
— id: 12556, year: 1996, vol: 94, page: 433, stat: Journal Article,

Evaluation of presence and functional activity of potentially self-reactive T cells in aged mice
Crisi GM; Tsiagbe VK; Russo C; Basch RS; Thorbecke GJ
1996 Mar;8(3):387-395, International immunology
Autoimmunity is known to increase in aging. A possible factor could be an alteration in the T cell repertoire with advancing age. Antibodies to the variable region of the beta chain of the TCR activate T cells and can serve as probes for analysis of the T cell repertoire. We have used V beta 3 and V beta 17a antibodies to determine the presence and functionality of normally deleted T cells bearing potentially self-reactive TCR in peripheral lymphoid tissue and blood from aged (SJL/J x BALB/c) F1, LAF1 and BALB/c mice. Although an occasional 20- to 24-month-old mouse exhibited V beta 3+ or V beta 17a+ T cells in their lymph nodes or peripheral blood lymphocytes (PBL) slightly above the range for normal young mice of these I-E+ strains, there was no striking 'escape' from the normal thymic deletion process. However, responsiveness to anti-V beta 3 and anti-V beta 17a was slightly higher in aged, and particularly in aged thymectomized (TX), than in young mice. This was in contrast to proliferative responses to stimulation with antibody to the normally expressed V beta 8, which were lower in the lymph nodes from aged than from young mice. The PBL of some 30- to 36-month-old mice were also examined. Enhanced numbers of 'forbidden' V beta bearing T cells were seen more frequently at this age. In spite of the age-related decrease in overall CD4/CD8 T cell ratios in all organs, the mice with relatively high V beta 17a + T cells exhibited proportionally more CD4+ cells in that V beta population. We conclude that the 'forbidden' T cells that respond to anti-V beta stimulation in the 20- to 24-month-old mice are most likely to extra-thymic origin, since they were more readily detectable in aged TX mice. Potentially self-reactive Cd4 (and CD8) single-positive T cells were detectable in PBL only in very aged (30-36 months old) euthymic mice
— id: 8722, year: 1996, vol: 8, page: 387, stat: Journal Article,

Development of human megakaryocytes: I. Hematopoietic progenitors (CD34+ bone marrow cells) are enriched with megakaryocytes expressing CD4
Dolzhanskiy A; Basch RS; Karpatkin S
1996 Feb 15;87(4):1353-1360, Blood
CD34 is expressed by essentially all human hematopoietic progenitors including cells of the megakaryocyte (MK) lineage. We have previously reported CD4 expression by some human MK (Blood 81:2,664, 1993). To study the role of maturation on CD4 expression by MK, we examined CD34+ bone marrow cells for their expression of CD41 (GPIIb-GPIIIa) and CD4 with specific monoclonal antibody (MoAb)-fluorochrome conjugates and for DNA polyploidization with propidium iodide or 7-aminoactinomycin D (7-AAD). Surprisingly, MK were at least 20-fold more common in the CD34+ progenitor pool (approximately 10%) than in the more mature CD34+ population (approximately 0.5%) of low density bone marrow cells. CD4 expression correlated with markers of immaturity in that CD4 was enriched among CD34+ cells, and the proportion of CD4+ MK declined with increasing ploidy. Almost all CD34+ polyploid ( > or = 8N) cells were CD4+. Despite these correlations with immaturity, CD34+CD4+ MK precursors were unable to produce MK colony-forming units (CFU-MK) when cultured under conditions that supported the growth of CFU-MK from CD34+CD4- MK lineage cells. MK became polyploid before the loss of either CD34 or CD4 expression. The presence of CD4 on these cells correlates with the onset of endomitotic reduplication and is associated with the loss of the ability of these cells to undergo normal mitotic division. The role of CD4 on immature MK as a differentiation antigen and/or receptor for the human immunodeficiency virus (HIV)-1 virus remains to be determined
— id: 12643, year: 1996, vol: 87, page: 1353, stat: Journal Article,

Effects of fibroblast growth factor-4 (k-FGF) on long-term cultures of human bone marrow cells
Quito FL; Beh J; Bashayan O; Basilico C; Basch RS
1996 Feb 15;87(4):1282-1291, Blood
Fibroblast growth factor-4 (FGF-4), a highly mitogenic protein encoded by the k-fgf/hst oncogene, stimulates the growth of a variety of cells of mesenchymal and neuroectodermal origin. Addition of FGF-4 to human long-term bone marrow cultures increased both the cell density of the stromal layer and the number of hematopoietic colony forming cells in the cultures in a dose-dependent manner. Hematopoiesis in the stromal layer persisted for up to 8 months. Erythropoiesis was maintained for up to 4 weeks, but granulocytes were the predominant nonadherent cell type. Cultures treated with FGF had increased numbers of monocytes compared with control cultures and some CD14+, CD45+ monocytes could still be detected after 8 months of continuous culture. The addition of the growth factor increased the rate of growth of the stromal layer and appeared to delay its senescence. Subcultures made in the presence of FGF-4 had up to 10-fold increases in plating efficiency and grew as relatively uniform monolayers. These subcultures retained the capacity to support hematopoiesis for several months, while untreated subcultures, made without FGF-4, grew erratically and generally lost the capacity to support hematopoiesis within 4 to 6 weeks. The improved growth after subculture greatly enhanced the reliability of limit-dilution assays of multipotential hematopoietic stem cells that use stromal cell monolayers. The primary effect of FGF-4 appeared to be on the stromal cells of the long-term bone marrow cultures, but a direct effect on hematopoietic progenitors could not be ruled out
— id: 7034, year: 1996, vol: 87, page: 1282, stat: Journal Article,

Flow cytometric determination of apoptosis in heterogeneous cell populations
Dolzhanskiy A; Basch RS
1995 Mar 13;180(1):131-140, Journal of immunological methods
We have shown that apoptosis and surface antigen expression can be detected simultaneously using multicolor flow cytometry. Apoptosis was measured with an in situ assay that makes use of the ability of the enzyme terminal deoxyribonucleotidyl transferase to catalyze the addition of biotinylated nucleotides to the free 3'-OH groups produced during endonucleolytic cleavage of DNA. The incorporation of the biotinylated nucleotides was quantified using fluorochrome-coupled streptavidin. Immunofluorescence was used to identify the phenotype of apoptotic cells using three color flow cytometry. In model systems, apoptosis was detected in human PBMNC treated with the DNA topoisomerase I inhibitor CAM and in murine thymocytes treated with DEX. The simultaneous application of this method for detecting apoptosis and immunofluorescence offers several advantages. (1) Apoptotic and necrotic cells can be distinguished. (2) The phenotype of the cells undergoing apoptosis can be determined in heterogeneous systems. Thus, we could show that T cells are relatively resistant to CAM-induced apoptosis compared to other peripheral blood mononuclear cells and that both double negative and single positive thymocytes are resistant to steroid-induced apoptosis. (3) The flow cytometric TdT assay to detect apoptosis-associated DNA degradation method is extremely sensitive compared with gel electrophoresis. As few as 2-5 x 10(3) cells give an adequate signal and it is possible to detect DNA strand breaks even when only a small proportion of the cells are undergoing apoptosis. Neither the sensitivity nor specificity of this method can be matched by any electrophoretic method of detecting apoptosis
— id: 6607, year: 1995, vol: 180, page: 131, stat: Journal Article,

Early thymic regeneration after irradiation
Fredrickson GG; Basch RS
1994 May-Jun;18(3):251-263, Developmental & comparative immunology
Whole body irradiation produces profound thymic atrophy. After sublethal irradiation, regeneration begins promptly and the earliest regeneration is from radioresistant intrathymic precursors. The progeny of these precursors expand rapidly and restore thymic cellularity to near normal within 2 weeks. We have used monoclonal antibodies specific for a variety of differentiation markers of the T lineage to analyze the early events in thymic regeneration. A three-color flow microfluorometric analysis revealed that the majority of the cells found early in the regenerative process have the phenotype of mature T cells. These include CD4-/CD8-; CD3hi as well as CD4+/CD8-; CD3hi and Cd4-/CD8+; CD3hi. The proportion of cells with mature phenotypes declines rapidly between day 6 and day 12. Not all of the early appearing cells have mature phenotypes. Among the early cells that do not express CD3 are both CD4 and CD8 single positive cells that express HSA and resemble the intrathymic precursors found in other systems. In these mice CD4 single positive predominate. There are other cells that are HSA positive but express low levels of CD4 and very low levels of Thy-1. These appear to include the earliest members of the T-lineage. In addition to relatively mature conventional T cells and early progenitors, the early developing population includes cells that express markers of the T-cell lineage including the T-cell receptor but do not express Thy-1. These Thy-1 negative T cells comprise a significant number of the earliest cells found after regeneration
— id: 6620, year: 1994, vol: 18, page: 251, stat: Journal Article,

Human megakaryocytes have a CD4 molecule capable of binding human immunodeficiency virus-1
Kouri YH; Borkowsky W; Nardi M; Karpatkin S; Basch RS
1993 May 15;81(10):2664-2670, Blood
Most human megakaryocytes (MGKs) express the CD4 antigen on their surface. Approximately 25% have a CD4 receptor density comparable to that of CD4+ T cells (Basch et al, Proc Natl Acad Sci USA 87:8085, 1990). In these studies, we show: (1) the presence of mRNA for CD4 in human MGKs; (2) the binding of human immunodeficiency virus-1 (HIV-1) to human MGKs; (3) the inhibition of binding by anti-CD4 (Leu3a) antibody or rCD4; (4) the infection of a human MGK line, CHRF-288 with HIV-1; and (5) inhibition of infection with anti-CD4. Human MGKs have mRNA for CD4 as shown by in situ hybridization with an RNA probe synthesized from a 3-kb cDNA sequence of plasmid pSP65.T4.8 containing the full-length CD4 sequence. MGKs (23% +/- 17%) bound HIV-1, as determined by anti-gp120 and anti-CD41 staining. Binding to human MGKs could be inhibited 55% to 75% with anti-CD4 or rCD4, respectively. Infection of a CD4+ MGK line (CHRF-288) could be accomplished with HIV-1, as determined by proviral DNA polymerase chain reaction and p24 production. Preincubation with anti-CD4 inhibited apparent proviral DNA infection by 100% and p24 production by 65% to 70%. Thus, human MGKs have a CD4 receptor capable of binding HIV-1. Using this receptor, HIV-1 can infect cells representative of the MGK lineage
— id: 13159, year: 1993, vol: 81, page: 2664, stat: Journal Article,

Separation of self-renewing hematopoietic progenitors on the basis of CD45 (T-200) antigen expression
Basch RS; Oh YD; Saha CS; Fredrickson GG; Hirst JA
1992 Jan;20(1):11-16, Experimental hematology
Using monoclonal antibodies recognizing the shared determinants of the CD45 (T-200) antigen we have been able to distinguish spleen colony-forming units (CFU-s) whose progeny are self-renewing from other colony formers on the basis of their quantitative expression of this antigen(s). We have also been able to identify a population of cells that is capable of producing 12-day colonies but has only a limited capacity to produce 8-day colonies. CFU-s8 are found primarily in the dim T-200 population, whereas CFU-s12 were found in both the bright and dim population, but the cells within the colonies produced by these two populations differ in their capacity for self-renewal as CFU-s. Only the colonies dissected after 12 days from the spleens of mice receiving T-200-bright bone marrow cells contained significant numbers of cells that were capable of forming colonies after retransplantation. We calculate the frequency of these cells in total bone marrow to be approximately 1 in 5000
— id: 13756, year: 1992, vol: 20, page: 11, stat: Journal Article,

B-cell subsets and platelet counts in HIV-1 seropositive subjects
Kouri YH; Basch RS; Karpatkin S
1992 Jun 13;339(8807):1445-1446, Lancet
A subset of B lymphocytes positive for the CD5 antigen have been implicated in several autoimmune disorders. To investigate their role in human immunodeficiency virus type 1 (HIV-1) infection, we studied peripheral-blood B and T lymphocytes from HIV-1-positive patients with (n = 13) and without (n = 18) thrombocytopenia, 8 patients with classic autoimmune thrombocytopenia, and 16 healthy controls. The proportion of CD5-positive B cells was significantly higher in the HIV-1-positive thrombocytopenic patients than in the healthy controls, as a result of both higher numbers of CD5-positive B cells and lower numbers of CD5-negative B cells. Platelet count was positively correlated with CD5-negative B-cell count (r = 0.6, p less than 0.001) and negatively correlated with proportion of B cells that were CD5 positive (r = -0.5, p less than 0.01) among the HIV-1-positive patients. The high concentrations of IgM-containing immune complexes in HIV-1-positive patients with autoimmune disorders may be due to changes in the CD5-positive B-cell subset
— id: 14363, year: 1992, vol: 339, page: 1445, stat: Journal Article,

The IgA receptors of T560, a murine IL-4-secreting, CD5-, IgG2A kappa+, BrMRBC-binding B lymphoma
Phillips-Quagliata JM; Rao TD; Maghazachi AA; Faria AM; Basch RS
1992 May 4;651:491-493, Annals of the New York Academy of Sciences
— id: 13598, year: 1992, vol: 651, page: 491, stat: Journal Article,

T560: an (H-2b x H-2a) F1 hybrid, phosphorylcholine (PC)-binding, murine B cell lymphoma that bears receptors for IgA and IgG, presents antigen and secretes IL-4
Rao TD; Maghazachi AA; Faria AM; Basch RS; Phillips-Quagliata JM
1992 Feb;4(2):107-118, International immunology
We describe T560, a tissue culture-adapted B lymphoma derived from the gut-associated lymphoid tissue (GALT) of a (B10 x B10.H-2a H-4b)F1 hybrid mouse. This lymphoma is interesting and useful not only because it bears an unusual IgA receptor, fully described elsewhere, but also because it is potentially capable of presenting antigen to T cells restricted by the MHC of either parent. Here we document that T560 cells are IgG2a kappa +, Ia+, B220+, J11d.2+, CD3-, CD4-, CD5-, Mac 1-, Mac 2-, non-specific esterase-. They bind bromelain-treated mouse RBC (BrMRBC) in a PC chloride-inhibitable manner but do not bind SRBC, ox RBC (ORBC) or TNP-ORBC. Two lines, T560.1 and T560.2, and several clones are available. T560.1 and its clones contain low numbers of IgA rosette-forming cells (RFC), intermediate numbers of IgG2a RFC and moderately high numbers of IgG2b RFC; T560.2 and its clones contain moderately high numbers of IgA RFC and low numbers of both IgG2a and IgG2b RFC. Both lines stimulate both B10 and B10.A cells in mixed lymphocyte reactions (MLR) and present keyhole limpet hemocyanin (KLH) to KLH-reactive T cells. T560.2 populations are, however, more efficient possibly because they have somewhat higher proportions of brightly fluorescent Ia+ cells and secrete larger quantities of lymphokine than T560.1 cells. They present PC-conjugated KLH (PC-KLH) approximately 20 times more efficiently than unconjugated KLH, suggesting that their PC binding receptors function in antigen uptake. They constitutively produce IL-1, IL-4 and IL-6, but not IL-2, IL-5 or TGF beta. Neither their IgA nor their IgG receptor expression is affected by IL-4 or by IFNs-alpha, -beta, or -gamma. In their ability to bind BrMRBC and secrete IL-4, they resemble the CH12 lymphoma but differ from it in that they are of F1 hybrid origin, are CD5-, bear IgG2a rather than IgM, do not bind sheep erythrocytes and have a receptor for IgA not present on CH12
— id: 13704, year: 1992, vol: 4, page: 107, stat: Journal Article,

Thymic stromal cells in culture. I. Establishment and characterization of a line which is cytotoxic for normal thymocytes and produces hematopoietic growth factor(s)
Brown KM; Spirito S; Basch RS
1991 May;134(2):442-457, Cellular immunology
Lines of thymic stromal cells have been established. One of these, designated TS-9, has been cloned and studied extensively. This line expresses both acid and alkaline phosphatases. Despite repeated cloning, TS-9 cells remain morphologically heterogeneous. The origin of these cells is not clear. They express low levels of immunologically identifiable cytokeratins, produce laminin, a basement membrane protein, but express antigens typically found on bone marrow stromal cells. The TS-9 cells are MHC Class I+ but Class II-. They express the Thy-1, Pgp-1, and Mac-2 antigens but not other lineage markers of T cells or macrophages. Coculturing TSC with normal thymocytes or with the CTLL-1 cell line leads to a profound inhibition of lectin-induced and/or IL-2 induced T cell proliferation. This requires direct cell-cell contact and ultimately results in the death of the bound lymphocytes. It cannot be reproduced by culturing the thymocytes with TSC culture supernatants. These supernatants do contain hematopoietic growth factor(s) which augment the growth of some T lineage cells and support the growth of monocytic colonies in semi-solid culture medium. Both normal thymocytes and a variety of T cell tumors bind to TSC but only the normal cells are killed as a consequence of this interaction. Neither the binding nor the killing appear to be MHC restricted. We suggest that this killing may provide a model for the effector mechanism of the negative selection imposed by the thymus on developing T cells
— id: 14059, year: 1991, vol: 134, page: 442, stat: Journal Article,

Thymic stromal cells in culture. 2. Binding of normal thymocytes to a cloned thymic stromal cell line
Palmer DK; Brown KM; Basch RS
1991 Dec;138(2):473-481, Cellular immunology
Thymic stromal cell line TS-9 was found to selectively bind a subpopulation of normal murine thymocytes. Selective binding allowed the isolation and phenotypic characterization of the adherent and nonadherent subpopulations of thymocytes. Flow cytometric analysis of fluorescently labeled thymocytes revealed that the adherent and nonadherent populations differ in maturity, with the adherent population enriched in immature thymocytes of the PNAhi, Thy-1hi, CD3-/lo, and CD4+/CD8+ double positive surface phenotype. A quantitative microwell assay was developed to measure the binding of thymocytes to TS-9. Thymocytes labeled with vital DNA stain Hoechst 33342 were allowed to bind to TS-9 in microwells and the intense fluorescence of this label was readily detected with a scanning fluorometer. The binding was trypsin-sensitive and hyaluronidase and PI-PLC resistant. The binding was also temperature dependent and sensitive to cytochalasin B. A panel of monoclonal antibodies to cell surface antigens including CD2, LFA-I/ICAM-I, and Thy-1 was screened in a quantitative binding assay for their ability to inhibit the binding of thymocytes to TS-9. The binding was partially inhibited by the C3C12 monoclonal antibody which recognizes the recently identified and apparently unique gp23,gp45 complex expressed on murine stromal cells
— id: 13835, year: 1991, vol: 138, page: 473, stat: Journal Article,

THYMIC REPOPULATION AFTER IRRADIATION IN AGED MICE
BASCH R S
1990 ;2(4):229-236, Aging immunology & infectious disease
The capacity of aged mice to regenerate their thymus after irradiation has been evaluated by transplanting serologically identifiable, hematopoietic precursors into histocompatbile recipients. The kinetics of appearance of the progeny of these transplanted cells has been measured and used to evaluate both progenitor number and the capacity of the organ to support proliferation and/or differentiation. The ability of the hematopoietic tissues of aged mice to provide cells capable of repopulating the thymus of an irradiated young animal persists throughout the lifetime of the animal. The thymus of aged mice also appears to retain the capacity to attract or capture circulating thymocyte precursors long after thymic involution has occurred. Despite this, thymic regeneration after irradiation is defective in many but not all aged mice. This defect persists even after intrathymic injection of the precursors suggesting that the deficit is a result of the inability of the organ, in aged mice, to provide an environment in which the precursors can proliferative adequately
— id: 98823, year: 1990, vol: 2, page: 229, stat: Journal Article,

Expression of CD4 by human megakaryocytes
Basch RS; Kouri YH; Karpatkin S
1990 Oct;87(20):8085-8089, Proceedings of the National Academy of Sciences of the United States of America
The CD4 antigen, which serves as the receptor for human immunodeficiency virus type 1 (HIV-1) on T cells, has been detected on human megakaryocytes. Recent evidence of impaired thrombopoiesis in HIV-1-related thrombocytopenia suggested that these cells could be directly infected by the virus and prompted a search for a receptor on megakaryocytes of normal subjects that could permit entry of HIV-1. Bone marrow specimens from uninfected normal control subjects were centrifuged over Ficoll-Hypaque (1.077 g/ml) and analyzed by three-color analysis with a flow cytometer utilizing monoclonal antibodies against CD4 and a glycoprotein present on the surface of megakaryocytes and platelets (GPIIb/IIIa; CD41), as well as 7-aminoactinomycin D, a stain for DNA. Cells presumed to be megakaryocytes were identified by having a DNA content greater than tetraploid and staining brightly with anti-CD41. Approximately 0.4% of the nucleated cells of the marrow met these criteria. Twenty-five percent of these megakaryocytes stained as brightly as CD4+ T cells. Several clones of antibody recognizing different epitopes of the CD4 molecule gave similar results. Platelets were CD4-. Staining of megakaryocytes with anti-CD4 was confirmed by direct microscopic examination of Percoll-gradient-enriched megakaryocytes employing two-color (CD4-phycoerythrin and CD41-fluorescein) immunofluorescence analysis and phase-contrast microscopy. The proportion of double-labeled cells among 112 phase-contrast-identifiable megakaryocytes from five bone marrow specimens varied between 20% and 26% with a mean and SD of 22% +/- 2.5%. Thus some human megakaryocytes express CD4 on their surface that should be capable of binding the HIV-1 gp120 envelope protein. This could serve as a portal of entry for HIV-1
— id: 14364, year: 1990, vol: 87, page: 8085, stat: Journal Article,

HUMAN MEGAKARYOCYTES HAVE A CD4-RECEPTOR ASSOCIATED WITH GPIB-POSITIVE CELLS
Basch, R; Kouri, Y; Gavalchin, J; Poiesz, B; Karpatkin, S
1990 Apr;38(2):A426-A426, Clinical research
— id: 32070, year: 1990, vol: 38, page: A426, stat: Journal Article,

Protection of mice against tumor growth by immunization with an oncogene-encoded growth factor
Talarico D; Ittmann M; Balsari A; Delli-Bovi P; Basch RS; Basilico C
1990 Jun;87(11):4222-4225, Proceedings of the National Academy of Sciences of the United States of America
The K-fgf/hst oncogene encodes a growth factor of the fibroblast growth factor (FGF) family that is secreted and transforms cells through a mechanism of autocrine cell proliferation. K-fgf-transformed cells are highly tumorigenic in immunocompetent allogeneic and syngeneic animals. BALB/c mice were immunized with a bacterial fusion protein consisting of a portion of the MS2 polymerase and of the human K-FGF precursor lacking only the first 4 amino acids or with a recombinant protein corresponding to the mature, secreted form of K-FGF (176 amino acids). They were then challenged with syngeneic K-fgf- or H-ras-transformed cells. Vaccinated animals exhibited a significant degree of protection against tumor induction, which was specific for K-fgf-transformed cells and correlated with the ability of the immunized mice to produce high titers of anti-K-FGF antibodies. Thus immunization with a single oncogene product can protect animals against tumor cells expressing this oncogene
— id: 14365, year: 1990, vol: 87, page: 4222, stat: Journal Article,

L3T4 antigen expression by hemopoietic precursor cells
Frederickson GG; Basch RS
1989 Apr 1;169(4):1473-1478, Journal of experimental medicine
L3T4 (CD4) is expressed on immature hematopoietic cells. Sorting bone marrow cells on the basis of their expression of this antigen produces populations of cells that are markedly enriched for multipotential stem cells (CFU-s) and for myeloid precursors (CFU-c). We believe that L3T4 is transiently expressed by most, if not all, hematopoietic precursors early in their maturation. We suggest that the expression of CD4 molecules on the surface of immature precursors is required for their interaction with Ia bearing cells within the hemopoietic inductive microenvironment(s) of the marrow and thymus
— id: 10673, year: 1989, vol: 169, page: 1473, stat: Journal Article,

A Thy-1 negative lymphoma cell variant defective in the formation of glycosyl-phosphatidylinositol membrane protein anchors
Teng MH; Hedayati S; Alexander AA; Barkin R; Basch RS; Buxbaum JN
1989 Apr;26(4):391-402, Molecular immunology
Thy-1 is a glycoprotein present on the membrane of murine cells of the T-lineage. The mature Thy-1 is anchored to the membrane via a glycolipid, phosphatidylinositide. In order to study the regulation of the synthesis and membrane insertion of this protein, the biochemical properties of a Thy-1.2 negative variant T-lymphoma cell (RL male 1.4) were studied. It contains intracellular Thy-1 protein but fails to express it on the cell surface. While the wild type and the mutant show similar labelling of the intracellular Thy-1 glycoprotein with amino acids, no ethanolamine is incorporated into the Thy-1 molecule of RL male 1.4. A plasmid, pT1, containing the normal Thy-1.2 gene and bacterial gpt gene was transfected into RL male 1.4 and into the murine plasmacytoma cell, J558L. A transfected plasmacytoma, T1J2, synthesized a normal sized Thy-1 protein and displayed the antigen on the membrane. In contrast, the mycophenolic acid resistant RL male 1.4 transfectants did not display Thy-1.2 on the cell surface, despite the presence of substantial amounts of Thy-1 intracellularly. Two other antigens known to be anchored in the membrane by phospholipid, Ly-6e and Qa-2, were also examined in RL male 1.4. RL male 1.4 did not express Ly-6e after alpha interferon induction. In addition, the expression of Qa-2 antigen was greatly diminished in RL male 1.4 in comparison to RL male 1.3. Thus, the defect in RL male 1.4 is not restricted to Thy-1.2, but includes other similarly anchored glycoproteins as well. This implies that the addition of phospholipid to core proteins is similar, if not identical, for all these molecules and that the RL male 1.4 cell lacks the capacity to from the lipid glycoprotein linkage required for the expression of these proteins on the cell surface
— id: 10689, year: 1989, vol: 26, page: 391, stat: Journal Article,

L3T4 ANTIGEN EXPRESSION BY HEMATOPOIETIC PRECURSOR CELLS
FREDRICKSON, GG; BASCH, RS
1988 MAR 25 ;2(6):A1661-A1661, FASEB journal
— id: 41799, year: 1988, vol: 2, page: A1661, stat: Journal Article,

RESTRICTION LENGTH POLYMORPHISM IN THE VARIABLE REGION OF THE TCR LOCUS LINKED TO HISTOCOMPATIBILITY ANTIGEN H-8 ON MURINE CHROMOSOME-14
BERMAN, JW; ROCHA, AJD; BASCH, R
1986 JUL-AUG ;24(5):328-330, Immunogenetics
— id: 41536, year: 1986, vol: 24, page: 328, stat: Journal Article,

Isolation of cell lines possessing functional and serological properties resembling those of thymocyte precursors
Goodwin LO; Rocha AJ; Basch RS
1986 Sep 11-17;323(6084):166-169, Nature
Thymocytes develop from a committed haematopoietic progenitor, referred to as a prothymocyte. They are uniquely capable of migrating to and restoring the thymus of a lethally irradiated host, a property which has been exploited as a specific assay for these cells. Like other committed haematopoietic progenitors, prothymocytes are found only in small numbers in even the richest sources (0.05-1.0% of the nucleated cells in bone marrow). Purification has proved difficult both in terms of finding a suitable starting material and in the degree of enrichment achieved. We now report the isolation of cloned lines of cells with some of the serological and functional properties of prothymocytes. One of these lines has been in continuous culture for almost 2 years. When injected into irradiated recipients, cells from this line migrate to the thymus and there develop into cells which resemble normal cortical thymocytes
— id: 14366, year: 1986, vol: 323, page: 166, stat: Journal Article,

CELL-CYCLE ANALYSIS TO EVALUATE THE INTERACTION BETWEEN DOXORUBICIN (DOX) AND THE CARDIOPROTECTIVE AGENT, ICRF-187
WADLER, S; GREEN, MD; BASCH, R; MUGGIA, FM
1986 MAR ;27(2):370-370, Proceedings (American Association for Cancer Research)
— id: 41429, year: 1986, vol: 27, page: 370, stat: Journal Article,

Thy-1 antigen expression by murine hematopoietic precursor cells
Berman JW; Basch RS
1985 Dec;13(11):1152-1156, Experimental hematology
Multipotential lymphohematopoietic stem cells detected by a 12-day spleen colony assay are uniformly Thy-1 positive. As these cells differentiate into stem cells with restricted developmental potential, the antigen is lost. The various restricted progenitor cells differ in their susceptibility to the cytolytic effects of anti-Thy-1 antiserum. Erythroid progenitors appear to lose the antigen more rapidly than any of the others tested, while macrophage precursors retain the antigen until relatively late in their developmental history. These differences in Thy-1 expression permit discrimination among the various progenitors
— id: 14367, year: 1985, vol: 13, page: 1152, stat: Journal Article,

EARLY PHASES OF THYMIC REGENERATION AFTER X-IRRADIATION
Fredrickson, GG; Basch, RS
1985 ;44(4):1298-1298, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 30968, year: 1985, vol: 44, page: 1298, stat: Journal Article,

N,N'-Bis(4-azidobenzoyl)cystine--a cleavable photoaffinity reagent
Ultee ME; Basch RS
1985 Sep;149(2):331-338, Analytical biochemistry
A water-soluble, cleavable, heterobifunctional photoaffinity label has been synthesized in one step from N-hydroxysuccinimidyl 4-azidobenzoate and cystine. The resultant compound, N,N'-bis(4-azidobenzoyl) cystine [(ABC)2], reacts with protein sulfhydryl groups through disulfide exchange to generate photoactive derivatives. Since [35S]cystine of high specific activity is readily available, it is possible to produce highly radioactive (ABC)2. ABC-derivatized ovalbumin is antigenic in vivo, and monoclonal antibodies specific for ABC have been produced. The antigen binding site of these antibodies was covalently labeled with ABC
— id: 14368, year: 1985, vol: 149, page: 331, stat: Journal Article,

A monoclonal antibody (AE3.d3) with mitogenic properties for murine B cells
Allouche M; Basch RS; Berman JW
1984 Nov;133(5):2301-2307, Journal of immunology
A monoclonal antibody, AE3.d3, derived from the fusion of rat splenocytes immunized against mouse brain with the myeloma SP2, has been produced, which has the property of inducing the proliferation of mouse lymphocytes. The mitogenic effect is highest in spleen and lymph node cells, where up to a 10-fold stimulation of 3H-TdR incorporation is observed. B lymphocytes are the most susceptible to this proliferative stimulus, and they are induced to differentiate into plaque-forming cells. T lymphocytes and 'null' cells (defined by the absence of Thy-1 or Ig on their surface) do proliferate, although to a smaller extent. The T cell subpopulation, isolated from either spleen or thymus, requires additional 'helper factors' in order to proliferate. The mitogenic response is not genetically restricted by H-2 type, and strains such as C3H/HeJ and CBA/N, in which B cell function is defective, as well as T cell-deficient strains such as BALB/c nude mice, are capable of responding to the stimulus of AE3.d3. Using immunofluorescence, we also examined the distribution of AE3.d3-positive cells in various lymphoid organs. The highest percentage of stained cells is found in the spleen (approximately 28%) and lymph node (18%), whereas only 14% of the bone marrow and 5% of the cells of the thymus are brightly stained with AE3.d3
— id: 14369, year: 1984, vol: 133, page: 2301, stat: Journal Article,

Isolation of highly malignant Thy-1-positive revertants from cultured cloned Thy-1-negative lymphoma cells of low tumorigenicity
Basch RS; Lakow E; Teng M; Buxbaum JN
1984 Jan;10(1):37-44, Somatic cell & molecular genetics
We have used a positive immunoselection method to isolate a Thy-1-positive revertant of a Thy-1-negative line. The technique makes use of the ability of surface bound antigen-antibody complexes containing the enzyme catalase to protect cells from the toxic effects of hydrogen peroxide. The revertant cells produce a Thy-1 molecule indistinguishable from that produced by the original parent line, and they resemble that line in being far more tumorigenic than the Thy-1-negative variant
— id: 14371, year: 1984, vol: 10, page: 37, stat: Journal Article,

Gene transfer in lymphoid cells: expression of the Thy-1.2 antigen by Thy-1.1 BW5147 lymphoma cells transfected with unfractionated cellular DNA
Berman JW; Basch RS; Pellicer A
1984 Nov;81(22):7176-7179, Proceedings of the National Academy of Sciences of the United States of America
We have transferred the gene coding for the Thy-1.2 alloantigen into a Thy-1.1-bearing T-cell lymphoma. BALB/c thymocyte DNA, precipitated with calcium phosphate, was used to effect the transfer. We report the stable transformation of lymphoid cells by total cellular DNA. To our knowledge, this has not been previously reported. Transient expression of the transfected gene could be detected by flow cytofluorometry, and 5% (range, 1.5%-11%) of the recipient cells had Thy-1.2 antigen detectable on their surface 48 hr after transfer. 'Stable' transformants were isolated by repeatedly selecting for cells expressing the Thy-1.2 antigen, by use of fluorescence-activated cell sorting or 'panning.' No metabolic selection was required. The transferred gene, detected by Southern blotting, encoded a product that is indistinguishable from the normal antigen by immunoprecipitation and NaDod-SO4/PAGE
— id: 14370, year: 1984, vol: 81, page: 7176, stat: Journal Article,

Cell separation using positive immunoselective techniques
Basch RS; Berman JW; Lakow E
1983 Feb 11;56(3):269-280, Journal of immunological methods
Positive immunoselection is the direct selection and recovery of cells which express a given specificity from among a heterogeneous group of contaminating cells. A variety of methods are available to effect such separations. The principles of affinity chromatography, using solid-phase matrices or cellular immunoadsorbents, are extensively used. Liquid-phase positive immunoselection can also be performed using either a fluorescence-activated cell sorter or by using 'cellular engineering' to protect a cell from an otherwise noxious environment. The enzyme catalase coupled to specific antibody has been used for this purpose and renders cells resistant to hydrogen peroxide. The various positive immunoselection techniques available are reviewed and evaluated in the following report
— id: 14372, year: 1983, vol: 56, page: 269, stat: Journal Article,

Identification of a new marker (Ly RL male 1) for cells of the T lineage by an auto-antithymocyte serum
Basch RS; Buxbaum JN; Zolla-Pazner S
1983 Oct 1;81(1):144-156, Cellular immunology
The sera of mice surviving challenge with a Thy-1-negative variant of the thymoma RL male 1 contain antibodies which identify a new cell surface antigen (Ly RL male 1) present on cells of the T lineage. This antigen appears early in the development of the lineage and it can be detected on most thymocyte precursors. Its presence on prothymocytes can serve to distinguish these cells from their multipotential precursors. The antigen is present on many thymocytes, and dividing thymocytes are more susceptible to its cytotoxic activity than is the total population. Ly RL male 1-antigen-positive cells can be detected in peripheral lymphoid tissues by both functional assays and absorption. Treatment of peripheral lymphoid cells with the antiserum leads to significant reduction in MLR and helper activity but does not alter mitogen reactivity or lymphocytotoxicity. Animals with significant serum levels of anti-RL male 1 are deficient in their ability to produce IgG antibody to sheep erythrocytes.
— id: 9316, year: 1983, vol: 81, page: 144, stat: Journal Article,

MG-1: a specificity identifying members of the macrophage and granulocyte lineages of mice
Berman JW; Basch RS
1983 Jan;11(1):43-55, Experimental hematology
An antigen (MG-1) which behaves as a lineage marker for immature granulocytes and cells of the monocytic series in mice is described. It is identified by rabbit anti-mouse brain antiserum, which has been exhaustively absorbed with thymocytes, red blood cells, and a Thy-1 negative variant of a T-cell lymphoma. MG-1 is present on immature granulocytes, declines in its surface expression as the cells differentiate and is absent from the most mature cells (segmented) of the series. Early monocytes are strongly positive for MG-1 and, with maturity, the amount of cell surface antigen increases. Adherent, phagocytic macrophages are brilliantly positive when stained with anti-MG-1 antiserum in an immunofluorescence assay. The antigen is present on most of the adherent cells of the lung, spleen and peritoneum. Many multipotential stem cells also express low levels of this antigen as do some bone marrow B cells
— id: 14373, year: 1983, vol: 11, page: 43, stat: Journal Article,

Effect of anti-relaxin antiserum on sperm motility in vitro
Sarosi P; Schoenfeld C; Berman J; Basch R; Randolph G; Amelar R; Dubin L; Steinetz BG; Weiss G
1983 May;112(5):1860-1861, Endocrinology
Rabbit anti-relaxin antisera, but not normal rabbit sera, causes a rapid decline of motility of washed human sperm. Preincubation of the antisera with relaxin eliminates this effect. This sperm immobilization effect can serve as a basis of a rapid screening test for anti-relaxin antisera and as a novel adjuvant to barrier contraceptive methods
— id: 24812, year: 1983, vol: 112, page: 1860, stat: Journal Article,

Thy-1 determinants are present on many murine hematopoietic cells other than T cells
Basch RS; Berman JW
1982 May;12(5):359-364, European journal of immunology
The development of a highly amplified immunofluorescence assay and the availability of monoclonal anti-Thy-1 antibodies have provided the methodology to reexamine the presence of Thy-1 antigen on murine lymphohematopoietic cells. The representation of this antigen is not, as previously believed, restricted to the T cell compartment of these cells. It is present on a significant number of mouse bone marrow cells (25-30%), including, as in the rat, multipotential stem cells, prothymocytes and some B cell precursors. Eosinophils and some immature myeloid cells are also antigen-positive
— id: 14374, year: 1982, vol: 12, page: 359, stat: Journal Article,

Serologic identification of early members of the T cell lineage
Berman JW; Basch RS
1982 Apr;128(4):1718-1722, Journal of immunology
The SC-1 antigen, identified by thymus-absorbed rabbit anti-mouse brain antiserum, is present on multipotential stem cells. Its presence on cells of the T lineage has been examined by immunofluorescence, and we have demonstrated that it is also a marker for thymic development. Although it is present on the majority of fetal and neonatal thymocytes, its expression declines rapidly and, as early as 1 mo after birth, adult levels are reached. In normal animals, these do not change during adult life, even in mice destined to develop a T cell leukemia. SC-1 does reappear transiently on cells in the regenerating thymus of sublethally irradiated mice. Although the antigen is not associated with preleukemic changes in the thymus, it is expressed on some cells of all spontaneous T lymphomas, and it is uniformly present on tissue culture lines of T cell lymphomas
— id: 14375, year: 1982, vol: 128, page: 1718, stat: Journal Article,

Demonstration of a hematopoietic stem cell antigen (SC-1) on a murine lymphoma and isolation of variants lacking the antigen
Basch RS; Panagiotatos T; Berman JW; Buxbaum JN
1981 Jun;107(3):379-384, Journal of cellular physiology
Murine multipotential hematopoietic stem cells (CFU-s) bear an antigen (SC-1) which is recognized by heterologous antisera to mouse brain. We have found that cloned Thy-1 negative variants of the T-cell lymphoma RL male 1 are sensitive to complement-mediated cytolysis by anti-brain serum and can absorb the anti-stem cell activity from the antiserum. We have isolated several subclones derived from a primary Thy-1 negative variant which are not susceptible to anti-brain serum. The surface of the resistant lines has little or no antigen capable of binding anti-mouse brain antibodies as measured by either immunofluorescence or a radioimmunoassay. These lines are also unable to absorb the antibodies responsible for the cytotoxic effect of rabbit anti-mouse brain serum against CFU-s. We conclude that the predominant antigen, serologically detectable on Thy-1 negative variants of RL male 1, is SC-1
— id: 14376, year: 1981, vol: 107, page: 379, stat: Journal Article,

Positive immunoselection using antibody-enzyme complexes
Lakow E; Basch RS
1981 ;44(2):135-151, Journal of immunological methods
We have developed an immunoselection technique using catalase-anti-catalase complexes coupled to specific antibodies to protect antigen positive target cells from the lethal effects of H2O2. The antibody-enzyme complexes are bound to the target cells through an antibody bridge with specificity for both the complexes and an anti-target cell antibody. In a model system, Thy-1 positive (RL male 1-3) cells were protected by incubation with rabbit anti-brain-associated theta antigen (BAT), sheep anti-rabbit IgG [F(ab)'2] and catalase-anti-catalase complexes. The amount and composition of the complexes adhering to the cells were measured by dual radiolabeling of the catalase and anti-catalase immunoglobulin. This technique provides a means of identifying and isolating large numbers of cells bearing any antigen for which specific antisera are available
— id: 14377, year: 1981, vol: 44, page: 135, stat: Journal Article,

Amplification of the biotin-avidin immunmofluorescence technique
Berman JW; Basch RS
1980 ;36(3-4):335-338, Journal of immunological methods
An amplification of the immunofluorescence technique which uses biotinylated antibody and fluoresceinated avidin is described. By introducing a sandwich technique using fluorescein-conjugated goat anti-avidin, a 5-fold enhancement of staining over the conventional immunofluorescence method is achieved, and the brightness is more than twice that achieved with the simple biotin-fluoresceinated avidin reaction
— id: 14380, year: 1980, vol: 36, page: 335, stat: Journal Article,

Terminal deoxynucleotidyl transferase expression in a Thy-l alloantigen variant lymphoma cell line
Bumol TF; Retzel EF; Douglas SD; Basch RS; Buxbaum JN; Faras AJ
1980 Dec;41(4):799-806, Immunology
Terminal deoxynucleotidyl transferase (TdT) expression was examined in the clones of the radiation induced murine leukemia, RL male 1, which differ in Thy-1.2 alloantigen expression and tumourigenicity in syngeneic mice. Both cell lines displayed predominant cytoplasmic localization of TdT and equal sensitivities to specific TdT inhibitors. The R1 male 1.3 + cell line (Thy-1.2 positive and tumourigenic) demonstrated overall higher levels of TdT activity and different elution patterns on phosphocellulose chromatography compared with the RL male 1.4 - (Thy-1.2 negative and poorly tumourgenic) cell line. These findings suggest an association of TdT expression with tumourigenicity properties in leukemic T lymphocytes
— id: 14378, year: 1980, vol: 41, page: 799, stat: Journal Article,

Immunologic basis of resistance to RL male 1 induced by immunoselected Thy-1.2 negative variants
Buxbaum JN; Basch RS
1980 Aug;125(2):673-678, Journal of immunology
Variant cell lines that have lost the Thy-1 antigen have a reduced capacity to induce tumors in syngeneic recipients when compared to Thy-1 positive clones. The negative variants are cloned, cultured cells obtained from the Thy-1.2(theta) positive BALB/c lymphoma RL male 1 in a single-step immunoselection procedure. The reduction appears to be related to an alteration in the host response to the tumor, since both the variant and parental cells induce tumors equally well in irradiated mice. Males are much more susceptible to the inoculated tumor cells, suggesting that the relevant response is restricted to females. A majority of female animals that survive challenge with the variant do not allow growth of the parental tumor when they are injected with a quantity of cells that is uniformly fatal in untreated recipients. Most of the surviving females have an antibody in their sera that is cytotoxic for the variant, its parent, and normal thymocytes. None of the few surviving males had significant titers of the antibody. Cell-mediated immunity directed toward the positive and negative tumor cells was demonstrable in half the surviving animals of both sexes
— id: 14379, year: 1980, vol: 125, page: 673, stat: Journal Article,

Murine leukemia virus-associated cell surface antigens in rats neonatally infected with Gross murine leukemia virus
Basch RS; Grausz D; Harris N; Mitchison NA
1979 Dec;63(6):1485-1492, Journal of the National Cancer Institute
The inoculation of newborn W/F, Lew, AS and DA rats with Gross murine leukemia virus (G-MuLV) resulted in the prompt appearance of cells with viral protein antigens (VPA) on their surfaces. These were first found in the bone marrow and spleen and later in the thymus gland. As the animals developed, the VPA-positive population expanded and the intensity of the fluorescence increased. In the spleen, the cells with the strongest fluorescence had the properties of T-cells, but in both spleen and bone marrow low levels of VPA were found on non-T-cells. The VPA-positive population expanded long before malignant cells could be detected and, in most animals, the entire T-cell compartment became antigen-positive. These animals were unable to respond to G-MuLV antigens and many eventually developed leukemia. However, some animals apparently broke the tolerance that followed neonatal infection and eliminated VPA-positive cells from their tissues
— id: 14381, year: 1979, vol: 63, page: 1485, stat: Journal Article,

ISOANTIBODY WITH SPECIFICITY FOR PROTHYMOCYTES, SOME THYMOCYTES AND A SUBSET OF PERIPHERAL T-CELLS
Basch, RS; Buxbaum, JN
1979 ;43(1):250-250, Journal of supramolecular structure
— id: 30135, year: 1979, vol: 43, page: 250, stat: Journal Article,

REDUCED TUMORIGENICITY OF LYMPHOMA-CELLS LACKING A NORMAL DIFFERENTIATION ANTIGEN
Buxbaum, J; Basch, R
1979 ;43(1):213-213, Journal of supramolecular structure
— id: 30134, year: 1979, vol: 43, page: 213, stat: Journal Article,

Concanavalin A is mitogenic for resident peritoneal macrophages
Wang AL; Basch RS
1979 Oct;101(1):157-167, Journal of cellular physiology
Con A, a known T-cell mitogen, is also mitogenic for resident peritoneal macrophages. The stimulated cells morphologically resemble macrophages and are actively phagocytic. The concentration of con A (30 micrograms/ml) required to stimulate 3H-TdR incorporation is ten times that required for T-cell activation. Con A must be present throughout the entire culture period to produce the maximum effect, and con A-depleted supernatant fluids from con A-stimulated cells cannot replace the con A requirement. Stimulation of 3H-TdR incorporation occurs after a 48-hour lag period and is maximal on the fifth to seventh day of culture. At the peak of the response, 20-30% of the macrophages can be stimulated to incorporate 3H-TdR, but little or no increase in the total number of cells present in the culture occurs. This and pulse-chase experiments indicate that only a single cycle of replication occurs in the stimulated cells. Con A-responsive peritoneal macrophages appear to be a distinct subpopulation and might play a different role in the interaction with T cells and B cells in the immune response than the con A-non-responsive cells
— id: 14382, year: 1979, vol: 101, page: 157, stat: Journal Article,

Hematopoietic thymocyte precursors: IV. Enrichment of the precursors and evidence for heterogeneity
Basch RS; Kadish JL; Goldstein G
1978 Jun 1;147(6):1843-1848, Journal of experimental medicine
A method has been developed for the enrichment of the hematopoietic precursors of thymocytes from spleen and bone marrow cells. Up to 40-fold enrichments were obtained resulting in preparations in which as few as 10(5) cells produced prompt repopulation of the thymus of an irradiated mouse. Precursor cells from bone marrow appear to contain the enzyme terminal deoxyribonucleotidyl transferase (Tdt), an agent suggested as a potential somatic mutator. This enzyme (Tdt) was not detectable in any spleen cell preparation examined, including one in which a 40-fold enrichment of thymocyte precursors had been produced. This is the first difference reported between the splenic and bone marrow precursors of thymocytes
— id: 14383, year: 1978, vol: 147, page: 1843, stat: Journal Article,

ANTIGEN CHARACTERIZING CFU-S AND HEMATOPOIETIC THYMOCYTE PRECURSORS
Basch, RS; Panagiotatos, T; Buxbaum, J
1978 ;19(3):176-176, Journal of supramolecular structure
— id: 29956, year: 1978, vol: 19, page: 176, stat: Journal Article,

Demonstration of thymus-leukemia (TL) antigens on mitochondria of lymphoid cells by immunoelectron microscopy
Jeng MW; Finegold MJ; Basch RS; Lamm ME
1978 Jan;38(1):41-44, Laboratory investigation
The presence of thymus-leukemia (TL) antigens on the surfaces of mitochondria isolated from TL+ cells, e.g., RADA 1 leukemia cells, and TL+ normal thymocytes, has been directly demonstrated by immunoelectron microscopy. Reagents used were TL alloantiserum and a hemocyanin conjugate of rabbit antibody to mouse IgG. No hemocyanin labeling was observed on mitochondria obtained from TL- cells, e.g., thymocytes of TL- strains, splenocytes of either TL+ or TL- strains, and TL- leukemia cells. The concurrence of TL antigens on the plasma and mitochondrial membranes was shown by the ability of intact cells to absorb all reactivity toward mitochondria
— id: 14385, year: 1978, vol: 38, page: 41, stat: Journal Article,

Thymopoietin enhances the allogeneic response and cyclic GMP levels of mouse peripheral, thymus-derived lymphocytes
Sunshine GH; Basch RS; Coffey RG; Cohen KW; Goldstein G; Hadden JW
1978 May;120(5):1594-1599, Journal of immunology
The action of the purified thymic factor, thymopoietin, on populations of post-thymic lymphocytes has been studied. Thymopoietin, at concentrations as low as 1.5 ng/ml, uniquely enhanced the proliferative response of peripheral T cells from lymph node and spleen to allogeneic stimulation. Enhancement of the allogeneic response (MLR) was not produced by several polypeptide hormones, including insulin, ACTH, HCG, or Ubiquitin. Treatment of spleen cells with anti-Thy-1 antiserum almost completely abolished the MLR. Thymopoietin's stimulatory effects could not reverse this. Thymopoietin treatment of Thy-1+-enriched spleen cell populations enhanced the MLR even when thymopoietin was removed as early as 2 min after incubation with responding cells. The interaction of thymopoietin with peripheral Thy-1+ cell populations produced a rapid and transient rise in cyclic GMP levels and slightly decreased cyclic AMP levels. These results suggest that thymopoietin interacts with one or more Thy-1+ subpopulations and that this interaction involves early changes in cyclic nucleotide metabolism
— id: 14384, year: 1978, vol: 120, page: 1594, stat: Journal Article,

Murine pluripotential stem cells lack Ia antigen
Basch RS; Janossy G; Greaves MF
1977 Dec 8;270(5637):520-522, Nature
— id: 14386, year: 1977, vol: 270, page: 520, stat: Journal Article,

Hematopoietic thymocyte precursors: II. Properties of the precursors
Basch RS; Kadish JL
1977 Feb 1;145(2):405-419, Journal of experimental medicine
The properties of hematopoietic cells which serve as the precursors of cortical thymocytes in irradiated reconstituted mice have been described. These cells have been termed 'prothymocytes.' They are 10- to 15-mum diameter cells of low buoyant density. They are nonadherent to glass wool and more resistant to the lytic effects of steroids and gamma-irradiation than their progeny. They lack detectable amounts of the surface markers associated with either B or T cells but do bear at least two antigens recognized by antisera to mouse brain
— id: 14388, year: 1977, vol: 145, page: 405, stat: Journal Article,

HEMATOPOIETIC PRECURSORS OF THYMOCYTES
Basch, RS; Kadish, JL
1977 ;6(6-7):679-679, Scandinavian journal of immunology
— id: 29574, year: 1977, vol: 6, page: 679, stat: Journal Article,

Analysis of thy-1 variants of murine lymphoma cells
Buxbaum JN; Basch RS; Szabadi RR
1977 Jan;3(1):1-15, Somatic cell genetics
Cells obtained from a radiation-induced T-cell lymphoma of BALB/c mice, RLmale-1, were adapted to long-term tissue culture. Clones of cells were obtained in soft agar and a clonally derived population studied for the frequency of mutation in the expression of the surface antigen Thy-1.2 (OC3H) by immunoselection. The mutation rate was 1.05-1.50 X 10(-6) per cell per generation. Antigenic and structural analysis of prototype positive and negative clones demonstrated clear differences between them
— id: 14389, year: 1977, vol: 3, page: 1, stat: Journal Article,

Hematopoietic thymocyte precursors. III. A population of thymocytes with the capacity to return ("home") to the thymus
Kadish JL; Basch RS
1977 Apr;30(1):12-24, Cellular immunology
— id: 14387, year: 1977, vol: 30, page: 12, stat: Journal Article,

DIFFERENCES BETWEEN THY-1 (+) AND (-) CLONES DERIVED FROM BALB-C LYMPHOMA-CELLS
SZABADI, RR; BUXBAUM, J; BASCH, R
1977 ;2(7):18-18, Journal of supramolecular structure
— id: 98694, year: 1977, vol: 2, page: 18, stat: Journal Article,

Hematopoietic thymocyte precursors. I. Assay and kinetics of the appearance of progeny
Kadish JL; Basch RS
1976 May 1;143(5):1082-1099, Journal of experimental medicine
A quantitative assay for the hematopoietic precursor of thymocytes has been developed. Using this assay the kinetics of appearance of the progeny of transfused bone marrow and spleen cells in the thymus of irradiated (760 R) mice has been studied. Precursor cells are seven to eightfold more common in bone marrow than in spleen and are absent from peripheral lymph nodes. They decline in number as the animals age. When hematopoietic cells are injected immediately after lethal irradiation only a small number of cells actually enter the gland. Their progeny are not detectable in the thymus for 8-12 days. The time of their detection depends both upon the size of the residual endogenous thymocyte population and the number of progenitor cells injected. Evidence has been presented that excludes thymic injury as the basis for the delay in the appearance of donor type cells and indicates that neither the production of a 'homing' signal in the irradiated animal nor the development of precursor cells are limiting factors in the rate of thymic repopulation. These studies indicate that only an exceedingly small number (less than 100) of prothymocytes are required to repopulate the thymus of an irradiated mouse. This restricted number of progenitors must produce the entire repertory of T-cell immunologic responsiveness seen in the first weeks after repopulation
— id: 14390, year: 1976, vol: 143, page: 1082, stat: Journal Article,

Antigenic and functional evidence for the in vitro inductive activity of thymopoietin (thymin) on thymocyte precursors
Basch RS; Goldstein G
1975 Feb 28;249:290-299, Annals of the New York Academy of Sciences
Thymopoietin, a polypeptide hormone isolated from bovine thymus, induced in vitro the differentiation of prothymocytes to cells with the antigenic and functional characteristics of intrathymic thymocytes. These changes included the acquisition of the differentiation antigens TL and Thy-1 (theta) and the ability to respond to the mitogen Con-A. Thymopoietin appears to be highly speicfic in inducing the prothymocyte to be highly specific in inducing the prothymocyte to thymocyte differentiation and does not affect the pluripotential stem cell measured by the colony forming assay (CFU-S), the erythropoietin-sensitive cell or B-cells. Experiments are in progress to determine whether additional hormonal inductive signals are required to complete the differentiation of an immunologically competent T-cell
— id: 14392, year: 1975, vol: 249, page: 290, stat: Journal Article,

Thymopoietin-induced acquisition of responsiveness to T cell mitogens
Basch RS; Goldstein G
1975 Dec;20(2):218-228, Cellular immunology
— id: 14391, year: 1975, vol: 20, page: 218, stat: Journal Article,

Thymic regeneration after lethal irradiation evidence for an intra-thymic radioresistant T cell precursor
Kadish JL; Basch RS
1975 Jan;114(1 Pt 2):452-458, Journal of immunology
The data presented indicate the existence of a significant pool of radioresistant stem cells which are capable of partially restoring the thymus of heavily irradiated mice. 3-H-TdR incorporation by the thymus of lethally irradiated mice begins 48 to 72 hr after irradiation and increases throughout the next 8 days. By the 9th day after 760 rads, typical corticomedullary architecture has been restored. 890 rads markedly suppressed, but did not totally eliminate this regeneration. Injection of large numbers of syngeneic bone marrow cells immediately after irradiation was without effect on the rate or extent of regeneration. Mice whose bone marrow and spleen were shielded from irradiation showed an identical amount of thymic regeneration as those receiving total body irradiation indicating that the precursor cell pool responsible for the early post irradiation phase of thymic regeneration is most likely an intrathymic population. The cells repopulating the thymus were morphologically indistinguishable from normal thymocytes and were susceptible to cytotoxic antisera against the thymic differentiation antigens Thy-1, TL, LyA2 and LyC2
— id: 14393, year: 1975, vol: 114, page: 452, stat: Journal Article,

Effects of antigen density and non-complement fixing antibody on cytolysis by alloantisera
Basch RS
1974 Aug;113(2):554-562, Journal of immunology
— id: 14394, year: 1974, vol: 113, page: 554, stat: Journal Article,

Induction of T-cell differentiation in vitro by thymin, a purified polypeptide hormone of the thymus
Basch RS; Goldstein G
1974 Apr;71(4):1474-1478, Proceedings of the National Academy of Sciences of the United States of America
— id: 14395, year: 1974, vol: 71, page: 1474, stat: Journal Article,

THYMIC REGENERATION AFTER LETHAL X-IRRADIATION - EVIDENCE FOR A RADIORESISTANT T CELL PRECURSOR
Kadish, JL; Basch, RS
1974 ;33(3):646-646, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 28380, year: 1974, vol: 33, page: 646, stat: Journal Article,

Haemoglobin polymorphism in the Rhesus macaque
Basch RS
1972 Aug 23;238(86):238-240, Nature: new biology
— id: 14397, year: 1972, vol: 238, page: 238, stat: Journal Article,

Hemoglobin synthesis in short-term cultures of human fetal hematopoietic tissues
Basch RS
1972 Apr;39(4):530-541, Blood
— id: 14399, year: 1972, vol: 39, page: 530, stat: Journal Article,

Nucleoside deaminase activity during the recovery of x-irradiated, bone marrow-protected mice
Basch RS; Malathi VG; Silber R
1972 Oct;80(2):261-265, Journal of cellular physiology
— id: 14396, year: 1972, vol: 80, page: 261, stat: Journal Article,

Inhibition of 3 -hydroxysteroid dehydrogenase in the rat adrenal cortex. A metabolic and morphologic study
Finegold MJ; Basch RS
1972 Jun;26(6):767-777, Laboratory investigation
— id: 14398, year: 1972, vol: 26, page: 767, stat: Journal Article,

3 -Hydroxy steroid dehydrogenase activity in the mitochondria of rat adrenal homogenates
Basch, R S; Finegold, M J
1971 Dec;125(4):983-989, Biochemical journal
— id: 14400, year: 1971, vol: 125, page: 983, stat: Journal Article,

Further studies on elastase-like esterases in human leukocyte granules
Janoff, A; Basch, R S
1971 Apr;136(4):1045-1049, Proceedings of the Society for Experimental Biology & Medicine
— id: 14401, year: 1971, vol: 136, page: 1045, stat: Journal Article,

Hemoglobin synthesis in mice after bone marrow transplantation
Basch RS
1970 Mar;133(3):865-869, Proceedings of the Society for Experimental Biology & Medicine
— id: 14402, year: 1970, vol: 133, page: 865, stat: Journal Article,

An improved method for counting tritium and carbon-14 in acrylamide gels
Basch RS
1968 Oct 10;26(1):184-188, Analytical biochemistry
— id: 14403, year: 1968, vol: 26, page: 184, stat: Journal Article,

Immunologic competence after thymectomy
Basch RS
1966 ;30(2):105-119, International archives of allergy & immunology
— id: 14404, year: 1966, vol: 30, page: 105, stat: Journal Article,

INHIBITION OF THE THIRD COMPONENT OF THE COMPLEMENT SYSTEM BY DERIVATIVES OF AROMATIC AMINO ACIDS
BASCH, R S
1965 Apr;94:629-640, Journal of immunology
— id: 141458, year: 1965, vol: 94, page: 629, stat: Journal Article,

QUANTITATIVE STUDIES ON HISTOCOMPATIBILITY ANTIGENS OF THE MOUSE
BASCH, R S; STETSON, C A
1963 Oct;1:469-480, Transplantation
— id: 141459, year: 1963, vol: 1, page: 469, stat: Journal Article,

The relationship between hemagglutinogens and histocompatibility antigens in the mouse
BASCH, R S; STETSON, C A
1962 May 3;97:83-94, Annals of the New York Academy of Sciences
— id: 141460, year: 1962, vol: 97, page: 83, stat: Journal Article,

Effects of 5-fluorodeoxyuridine and related halogenated pyrimidines on the sand-dollar embryo
KARNOFSKY, D A; BASCH, R S
1960 Feb;7:61-71, Journal of biophysical & biochemical cytology
The embryo of the sand-dollar (Echinarachnius parma) was exposed to various concentrations of fluorinated pyrimidines immediately after fertilization. FUDR (5-fluorodeoxyuridine) was most active, and a concentration of 2 to 4 mgamma/10 cc. (0.8 to 1.6 x 10(-6) m.eq./liter) blocked development at the early blastula stage. Larger doses interrupted development at the same stage. This effect was prevented by thymidine (TDR) and thymine (T); and these pyrimidines protected against many times the minimal lethal concentration of FUDR. TDR was active as a protective agent if added just before early blastula formation. The other fluorinated pyrimidines, 5-fluorouracil (FU), 5-fluorouridine (FUR), 5-fluorocytidine (FCR), 5-fluorodeoxycytidine (FCDR), and 5-fluoroorotic acid (FO), were also studied. These drugs produced effects on embryonic development similar to those seen with FUDR. The effective concentrations, however, varied greatly. T and TDR provided protection against these drugs, but in most cases they were not so effective as against FUDR. 5-Bromodeoxyurdine (BrUDR), beginning at the early blastula stage, caused a random pattern of embryonic death up to the pluteus stage. This drug has been shown to be incorporated into bacterial DNA. BrUDR protected embryos against the early lethal effects of FUDR presumably acting as a thymidine substitute, but the embryos died subsequently in a pattern similar to that seen with BrUDR alone. FUDR and BrUDR appear to inhibit the formation and alter the structure of DNA, respectively, distinctive effects whch may provide a means for studying the role of DNA in embryonic development
— id: 141461, year: 1960, vol: 7, page: 61, stat: Journal Article,