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M S Sandrin

Publications and source records attributed to M S Sandrin.

At least 73 records · Page 4Linked to original sources
PubMed1992

Isolation and characterization of cDNA clones for mouse Ly-9.

We describe the production and characterization of a mouse mAb, S-450-33.2, recognizing the Ly-9.2 specificity. This mAb was used to purify Ly-9 molecules from lymphoid cell lines, and the amino-terminal amino acids were determined. The mAb was also used in a eukaryotic expression system, to isolate cDNA clones encoding Ly-9. Analysis of RNA showed that Ly-9 expression is lymphocyte specific, as determined by the presence of a single hybridizing 2.4-kb species found only in lymphoid cells. Genomic DNA analysis indicated that Ly-9 is encoded by a single-copy gene of 10 to 15 kb. The predicted polypeptide belongs to the Ig superfamily of cell surface molecules with four extracellular Ig-like domains, i.e., a non-disulfide-bonded V domain, a truncated C2 domain with two disulfide bonds, a second non-disulfide-bonded V domain, and a truncated C2 domain with two disulfide bonds (V-C2-V-C2). The sequence data also support the view that Ly-9 belongs to the subgroup of the Ig superfamily that includes Bcm-1, CD2, and LFA-3.

Amino Acid Sequence↗
PubMed1991

The isolation of cDNA clones for CD48.

HuLy-m3 is an Mr 47,000 pan-leukocyte antigen detected by the monoclonal antibody (mAb) 5-4.8. This report describes the isolation and analysis of a cDNA clone encoding HuLy-m3. Serological analysis demonstrated that antibodies of the CD48 cluster also reacted with transfected cells expressing HuLy-m3. The DNA sequence of the clone suggests linkage to the cell membrane through a glycosyl phosphatidylinositol tail and this was verified experimentally. Sequence similarity with the human B-cell activation antigen Blast-1 was noted.

Amino Acid Sequence↗
PubMed1990

Active tyrosine phosphatase in immunoprecipitates of multiple isoforms of Ly-5.

Using tumour cell lines expressing specific isoforms of murine Ly-5 (molecular weights of 180,000, 200,000 and 240,000) we find that all forms of Ly-5 and immuno-affinity purified forms of Ly-5 contain tyrosyl phosphatase activity. These results demonstrate that these isoforms of Ly-5 belong to the same family of functional receptor-linked tyrosine phosphatases as the human leukocyte common antigen. CD45.

Animals↗
PubMed1989

Functional studies of stable L cell transfectants expressing intercellular adhesion molecule 1 [ICAM-1].

High molecular weight DNA isolated from human tonsil was transfected into mouse L cells to produce transfectants expressing the human intercellular adhesion molecule [ICAM-1]. The transfected ICAM-1 molecule was highly expressed on the cell membrane and our studies show that the transfected ICAM-1 molecule was a fully functional adhesion protein. All leucocyte subtypes showed specific binding to the ICAM-1 transfectants, their adhesion being inhibited by Fab1 fragments of W-CAM-1 antibody and LFA-1 MoAb (leucocyte function antigen). B cell lines (RAJI, Nalm1) showed the highest degree of ICAM-1 mediated adhesion. Normal lymphoblasts showed comparable levels of binding whilst normal neutrophils (both resting and activated by (N-formyl-methionyl-leucyl-phenylalanine) fMLP) showed the least ICAM-1-mediated adhesion. Despite a significant level of adhesion to ICAM-1 transfectants shown by T lymphoblasts generated in a two way MLR there was no evidence of cytolysis of ICAM-1 transfectants. These studies demonstrate the potential of ICAM-1 transfectants as tools for analysis of the role of ICAM-1 in lymphoid adhesion.

Animals↗
PubMed1987

Isolation of the CD7 gene from the DNA of transfected L cells.

Using DNA from L cells which expressed high levels of the CD7 (Leu-9 or HuLy-m2) antigen obtained after two cycles of transfection, a genomic library was constructed in the lambda phage Charon 4A. Recombinant clones containing the gene coding for this antigen were identified by first screening the library with both the HSV-tk gene and a probe detecting the human repetitive (Alu) sequences. DNA from 10 tk+ and 12 Alu+ recombinant clones was used to transfect L cells which were analyzed for the cell-surface expression of CD7 either early (48-72 h posttransfection) or later when hypoxanthine aminopterin thymidine-resistant colonies were obtained. Transfection with either Alu+ or tk+ recombinant phages led to transient early expression of CD7, and stable CD7+ transfectants were also established. Thus the CD7 gene has been isolated in a number of clones in association with either the Alu repetitive sequence or with the HSV-tk gene; the insert size in one of the genomic clones was 13.5 kb.

Animals↗
PubMed1987

Gene transfection of the HuLy-m2 (Leu-9) antigen into mouse L cells.

Human DNA was transfected into mouse L cells and tk+ HuLy-m2+ (= CD7+) transfectants isolated after growth in hypoxanthine, aminopterin, thymidine medium and repeated cloning. After several cycles of transfection, greater than 90% of HuLy-m2+ L cells could be detected, by rosetting and by cytofluorography, which showed the transfectants to have a density of CD7 two to five times that found on peripheral blood lymphocytes. Despite this, the 37 kd CD7+ dimer could only be identified with difficulty using cell-surface radioiodination and sodium dodecyl sulfate-polyacrylamide gel electrophoresis techniques. An antiserum was produced (C3H anti-HuLy-m2+ L cells) which, after absorption, was shown to react with HuLy-m2+ antigens present on human thymocytes and lymphocytes and on CD7+ transfected L cells.

Animals↗
PubMed1986

Isolation and analysis of primitive hemopoietic progenitor cells on the basis of differential expression of Qa-m7 antigen.

In the presence of the hemopoietic growth factor CSF-1, the later committed cells of the macrophage lineage can be detected by their ability to form small colonies in clonal agar culture (CFCCSF-1). Synergistic factors have been described that in combination with CSF-1 stimulate developmentally early hemopoietic progenitor cells of high proliferative potential (HPP-CFC). By using a monoclonal antibody to the Qa-m7 antigenic determinant, we investigated and compared the expression of Qa-m7 on CFCCSF-1 and on HPP-CFC of two types that grow in response to either 1) CSF-1 plus synergistic factor from human placenta-conditioned medium (HPP-CFCHplac+CSF-1) or 2) CSF-1 plus synergistic factor from conditioned medium of the WEHI-3 myelomonocytic cell line (HPP-CFCW+CSF-1). We have shown that HPP-CFC of both types express relatively more Qa-m7 antigen than CFCCSF-1 and can be separated and enriched on this basis by discontinuous buoyant density centrifugation and fluorescence-activated cell sorting of normal bone marrow. Significant enrichments of HPP-CFCHPlac+CSF-1 (43.5-fold) and HPP-CFCW+CSF-1 (28.8-fold) have been achieved with cloning efficiencies of HPP-CFC in the most enriched fractions reaching 4 to 5%. These results clearly illustrate the fact that there are populations of progenitor cells from normal, unperturbed bone marrow that strictly require a combination of two hemopoietic growth factors (CSF-1 plus synergistic factor) in order to be detected.

Animals↗
PubMed1986

A genomic clone encoding the alpha chain of the OKM1, LFA-1, and platelet glycoprotein IIb-IIIa molecules.

LFA-1, an antigen involved in cytolytic T lymphocyte-mediated killing, and Mac-1, the receptor for complement component C3bi, constitute a family of structurally and functionally related cell surface glycoproteins involved in cellular interactions. In both mouse and man, Mac-1 (OKM1) and LFA-1 share a common 95-kDa beta subunit but are distinguished by their alpha chains, which have different cellular distributions, apparent molecular masses (165 and 177 kDa, respectively), and peptide maps. We report the isolation of a genomic clone from a human genomic library that on transfection into mouse fibroblasts produced a molecule(s) reactive with monoclonal antibodies to OKM1, to LFA-1, and to platelet glycoprotein IIb-IIIa. This gene was cloned by several cycles of transfection of L cells with a human genomic library cloned in lambda phage Charon 4A and subsequent "rescue" of the lambda phage. Transfection with the purified recombinant lambda DNA yielded a transfectant that expressed the three human alpha chains of OKM1, LFA-1, and glycoprotein IIb-IIIa, presumably in association with the murine beta chain.

Antibodies, Monoclonal↗
PubMed1985

Variable expression of Qa-m7, Qa-m8, and Qa-m9 antigenic determinants on primitive hemopoietic precursor cells.

Using monoclonal antibodies, we have analysed the distribution of three recently described Qa antigenic determinants (Qa-m7, Qa-m8 and Qa-m9) on murine clonable hemopoietic progenitor cells and spleen colony-forming units (CFU-S). Cytotoxicity experiments showed that Qa-m7 was expressed on almost all the progenitor cells (colony-forming cells, CFC) of megakaryocytes (MEG-CFC), erythroid cells (E-CFC), B lymphocytes (BL-CFC), and mixed colonies (MIX-CFC) as well as day 13 CFU-S, and a major proportion of granulocyte-macrophage colony-forming cells (GM-CFC) and day 8 CFU-S. Experiments using four sources of granulocyte-macrophage colony-stimulating activity suggested differential expression of Qa-m7 on subpopulations of GM-CFC, those preferentially forming macrophage colonies having lowest Qa-m7 antigen density. Immune rosetting techniques demonstrated the selective expression of Qa-m8 on approximately 50% of MEG-CFC, MIX-CFC and day 13 CFU-S, a pattern similar to that of Qa-m2. In contrast, Qa-m9 was not detected on any of the primitive hemopoietic precursors assayed. The results demonstrate the complexity of the Qa antigenic system, and suggest a possible role for these antigens in hemopoietic differentiation.

Animals↗
PubMed1984

The Ia-1 gene effects T-B cell collaboration for the in vitro antibody response.

The I-A subregion mutant B6.C-H-2bm12 (bm12) and the C57BL/6 parent were used to examine the role of the Ia-1 gene product as a restriction element in the antibody response to sheep red blood cells (SRBC). Using an in vitro culture system, it was shown that cooperation between histocompatible T cells, B cells and macrophages was required to generate a secondary IgM response to SRBC. The alteration in the Ia-1 gene in bm12 altered the ability of bm12 T cells to collaborate with C57BL/6 B cells, but not with C57BL/6 macrophages. Similarly, C57BL/6 T cells could not collaborate with bm12 B cells. The mutation in bm 12 did not affect the ability of T cells to interact with C57Bl/6 macrophages, either in vitro or in vivo, or of bm12 macrophages to interact with C57BL/6T cells. Thus in this system, the Ia-1 gene product restricts T-B cell interaction but not T cell-macrophage interaction.

Animals↗
PubMed1984

Monoclonal antibodies detect polymorphic determinants shared by I-A and I-E antigens.

Binding data on inbred mouse strains and immunochemical isolation of Ia antigens with subsequent separation on non-reduced/reduced two-dimensional gels provide evidence for the cross-reactivity of monoclonal antibodies with I-A and I-E products. Thus two monoclonal antibodies were found to react with A alpha A beta as well as E alpha E beta dimers. One of these mAbs, K22 -42, reacts with the precursor form of E beta chain of B10.GD mice which is associated with the invariant chain (Ii). This indicates that the respective determinant on E beta is formed prior to association of E beta with E alpha.

Animals↗