title: Identification of a new lymphocyte subset surface antigen, the expression of which disappears after in vitro and in vivo stimulation. Distribution, biochemistry, and functional studies.
abstract: Two monoclonal antibodies (MoAbs) are described (MD 2.6, IgG1 and MD 4.3, IgG2a) that react with a nonlineage specific lymphocyte subset surface antigen. This antigen is expressed on B cells, a subset of both T8+ and T4+ cells, cells that exert killer and natural killer cell activity in vitro, B cells in lymph nodes, and a small percentage of thymocytes. Expression of the antigen was found to be variable on T cells but not on B cells among individuals. Following polyclonal activation, expression of the determinant detected was lost from the cell surface. Both MD+ and MD+ cells responded to PHA and in MLC. MLC resulted in the generation of cytotoxic T lymphocytes and primed T lymphocytes in both the MD+ and MD+ subpopulations. In contrast, the response to soluble antigens was found to reside almost exclusively in the MD-subset. Immunoprecipitation indicates that the MoAbs react with an antigen that has a molecular weight of 220-240 KD which can be cleaved into subunits of 70-80 kD by beta-mercaptoethanol.
mesh_terms: D000911:Antibodies, Monoclonal / Q000096:biosynthesis / Q000276:immunology*; D000918:Antibody Specificity; D000920:Antibody-Dependent Cell Cytotoxicity; D000954:Antigens, Surface / Q000032:analysis* / Q000276:immunology; D005455:Fluorescent Antibody Technique; D007694:Killer Cells, Natural / Q000276:immunology; D008198:Lymph Nodes / Q000166:cytology; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D008214:Lymphocytes / Q000145:classification* / Q000276:immunology; D008970:Molecular Weight; D010835:Phytohemagglutinins / Q000494:pharmacology; D011233:Precipitin Tests; D012995:Solubility; D013950:Thymus Gland / Q000166:cytology
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D010835:Phytohemagglutinins