title: A monoclonal antibody that binds preferentially to human suppressor T cells.
abstract: A monoclonal antibody termed JM3-3-3A was produced by somatic cell hybridization. The reactivity was assessed by indirect immunofluorescence. JM3-3-3A was reactive with 41% human peripheral blood T cells and 48% non-T cells. Among various human lymphoblastoid cell lines (MOLT 4F, JM, and TALL-1), TALL-l was found not to be reactive with JM3-3-3A. Human peripheral blood T cells fractionated by JM3-3-3A-coated dish panning were submitted to functional studies. JM3-3-3A positive T cells responded to mitogens, concanavalin A and phytohemagglutinin-P much better than JM3-3-3A negative T cells in the presence or absence of adherent cells. JM3-3-3A positive T cells showed suppressor activity and JM3-3-3A negative T cells showed helper activity in pokeweed mitogen-induced Ig production. More than fifty percent of the JM3-3-3A positive T cells were reactive with OKT8 which binds to suppressor/cytotoxic T cells, whereas 18% of JM3-3-3A negative T cells were reactive with OKT8. In addition, immunoprecipitation experiments identified a protein with an approximate molecular weight of 43,000 as a cell surface antigen for JM3-3-3A. Thus, the reactivity of JM3-3-3A showed a wide distribution but human peripheral blood T cells could be dissected functionally by this antibody.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis / Q000276:immunology*; D000921:Antibody-Producing Cells / Q000276:immunology; D000954:Antigens, Surface; D001666:Binding Sites, Antibody; D002460:Cell Line; D002469:Cell Separation; D005260:Female; D006462:Hemolytic Plaque Technique; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008934:Mitogens / Q000494:pharmacology; D013601:T-Lymphocytes / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D007074:Immunoglobulin G; D008934:Mitogens