title: A monoclonal antibody reactive with the human cytotoxic/suppressor T cell subset previously defined by a heteroantiserum termed TH2.
abstract: A hybridoma-secreting monoclonal antibody was produced from the spleen cells of a mouse immunized with human thymocytes. This hybridoma antibody, termed OKT5, was reactive by indirect immunofluorescence with 80% of human thymocytes but only 20% of peripheral blood T cells. Moreover, OKT5 was unreactive with normal B cells, null cells, and macrophages at any dilution tested. A similar pattern of reactivity was seen with an equine antiserum to human thymocytes termed anti-TH2. Fluorescence-activated cell sorting demonstrated that the OKT5 antibody reactivity on peripheral T cells was restricted to the majority of the previously defined TH2+ subpopulation. In functional studies, the OKT5+ subset, like the TH2+ subset, proliferated well to the mitogen Con A and to alloantigens, and contained cytotoxic effector cells after sensitization in MLC, and suppressor effector cells after activation with Con A. In addition, like the TH2+ T cell, the OKT+ T cell was virtually unresponsive to soluble antigen. Thus, the OKT5 monoclonal antibody is reactive with the cytotoxic/suppressor T cell subset. OKT5 should provide an important probe to assess the status of suppressor cells in human disease.
mesh_terms: D000818:Animals; D000906:Antibodies; D001402:B-Lymphocytes / Q000276:immunology; D002455:Cell Division; D002459:Cell Fusion; D002469:Cell Separation; D002999:Clone Cells / Q000276:immunology; D003208:Concanavalin A / Q000494:pharmacology; D003602:Cytotoxicity, Immunologic; D005260:Female; D006041:Goats; D006736:Horses; D006801:Humans; D007106:Immune Sera / Q000494:pharmacology*; D007074:Immunoglobulin G; D007959:Lymphocyte Culture Test, Mixed; D008264:Macrophages / Q000276:immunology; D051379:Mice; D013601:T-Lymphocytes / Q000145:classification* / Q000166:cytology
chemical_list: D000906:Antibodies; D007106:Immune Sera; D007074:Immunoglobulin G; D003208:Concanavalin A