Immunosuppressive activity of T cell clones generated from human T cells stimulated with autologous TPHA cells.
T cell clones were generated from human T cells stimulated with autologous phytohemagglutinin (PHA)-activated T (TPHA) cells. Characterization of three T cell clones originated from donor SF and one from donor JM showed that they proliferated when stimulated with autologous TPHA cells, non-T cells, and peripheral blood mononuclear cells, but did not proliferate when stimulated with allogeneic TPHA cells, non-T cells, and mononuclear cells, with autologous and allogeneic resting T cells, and with PHA. These results in conjunction with the blocking of the proliferation by anti-histocompatibility leukocyte antigen class II monoclonal antibodies indicate that these class II antigens are involved in the proliferation of T cell clones stimulated with autologous lymphoid cells. The four T cell clones are cytotoxic neither to autologous lymphoid cells nor to a panel of cultured human cell lines. The four T cell clones display immunosuppressive activity, since they inhibit the proliferation of autologous and allogeneic cells stimulated with antigens and mitogens and the secretion of immunoglobulin by B cells stimulated with pokeweed mitogen in presence of T cells. Furthermore, the four T cell clones display differential inhibitory activity on the proliferation of cultured human cell lines. The immunosuppressive activity is species-specific, since the T cell clones do not inhibit the proliferation of murine cells. The suppression is mediated by a factor(s) with an apparent m.w. of 13,000 to 16,000. The suppressor activity is labile at alkaline pH and is lost following incubation with pronase (100 U/ml) for 30 min at 37 degrees C.
D000911:Antibodies, Monoclonal / Q000276:immunology; D002478:Cells, Cultured; D002999:Clone Cells / Q000276:immunology; D006684:HLA-DR Antigens / Q000276:immunology; D006801:Humans; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D010835:Phytohemagglutinins / Q000494:pharmacology; D013491:Suppressor Factors, Immunologic / Q000502:physiology; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
D000911:Antibodies, Monoclonal; D006684:HLA-DR Antigens; D010835:Phytohemagglutinins; D013491:Suppressor Factors, Immunologic