Concanavalin A induces suppressor cell activity in both T gamma and T non-gamma cells: most of the suppressor cells do not carry HLA-DR antigens.
Concanavalin A (Con A) stimulation of T lymphocytes for 48 h induced a dose-dependent increase in the percentage of T gamma cells, and proliferation of these cells was dependent on pre-existing T gamma cells. Con A stimulation also induced a dose-dependent increase in suppressor cell activity as measured in a Con A/mixed lymphocyte culture assay. Removal of T gamma cells before stimulation with Con A did not influence suppressor cell activity, whereas depletion of T gamma cells after Con A stimulation significantly reduced the suppression. Treatment of T lymphocytes with monoclonal anti-HLA-DR antibodies and complement significantly increased the percentage of T gamma cells and also increased the suppressor cell activity, both when the cells were treated before and when they were treated after Con A stimulation. Similarly, increased suppressor cell activity was also seen when T mu cells were removed. The results indicate that Con-A-induced suppressor cells are recruited from both T gamma and T non-gamma cells and also suggest that most of the Con-A-induced suppressor cell activity is exerted by HLA-DR-negative cells.
D000818:Animals; D002469:Cell Separation; D003208:Concanavalin A / Q000494:pharmacology*; D003601:Cytotoxicity Tests, Immunologic; D004306:Dose-Response Relationship, Immunologic; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D006801:Humans; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D011817:Rabbits; D011947:Receptors, Antigen, B-Cell / Q000276:immunology; D011961:Receptors, Fc; D012397:Rosette Formation; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
D000949:Histocompatibility Antigens Class II; D011947:Receptors, Antigen, B-Cell; D011961:Receptors, Fc; D003208:Concanavalin A