title: Human suppressor T cells induced by concanavalin A: suppressor T cells belong to distinctive T cell subclasses.
abstract: Human peripheral blood lymphocytes were stimulated by concanavalin A (Con A) and then evaluated by their suppressive activity for thymus-derived (T) cell- and bone marrow-derived (B) cell-proliferative responses to mitogen and allogeneic cells. Con A-activated T cells markedly suppressed these responses, but Con A-activated B cells failed to demonstrate suppressor activity. Discontinuous bovine serum albumin (BSA) density gradient separation of T cells which had been activated by Con A demonstrated that a fraction containing blast cells as well as fractions containing unproliferated cells manifest the same degree of suppressor capabilities. However, when density gradient separation of T cells followed by subsequent incubation with Con A was performed, fractions of proliferating cells of low density exhibited no suppression; a fraction containing high density T cells produced marked suppression, but this fraction incorporated only little thymidine in response to Con A. Thus, these studies indicate that Con A-induced suppressor T cells belong to a distinctive subpopulation which has already been programmed to express this function before exposure to Con A and that cell proliferation may not be a prerequisite for the development of such suppressor T cells.
mesh_terms: D001402:B-Lymphocytes / Q000276:immunology; D002469:Cell Separation; D002499:Centrifugation, Density Gradient; D003208:Concanavalin A / Q000494:pharmacology*; D006801:Humans; D007165:Immunosuppression Therapy; D008213:Lymphocyte Activation; D013601:T-Lymphocytes / Q000276:immunology*; D013997:Time Factors
chemical_list: D003208:Concanavalin A