Concanavalin A-induced suppressor activity of human lymphocyte subpopulations.

Human peripheral blood lymphocytes after incubation with concanavalin A (Con A) suppressed the mitogenic effect of Con A on fresh autologous lymphocytes. The suppression was mediated by T cells, but the participation of nylon-wool-adherent cells was also found. Nylon-wool-adherent cells, after removal of phagocytes and adherent T cells resulting in a pure B cell population exerted strong suppressive effect; adherent T cells were less active. Non-T, non-B cells (null cells) were the least active as suppressors. The Con A-induced suppressor test does not simply reflect the activity of suppressor T cells.