Concanavalin A induction of suppressor activity in the T-helper subset defined by monoclonal antibodies.

Human monocyte-depleted peripheral blood mononuclear cells were separated in T4+ and T8+ populations by a panning technique. Petri dishes coated with goat anti-mouse antibodies were plated by peripheral blood mononuclear cells coated by monoclonal antibodies, either T4 or T8. The cell populations were separated into adherent and non-adherent populations based on binding to the goat anti-mouse-coated plastic dishes. The purity of the adherent populations was 96%. T4+ and T8+ populations were used as effector cells in the concanavalin A-induced suppressor test. The T4+ population revealed a pronounced suppressor activity similar to that exhibited by the T8+ population. This finding was independent of two different sources of monoclonal antibodies, T4/T8 and OKT4/OKT8. The registered suppressor activity in the monoclonal antibody-defined helper population could not be explained either by a switch of the membrane phenotype from T4+ to T8+ cells or by an increased interleukin 2 consumption of the concanavalin A-treated cells.