Concanavalin-induced suppressor cells: characterization on the basis of corticosteroid and radiation sensitivity.

Experiments were performed to examine whether the concanavalin A (Con A)- induced suppressor cells of several in vitro T- and B-lymphocyte functions constitute a functionally unique cell population. This study included simultaneous studies of three different assays of suppression of T- and B-lymphocyte functions. We found that Con-A-induced suppressor cells which inhibit the allogeneic mixed lymphocyte reaction (MLR) and the pokeweed mitogen-induced, plaque-forming cell (PEC) response are radiation sensitive at doses greater than 1000 rad, but corticosteroid resistant, while those suppressing allogeneic cell-mediated lympholysis (CML) are both radiation and corticosteroid resistant. These studies indicate either that Con-A-induced suppressor cells include heterogeneous populations which are differentially sensitive to corticosteroids and radiation, or that functionally distinct suppressor mechanisms are variably sensitive to these agents.