Prevention of induction of suppressor activity in human mononuclear leukocytes by ascorbate and cysteine in vitro.

Concanavalin A (con A) and the non-steroidal anti-inflammatory drug benoxaprofen caused increased oxidative metabolism and suppressor activity in human mononuclear leukocytes in vitro. The relationship between enhanced oxidative metabolism and suppressor activity in MNL was investigated using the water-soluble anti-oxidants ascorbate and cysteine at fixed concentrations of 1 X 10(-3) M. Ascorbate and cysteine inhibited both the induction of suppressor activity and increased oxidative metabolism in MNL caused by con A and benoxaprofen. It is proposed that ascorbate and cysteine prevent the induction of non-specific suppressor activity in MNL by an anti-oxidant mechanism.