THALIDOMIDE INCREASES THE SYNTHESIS OF IL-2 IN CULTURES OF HUMAN MONONUCLEAR-CELLS STIMULATED WITH CONCANAVALIN-A, STAPHYLOCOCCAL-ENTEROTOXIN-A, AND PURIFIED PROTEIN DERIVATIVE

Thalidomide significantly increases the quantity of extracellular IL-2 in cultures of human mononuclear cells stimulated with mitogens or an tigen. Cells from 7 donors exposed for 2 h to 4.0 mu g/ml of thalidomi de and stimulated for 16-18 h with 20 mu g/ml of Concanavalin-A (Con-A ) averaged producing 187 +/- 49% more IL-2 than cells stimulated with Con-A alone. In similar experimental procedures and comparisons the pg /ml of IL-2 secreted by thalidomide-treated cells from five donors sti mulated with 50 ng/ml of Staphylococcal enterotoxin A (SEA) increased by 159 +/- 32%, and the pg/ml of IL-2 secreted by thalidomide-treated cells from 2 donors stimulated with 5.0 mu g/ml of purified protein de rivative of Mycobacterium tuberculosis increased by 120 +/- 4%. Thalid omide also significantly increases the quantity of intracellular IL-2 in cells stimulated with mitogens. Cells exposed to thalidomide and st imulated with Con-A had an increase in intracellular IL-2 of 130% afte r 8 h and 157% after 12 h in culture; cells stimulated with SEA had an increase in intracellular IL-2 of 120% after 8 h and 182% after 12 h in culture. Thalidomide did not alter the percent of lymphocytes expre ssing the ct-chain of IL-2 receptor, nor did it significantly increase incorporation of [H-3]thymidine by cells.