Suppressive effects of 2-acetylaminofluorene on concanavalin A-stimulated murine splenocyte proliferation in vitro: inhibition of interleukin-2 receptor expression.

Treatment of 2-acetylaminofluorene (AAF) to murine splenocyte culture produced a dose-related suppression on the lymphoproliferative response to concanavalin A (Con A). The amount of interleukin 2 (IL-2) activity in the culture supernatants was increased when AAF was treated for 48 hr. Since IL-2 activity did not increase if AAF was treated for the last 4 hr of a 48-hr culture period, the increase of IL-2 activity in culture supernatants did not appear to be due to the leakage of IL-2 from intracellular pool. Treatment of colchicine, an agent known to increase IL-2 activity in culture supernatants by inducing the cytoskeletal structure modification, increased IL-2 activity in splenocyte culture supernatants in 4 hr treatment. Meanwhile, the IL-2 receptor alpha (IL-2R alpha) positive cell population was decreased by the treatment of AAF. These results suggested that suppressive effects of AAF on the lymphoproliferative response to Con A in murine splenocyte culture may be associated with the inhibition of IL-2 receptor expression.