The effects of TYB-2285 and its metabolites on lymphocyte responses in vitro.

1. We examined the effects of TYB-2285 and its metabolites (TC-286 and TC-326) on antigen-induced lymphocyte proliferation, allogeneic mixed lymphocyte reaction (MLR) and mitogen-induced lymphocyte proliferation. 2. Splenic lymphocytes from C57BL/6 strain mice sensitized with human serum albumin were cultured with the antigen in the presence of TYB-2285 or its metabolites (10(-7)-10(-4) M). The lymphocyte proliferation enhanced by antigen was inhibited by TYB-2285 and its metabolites in a dose-dependent manner. 3. Splenic lymphocytes collected from C57BL/6 and Balb/C strain mice were cocultured in the presence of TYB-2285 and its metabolites (10(-7)-10(-4) M). Allogeneic MLR was inhibited by TYB-2285 and its metabolites in a dose-dependent manner. 4. Splenic lymphocytes from C47BL/6 strain mice were cultured with concanavalin A (Con A) in the presence of TYB-2285 and its metabolites (10(-7)-10(-4) M). TYB-2285 and its metabolites did not affect Con A-induced lymphocyte proliferation. Cyclosporin A showed an inhibitory effect on Con A-induced lymphocyte proliferation that was as strong as the inhibitory effect on antigen-induced lymphocyte proliferation and allogeneic MLR at a lower concentration.