Effects of C_2-ceramide on activation and proliferation of mouse T lymphocytes in vitro

Aim:To investigate the effects of C2-ceramide on activation and proliferation of murine T lymphocytes,and to elucidate the mechanism of the immunosuppressive effect of C2-cer. Methods: Lymphocytes were isolated from lymphoid nodes of mouse,and were stimulated with polyclonal activators ConA or PMA plus Ion,and then were co-cultured with C2-cer of different final concentration.The expression of CD69(the early marker of the activated T cells) on T lymphocytes were measured by flow cytometry combined with two colored monoclonal antibodies.While,the effect of C2-cer on the proliferation of T lymphocytes in response to ConA or PMA plus Ion stimulation was determined by flow cytometry combined with carboxyl fluorescein-diacetate-succinimidyl ester(CFDA-SE) staining technology,and the proliferation index(PI) was analyzed by ModFit software.Results: C2-cer(final concentration is 25,50 and 75 μmol/L) can inhibit the expression of CD69 on activated T lymphocytes in a dose-dependent manner(P0.01).The expression rate of CD69 on T cells in response to ConA was(60.13±1.18)%.After treatment with C2-cer,the expression rate of CD69 reduced to(54.56±1.14)%,(48.73±1.26)% and(27.09±1.07)% respectively(P0.01);C2-cer can inhibit the proliferation of T lymphocytes stimulated by ConA at all experimental concentration.The proliferation index(PI) of T cells in ConA group is(1.81±0.25),and the PI value of T cells in C2-cer group is(1.46±0.01),(1.25±0.04) and(1.18±0.03),respectively(P0.05);C2-cer can also inhibit the proliferation of T lymphocytes stimulated by PMA+Ion at all experimental concentration.The proliferation index(PI) of T cells in PMA+Ion group is(1.47±0.01),and the PI value of T cells in C2-cer group is(1.27±0.01),(1.11±0.01) and(1.05±0.01),respectively(P0.05).Conclusion:C2-cer can effectively inhibit the activation and proliferation of mouse T lymphocytes in vitro.