环孢菌素A对T细胞激活的抑制及IL-2的调节作用

The Inhibitory Effects of CyA on T Cell Activation and the up-regulatory Effect of Exogenous IL-2 in the Process

本文通过环孢菌素A(CyA)对人外周血单个核细胞(PBMC)体外作用的实验研究,对CyA的免疫抑制作用及其机制进行了初步探讨。结果表明:1.CyA能显著抑制PHA诱导的T细胞增殖反应,抑制作用主要发生于增殖早期,尤以0～4小时最为显著,且抑制强度随CyA浓度增加而增强;2.CyA对PHA激活的T细胞表面Tac抗原的表达呈强烈的抑制作用,抑制率为64.59％;3.增加培养液中IL-2的含量可在一定程度上逆转由CyA所致的增殖抑制作用。本研究提示:降低IL-2受体的表达和抑制IL-2的分泌很可能是CyA增殖抑制的作用基础。

The influence of CyA on T cell activation in vitro was investigated by examining T cell proliferation and Tac expression. Results show that CyA exerted marked inhibitory effect on PHA-induced T cell proliferation if the drug was added to the cells at the same time of mitogen stimulation or at the early phase of the process, and there was a dose-dependent inhibition of ~3H-TdR incorporation; adding CyA to PHA stimulated lymphocytes led to blocking of Tac expression, the difference was significant (P<0.0001); adding exogenous IL-2 to CyA treated lymphocytes resulted in the reversal of the antiprolif erative effect to a different extent. Our results suggest that the inhibitory effect of CyA on T cell proliferation is most probably mediated by blocking IL-2 production as well as Tac expression.