ABSTRACT
AIM: IL-12 acts upon T lymphocytes and activates its receptor complexes of ?1/?2 ,and so IL-12 can regulate TH1/TH2 balance. Our study is aimed at IL-12-inducing apoptosis of T cells and expression and signal transduction of Fas/FasL during T cell apoptosis. METHODS: The apoptosis of T cells was detected by Annexin V staining cytometry and the expression of Fas/FasL under different inhibitors were detected by semi-quantitative PCR. RESULTS: IL-12 induced the human leukemic T cell line(TIB-152) and the human lymphoma T cell line(HTB-176) and the normal human T cells to undergo apoptosis. The FasL expression at 6 hours after treatment with IL-12 increased apparently, and reached the max at 24 hours, and FasL expression induced by IL-12 was inhibited by PKC inhibitor. But IL-12 did not influence Fas expression. CONCLUSIONS: IL-12 can induce T cells to undergo apoptosis which is characterized by early membrane changes, the inducing effect is correlated with the concentration of IL-12 and the maturation of T cells. FasL participates in the progression of T cell apoptosis as a apoptosis mediator, and the effect of IL-12 on FasL expression may be related with PKC pathway.