天花粉蛋白抑制抗CD3mAb诱导的淋巴细胞内PKCα激活

Trichosanthin Suppresses the Anti-CD3 mAb Induced Activation of PKCα in Lymphocytes

利用免疫印迹技术和蛋白激酶自身磷酸化方法,研究了天花粉蛋白（Tk）对在淋巴细胞信号传导中起重要作用的PKC的影响。天花粉蛋白脉冲处理过的PBMC,其经由抗CD3mAb诱导的PKCα的活化转位情况受阻, PKC自身磷酸化也被遏制,表明Tk能够抑制PBMC中PKCα的激活。研究结果提示Tk诱发人体免疫低反应至少部分是通过抑制淋巴细胞内PKC激活而实现的。

Trichosanthin (Tk) could inhibit the lymphoproliferation induced by soluble antigen or anti-CD3 mAb in vitro. But the mechanism of inhibition is still in vague. In this paper, the effect of Tk on PKC isozyme was studied by immunoblotting and in vitro kinase assay. The translocation of PKCa as well as the autophosphorylation of PKC in PBMC was inhibited after it was pulsed with Trichosanthin, indicating blocked activation of PKCa. It suggests that Tk suppress lymphoproliferation partially in consideration of inhibition of the activation of cytosloic PKC-