CD59锚定蛋白对CD55介导的T细胞信号转导的增强效应

The enhancement effect of CD59 on CD55-mediated T cell signal transduction

目的:研究糖基磷脂酰肌醇(GPI)锚定蛋白CD59对CD55介导T细胞信号转导的增强效应。方法:实验分为未转染的Jurkat细胞组(Ⅰ组)、转染空质粒的Jurkat细胞组(Ⅱ组)及转染CD59干扰质粒的Jurkat细胞组(Ⅲ组)。用RT-PCR检测3组细胞中的CD59基因表达水平。用噻唑蓝(MTT)比色法、免疫印迹技术和激光共聚焦扫描显微镜分别检测CD55与CD59联合作用对3组Jurkat细胞的增殖效应,Src家族酪氨酸激酶(SrcPTK)磷酸化的水平及细胞内钙离子的变化。结果:稳定转染后,Ⅲ组细胞CD59分子的表达被成功抑制。Ⅰ组和Ⅱ组细胞CD55与CD59联合作用后增殖能力,SrcPTK磷酸化水平及钙离子浓度均明显高于Ⅲ组(P<0.05);但Ⅰ组和Ⅱ组之间无差异。结论:CD59可增强CD55对T细胞信号转导的效应。

aim：To study the enhancement effect of glycosylphosphatidyl inositol （GPI）-anchored protein CD59 on CD55-mediated T ceil signal transduction. METHODS： Human Jurkat cells were divided into 3 groups： Jurkat cells （ Ⅰgroup）, Jurkat cells transfected with blank plasmid （ Ⅱ group） and Jurkat cells transfected with siRNA plasmid （ Ⅲ group）. CD59 mRNA level was detected by RT-PCR. The cell proliferation activity of the three groups was measured by MTTcolorimetry after crosslinking anti-CD55 mAb and anti-CD59 mAb. The phosphorylation levels of Src family of protein tyrosine kinase （PTK） were investigated by immunoblot analysis, and the kinetic changes of [ Ca^2＋] in T cell endochylema were determined by Laser scanning confocal microscope imaging. RESULTS： CD59 expression was successfullyinhibited in Ⅲgroup cells after transfecting. The cell proliferation, phosphorylation levels of Src family of PTK and degree of [ Ca^2＋] in Ⅰ and Ⅱ groups were increased compared with Ill group （ P 〈 0.05 ）, after crosslinking of CD55 and CD59 antibodies, but there was no difference between Ⅰ group and Ⅱ group. CONCLUSION： CD59 can enhance the effect of CD55-mediated T cell signal transduction.