CD59与CD55锚固蛋白对T细胞活化信号转导的作用

THE EFFECTS OF CD59 AND CD55 ON ACTIVATION-SIGNAL TRANSDUCTION OF T CELL

目的研究糖基磷脂酰肌醇（GPI）锚固蛋白CD59、CD55在脂筏介导T细胞信号转导通路中的作用。方法应用siRNA技术,构建针对CD55与CD59基因的重组载体pSUPER-siCD55、pSUPER-siCD59。实验分为未转染的Jurkat细胞组（Ⅰ组）、转染pSUPER-siCD59重组质粒的Jurkat细胞组（Ⅱ组）及转染pSUPER-siCD55重组质粒的Jurkat细胞组（Ⅲ组）。RT-PCR方法检测转染细胞中CD55和CD59基因mRNA的表达。噻唑蓝（MTT）比色法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细胞的增殖效应以及细胞内钙离子的变化。结果与Ⅰ组比较,Ⅱ组细胞CD59和Ⅲ组细胞CD55 mRNA的表达均明显减少（F=595.14、699.06,q=45.70~47.25,P〈0.05）。Ⅰ组细胞CD55与CD59联合作用后增殖能力和钙离子浓度均明显高于Ⅱ组、Ⅲ组（F=97.02、189.47,q=13.69~26.39,P〈0.01）,Ⅱ组低于Ⅲ组（q=5.43、6.42,P〈0.05）。结论 CD59和CD55在T细胞活化信号转导通路中存在协同效应,其中CD59起到重要作用。

Objective To study the synergistic effects of glycosylphosphatidyl inositol（GPI）-anchored protein CD59 and CD55 in lipid raft-mediated T cell signal transduction. Methods Construction of recombinant vectors pSUPER-siCD55and pSUPER-siCD59 targeting CD55 and CD59 gene with siRNA technique.Human Jurkat cells were divided into three groups： Jurkat cell group（group 1）,Jurkat cells transfected with pSUPER-CD59-siRNA plasmid（group 2） and Jurkat cells transfected with pSUPER-CD55-siRNA plasmid（group 3） The expressions of CD59 and CD55 mRNA in transfected cells were detected by RT-PCR.The cell proliferation activity of the three groups was measured by MTT colorimetry after crosslinking anti-CD55 mAb and anti-CD59 mAb,and the changes of calcium ion concentration in the cytoplasm were determined by laser scanning confocal microscope.Results Compared with group 1,expressions of CD59 mRNA in group 2 and CD55 mRNA in group 3 were significantly decreased（F=595.14,699.06;q=45.70-47.25;P0.05）.The reproductive activity and calcium ion level in group 1,after crosslinking of CD55 and CD59,were higher than that in both groups 1and 3（F=97.02,189.47;q=13.69-26.39;P0.01）,but that in group 2 were lower than group 3（q=5.43,6.42;P0.05）. Conclusion CD59 and CD55 have synergistic effects on activation signal transduction of T cell,in which,CD59 being more important.