CD59促进LAT介导的T细胞活化

CD59 has a positive effect on LAT induced T lymphocytes activation

目的:研究CD59分子在LAT(Linker for activated T cells)介导的T系淋巴细胞活化中所起的作用。方法:构建LAT-GFP融合蛋白,以逆转录病毒为载体转染Jurkat细胞,建立稳定转染细胞株(Jurkat-GFP)。分别使用CD59抗体刺激和pSUPER-siCD59干扰质粒(GFP标记)沉默Jurkat-GFP细胞。免疫荧光观察CD59和LAT分子在细胞膜的表达和定位;MTT比色法检测细胞增殖率的变化;Western blot检测LAT活化信号转导通路中相关蛋白分子磷酸化水平。结果:荧光显微镜下可见Jurkat-GFP细胞绿色荧光表达于细胞膜,转染干扰质粒后细胞膜和细胞质均有绿色荧光表达。激光共聚焦显微镜下可见CD59抗体刺激前CD59和LAT分子均匀分布于细胞膜,且转染干扰质粒的Jurkat-GFP细胞CD59表达量下降。CD59抗体刺激后CD59分子和LAT分子点状聚集共定位于细胞膜。MTT结果表明相对于正常Jurkat-GFP细胞,抗体活化后细胞增殖速率明显升高(P>0.05),而电转干扰质粒后细胞生长减慢。Western blot结果表明,CD59抗体刺激后细胞ZAP-70、LCK、PLC-r总蛋白表达无明显差异(P>0.05),而磷酸化蛋白表达显著增高(P<0.05)。结论:抗体活化后细胞膜上CD59和LAT分子聚集并共定位于细胞膜,且细胞信号转导通路下游分子磷酸化水平增高,进一步证实CD59分子经抗体活化后可促进LAT介导的T细胞信号转导。

Objective：To investigate the function of CD 59 in LAT induced T lymphocytes＇proliferation and activation.Methods：Transfected LAT-GFP recombinant lentiviral vectors into Jurkat cells and established a fusion-protein stable express cell line （ Jurkat-GFP ）.Junket-GFP cells were transfected with pSUPER-siCD59 plasmids by electroporetion or stimulated by anti-CD59 antibody.The cellular locations of CD 59 and LAT were observed under fluorescence microscope with the immunofluorescence cytochemistry.The cells proliferation were measured by MTT assay.Furthermore,Western blot was used to detect the total and phosphorylation levels of several down-stream proteins after T cell activated .Results： Jurkat-GFP cells successfully transfected with pSUPER-siCD59 plasmids showed lower fluorescence staining.CD59 and LAT distributed uniformly on the cell surface before stimulated with anti-CD59 antibody and formed clusters once upon stimulation.Jurkat-GFP cells stimulated with anti-CD59 antibody showed a higher level of proliferation and protein phosphorylation ,compared with the others.Conclusion：CD59 contributed to LAT induced signaling transduction of T lymphocytes ,and stimulated CD59 molecule partly promoted T cell activation.