论文部分内容阅读
目的:探讨CTLA4Ig修饰的树突状细胞(DC)对T细胞增殖和细胞毒性T细胞(CTL)细胞毒活性的影响。方法:采用脂质体转染法,将质粒pG/CTLA4Ig转入DC。采用ELISA和SDS-PAGE鉴定转染质粒pG/CTLA4Ig的DC培养上清。以C57BL/6小鼠的单个核细胞作为反应细胞,以未修饰的DC及修饰的DC作为刺激细胞,共培养6 d,用MTT比色法检测细胞的增殖。用乳酸脱氢酶法和ELISA法,分别测定细胞毒活性及T细胞凋亡。结果:CTLA4Ig融合蛋白和修饰的DC,对同种细胞刺激的增殖反应有明显地抑制作用;而未修饰的DC可显著诱导淋巴细胞增殖反应。CTLA4Ig融合蛋白和修饰的DC,对特异性CTL的细胞毒活性有明显地抑制作用,且可诱导T细胞凋亡。结论:稳定表达CTLA4Ig融合蛋白的DC,对T细胞增殖和对CTL的细胞毒活性具有明显地抑制作用,并可诱导T细胞凋亡。
Objective: To investigate the effect of CTLA4Ig-modified dendritic cells (DCs) on T cell proliferation and cytotoxic T lymphocyte (CTL) cytotoxicity. Methods: The plasmid pG / CTLA4Ig was transfected into DC by lipofection. The DC culture supernatants of transfected plasmid pG / CTLA4Ig were identified by ELISA and SDS-PAGE. Mononuclear cells of C57BL / 6 mice were used as reactive cells, unmodified DCs and modified DCs were used as stimulator cells for 6 days. The proliferation of the cells was detected by MTT assay. Cytotoxicity and T cell apoptosis were determined by lactate dehydrogenase and ELISA respectively. Results: The CTLA4Ig fusion protein and modified DC significantly inhibited the proliferative responses induced by allogeneic cells. However, unmodified DCs significantly induced lymphocyte proliferation. CTLA4Ig fusion protein and modified DC, cytotoxic activity of specific CTL was significantly inhibited, and can induce T cell apoptosis. CONCLUSION: DCs stably expressing CTLA4Ig fusion protein can significantly inhibit T cell proliferation and CTL cytotoxicity and induce T cell apoptosis.