GPI-B7-1分子膜表面修饰瘤苗抗肿瘤作用的研究

目的：研制抗肿瘤免疫治疗的新疫苗。方法: 用含目的基因的质粒pcDNA3.1(+)/GPI-B7-1转染QK10341细胞，提取膜蛋白GPI-B7-1, 经Western blotting鉴定后，用蛋白转化法锚定在肿瘤细胞SKOV3膜上，取正常健康人外周血中非贴壁的淋巴细胞， 进行淋巴细胞扩增和CTL功能检测，并检测细胞培养液中IL-2、TNF-α和IFN-γ水平，FCM检测CTL的Fas表达水平。结果:与野生型SKOV3细胞比较，用GPI-B7-1修饰的SKOV3细胞能够更有效地刺激淋巴细胞增殖、诱导特异CTL杀伤活性(P<0.01)，还可诱导 CTL表达的Fas水平升高等活性增强以及分泌的IL-2、IFN-γ和TNF-α等细胞因子水平均显著上升(P<0.05)。结论: B7-1基因在肿瘤细胞中表达可增强其免疫原性，在体外有效诱导T细胞活化， 显著增强T细胞杀伤肿瘤细胞的活性；对防治肿瘤侵袭具有一定作用。

Effects of B7-1 gene expression on the biological characteristics of hepatocarcinoma cells

AIM:Modification of tumor cells with B7-1 (CD80) costimulatory adhesion molecules has been proposed as a means to develop therapeutic cancer vaccines for use in human immunotherapy. METHODS:Glycosyl-phosphatidylinositol (GPI)-anchored B7-1 was transfered into QK10341 cell membranes with the plasmid of pcDNA3.1(+)/GPI-B7-1 by lipofectamine transfection. Then the GPI-B7-1 protein was isolated and purified from QK10341 cells. The SKOV3 cells incubated with GPI-B7-1 protein resulted in stable incorporation of B7-1 on SKOV3 cell membranes. Expression of B7-1 in tumors by protein transfer created an immunogenic tumor cell that induced antitumor immunity. The growth curve of T cells, the change of Fas (CD95) expression on cell membranes, and level of cytokines secreted from CTL were determined by MTT, FCM, and ELISA, respectively. The cytotoxicity alteration of the CTL was also studied. RESULTS:Compared with SKOV3 cells, B7-1-SKOV3 cells more effectively induced the proliferation of effector lymphocytes and the generation of specific lytic activity (P<0.01). The level of cytokine secretion also increased. CONCLUSION:The costimulation signal of B7-1 is required for the activation and proliferation of T lymphocytes. The B7-1 expression in SKOV3 tumor cells can increase their immunogenicity and induce more effective T lymphocytes activation.