转染B7-1基因的Raji和Jurkat细胞诱导细胞因子mRNA表达的研究

Study on Expression of Cytokines mRNA Induced by B7-l-transfected Raji and Jurkat Cells

为探讨B7共刺激分子在T细胞活化和分化中的作用,利用脂质体介导的转基因技术将B7基因导入恶性血液病细胞系Raji和Jurkat细胞,用流式细胞术检测转基因前、后B7-1基因的表达,用RT-PCR检测T细胞表面细胞因子IL-2,IL-4和IFN-γ mRNA的表达及这3种细胞因子在转基因后4,12,20及48小时的时间动态变化。结果发现,B7^+ Raji细胞可诱导T细胞分泌细胞因子IL-2,IL-4和IFN-γ,B7^+ Jurkat细胞可诱导IL-2和IFN-γ的分泌,而B7^- Raji细胞及B7^- Jurkat细胞均未诱导细胞因子的分泌。IL-2和IL-4在T细胞活化4小时即可检测到,IFN-γ在T细胞活化12小时可检测到,在20小时出现峰值。结论:B7-1基因的导入可有效地增强肿瘤细胞的免疫原性,激活T细胞,B7-1在T细胞活化和分化中起着更主要的作用。

To investigate the function of B7 co-stimulator in activation and differentiation of T cell,B7 gene was transfected into Raji and Jurkat cells by liposome,B7 expression in tumor cells was detected with flow cytometry,and expression of IL-2,IL-4 and IFN-ymRNA was detected by RT-PCR.Kinetics of secretion of three cytokines were also analyzed at 4,12,20 and 48 hours after gene transfection.The results showed that B7+ Raji cells could induce mRNA expression of IL-2,IL-4 and IFN-y on T cell surface; B7+ Jurkat cells could induce secretion of IL-2 and IFN-y.However,B7 Raji and B7 Jurkat cells could not induce secretion of cytokines.Kinetics of the three cytokines secretion were different,IL-2 and IL-4 were only detectable after 4 hours of T cell activation,whereas IFN-y was detectable after 12 hours of stimulation.The peak levels of IL-2,IL-4 and IFN-y were found at 20 hours after activation.It was concluded that tumor cell lines transfected B7 gene could enhance their immunocompetence,activating T cell efficiently and B7-1 play more critical role in T cell activation and differentiation.