miR-491通过调控T细胞的增殖和凋亡在诱导T细胞衰竭中的作用机制研究

项目名称： miR-491通过调控T细胞的增殖和凋亡在诱导T细胞衰竭中的作用机制研究

项目编号： No.81202310

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 医学免疫学、法医学

项目作者： 肖斌

作者单位： 中国人民解放军第三军医大学

项目金额： 23万元

中文摘要： T细胞衰竭是指T细胞在特定情况下出现的功能抑制或失衡，其发生机制仍不清楚。研究证实，miRNAs可参与调控T细胞的增殖、凋亡和分化，那么miRNAs是否也能调控T细胞衰竭？我们在前期研究证实，miR-491在衰竭T细胞中表达上调，过表达miR-491能抑制T细胞增殖，促进T细胞凋亡，且miR-491启动子序列中可能含有SMAD结合位点，提示miR-491可能参与诱导T细胞衰竭。本项目拟利用逆转录病毒和AntagomiR系统，体内和体外过表达及抑制miR-491，研究其对T细胞增殖、凋亡以及衰竭表型的影响，同时通过荧光素酶、siRNA、CHIP等鉴定miR-491的靶基因和上游表达调控因子，以验证假说：miR-491可能通过下调靶基因（如Bcl-w、TCF7和CDK4）的表达，抑制T细胞增殖，促进T细胞凋亡，从而诱导T细胞衰竭，而miR-491的高表达可能受TGF-β-SMAD通路的调控。

中文关键词： miR-491；T细胞衰竭；增殖；凋亡；肿瘤

英文摘要： T cell exhaustion is a state of T cell dysfunction that arises during chronic infections and cancer, the exact mechanism is not clear. MicroRNAs are small non-coding RNAs, which can negatively regulate gene expression. There are increasing evidences that microRNAs can regulate the function of T cells including proliferation, apoptosis, and differentiation. Whether microRNAs are involved in the regulation of T cell exhaustion? In our previous study, we found miR-491 was significantly up-regulated in exhausted T cells, and overexpression of miR-491 can inhibit the proliferation and induce apoptosis of T cells. Above data suggest miR-491 may play potential role in the induction of T cell exhaustion. In current project, we plan to study the role of miR-491 on the proliferation, apoptosis and exhaustion phenotype in vitro and in vivo by using retrovirus expression system and antagomiR which can overexpress or inhibit miR-491 level. Then we want to identify the target gene and transcription factor of miR-491 by using luciferase report system, siRNA, western-blot, and Chip. In conclusion, our hypothesis is that miR-491 is up-regulated in exhausted T cells, and miR-491 may inhibit the proliferation and induce the apoptosis of T cells by down-regulating the target genes of Bcl-w, TCF-7, and CDK-4, it will result in the

英文关键词： miR-491；T cell exhaustion；proliferation；apoptosis；tumor