微小RNA-7对CD4+T细胞功能的调控作用及机制研究

Recent evidences showed that microRNAs-7 played an important role in the development of various organs and related clinical diseases. However, the potential role of miR-7 in host immune function remains to be elucidated. Most recently, we found that the expression of miR-7 in activated CD4+T cells increased significantly. Moreover, we constructed miR-7 knock down (KD) mice using miRNA sponge technology and found that the proliferation and IFN-g secretion of CD4+T cells in miR-7 KD mice was elevated compared with those in wild type (WT) mice in vitro, indicating that miR-7 was an important novel negative regulator in the function of CD4+T cells. In the present study, we aimed to further investigate the possible effect of altered expression of miR-7 on the activation, proliferation and related cytokine secretion of CD4+T cells in vitro. Furthermore, combining adoptive cell transfer assay, we further detected the possible influence of altered expression of miR-7 in CD4+T cells on the antitumor effect of CD8+T cells in vivo. Finally, the potential target molecules of miR-7 also were identified by using gene chip technology combined luciferase reporter assay and western blot. This prospective data would provided evidence for successive study on the role of miR-7 in the development and differentiation of CD4+T cells, as well as for the development of strategy of manipulation of CD4+T cell function for the immunobiological therapy against related clinical diseases.

微小RNA-7在机体组织器官发育和多种临床疾病发生中具有重要作用，然而其在机体免疫系统功能中的作用仍待研究阐明。我们新近发现miR-7在CD4+T细胞活化过程中明显上调，且利用海绵体技术构建了miR-7基因敲减（KD）小鼠，发现miR-7KD小鼠CD4+T细胞体外增殖和IFN-g分泌明显增强，提示miR-7可能是CD4+T细胞功能重要的新负调控分子。在此基础上，本项目拟进一步观察改变miR-7表达对CD4+T细胞体外活化、增殖和相关细胞因子分泌的影响；并整合过继细胞转输实验观察改变miR-7表达对CD4+T细胞辅助CD8+T细胞抗肿瘤效应的作用；最后，利用基因芯片技术、荧光素酶基因报告系统，结合Western Blot来探讨miR-7调控CD4+T细胞功能的靶分子机制。预期结果可为后续探讨miR-7在CD4+T细胞发育和分化中的作用，以及临床相关疾病免疫生物治疗策略开发提供新的实验依据。

微小RNA-7在机体组织器官发育和多种临床疾病发生中具有重要作用，然而其在机体免疫系统功能中的作用仍待研究阐明。我们新近发现miR-7在CD4+T细胞活化过程中明显上调，且利用海绵体技术构建了miR-7基因敲减（KD）小鼠，发现miR-7KD小鼠CD4+T细胞体外增殖和IFN-g分泌明显增强，提示miR-7可能是CD4+T细胞功能重要的新负调控分子。在此基础上，本项目进一步观察发现：（1）在CD4+T细胞活化过程中，miR-7表达明显上调；（2）miR-7敲减后可显著增强CD4+T细胞的体外活化、增殖和相关细胞因子分泌，涉及到CD69、CD44、IFN-g等表达改变；（3）过继细胞转输实验结果显示miR-7敲减可明显增强CD4+T细胞体内活化和功能，包括CD69和IFN-g表达明显上调，而CD62L明显下调；（4）基因芯片技术筛查，结合生物信息学分析，以及荧光素酶基因报告系统等实验显示miR-7调控CD4+T细胞功能，主要通过其靶分子MAPK4途径来发挥。本项目结果为后续探讨miR-7在CD4+T细胞发育和分化中的作用，以及临床相关疾病免疫生物治疗策略开发提供了新的实验依据。