诱导性Foxp3+调节性T细胞相关特征miRNA对其抑制功能维持的作用研究

Inducible Foxp3+ regulatory T cell was a functional subset of CD4+CD25+ regulatory T cell. However, the underlying mechanism of function sustainment of inducible Foxp3+ regulatory T cells remains to be elucidated. Recent evidences showed that miRNAs controlled the generation and function of CD4+CD25+ regulatory T cells. However, the expression and its potential function of associated miRNAs in inducible Foxp3+ regulatory T cells remains to be further investigated. Our previous data showed that miR-126, a member of miRNAs family, could regulate the induction of Foxp3+ regulatory T cells. In the present study, we aimed to establish the profile of miRNAs on inducible Foxp3+ regulatory T cells using Solexa deep sequencing technology combined Realtime PCR probe assay. And we further investigated the possible effect of specific miRNAs on the suppressive function in vitro and in vivo, as well as the expression of functional molecules, of inducible Foxp3+ regulatory T cells through altering specific miRNAs expression using lentivirus expression vector. Moreover, the potential target molecules of specific miRNAs also were identified by using gene chip technology combined western blot, as well as luciferase reporter assay and genic mutation. This prospective data would provided evidence for successive study on the mechanism through which miRNAs regulates the function of CD4+ CD25+ regulatory T cells and for the exploration of immunobiological therapy of related clinical diseases.

诱导性Foxp3+调节性T细胞是CD4+CD25+调节性T细胞的重要功能亚群，其功能维持调控机制仍未阐明。新近研究显示miRNA对CD4+CD25+调节性T细胞发育分化和功能有重要作用。我们在前期研究中发现miRNA家族成员miR-126可以调节Foxp3+调节性T细胞的外周诱导。在此基础上，本项目拟利用Solexa深度测序技术和Real-time PCR探针法检测诱导性Foxp3+调节性T细胞的miRNAs表达特征谱；进而利用慢病毒载体表达系统改变特征miRNAs的表达，观察其对诱导性Foxp3+调节性T细胞功能相关分子、体内外抑制功能的影响；进一步利用基因芯片技术、荧光素酶基因报告载体系统、基因定点突变技术结合Western Blot来探讨特征miRNAs作用的靶分子机制。项目预期结果将为深入探讨miRNA对调节性T细胞功能的调控作用及临床相关疾病免疫生物治疗靶标开发提供新的实验依据。

诱导性Foxp3+调节性T细胞是CD4+CD25+调节性T细胞的一个重要亚群，其在机体外周免疫自稳和相关疾病发生中发挥了重要作用，然而其抑制功能的不稳定性是影响其临床应用的重要障碍，且相关维持机制仍远未阐明。在本研究生中，我们利用芯片技术筛查发现微小RNA家族成员-微小RNA-30a（miR-30a）在iTregs中低表达；进一步研究发现miR-30a可下调iTregs抑制功能相关膜分子CTLA4和GITR的表达，同时iTregs分泌IL-10和TGF-b的能力明显削弱；并且，iTregs体外抑制CD4+T细胞增殖的能力明显降低。过继转输实验发现，miR-30a可显著削弱iTregs在体内对CD8+T细胞活化和功能的抑制作用和抗肿瘤效应。机制方面，我们发现miR-30a可调节iTregs中靶分子SOCS1的表达，同时相关信号途径STAT1和Akt传递发生改变。项目结果提示，miR-30a是iTregs抑制功能维持的新的调控分子，为后续深入探讨iTregs抑制功能维持机制，以及开发基于iTregs抑制功能的临床相关疾病诊治新策略提供了新的实验依据。