miR-98调控原发性干燥综合征Breg细胞免疫抑制功能缺陷的机制研究

Primary Sjögren's syndrome (pSS) is a common autoimmune-mediated chronic inflammatory disease . Our previous study revealed that, though numerically increased , peripheral blood regulatory B (Breg) cells from pSS patients were functionally impaired as they were not able to inhibit the inflammatory factors produced by T cells. What’s more, patients with high expression of Breg cells have higher disease activity. These results suggest that Breg cells play an important role in the pathogenesis of the disease. Our present study is to further investigate the mechanism of Breg cells regulated by microRNA (miRNA) in pSS. By using gene expression profiling spectrum to screen differentially expressed miRNA, we find miR-98 expression significantly increased in pSS. We will further predictive and define target gene by using Bioinformatics and Luciferase Reporter System. Next, we will testify this differentially expressed miRNA in peripheral blood and tissue Breg cells, and then by knocking down or overexpression of selected miRNA in B cells in vitro aim to verify that miR-98 regulates target gene. In addition, miRNA antagomir and agomir will be constructed to perform miRNA function studies in model animals. We hope to elucidate the role of miR-98 in Breg cell suppression work in pSS, explore the new molecular pathogenesis and provide evidence for miR-98-drived target therapy.

原发性干燥综合征(pSS)是一种常见的自身免疫介导的慢性炎性疾病。我们前期研究发现，pSS患者外周血调节性B（Breg）细胞高表达，但免疫抑制功能缺陷，不能抑制T细胞炎性因子产生，并且Breg细胞高表达的pSS患者有更高的疾病活动度，提示Breg细胞在该病的慢性炎症发病过程中起重要作用。本课题将在上述研究基础上进一步探讨miRNA对pSS患者Breg细胞功能的调控。通过基因表达谱数据筛选，我们预试验发现pSS患者Breg细胞差异表达miR-98。接下来拟应用生物信息学方法预测其靶基因，采用荧光素酶报告系统确定靶基因；体外阻断或过表达miR-98，观验证细胞中miR-98对靶基因调控；构建阻断或过表达miR-98小分子载体，在模型动物体内进行miRNA功能研究。本项目将阐明miR-98在Breg细胞免疫抑制中的作用，探索新的分子发病机制并为miR-98作为pSS治疗新靶点提供充分的科学证据。

B细胞在pSS发生发展中起着实际的核心作用，但其分子机制仍不明确。我们先前的研究证实调节性B细胞功能异常可能是其中的的机制之一，但是其中的分子通路、信号途径仍不清楚。在国家自然科学基金委的资助下，我们按照研究计划,系统的探讨了miR-98在pSS Breg细胞中的表达异常及其促进Breg功能异常的作用机制。主要取得如下成果： (1) miR-98在干燥综合征Breg细胞内高表达，并且通过miRanda、TargetScan及PicTar预测其潜在靶基因为IL-10；（2）扩大样本量验证miR-98靶向IL-10；（3）动物实验揭示miR-98对NOD小鼠表征有影响。综上所述，本项目结果提示，miR-98可能作为治疗潜在靶点，改善pSS免疫紊乱状态。