免疫系统关键生理功能之一在于能够正确区别自我与非我。炎性辅助性Th17细胞及免疫抑制性Treg细胞分化发育及功能动态平衡对于维持正常免疫稳态至关重要。由遗传及环境多因素共同引发的免疫系统功能失常性自身免疫病，常常涉及多种T细胞亚型介导的炎性病理反应，导致患者自身组织损伤，造成严重病患及沉重社会负担。已发表及我们前期研究数据表明，在自身免疫性疾病发生发展过程中，Th17/Treg介导免疫平衡被打破，其具体分子细胞及生理机制尚有待进一步深入研究。结合前期研究结果，本项目申请中我们利用单细胞测序等新型高通量技术手段，拟发现自身免疫性疾病组织微环境不同细胞亚型间相互作用及功能调控的动态变化，重点关注Th17/Treg免疫平衡调控新分子机制，期待发现新免疫调控靶点，筛选开发新靶向治疗药物，为自身免疫性疾病治疗提供新策略新手段。

A critical function of our immune system is to discriminate self from nonself. The functional interaction and immune balance between inflammatory effector Th17 cells and immune suppressive Treg cells are essential for the maintenance of immune homeostasis in healthy individuls. Autoimmune diseases can be induced by the complex interactions among genetic and environmental risk factors. Although the causes of autoimmune disease can be various, T cell mediated inflammatory responses contribute to the pathogenesis of autoimmune diseases. Published data and our own ongoing studies have indicated that the immune balance between Th17 and Treg function is impaired in various types of autoimmune diseases. Understanding the precise regulation of the balance between Th17 and Treg could be an important therapeutic strategy for treating autoimmune disease. Unfortunately, the mechanisms that maintain the balance between Th17 and Treg remain elusive. In summary, we try to discover the common characterics and specific features of different autoimmune diseases by using new techniques, especially the single cell sequencing method to analyze immune cell-cell interaction and regulation under pathological condition. We expect our new findings on molecular mechanism underlying the balance between Th17 and Treg could be helpful to discover novel drug targets for therapeutic application against autoimmune disorders.