口腔扁平苔藓是一种T细胞介导的自身免疫性疾病，CD4+CD25+调节性T细胞在机体免疫稳态的维持中发挥了重要作用。以往研究证明，OLP患者中该群细胞比例增高，且对效应T细胞增殖的抑制作用显著降低，然而其具体机制尚未阐明。IL-6/Stat3可参与下调Treg的功能，且已有研究证实OLP患者中IL-6较正常对照显著增高。本研究拟采用流式细胞术、ELISA，RT-PCR、磁珠分选、细胞共培养，分子生物学技术和方法就OLP患者Treg调节功能下降的机制进行以下研究：①OLP患者Treg的数量和表型，T细胞IL-6R的表达；②OLP患者Treg的体外抑制功能；③OLP血清和细胞培养上清中相关细胞因子水平；④IL-6对OLP患者Treg体外抑制功能的影响和机制；⑤IL-6对T细胞转录因子Stat3磷酸化的影响。

Oral lichen planus is a T cell-mediated autoimmune disease, CD4+CD25+ regulatory T cells plays a critical role in the maintenance of immune homeostasis and prevention of autoimmunity. Past studies have demonstrated that the proportion of CD4+CD25+ T cells in OLP patients was significant higher than that in healthy controls, and the inhibition function of CD4+CD25+T cells cells to CD4+CD25- T cells proliferation was impaired. Nevertheless, the specific mechanism and how the impaired immunomodulation of CD4+CD25+ Treg cells contributes to the OLP pathogenesis remains largely unknown. IL-6 in OLP patients serum was significantly higher than healthy controls, and the existing research confirmed that IL-6/Stat3 contributes to impaired function of regulatory T cell.In this study, we intend to utlize flow cytometry and ELISA, RT-PCR, magnetic bead separation, cell coculture, molecular biology techniques to explore whether there is intrinsic defect or secondary dysfunction of CD4+CD25+regulatory T cells in the following aspects: (1) The number of CD4 + CD25 + T cells in peripheral blood and phenotype; (2) OLP CD4 + CD25 + T cells in vitro inhibitory function; (3) Related cytokines in serum and cell culture supernatant level; (4) IL-6 involved CD4 + CD25 + T cells in vitro inhibitory function; (5) IL-6-mediated phosphorylation of Stat3 in T cells.