NKG2D受体影响幼年特发性关节炎CD4+T细胞与树突状细胞相互作用的研究

Juvenile idiopathic arthritis (JIA) is the most common connective tissue disease in childhood and serious harm to children's physical and mental health. The pathogenesis of JIA is not clear, and abnormal differentiation and function of T cells mediated by interaction of CD4+T cells and antigen presenting cells play an important role. In early study,we found NKG2D receptor on CD4+T cells were activated in JIA patients, which induced the level of Th17 cells. On the basis, we study the effects of NKG2D and its ligands on the activations of naive T cells and memmory T cells in patiens with systemic, polyarticular and pauciarticular JIA in this project. By the gene silencing method of CRISPR-Cas9, We study the role of NKG2D recepotr in the interactions of CD4+T cells and the most powerful antigen presenting cell dendritic cells (DC), the direct and indirect impacts on T cell differentiation to Th1/Th2 or Th17/Treg subsets. We investigate the pathogenesis during the cell interactions, including T cells proliferation, T cells productions of cytokines IL-10、IL-17、TGF-β、IL-12、IFN-γ and IL-4, T cells expressions of specific transcription factor for T cell differentiation RORc、Foxp3、T-bet and GATA-3, and DCs expressions of surface active molecules and NKG2D ligands MICA/B, DCs productions of cytokines IL – 10、TGF - β and IL – 12. Understanding the inflammatory and immune regulatory functions of NKG2D recepor is benefit to exploration pathogenesis and new therapeutic targets of JIA.

幼年特发性关节炎（JIA）是儿童最常见结缔组织疾病，抗原递呈细胞与T细胞相互作用影响T细胞亚群分化异常在发病中起核心作用。前期发现JIA的CD4+T细胞NKG2D受体活化，促进Th17表达，在此基础上，我们研究NKG2D及其配体活化在JIA全身型、少关节型和多关节型患儿初始和记忆T细胞活化中的作用。通过新型基因沉默工具CRISPR-Cas9研究NKG2D受体在CD4+T细胞与功能最强大抗原递呈细胞树突状细胞（DC）相互作用中，直接和间接影响Th1/Th2、Th17/Treg 亚群分化机制，包括T细胞增殖、表达分化特异性细胞因子和转录因子、DC表达活性分子和分泌细胞因子情况。该研究对明确作用有争议的NKG2D受体在JIA炎症反应和免疫调控中作用有重要意义，证实NKG2D受体影响CD4+T细胞分化是JIA发病机制之一，调节该受体功能是JIA新的治疗靶点。

幼年特发性关节炎（JIA）是儿童最常见结缔组织疾病，抗原递呈细胞与T细胞相互作用影响T细胞亚群分化异常在发病中起核心作用。本项目研究NKG2D及其配体活化在JIA全身型、少关节型和多关节型患儿T细胞活化和分化中的作用。首先证实了NKG2D在JIA各个亚型活动期表达明显增高，证实其参与JIA炎症反应，控制该受体的活化是治疗JIA炎症的途径之一。在此基础上，通过慢病毒载体构建基因沉默和过表达NKG2D的CD4+T细胞，并与抗原递呈细胞树突状细胞（DC）相互作用，发现NKG2D促进CD4+T细胞分泌IL-12，减少IL-10、TGF-β分泌，增加CD4+IL-17+T细胞和CD4+IFN-γ+Th1细胞，抑制CD4+CD25+Foxp3+Treg细胞和CD4+IL-4+Th2细胞比例。NKG2D还促进DC表达NKG2D配体MICA和MICB，抑制DC分泌IL-10、TGF-β，增加DC分泌IL-12，证实NKG2D受体通过直接和间接影响JIA患儿CD4+T细胞和DC，从而影响CD4+T细胞亚群CD4+CD25+Foxp3+Treg细胞、Th17细胞、Th1细胞和Th2细胞分化，提示控制NKG2D受体活化是抑制JIA患儿自身免疫炎症反应和诱导免疫耐受的有效靶点。