【摘要】 目的探讨CD200/CD200受体1(CD200R1)信号轴在类风湿关节炎(RA)免疫病理机制中的作用。方法采用免疫组化法、流式细胞仪检测RA滑膜、外周血细胞CD200/CD200R1表达水平,观察强化CD200/CD200R1信号对RA破骨细胞分化及T辅助17(Th17)细胞增殖、分化的作用。结果 RA患者滑膜及外周血CD200+(3.55%±0.24%vs.14.37%±1.54%,P<0.0001)及CD200R1+(11.19%±1.23%vs.20.57%±1.26%,P<0.0001)细胞明显低于健康对照者,经英夫利西单抗联合甲氨蝶呤治疗后,外周血CD200/CD200R1表达明显升高(P<0.0001),且CD200R1变化水平与血沉(ESR)、C反应蛋白(CRP)、疾病活动性评分(DAS28)呈负相关。细胞培养发现通过上调CD200/CD200R1信号可以抑制CD4+辅助性T细胞向Th17细胞增殖分化(46.86%±1.08%vs.54.06%±1.80%,P<0.01),促进凋亡(1.21%±0.11%vs.0.82%±0.06%,P<0.0001)、坏死(13.54%±0.31%vs.3.82%±0.19%,P<0.0001),并抑制趋化因子配体20(CCL20)-趋化因子受体6(chemokine receptor 6,CCR6)介导的Th17细胞的炎性趋化(359.30±35.25vs.1992.00±318.00,P<0.0001)。此外,强化CD200/CD200R1信号还可降低单核诱导的破骨细胞形成。结论 RA滑膜及外周血CD200/CD200R1信号存在表达与功能异常,通过调控Th17细胞及破骨细胞免疫应答,有望成为RA抗炎治疗的新靶点。更多还原

【Abstract】 Objective To evaluate the functional status of CD200/CD200R1 interactions in patients with rheumatoid arthritis (RA). Methods The expression of CD200 and CD200R1 by CD4+ cells, CD14+ cells and synovium was examined by flowcytometry and immunohistochemistry, and compared between RA patients before and after treatment with infliximab(IFX) plus methotrexate(MTX), and also healthy controls (HCs). Sorted CD4+ T cells were stained with CFSE and Annexin V/PI for evaluating the effect of CD200 on cell proliferation and apoptosis. Moreover, the effect of CD200 on osteoclastogenesis and on T helper 17 (Th17) differentiation and function was determined by immunocytochemistry, flowcytometry and transwell migration assay. Results In RA patients, the numbers of CD200+ cells [(3.55%±0.24%) vs. (14.37%±1.54%),P<0.0001] and CD200R1+ cells [(11.19%±1.23%) vs. (20.57%±1.26%),P< 0.0001] from peripheral blood mononuclear cells(PBMC) were significantly lower than those in HCs, whereas the expression of CD200+ cells was higher in RA synovium compared to that in HCs. This abnormal expression could be corrected after treatment with IFX plus MTX(P< 0.0001) and was correlated with lower level of ESR、CRP and DAS28. Importantly, the engagement of CD200 receptor on CD14+ T cells with CD200Fc fusion protein in vitro reduced the osteoclastogenesis. Whereas the engagement of CD200 receptor on CD4+ T cells with CD200Fc fusion protein in vitro inhibited CD4+ T cells proliferation [(46.86%±1.08%) vs.(54.06%±1.80%),P<0.01], promoted its apoptosis [(1.21%±0.11%) vs.(0.82%±0.06%), P<0.0001] and necrocytosis [(13.54%±0.31%) vs.(3.82%±0.19%), P<0.0001], reduced CD4+ T cells differentiation into Th17 cells as well as down-regulated CCL20-CCR6-mediated Th17 chemotaxis in RA [(359.30± 35.25) vs.(1992.00±318.00),P<0.0001].Conclusions CD200 and CD200R1 expression and function are abnormal in RA and may contribute to the immunopathogenesis of RA involved in irritating Th17 cells and osteoclastogenesis.更多还原