IL-22诱导类风湿关节炎患者滑膜成纤维细胞分泌 IL-6促进 Th17细胞分化的研究

Interleukin-22 promotes Th17 cells differentiation through up-regulating IL-6 production by rheuma-toid arthritis synovial fibroblasts

目的：探讨白细胞介素-22（IL-22）刺激类风湿关节炎滑膜成纤维细胞（RASF）产生白细胞介素-6（IL-6）的水平，及间接调控IL-17＋CD4＋T（Th17）细胞分化的能力。方法分离RASF 6例，建立体外培养体系，IL-22刺激RASF，qRT-PCR及ELISA检测IL-6的表达；IL-22R1封闭抗体及抑制剂实验检测IL-6产生所涉及的特异性受体及其下游信号通路；建立RASF与健康志愿者CD4＋T细胞共培养体系和Transwell 体系，流式细胞术检测体系中各组 Th17细胞比例。结果 IL-22刺激RASF呈时间和剂量依赖性产生IL-6（P＜0．05），且IL-6产生依赖于IL-22R1及其下游的p38和JAK2通路（P＜0．05）；共培养体系和Transwell体系中发现IL-22预刺激RASF组较未刺激组Th17细胞比例增加，阻断IL-22R1或IL-6均能降低Th17细胞比例。结论 IL-22刺激RASF产生IL-6，进而促进Th17细胞分化，中和IL-22是RA治疗的有效策略。

Objective To investigate the effects of interleukine-22 （ IL-22 ） on the expression of interleukin-6 （IL-6） by rheumatoid arthritis synovial fibroblasts （RASF）, and to analyze their association with IL-17＋CD4＋T （Th17） cells differentiation.Methods RASF were isolated from six patients with rheu-matoid arthritis （ RA） and cultured in vitro.The expression of IL-6 at mRNA and protein levels by RASF were detected by qRT-PCR analysis and ELISA after treatment with different concentrations of IL -22 for dif-ferent periods of time.Anti-IL-22R1 blocking antibody and inhibitor assay were used to analyze the specific receptor and its downstream signaling pathways associated with IL-6 production.IL-22 pre-treated RASF and CD4＋T cells were co-cultured for 3 days in the presence or absence of anti-IL-22R1 or anti-IL-6 to measure the percentage of Th 17 cells by flow cytometry .Results The expression of IL-6 by RASF was increased up-on IL-22 stimulation in a dose and time dependent manner （P〈0.05）, and that was closely related to IL-22R1 and its downstream signaling pathways of p38 and JAK2 （P〈0.05）.Coculturing CD4＋T cells with RASF and Transwell system indicated that the percentage of Th 17 cells was increased in IL-22 pre-treated group as compared with that in IL-22 untreated group , but it could be downregulated by either blocking IL-22R1 or IL-6.Conclusion IL-22 promoted the expression of IL-6 by RASF and further enhanced Th 17 differentiation.Neutralizing IL-22 in synovium of patients with RA might be an effective therapeutic strategy for RA treatment.