诱导共刺激分子转基因小鼠类风湿性关节炎中滤泡辅助性T细胞的极化

Tfh polarization of ICOS-Transgenic mice in Rheumatoid arthritis mediated by ICOS/ICOSL signaling pathway

目的探讨可诱导共刺激分子（ICOS）转基因小鼠类风湿性关节炎（RA）模型中ICOS信号对滤泡辅助性T细胞（Tfh）极化的影响。方法1．流式细胞仪分析测定ICOS转基因（ICOS-Transgen-ic，ICOS-Tg）小鼠及其野生型对照（WT）小鼠脾细胞CD4＋T淋巴细胞共刺激分子ICOS在不同时期的表达趋势及特征；2．ELISA检测脾淋巴细胞培养悬液中干扰素（IFN）-γ、IL-21、IL-23、IL-17的水平；结果1．野生型RA小鼠脾CD4＋T淋巴细胞表面的ICOS的表达水平从4w到12w为上升趋势（％）（4W：6．5±1．0；7W：13．2±1．3；12W：23．5±2．1）；ICOS-Tg小鼠脾CD4＋T淋巴细胞表面ICOS的表达三期同样呈上升趋势（％）（4W：8．2±0．9；7W：17．2±1．5；12W：31．6±3．0），但与野生型小鼠相比各期均表达上调（均P〈0．05）；2．野生型小鼠IFN-γ从4W开始表达上升，7周达峰值后下降，ICOS-Tg小鼠同野生型小鼠相比，趋势相同但表达在各期呈下调趋势，差异有统计学意义（4W^20W均P〈0．05）；野生型小鼠的IL-21、IL-23及IL-17的表达于4周上升，12周达峰值后下降，ICOS-Tg小鼠同野生型小鼠相比，三者的各期表达趋势相同但呈上调趋势（IL-21和IL-17有统计学意义，P〈0．05；IL-23无统计学意义，P〉0．05）。结论RA小鼠在其致病过程中共刺激信号ICOS呈上调表达；ICOS-Tg小鼠同野生型小鼠相比，其脾淋巴细胞培养上清中IFN-γ呈显著下调趋势；Tfh分化相关的细胞因子IL-21、IL-17则均显著上调表达。Tfh细胞及其作用因子很可能参与了RA的免疫应答，与RA的发生发展有关。

Objective To explore the enhance of inducible costimulator（ICOS） signaling effection on the costimulatory molecules and cytokine expression levels associated with the polarization of Tfh in ICOS-Tg mice of RA. Methods 1. Determination of flow cytometric analysis of spleen cells CD4 ＋ T cell eostimulatory molecules ICOS;2 The detection of eytokines IFN-γ、IL-21 、IL-23、IL-17 in euhured splenocytes suspension by ELISA; Results The expression of ICOS in splenic CD4 ＋ T lymphoeytes were gradually increased, peaking at 12 weeks,followed by a slow decline after 16 weeks remained at a high level of expression with the development of the course（4w：6.5± 1.0;7w： 13.2 ± 1.3 ; 12w：23.5 ± 2.1 ） ; compared to wild type mice, ICOS-Tg mice showed up-regnlated expression of ICOS （ 4w ： 8.2 ± 0.9 ; 7w ： 17.2 ± 1.5 ; 12w ： 31.6 ± 3.0 ） ; the expression IL-21, IL-23, IL-17 of ICOS-Tg mice was significantly upregulated; the level of IFN-γ was downregnlated compared with wild type. Conclusion Tfh cells may be involved in the immune response of RA. ICOS may be the key signaling on Tfh polarized immune responses.