滤泡辅助性T细胞(TFH)在炎性肠病中的表达研究

Roles of follicular helper T cells in pathogenesis of inflammatory bowel diseases

目的观察新型CD4+T辅助细胞亚群-滤泡辅助性T细胞(T follicular helper cells,TFH)在炎性肠病(inflammatory bowel diseases,IBD)中的表达,探究其在IBD发病中的作用及机制。方法用饮用葡聚硫酸钠(dex-tran sulfate sodium,DSS)的方法建立IBD动物模型,密度梯度离心法分离小鼠脾淋巴细胞,采用不同荧光素标记的CD4I、COS、CD40L、CXCR5抗体进行流式细胞染色,分析上述TFH的表面标记在DSS诱导IBD(DSS-IBD)模型中的变化;同时提取淋巴细胞RNA,用实时定量PCR检测TFH的特异性转录因子Bcl-6和效应分子IL-21的表达变化。结果与结论与对照组相比,DSS-IBD模型动物CD4+ICOS+,CD4+CD40L+,CD4+CXCR5+T细胞的比例,以及Bcl-6和IL-21在mRNA表达水平均显著下降,显示TFH亚群的功能调节失常可能是该类IBD的重要发病机制之一。

Objective To identify the possible roles of a new CD4＋T helper cell subset,T follicular helper cells（TFH）,in the pathogenesis of inflammatory bowel diseases（IBD）.Methods IBD models were established by DSS drinking.Lymphocytes were isolated from the spleen of mice and were triple stained for ICOS,CD40L,CXCR5 expression on CD4＋T cells.Meanwhile,the expression of TFH transcription factors and cytokines,including Bcl-6 and IL-21 in lymphocytes,was also examined by real-time PCR.Results and Conclusion In the DSS induced IBD model,the percentage of CD4＋ ICOS＋,CD4＋ CD40L＋,and CD4＋ CXCR5＋T cells was significantly decreased.So did the expression of Bcl-6 and IL-21,the typical transcriptional factor and cytokine of TFH.Our data suggest deregulation of TFH subset in the pathogenesis of DSS induced inflammatory models.The underlying mechanisms remain to be determined.