Th1、Th2和Th17细胞失衡与克罗恩病的关系

摘要

免疫功能紊乱是炎症性肠病发病的关键环节,研究发现Th1、Th2和Th17细胞比例失衡与肠道免疫失调相关.目的:探讨Th1、Th2和Th17细胞失衡与克罗恩病(CD)的关系.方法:收集2013年1月-2014年12月温州医科大学附属第二医院收治的CD患者36例,同期行肠息肉摘除术患者40例作为对照组,分别取病变部位肠组织和正常肠组织,采用real-time PCR和免疫组化法检测Th1、Th2、Th17细胞相关转录因子(T-bet、GATA-3、RORγt)和细胞因子(IFN-γ、IL-4、IL-17A)表达.结果:与对照组相比,CD组肠组织中T-bet、RORγt mRNA表达、IFN-γ、IL-17A mRNA和蛋白表达以及代表Th1/Th2、Th17/Th2比例的T-bet/GATA-3、RORγt/GATA-3比值均显著增高(P<0.05),各转录因子与相应细胞因子表达呈显著正相关(P<0.05).IFN-γ和IL-17A免疫阳性物质均定位于细胞质,在CD患者中阳性细胞主要分布于上皮层和黏膜固有层.分层分析显示活动期CD的上述指标均显著高于缓解期(P<0.05);活动期CD代表Th17/Th1比例的RORγt/T-bet比值亦较缓解期显著增高(P<0.05).结论:肠组织中Th1、Th2和Th17细胞失衡与CD密切相关,Th1、Th17细胞极化可能在其中起重要作用,活动期CD以Th17细胞极化为著.%Dysregulated immune response is crucial for the pathogenesis of inflammatory bowel disease.Recent studies suggested that imbalance among Th1, Th2 and Th17 cells was closely related to the aberrant intestinal immune response.Aims: To investigate the association of imbalance among Th1, Th2 and Th17 cells and Crohn''s disease (CD).Methods: Thirty-six CD patients admitted from Jan.2013 to Dec.2014 at the Second Affiliated Hospital of Wenzhou Medical University were enrolled;40 patients undergoing intestinal polypectomy were collected as controls.Inflamed and normal mucosal tissues were obtained from CD patients and the controls, respectively;expressions of Th1, Th2 and Th17 cells related transcriptional factors (T-bet, GATA-3 and RORγt) and cytokines (IFN-γ, IL-4 and IL-17A) were determined by real-time PCR and immunohistochemistry.Results: In comparison with the controls, mRNA expression of T-bet and RORγt, mRNA and protein expressions of IFN-γ and IL-17A, as well as the ratios for T-bet/GATA-3 and RORγt/GATA-3, which represented balance of Th1/Th2 and Th17/Th2, respectively, were all significantly increased in inflamed mucosal tissue in CD patients (P<0.05).Expression of each of the three transcriptional factors was positively correlated with its corresponding cytokine (P<0.05).IFN-γ+ and IL-17A+ cells mainly located in the intestinal epithelial layer and lamina propria with cytoplasmic immunoreactivities in CD patients.In the stratified analysis, all the above-mentioned parameters were significantly higher in active CD than in inactive CD (P<0.05);furthermore, the ratio for RORγt/T-bet, which represented balance of Th17/Th1, was also increased significantly in active CD (P<0.05).Conclusions: Imbalance among Th1, Th2 and Th17 cells in intestinal mucosal tissue was closely related with CD.Polarization of Th1 and Th17 cells are involved in this process, and Th17 polarization is predominant in active disease.