节点文献
感染后内脏高敏感小鼠肠道黏膜固有层树突细胞对CD4~+T细胞的活化作用
Effect of Dendritic Cells from Intestinal Lamina Propria on Activation of Cd4~+ T Cells in Post-infectious Visceral Hypersensitivity Mice
【作者】 王文峰；
【导师】 侯晓华；
【作者基本信息】 华中科技大学 ， 消化内科， 2010， 硕士
【摘要】 背景在最近的研究中,越来越多的证据表明在PI-IBS肠道粘膜中存在T细胞介导的低度炎症。树突状细胞(Dendritic cell,DC)作为肠道免疫系统最重要的抗原提呈细胞在肠道免疫系统激活的作用少有研究。目的研究肠道黏膜固有层DC在急性肠道感染的不同阶段对CD4~+ T细胞的影响,探讨DC在维持肠道感染消退后肠道黏膜免疫系统持续激活中的作用。方法旋毛虫感染NIH小鼠(250-300条/只),建立旋毛虫感染后内脏高敏感小鼠模型以模拟人类PI-IBS,包括感染后8周组、感染后2周组、正常对照组;肠道组织标本HE染色确定炎症变化;MACS免疫磁珠分选肠道黏膜固有层DC和脾脏CD4~+ T细胞,于体外共培养120 h,ELISA法检测细胞培养上清液中Th17、Th2、Th1相关细胞因子(IL-17、IL-4、IFN-γ)水平及IL-23水平。结果肠道组织HE染色证明,感染后2周为急性炎症期,感染后8周未见炎症表现。与单独培养相比,CD4~+ T细胞与DC共培养后,感染后8周组IL-17水平增加值明显高于对照组(P=0.001)和感染后2周组(P=0.279);感染后2周组IL-4水平增加值明显高于对照组(P=0.041)和感染后8周组(P=0.204);三组间IFN-γ水平增加值差异均无统计学意义;与正常对照组比较,体外树突状细胞培养上清液IL-23水平在感染后2周组呈增高趋势,但无统计学意义,而在感染后8周组显著增高(P=0.043),且感染后8周组显著高于感染后2周组(P=0.041)。结论感染后内脏高敏感小鼠肠道黏膜固有层DC活化Th17细胞可能是肠道感染消退后维持肠道黏膜免疫系统持续激活的主要机制。
【Abstract】 Background: More and more evidences indicate that T cell-mediated low-grade inflammation presents in intestinal mucosa of post-infectious irritable bowel syndrome (PI-IBS). Dendritic cells (DC) are the most important antigen presenting cells in intestinal mucosal immune system, however, its role in the initiation of PI-IBS is still uncertain.Aims To investigate the effect of DC from intestinal lamina propria on CD4~+ T cells in different phases of acute intestinal infection, and its role in sustained activation of intestinal mucosal immune system after recovery of intestinal infection.Methods Visceral hypersensitivity was induced by Trichinella spiralis infection in mice to mimic human PI-IBS. DC in intestinal lamina propria and CD4~+ T cells in spleen were isolated by MACS? MicroBeads and cocultured in vitro for 120 hours, the Th17, Th2 and Th1 related cytokines (IL-17, IL-4 and IFN-γ) and IL-23 in the supernatant were determined by ELISA.Results Compared with CD4~+ T cells cultured alone, the increment of IL-17 in supernatant of CD4~+ T cells cocultured with DC was significantly higher in 8-week PI group than that in control group ( P=0.001) and 2-week PI group (P=0.279); the increment of IL-4 was significantly higher in 2-week PI group than that in contral group (P=0.041) and 8-week PI group (P=0.204); no significant difference was found in the increment of IFN-γamong the three groups;In vitro dendritic cell culture, IL-23 secretion significantly increased in 8-week PI group compared with normal control group (P=0.043) or 2-week PI group (P=0.041).Conclusions DC from intestinal lamina propria in PI visceral hypersensitivity mice can effectively promote the activativation of Th17 cells, which might be the main mechanism of sustained activation of intestinal mucosal immune system after recovery of intestinal infection.