三硝基苯磺酸诱导肠道炎性疾病小鼠模型免疫致病机制的探讨  

Immunopathological mechanism of TNBS-induced inflammatory bowel disease in mice

作　　者：杨蕾 孟庆红 左丽 

机构地区：[1]贵州医科大学基础医学院免疫学教研室,贵阳550025

出　　处：《中华微生物学和免疫学杂志》2017年第8期567-572,共6页Chinese Journal of Microbiology and Immunology

基　　金：贵阳市科技计划项目[筑科合同（2012204）38];贵州省教育厅自然科学研究项目[黔教科（2011）030]

摘　　要：目的 用三硝基苯磺酸（TNBS）/50％乙醇灌肠,建立肠道炎性疾病（IBD）小鼠模型,通过分析结肠组织学变化及肠系膜淋巴结内T细胞亚群相关的细胞因子及转录因子RORγt的表达,探讨其可能的免疫致病机制.方法 将6～8周龄的BALB/c雌鼠随机分为TNBS造模组和正常对照组.模型组用 5％ TNBS/50％乙醇（1∶1）200 μl灌肠复制IBD模型,对照组予PBS灌肠.观察实验小鼠体征改变及其结肠的病理改变,利用real-time PCR动态检测实验动物肠系膜淋巴结Th1类细胞因子（IL-2、IFN-γ、IL-12p40）,Th2类细胞因子（IL-4）,Treg相关细胞因子（IL-10）,Th17相关的细胞因子（IL-21、IL-23、IL-17）及转录因子RORγt表达的变化.结果 模型组第3天体征异常,肠黏膜轻度充血、水肿;HE染色提示结肠轻度炎症;第6天体征和肠黏膜病变加重,HE染色可见结肠大量炎细胞浸润.Real-time PCR检测肠系膜淋巴结中各类相关细胞因子mRNA水平,造模第3天,Th17相关的细胞因子（IL-21、IL-23、IL-17）mRNA水平变化最为明显,差异有统计学意义,而其他Th细胞亚群相关细胞因子mRNA水平均无明显改变;造模第6天,Th1类细胞因子（IL-2、IFN-γ、IL-12p40）及Treg相关细胞因子IL-10的mRNA上调,差异有统计学意义,而 Th17相关的细胞因子（IL-21、IL-23、IL-17）及其关键转录因子RORγt的mRNA表达较第3天有不同程度的下降,但仍高于正常对照,差异有统计学意义.结论 提示在TNBS诱导的IBD小鼠模型中,Th17细胞在炎症早期发挥重要作用,随着病程进展,Th1和Th17细胞共同介导肠道的免疫病理损伤.Objective To study the possible pathogenesis of TNBS （2,4,6-trinitrobenzenesulfonic acid）-induced inflammatory bowel disease （IBD） in a mouse model by analyzing histological changes in colon and the expression of cytokines and transcription factor RORγt related to T cell subsets in mesenteric lymph nodes.Methods Female BALB/c mice aged 6-8 weeks were randomly grouped into two groups： IBD model and normal control groups.The mouse model of IBD was established by treating mice with 200 μl of 5％ TNBS/50％ ethanol solution （1∶1） through intestinal instillation, while the mice in the normal control group were instilled with PBS.Pathological changes in colon samples of mice were observed.Real-time PCR was performed to detect the dynamic expression of Th1 cytokines （IL-2, IFN-γ and IL-12p40）, Th2 cytokine （IL-4）, Treg-related cytokine （IL-10）, Th17 cell-related cytokines （IL-17, IL-21 and IL-23） and transcription factor RORγt in mesenteric lymph nodes.Results The mice in the model group begun to show abnormal vital signs such as diarrhea, loss of weight and reduced activity, and mild hyperemia of intestinal mucosa and edema from the third day after modeling.Slight lesions were observed in histological slices of colon tissues stained with hematoxylin and eosin （HE）.The expression of IL-21, IL-23 and IL-17 at mRNA level were significantly increased, while the expression of other cytokines showed no significant change.On the sixth day after modeling, many pathological symptoms and intestinal mucosal lesions were aggravated, and marked infiltration of inflammatory cells was observed in histological slices of colon tissues, which indicated that the IBD model was successfully induced by TNBS.Compared with the control group, the IBD model group showed significantly enhanced expression of IL-2, IL-12p40 and IL-10 in mesenteric lymph nodes at mRNA level on the sixth day after modeling.Although the expression of IL-21, IL-23, IL-17 and RORγt at mRNA level on the sixth day were down-regul

关 键 词：三硝基苯磺酸 BALB/C鼠 肠道炎性疾病 T细胞亚群 细胞因子 

分 类 号：R-332[医药卫生] R574