对三硝基苯磺酸/乙醇与免疫复合物联合诱导的结肠炎动物模型免疫机制的探讨

Investigation of immunological mechanism in rat colitis model induced by TNBS/ethanol and immunocomplex

目的:从细胞免疫和体液免疫的角度证实免疫复合法制作IBD动物模型较之目前引起学者广泛关注的三硝基苯磺酸/乙醇诱导的结肠炎动物模型更符合B淋巴细胞和T淋巴细胞混合作用所致IBD的要求,证实此模型可能是一种更为理想的IBD动物模型,并有利于探讨炎症性肠病的发病机制。方法:SD大鼠168只,雌雄各半,分为①正常对照组42只;②三硝基苯磺酸/乙醇模型组42只;③免疫复合物组42只;④三硝基苯磺酸/乙醇与免疫复合物联合诱导的结肠炎动物模型组42只(以上每组雌雄各半)。分别于造模后1、2、3、4、6、9、12周末将大鼠处死(各组每周处死6只,雌雄各半)。观察各组外周血CD4+T细胞的变化,结肠组织CD4+T细胞表达,血清中IgG含量。结果:三硝基苯磺酸/乙醇与免疫复合物联合诱导的结肠炎动物模型组大鼠外周血CD4+T细胞百分含量均数为(44.8086±9.1830)%;结肠组织CD4+T细胞计数均数为179.8571±35.9546;血清中IgG含量均数为0.5360±0.1205皆明显高于其余各组,具有统计学意义。结论:从免疫机制的视角证实上述联合诱导的结肠炎动物模型是一种较理想的IBD动物模型,可作为研究IBD发病机制及评估药物疗效的有益工具。

Objective：From point of view of cellular and humoral immunity,to confirm that the colitis model induced by TNBS/ethanol and immunocomplex is better fitted with intermingled infiltration of B lymphocytes and T lymphocytes than TNBS/ethanol model which draws widespread attention in scholars in IBD, and to assess its value in research study of inflammatory bowel disease. Methods： 168 Sprague-Dawley rats,female and male were hold a half one another, which were divided into four groups; （ 1 ） Fourty two rats as control group, where normal saline was instilled into rats colon at 100 mg/kg; （2） 42 rats as TNBS/ethanol group, in which the rats was instilled with TNBS dissolved in 50% ethanol at 100 mg/kg; （3） 42 rats as the immunocomplex group,where antigen-emolsifier containing 8 mg of the antigen was injected into digiti pedis and fold inguen at interval of two weeks;（4） 42 rats as TNBS/ethanol and immunocomplex group, with both immunizatian and instillation of TNBS/ethanol. CD4^＋ T cells in peripheral blood and in colonic organism were observed and IgG in serum was measured at the 1 st, 2 nd, 3 rd,4 th, 6 th, 9 th and 12 th weekend after the model was established. Results： The mean percentage of CD4^＋ T cells in peripheral blood was 44.81 ＋ 9.183 0% ,and that in colonic tissues was 179.8 ± 35.9,in TNBS/ethanol and immunocomplex model,which was significently increased than other groups. The content of IgG inserum of the rats in TNBS/ethanol and immunocomplex was 0.54 ± 0. 120 5, which was significently increased than other groups. Conclusion： In the view of immunological mechanism, it is verified that TNBS/ethanol and immunocomplex induces rat distal colitis, which is an ideal model of IBD and may serve as a tool for investigation of the pathogenesis and pharmaceutical effect of IBD.