日本血吸虫感染诱导的Th免疫偏移对小鼠胶原性关节炎的影响

发布时间：2018-05-02 04:24

本文选题：日本血吸虫 + 免疫调节　；参考：《安徽医科大学》2011年博士论文

【摘要】：目的机体接触包括蠕虫在内的病源微生物机会减少,尤其在幼年时期免疫系统失去病源微生物的塑造和协调,是导致西方发达国家自身免疫性疾病和过敏性疾病发病率迅速增高的主要原因之一。蠕虫感染能激发强烈的Th2免疫应答,可以改善Th1介导的自身免疫性疾病的临床症状和病理过程。日益增多的流行病学及实验研究证实了蠕虫对自身免疫性疾病及过敏性疾病的保护作用,显示了优异的临床应用价值。目前利用猪鞭虫卵治疗炎症性肠病(inflammatory bowel disease,IBD)患者已取得良好的临床效果。类风湿性关节炎(rheumatoid arthritis,RA)是一种严重危害人类健康的慢性自身免疫性疾病,该病发病率和致残率高,目前仍无有效的治疗方法。研究表明,CD4+效应T细胞和调节性T细胞免疫失衡参与RA发病的各个环节,RA的致病与Th1/Th17密切相关。日本血吸虫感染可诱导强烈的Th2优势应答。本研究试图利用血吸虫感染和血吸虫抗原诱导的Th2免疫偏移来恢复RA失衡的Th免疫应答。用CIA鼠构建血吸虫感染的RA模型,观察CD4+T细胞亚群的网络调节,探讨RA的发病、转归及免疫抑制性的治疗作用。为筛选特异性抑制RA过度的Th1/Th17免疫应答的新型免疫调节剂奠定基础。方法: 建立雄性DBA/1小鼠胶原性关节炎(Collagen Induced-arthritis,CIA)模型,分别用单、双性日本血吸虫尾蚴(25±2条)于造模前2W、造模后4W(关节炎模型建立后)经腹部皮肤感染小鼠,SPF级环境饲养,关节炎指数评价多发性关节炎病变的发生及严重程度。12W后处死动物, ELISA (enzyme linked immunosorbent assay,ELISA)检测血清胶原特异IgG、IgG1、IgG2a水平,比较血吸虫干预对CIA鼠自身抗体形成的影响;流式细胞术(flow cytometry,FCM)检测脾淋巴细胞CD4+T细胞亚群,分析血吸虫感染对T细胞免疫应答的作用;Real time PCR检测炎症关节内部细胞因子mRNA表达水平;取足爪组织观察血吸虫感染对小鼠关节炎组织病理学的影响;评价血吸虫活虫感染对自身免疫性关节炎小鼠的免疫调节作用。结果: 与对照组相比,预先感染日本血吸虫尾蚴显著减轻小鼠关节炎的病情,降低关节炎的发病率,改善病理损害;血清中胶原特异性IgG、IgG2a显著降低,IgG1水平升高;脾淋巴细胞应对多克隆及抗原特异性刺激诱发的增殖反应明显降低;日本血吸虫感染显著抑制CIA小鼠IFN-γ+CD4+ T细胞比例,提高IL-4+CD4+ T细胞百分比。仅在双性感染的CIA鼠发现CD25highCD4+ Treg(regulatory T cells,Treg)的增殖及IL-17+CD4+ T细胞的抑制。血吸虫感染显著降低了脾细胞培养上清中INF-γ、TNF-α、IL-1β和IL-6的表达水平,提高IL-10表达。此外,血吸虫感染显著上调炎症关节内部炎症因子及NF-κB配体-受体活化因子(receptor activator of NF-κB ligand, RANKL)的表达。对于已经建立的感染模型并出现明显临床症状的CIA小鼠,感染血吸虫尾蚴不仅不能改善病情,反而加重病情。结论: 日本血吸虫预先感染诱导的Th2优势应答可显著抑制CIA异常的Th1应答,减少炎症介质的释放,减轻病情,改善病理损害;双性感染还可上调Treg,抑制CIA小鼠过度的Th17应答。血吸虫感染对CIA的保护作用依赖于Th2优势应答的预先建立,使异种Ⅱ型胶原不能有效启动致病性的Th1免疫应答。血吸虫成虫抗原亦能有效激发抗炎性的Th2优势应答。
[Abstract]:objective
One of the main reasons for the rapid increase in the incidence of autoimmune and allergic diseases in western developed countries is one of the main reasons for the decrease of organisms' exposure to pathogenic microorganisms, including worms, especially in the early years of the immune system, which leads to the rapid increase in the incidence of autoimmune diseases and allergic diseases in western developed countries. The clinical symptoms and pathological processes of autoimmune diseases mediated by good Th1. An increasing number of epidemiological and experimental studies have confirmed the protective effects of worms on autoimmune diseases and allergic diseases, showing excellent clinical value. Currently, the use of porcine flagellate eggs for the treatment of inflammatory bowel disease (inflammatory bowel disease, IBD) A good clinical effect has been achieved.
Rheumatoid arthritis (RA) is a chronic autoimmune disease which seriously endangers human health. The incidence and disability rate of this disease are high, and there is still no effective treatment. The study shows that the CD4+ effect T cell and the regulatory T cell immune imbalance are involved in every link of the pathogenesis of RA, and the pathogenesis of RA is closely related to Th1/Th17. Schistosoma japonicum infection can induce strong Th2 dominance response. This study attempts to restore the Th immune response to RA imbalance by using the Th2 immunization induced by Schistosoma infection and Schistosoma antigen. The RA model of Schistosoma infection was constructed with CIA mice, the network regulation of CD4+T cell subsets was observed, and the pathogenesis, prognosis and immunosuppression of RA were discussed. To lay the foundation for screening new immunomodulators that specifically inhibit RA over Th1/Th17 immune response.
Method:
The model of Collagen Induced-arthritis (CIA) in male DBA/1 mice was established, and the single and double sex Schistosoma japonicum cercariae (25 + 2) were used before the model of 2W. After modeling, 4W (after the establishment of arthritis model), the mice were infected with the abdominal skin, the SPF level environment was raised, and the arthritis index was used to evaluate the occurrence and severity of multiple arthritis. After 12W, the animals were killed, and ELISA (enzyme linked immunosorbent assay, ELISA) was used to detect the serum collagen specific IgG, IgG1 and IgG2a levels. The effects of schistosomiasis intervention on the formation of autoantibodies in CIA rats were compared, and the flow cytometry (flow) was used to detect the subsets of spleen lymphocyte subsets and the effect of schistosomiasis infection on the immune response of the cells. Al time PCR was used to detect the expression level of cytokine mRNA in the inflammatory joints, and the effect of schistosomiasis infection on the histopathology of arthritis in mice was observed and the immunoregulation effect of schistosomiasis on autoimmune arthritis mice was evaluated.
Result:
Compared with the control group, the pre infection of Schistosoma japonicum cercariae significantly alleviated the condition of arthritis in mice, reduced the incidence of arthritis and improved the pathological damage. The serum collagen specific IgG, IgG2a decreased significantly, and the level of IgG1 increased, and the proliferation response induced by polyclonal and antigen specific stimulation in spleen lymphocytes was significantly reduced; Japanese blood sucking. The proportion of IFN- gamma +CD4+ T cells in CIA mice was significantly inhibited and the percentage of IL-4+CD4+ T cells was increased. The proliferation of CD25highCD4+ Treg (regulatory T cells) and inhibition of IL-4+CD4+ cells were found only in the CIA mice infected with bisexual infection. In addition, IL-10 increased the expression of inflammatory factors in the inflammatory joints and the expression of NF- kappa B ligand receptor activator (receptor activator of NF- kappa B ligand, RANKL). The infection of the cercariae of the infected schistosoma cercariae was not only unable to improve the condition of the infected mice. Aggravate the condition.
Conclusion:
The preinfection induced Th2 response of Schistosoma japonicum can significantly inhibit the Th1 response of the abnormal CIA, reduce the release of the inflammatory mediators, reduce the condition and improve the pathological damage. The double sex infection can also increase the Treg and inhibit the excessive Th17 response of the CIA mice. The protection of the schistosomiasis infection to CIA depends on the pre establishment of the Th2 dominance response. Type II collagen can not effectively activate pathogenic Th1 immune response. Schistosoma japonicum adult antigen can also effectively stimulate the Th2 dominant response of anti-inflammatory.

【学位授予单位】：安徽医科大学
【学位级别】：博士
【学位授予年份】：2011
【分类号】：R392

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