调节性T细胞（Tregs）参与旋毛虫慢性感染免疫调节作用机制研究

Trichinellosis is an important food-borne zoonotic parasitic disease, which hazards public health and represents an economic problem in porcine animal production. It has been confirmed that the regulatory T cells (Tregs) play an important role in immune regulation during many parasites infection. In view of scientific question about the mechanisms of immune regulation in Trichinella infection has not been clarified, the mechanisms of Tregs immune regulation in Trichinella chronic infection will be studied in this research programme. In order to determine the relationship between the immune regulatory role of Treg and DCs subsets in T.spiralis chronic infection, the endritic cells (DCs) differentiation and its Th polarization function and Tregs induced activation will be studied firstly in T.spiralis chronic infection with flow cytometry, quantative PCR, ELISA ,etc.On this basis of it, the function of CTLA-4, a molecule on the surface of Tregs, the cytokine IL-10 and TGF-beta will be studied in Tregs immune regulation with geneknock mice, antibody neutralization and immunohistochemistry ,etc. I believe that the mechanism of Tregs immunoregulation during T.spiralis chronic infection will be revealed in this study. It is very important for riching the basic immunology theory of Trichinella, improving the effectiveness of vaccine and the development of new drug control trichinosis.

旋毛虫病（Trichinellosis）是重要的食源性人兽共患寄生虫病，危害人类健康的同时给畜牧业造成巨大的经济损失。已证实调节性T细胞（Tregs）在多种寄生虫感染免疫调节中发挥关键作用。鉴于旋毛虫感染免疫调节机制尚未阐明，本项目首先采用流式细胞术、荧光定量PCR、ELISA等技术进行T.spiralis慢性感染中诱导树突状细胞（DCs）分化、Th极化及其对Tregs诱导活化研究以确定Treg的免疫调节作用及其与DCs亚群之间的关系。进而应用抗体中和、免疫组织化学等方法并结合基因敲除小鼠研究Tregs表面分子CTLA-4和细胞因子IL-10、TGF-β对Tregs在慢性感染免疫调节过程中的作用，旨在初步揭示Tregs参与T.spiralis慢性感染免疫调节作用机制。该机制的揭示对于丰富旋毛虫基础免疫学理论、提高疫苗免疫效力以及开发新型药物防治旋毛虫病具有重要意义。

背景：旋毛虫病（Trichinellosis）是重要的食源性人兽共患寄生虫病，危害人类健康的同时给畜牧业造成巨大的经济损失。由于对该病免疫致病机理还没有完全清楚，导致该病的免疫防治效果不甚理想。.内容：本研究采用流式细胞术、荧光定量PCR、ELISA等技术进行T.spiralis慢性感染中诱导树突状细胞（DCs）分化、Th极化及其对Tregs诱导活化研究以确定Treg的免疫调节作用及其与DCs亚群之间的关系。进而应用抗体中和、免疫组织化学等方法并结合基因敲除小鼠研究Tregs表面分子CTLA-4和细胞因子IL-10、TGF-β对Tregs在慢性感染免疫调节过程中的作用，旨在初步揭示Tregs参与T.spiralis慢性感染免疫调节作用机制。.结果：研究发现小鼠感染旋毛虫后树突状细胞表面CD40、CD80、CD86等标志分子表达量显著增加，各亚群出现明显分化，说明旋毛虫能够刺激小鼠体内DCs活化，同样在E/S抗原刺激DCs体外实验中得到证实，说明E/S抗原在旋毛虫刺激DCs活化中发挥关键作用。此外，活化DCs可诱导辅助性T细胞向TH2方向极化，这与以往已有研究结果相一致。进而发现小鼠感染旋毛虫后MLN、ILN、CLN中CD4+CD25+Foxp3+Tregs的数量显著增加，且其增加部位与旋毛虫在小鼠体内的寄生部位相关；同时，CD103、CTLA-4等相关标志分子表达量也显著增加，这表明旋毛虫感染能诱导Tregs活化并向感染部位募集而发挥免疫抑制作用。最后，研究证实Tregs对效应性T细胞的抑制作用是通过CTLA-4、IL-10及TGF-β的共同作用实现的。.意义：本研究结果对于丰富旋毛虫基础免疫学理论、提高疫苗免疫效力以及开发新型药物防治旋毛虫病具有重要意义。