旋毛虫感染早期小鼠肠道病理变化及免疫调节相关细胞因子表达的研究

目的 探究旋毛虫感染早期如何诱导肠道病理变化及免疫调节相关细胞因子表达情况。方法 通过苏木素伊红染色方法观察旋毛虫感染BALB/c鼠早期4个关键时间节点肠道病理学变化,采用电化学发光免疫分析法(Meso Scale Discovery,MSD)检测感染早期肠系膜淋巴结相关细胞因子表达情况。结果 肠道病理学结果表明,肠粘膜增厚,嗜酸性粒细胞浸润,数量明显增多。MSD结果显示,感染后6 h肠系膜淋巴结Th1型细胞因子(IL-2)表达水平显著降低,其他细胞因子无显著变化;感染后3 d至6 d,Th1型细胞因子(IL-2、IFN-γ)和Th2型细胞因子(IL-4、IL-10)表达水平均显著升高,呈Th1 / Th2混合型免疫应答。结论 旋毛虫感染后6 h至6 d肠道炎症随感染时间延长加重,感染后6 h Th1型免疫应答受到抑制,随后旋毛虫通过诱导机体产生以Th2型为主的混合型免疫应答,实现旋毛虫在机体内的长期寄生。

Histopathology of intestine and expression of immunomodulatory cytokines of mice infected with Trichinella spiralis at early period

Trichinella spiralis can cause immunosuppression during the intestinal phase of early infection. However, the previous results are still insufficient for a full understanding of the phenomenon and mechanism. In the study, immune cells and cytokines profiles were investigated by histopathology and Meso Scale Discovery (MSD) in the intestine of mice infected with T. spiralis. The histopathology of intestine showed obvious intestinal mucosa thickening and eosinophils infiltration. The levels of IL-2 were significantly decreased in mesenteric lymph nodes at 6 hours after infection which suggested that Th1 immune response was suppressed. Th1 cytokines IL-2, IFN-γ and Th2 cytokines IL-4, IL-10 were all increased in mesenteric lymph nodes from 3 to 6 days post-infection (dpi), while Th2 cytokines increased more than Th1 indicated a hybrid Th1/Th2 response with a predominant Th2 response during the early phase of infection. In conclusion, our findings suggest that T. spiralis induced immune response is a complicated process which can change the immune balance of the host.