中文摘要：

目的：考察胶原关节炎大鼠肠道黏膜免疫的改变及羟基积雪草苷的调节作用。方法：在Wistar大鼠复制胶原关节炎模型,其后将大鼠分为正常对照组、模型组和羟基积雪草苷组,灌胃给药,连续21 d。ELISA法测定大鼠肠内容物中s Ig A含量及小肠组织中IFN-γ含量。流式细胞术检测小肠上皮内及固有层细胞中CD4＋和CD8＋T细胞的比例,计算CD4＋/CD8＋比值。实时定量PCR法检测小肠组织中CD80、CD86、IL-6、IL-12及Foxp3 mRNA的表达水平。结果：与正常对照组比较,模型组大鼠肠内容物中s Ig A含量及小肠组织中IFN-γ含量显著升高,小肠上皮内及固有层T细胞中CD4＋/CD8＋比值上升,小肠组织中CD80、CD86、IL-6和IL-12 mRNA表达显著上调,而Foxp3 mRNA的表达变化无统计学意义。羟基积雪草苷灌胃给药可降低模型大鼠肠内容物s Ig A和小肠组织IFN-γ含量、CD4＋/CD8＋比值及CD80、CD86、IL-6和IL-12 mRNA的表达,显著上调Foxp3 mRNA的表达。结论：关节炎状态下大鼠肠道黏膜免疫应答上调,抗原呈递细胞异常活化且免疫耐受状态遭到破坏,羟基积雪草苷可下调关节炎大鼠肠道黏膜免疫应答,促进肠道黏膜免疫耐受的形成和维持。

英文摘要：

Objective ：To explore the changes of intestinal mucosal immunity in collagen-induced arthritis rats and the impact of madecassoside on these changes. Methods：Collagen-induced arthritis was established in female Wistar rats. Treatment group was orally administrated madecassoside once daily for consecutive 21 days ,while blank control and model groups were orally administered saline at the same volume. The concentrations of slgA in small intestine content and IFN-T in small intestinal tissue homogenate were determined by ELISA. The proportions of CD4＋ T and CD8 ＋ T in the epithelium and laminar propria of small intestine were detected by flow cytom- etry, and the ratios of CD4＋/CD8 ＋ were calculated. The relative expressions of CD80, CD86 ,IL-6, IL-12 .and Foxp3 mRNA in the small intestine were determined by real-time PCR. Results ： Compared with blank control rats, the concentrations of slgA in small intestine con- tent and IFN-＇y in small intestinal tissue homogenate from model rats were increased, the ratios of CD4＋/CD8＋ in the epithelium and laminar propria of small intestine were higher and the relative expressions of CD80,CD86 ,IL-6 and IL-12 mRNA in the small intestine were increased. Madecassoside treatment decreased the concentrations of slgA in small intestine content and IFN-y in small intestinal tissue, downregulated the ratios of CD4＋/CD8 ＋ in the epithelium and laminar propria and decreased the relative expressions of CD80, CD86, IL-6 and IL-12 mRNA, while upregulated the relative expression of Foxp3 mRNA in the small intestine. Conclusion ：The intesti- nal mucosal immune response is enhanced in collagen-induced arthritis rats, the antigen presenting cells are activated abnormally and the immune tolerance is disturbed. Madecassoside treatment can downregulate the intestinal mucosal immune response and benefit for the induction and maintenance of intestinal immune tolerance.