| Inflammatory bowel disease(IBD) is a chronic autoimmune disease occurred in thegastrointestinal tract, including ulcerative colitis(UC) and Crohn’s disease (CD). Abdominal pain,diarrhea and other gastrointestinal symptoms as the main performances; intestinal inflammationand damage of the intestinal mucosa as the main characteristics. IBD can occured in any ages, itwill persistent for a long time and seriously affecting people’s lives and its clinical symptoms arenot obvious. In recent years, with the improvement of people’s life quality and the improvementof diet structure, there is an upward trend in the incidence of IBD in our country, its etiology andpathogenesis is still unclear. Currently, it is proposed the "hygiene hypothesis"of IBD, namelythe IBD tends to occur in chronic intestinal infection less area. Epidemiological investigationshowed that the incidence of IBD in developed countries is higher, and in poor health condition,densely populated countries incidence is relatively low. Good health condition and low parasitesinfection make people more susceptible to IBD. This study based on immune features ofTrichinella spiralis infection and the interaction between intestinal worms and IBD, proposedthis hypothesis that T. spiralis infection may influence animal models of IBD, which is inducedby Citrobacter rodentium and study the possible immunological mechanisms of IBD.We select24only3-4weeks of female BALB/c mouse, randomly divided into4groups,respectively: normal group (PBS), C. rodentium induced enteritis model group (CR), T. spiralisinfection group (TS) and T. spiralis and C. rodentium coinfection group (TS+CR group);21days after T. spiralis muscle larvaes infection, give each mice2×109CFU/mL of C. rodentium toinduce mice CD animal model. Observe the changes of each index in mouse, including theweight changes, colon injury macroscopic and microscopic lesion, C. rodentium quantitychanges in faeces, explore the treatment effection of T. spiralis to C. rodentium induced mousemodels of CD. ELISA detected the variation in content of mice serum IgG1and IgG2a;Theexpression of IFN-gamma, IL-12, IL-10, IL-4, IL-17levels and the number of Foxp3+Treg cellsin spleen and MLN were measured by FCM.We explained the immune regulated roles ofcytokines from cellular and molecular levels and discusses the immune mechanism for T.spiralis to intervene the CD mice model.The results demonstrated that coinfected with T. spiralis and C. rodentium group mice thebody weight was significantly higher than that of CR group, the clinical symptoms were also lower than that of CR group.On the14days,the colon injury degrees of coinfected group frommacro and micro levels were attenuated compared with the control group.It showed fewerdamage on the colon bowel wall,narrower adhesion range,less inflammatory cells infiltration,reduced congestion and the submucosa edema was disappeared. The C. rodentium content in perfaeces was still lower in coinfection group than that of CR group.after previously infected with T.spiralis rodentium faeces induction model group mice C. rodentium content was lower than thatin group CR mice; The ELISA result displayed that the group which was previously infectedwith T. spiralis the expression of serum IgG1was increased (P<0.01), at the same time theexpression of serum IgG2a was increased in CR group (P<0.05); FCM test results showed that7days post C. rodentium infection the expression levels of IFN-gamma, IL-10, IL-4and IL-17had no significant changes (P>0.05);14days post C. rodentium infection,the expression ofIFN-gamma, IL-12and IL-17in spleen of coinfection group were significantly higher thancontrol group (P<0.05); Compared with CR group, the expression leveals of IFN-gamma, IL-12,and IL-17were lower (P<0.05), while the expression of IL-4was increased (P<0.05), theexpression of IL-10had no significant change (P>0.05);14days post C. rodentium infection,theexpression of IFN-gamma, IL-12and IL-17in MLN of coinfection group were significantlydecreased(P<0.05),Compared with CR group, the expression leveals of IL-4was higher(P<0.05),while the IL-10had no obviously changed (P>0.05);The Flow Cytometer analysis resultsexhibited that the percentage of CD4+Foxp3+Treg cells obviously increased in spleen and MLNof T. spiralis infection group(P<0.05). The expression leveals of Foxp3+Treg cells in spleen andMLN of coinfection group was lower than that of T. spiralis infection group(P<0.05),while theexpresssion leveals of Foxp3+Treg cells in spleen and MLN of coinfection group mice was noobviously changed compared with CR group(P>0.05).The study shows that previously infected with T. spiralis showed well therapeutic effectson CD mice model,and its mechanism may be involved in the induced Th2cytokines toinfluence Th1immune response induced by C. rodentium,making the imbalances inmune in CDmice model recovery to intervene the IBD. |
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