Effect of tuft-IL-25-ILC2 pathway on mouse small intestine stimulated by Trichinella spiralis ES antigen

ObjectiveTo explore the regulatory effect of Trichinella spiralis ES antigen on the intestinal immune function, we observed the immune response of mouse small intestine to this antigen by quantifying the changes in the related cytokines of Tuft-IL-25-ILC2 pathway. MethodsA total of 30 BALB/c female mice were randomly divided into three groups: control group, Trichinella excretion-secretion (ES) antigen stimulation group, and IL-25 blocking group. The mice in the control group were injected intraperitoneally with PBS; those in the ES antigen stimulation group were injected intraperitoneally with ES antigen once per day for 7 consecutive days; and those in the IL-25 blocking group were injected intraperitoneally, first with anti-mouse IL-25 monoclonal antibody and 3 days later with ES antigen. Alcian blue-nuclear fast red staining was employed to observe the changes in the number of small intestinal goblet cells. The number of Tuft cells was determined by immunofluorescence chemical analysis, and the expression levels of IL-25, IL-13, IL-25R, Pou2f3, and ROR mRNA were quantified by RT-PCR. Key resultsThe results of Alcian blue-nuclear fast red staining showed that, compared with the control group, the number of goblet cells in the small intestinal tissue of mice in the ES antigen stimulation group increased, and the difference was statistically significant (P<0.05). Compared with the ES antigen stimulation group, the number of goblet cells in the small intestinal tissue of the mice in the IL-25 blocking group was slightly decreased (P<0.05). Immunofluorescence analysis showed that, compared with the control group, the number of Tuft cells in the ES antigen-stimulated group increased (P<0.05), while in the IL-25 blocking group, the number of Tuft cells was decreased compared with that in the ES antigen stimulation group (P<0.05). RT-PCR analysis showed that, compared with the control group, the mRNA expression levels of IL-25, IL-13, IL- 25R, ROR and Pou2f3 in the small intestine of mice in the ES antigen stimulation group were increased (P<0.05); compared with the ES antigen stimulation group, the IL-25, IL-13, IL-25R, ROR and Pou2f3 mRNA expressions in the tissues of the mice in the IL-25 blocking group were decreased, and the difference was statistically significant (P<0.05). ConclusionThe small intestinal mucosa of mice stimulated by Trichinella ES antigen may possess an immune function via the Tuft-IL-25-ILC2 pathway.