Figure 3.

Immunological responses with Treg cell depletion. Intraperitoneal injection of anti-CD25 antibody 24 h prior to allergen challenge led to (A) significant reduction of splenic Treg cell frequencies below 2% and (B) significant downregulation of both FOXP3 and IL-10 in the gut. Statistical differences between Treg-depleted and non-depleted groups were assessed by Mann–Whitney U test. * p < 0.05, ** p < 0.01, and **** p < 0.0001. Quantification of (C) mast cells per mm² of crypt area and (D) eosinophils per mm² of villus in the small intestine. Levels of serological (E) tropomyosin-specific IgE measured by ELISA and (F) local expression of Th2 cytokines in the small intestine detected by qPCR. Note that Treg cell depletion in pMED171-treated animals only led to restoration of local inflammatory responses but not systemic Th2 activities. Data are shown as individual data points denoted by different symbols for each experimental group with mean ± SD. Statistical differences among different experimental groups were determined by Bonferroni post-test after one-way ANOVA. Groups denoted by the same alphabet are not significantly different, while those denoted by different alphabets are statistically different (p < 0.05). ns = not significant.