A role for regulatory T cells and TGF-β in intestinal IgA to rotavirus (137.22)

Abstract

Abstract Regulatory T cells (Tregs) play an important role in suppression of effector T cell function and inflammation. Recently Tregs have been shown to play a role in mucosal IgA production through production of TGF-β1, suggesting they also can induce B cell responses. During rotavirus (RV) infection, there is little effector T cell activation but a profound intestinal IgA response. Using flow cytometric based approaches, we observed a significant increase in total number of FoxP3+CD25+CD4+ T cells in both MLNs (5 fold) and PPs (2 fold) 2-4 days post RV infection compared to uninfected mice. We also detected a significant increase in the total number of TGF-β1+ cells and the total number of TGF-β1+CD4+ cells in both tissues isolated from infected mice compared to uninfected mice. The increased number of FOXP3+ Tregs and CD4+/TGF-β1 expression in PP and MLN during RV infection concurrent with previously observed B cell activation and rotavirus-specific IgA production suggests that Tregs might play an important role in the induction of rotavirus specific intestinal IgA in these immune tissues through production of the critical switch factor, TGF-β1.