Preferential Generation of Follicular B Helper T Cells from Foxp3 + T Cells in Gut Peyer's Patches

Abstract

Most of the immunoglobulin A (IgA) in the gut is generated by B cells in the germinal centers of Peyer's patches through a process that requires the presence of CD4 + follicular B helper T(T FH ) cells. The nature of these T FH cells in Peyer's patches has been elusive. Here, we demonstrate that suppressive Foxp3 + CD4 + T cells can differentiate into T FH cells in mouse Peyer's patches. The conversion of Foxp3 + T cells into T FH cells requires the loss of Foxp3 expression and subsequent interaction with B cells. Thus, environmental cues present in gut Peyer's patches promote the selective differentiation of distinct helper T cell subsets, such as T FH cells.