Critical Role of Commensal Flora-Dependent Type 3 Innate Lymphoid Cells (ILC3) for the Induction and Regulation of Paneth Cells

Intestinal epithelial cells (ECs) have fucosylation which is one of glycosylation pattern　for the creation of cohabitation and protective niches. Our previous research showed that fucosylation of Peyer’s patch M cells and columnar ECs was distinctly regulated by two forms of α(1,2) fucosyltransferase: Fut1 and Fut2, respectively. However, further analysis using Fut1- and Fut2-deficient mice revealed that fucosylation of Paneth cells is regulated by both Fut1 and Fut2, and Paneth cells can be at least divided into two subsets, Fut1 only, and Fut2 expressed double positive cells. We also revealed that Fut2 expressing Paneth cells is induced and regulated by ILC3 in commensal bacteria-dependent manner. Moreover, the expression of Reg-III family, which is a pivotal player of the immunosurveillance in the intestine, is associated with Fut2-expressing Paneth cells by the commensal flora-ILC3 axis dependent mannar. Taken together, our findings suggest that the commensal flora-ILC3 axis plays critical roles for induction and regulation of Fut2- and Reg-III-positive Paneth cells. Our current study is aiming at the molecular and cellular understanding of the commensal flora-ILC3 axis dependent Paneth cells for their contributions in the creation of healthy intestinal environments.