Molecular Modulation of Intestinal Epithelial Barrier: Contribution of Microbiota
Influenced by the microbiota, intestinal epithelial cells (IECs) elaborate cytokines, including thymic stromal lymphoprotein (TSLP), transforming growth factor (TGF), and interleukin-10 (IL-10), that can influence pro-inflammatory cytokine production by dendritic cells (DC) and macrophages present in the lamina propria (GALT) and Peyer’s patches. Signals from commensal organisms may influence tissue-specific functions, resulting in T-cell expansion and regulation of the numbers of Th-1, Th-2, and Th-3 cells. Also modulated by the microbiota, other IEC derived factors, including APRIL (a proliferation-inducing ligand), B-cell activating factor (BAFF), secretory leucocyte peptidase inhibitor (SLPI), prostaglandin E2 (PGE2), and other metabolites, directly regulate functions of both antigen presenting cells and lymphocytes in the intestinal ecosystem. NK: natural killer cell; LN: lymph node; DC: dendritic cells. (Modified from Sharma R, Young C, Mshvildadze M, Neu J. Intestinal Microbiota Does It Play a Role in Diseases of the Neonate? NeoReviews Vol.10 No.4 2009 e166, with permission).