Toll-like receptors 2 and 4 modulate intestinal IL-10 differently in ileum and colon:

BackgroundInflammatory bowel diseases are consequence of an intestinal homeostasis breakdown in which innate immune dysregulation is implicated. Toll-like receptor (TLR)2 and TLR4 are immune recognition receptors expressed in the intestinal epithelium, the first physical-physiological barrier for microorganisms, to inform the host of the presence of Gram-positive and Gram-negative organisms. Interleukin (IL)-10 is an essential anti-inflammatory cytokine that contributes to maintenance of intestinal homeostasis.AimOur main aim was to investigate intestinal IL-10 synthesis and release, and whether TLR2 and TLR4 are determinants of IL-10 expression in the intestinal tract.MethodsWe used Caco-2 cell line as an enterocyte-like cell model, and also ileum and colon from mice deficient in TLR2, TLR4 or TLR2/4 to test the involvement of TLR signaling.ResultsIntestinal epithelial cells are able to synthesize and release IL-10 and their expression is increased after TLR2 or TLR4 activation. IL-10 regulation seems to...