No abstract

Mucosal surfaces represent the main sites in which environmental microorganisms and antigens interact with the host. In particular the intestinal mucosal surfaces are in continuous contact with a heterogeneous population of microorganisms of the endogenous flora and are exposed to food and microbes. As a result, the immune system of the host has to discriminate between pathogenic and commensal microorganisms. This article reviews the types of sentinel cells that continuously sense the environment and coordinate immune defenses as well as the mechanisms of the innate and adaptive immune systems that are activated by bacterial and viral molecular patterns leading to inflammatory, allergic, or regulatory immune response with special emphasis on probiotic bacteria. J. Nutr. 137: 756S-772S, 2007.

Our study indicates that TLR9 signaling mediates, at least in part, the anti-inflammatory effects of natural commensal-origin DNA on the gut because TLR9 silencing abolished the inhibitory effect of natural commensal-origin DNA on TNF-alpha-induced IL-8 secretion in polarized IECs. The nature of the TLR9 agonist, the polarity of cells, and the tight junction integrity of IECs has to be taken into account in order to predict the outcome of TLR9 signaling. (Inflamm Bowel Dis 2010).

No abstract

Lactic acid bacteria inhibits NFκB‐mediated transcriptional activation of IBD causing factors (IL‐23/IL‐17/CD40) by reducing histone acetylation while enhancing DNA methylation.