Mouse intestinal innate immune responses altered by enterotoxigenic Escherichia coli (ETEC) infection.

Enterotoxigenic Escherichia coli (ETEC) is an important cause of human and porcine morbidity and mortality. The current study was conducted to identify intestinal immunity that is altered in a mouse model of ETEC infection. Innate immune responses and inflammation were analyzed. The activation of signal transduction pathways, including toll like receptor 4 (TLR-4)-nuclear factor kappa B (NF-κB) and mitogen-activated protein kinases (MAPK), was analyzed using immunoblotting and PCR array analyses. We found that ETEC infection promoted the expression of pro-inflammatory cytokines through the activation of the NF-κB and MAPK pathways. Meanwhile, ETEC infection affected sIgA transportation and Paneth cell function. These data improve our understanding of how ETEC causes disease in animals.