Toll-Like Receptor-4 Dependent Intestinal and Systemic Sequelae Following Peroral Infection of IL10 Deficient Mice Harboring a Human Gut Microbiota.

Zoonotic , including and , are among the most prevalent agents of food-borne enteritis worldwide. The immunopathological sequelae of campylobacteriosis are caused by Toll-like Receptor-4 (TLR4)-dependent host immune responses, induced by bacterial lipooligosaccharide (LOS). In order to investigate -host interactions, including the roles of the human gut microbiota and TLR4, upon infection, we applied a clinical acute campylobacteriosis model, and subjected secondary abiotic, TLR4-deficient IL10 mice and IL10 controls to fecal microbiota transplantation derived from human donors by gavage, before peroral challenge. Until day 21 post-infection, could stably colonize the gastrointestinal tract of human microbiota-associated (hma) mice of either genotype. TLR4-deficient IL10 mice, however, displayed less severe clinical signs of infection, that were accompanied by less distinct apoptotic epithelial cell and innate as well as adaptive immune cell responses in the colon, as compared to IL10 counterparts. Furthermore, infected IL10, as opposed to TLR4-deficient IL10, mice displayed increased pro-inflammatory cytokine concentrations in intestinal and, strikingly, systemic compartments. We conclude that pathogenic LOS might play an important role in inducing TLR4-dependent host immune responses upon infection, which needs to be further addressed in more detail.