Lipopolysaccharide-induced human enterocyte tolerance to cytokine-mediated interleukin-8 production may occur independently of TLR-4/MD-2 signaling.

Intestinal epithelial cells (IEC) are constantly exposed to bacterial components, such as LPS, without triggering proinflammatory immune responses. This study demonstrates that chronic exposure of human-derived IEC to LPS induces tolerance to an endogenous inflammatory cytokine (IL-1beta) activated IL-8 response that occurs independently of TLR-4/MD-2 signaling. IL-8 production in response to activation by unrelated TNF-alpha and PMA signaling pathways is also inhibited, indicating a broad-spanning tolerance.