LPS-induced gene expression in mouse small intestinal epithelial cells

Intestinal epithelial cells express the lipopolysaccharide (LPS) receptor Toll-like receptor (TLR4) and are responsive to LPS stimulation. Following LPS exposure, epithelial cells, similar to myeloid cells such as macrophages, acquire a state of tolerance. Innate immune tolerance is characterized by a lack of expression of proinflammatory genes in response to repeated stimulation. Tolerant epithelial cells, however, exhibit sustained expression of a distinct set of genes encoding for proteins involved in metabolism and homeostasis. This study comparatively analyzes the gene expression profile 6 hours after LPS stimulation (acute response) versus 6 hours LPS followed by 90 hours incubation in the absence of LPS (tolerant response). We used microarrays to detail the global program of gene expression under unstimulated (control), LPS stimulated (6 hours), and tolerant (96 hours) conditions. Three biological replicates each from naive cells, 6 hour LPS-stimulated cells, and 6 hour LPS-stimulated plus 90 hour LPS-free medium-incubated cells were examined and compared.