The roles of pathogen-associated molecular patterns in atherosclerosis.

Stimulation of Toll-like receptors, which serve to initiate inflammatory signaling in response to the detection of conserved microbial pathogen-associated molecular patterns (PAMPs), has been shown to play a central role in the development of atherosclerosis. In this review, the recent evidence supporting a role for both infection- and commensal-derived PAMPs in the pathogenesis of atherosclerosis will be discussed. Potential sources of PAMPs, their routes of delivery to the artery wall and the mechanisms by which PAMPs may affect vascular function independently of bacteremia or infection of the artery wall with viable organisms will be examined. Finally, the recent evidence that obesity and high-fat diets may each promote translocation of commensal-derived endotoxin from the gut into the circulation to induce inflammation, insulin resistance and atherosclerosis will be discussed.