P-selectin binds to bacterial lipopolysaccharide

Multiple organ failure associated with disseminated intravascular coagulation is a frequent complication in septic shock patients. Accumulation of platelets and neutrophils in the organs contributes to the manifestation of lipopolysaccharide (LPS)-induced organ failure. Although a direct interaction between LPS and platelets is well documented, the nature of the surface receptor for LPS on platelets is unknown. In this article we show that P-selectin is a receptor for LPS. The binding of LPS to P-selectin is independent of Ca2+, and is blocked by antibodies to P-selectin, lipid A and fucoidan. Platelets pre-treated with thrombin showed fourfold higher binding of fluorescein isothiocyanate (FITC)-conjugated LPS compared to untreated platelets and the binding of FITC-conjugated LPS to platelets was blocked in the presence of anti-P-selectin antibodies. It is likely that the binding of LPS via P-selectin on activated platelets or epithelium could have a significant role in the pathophysiology of organ failure in septic shock.