A new model of macrophage stimulation by bacterial lipopolysaccharide.

Infection occurring in patients suffering from severe trauma or burns often leads to hypotension, disseminated intravascular coagulation, multiorgan failure, and death. These latter pathophysiologic changes often are associated with Gram-negative sepsis and endotoxemia. Substantial progress has been made in understanding the effector mechanisms for endotoxin (LPS) action with the recognition of the importance of LPS-inducible products of cells of monocytic lineage in mediating LPS-induced injury. Here we will review recent evidence that supports a model for monocyte/macrophage activation by LPS that involves a plasma protein known as lipopolysaccharide binding protein (LBP) and the monocyte differentiation antigen, CD14.