Endotoxin interactions with lipopolysaccharide-responsive cells.

Recent work has identified two proteins that work together to enable many cell types to respond to endotoxin. These two proteins, lipopolysaccharide (LPS) binding protein (LBP) and CD14, also participate in cellular internalization of endotoxin, which may occur independently of cellular activation. Current work with antibodies to LBP and CD14 as well as "knockout" mice in the context of LPS-initiated endotoxic shock suggests that inhibition of this pathway could be therapeutically useful. These observations point to the need to identify new molecules that mediate LPS-initiated transmembrane signaling and internalization of LPS-protein complexes.