Multiple receptors for endotoxin.

Recent studies have identified three classes of receptor molecules involved in recognition of endotoxin. Two classes of receptors, the CD18 antigens and the scavenger receptor, recognize lipopolysaccharide directly and function principally in its catabolism. A third molecule, CD14, recognizes lipopolysaccharide with the aid of a serum protein, lipopolysaccharide-binding protein, and may be a principal mediator of secretory responses of leukocytes.