[The endotoxin receptor CD14].

The knowledge about molecular mechanisms of endotoxin (LPS) recognition by cellular receptor CD14 and its consequences as well as the relationship between soluble and membrane-bound receptor is reviewed. The binding of endotoxins to membrane-bound CD14 is mediated by special so-called LPS-binding serum proteins. The mechanism of signal transduction is not yet known. After activation by LPS, monocytes produce free oxygen radicals, IL-1, IL-6, TNF alpha and other mediators. CD14 is present in normal serum as soluble receptor which can neutralize endotoxins in respect to their monocyte activating capacity.