ABSTRACT
The identification of membrane-bound CD 14 as part of a multicomponent lipopolysaccharides (LPS) receptor functionally linked to the initiation of intracellular events associated with LPS-induced leukocyte activation has facilitated our understanding of at least one mechanism of antibody-mediated LPS neutralization. Despite limited information regarding the formation and clearance of immune complexes comprised of LPS and LPS antibodies, it must be assumed that the formation of such complexes and their opsonization by complement play a critical role in the disposal of endotoxin by the infected host. LPS antibodies and serum complement thus serve complementary attachment and phagocytosis-promoting opsonic functions, resulting in collaborative mechanisms of opsonophagocytic killing. Polyreactive LPS antibodies may play a more sinister pathogenic role in human autoimmune disease based upon their cross-reactivity with host tissues containing molecular structures mimiced by bacterial LPS. Lipopolysaccharides, or endotoxins, are biologically active structural components of the outer cell membrane of all gram-negative bacteria.
