Chemical structure of lipopolysaccharides and endotoxin immunity.
Lipopolysaccharides (endotoxins) of gram-negative bacteria consist of 2 components with distinct physico-chemical character: a heteropolysaccharide and a covalently linked lipid, termed lipid A. The chemical structure of lipid A, which represents the toxic center of lipopolysaccharides, is discussed. Evidence is presented that lipid A antiserum suppresses the pyrogenic effect of lipid A and lipopolysaccharides in rabbits. The protective power of lipid A antiserum, however, is only expressed in animals which have been pretreated with lipid A or lipopolysaccharide indicating that other than humoral factors, perhaps cellular, also participate in endotoxin fever (cross) immunity. The fever resistance mediated by lipid A antiserum seems to be endotoxin-specific with regard to both the preparative and the challenging injection. Lipid A antiserum therefore may serve as a tool to discriminate between fever caused by endotoxins and that induced by other pyrogens.
D000042:Absorption; D000818:Animals; D003429:Cross Reactions; D004731:Endotoxins / Q000276:immunology; D004912:Erythrocytes / Q000276:immunology; D007106:Immune Sera; D007109:Immunity; D008055:Lipids / Q000032:analysis / Q000276:immunology; D008070:Lipopolysaccharides / Q000032:analysis*; D011134:Polysaccharides / Q000032:analysis; D011749:Pyrogens / Q000037:antagonists & inhibitors; D012313:RNA; D011817:Rabbits; D012486:Salmonella typhimurium / Q000276:immunology; D012756:Sheep
D004731:Endotoxins; D007106:Immune Sera; D008055:Lipids; D008070:Lipopolysaccharides; D011134:Polysaccharides; D011749:Pyrogens; D012313:RNA