Specific binding of lipopolysaccharides to mouse macrophages--II. Involvement of distinct lipid a substructures.
The interaction of lipopolysaccharide-binding sites of mouse macrophages with the Lipid A region of endotoxins (LPS) was demonstrated by direct binding of labeled Lipid A conjugates, by inhibition of the binding of labeled LPS with anti-Lipid A monoclonal antibodies, and by the considerable reduction of this binding after chemical and enzymatic removal of the fatty acid esters of the LPS. The substructures of Lipid A required for the specific binding of LPS to macrophages were analyzed by the use of synthetic lipids consisting of mono- or disaccharide derivatives of glucosamine. The two phosphate groups of Lipid A (at positions 1 and 4') as well as certain hydroxyl groups, appeared to play a critical role in the binding. However, the reactivities of the synthetic lipids with the macrophage surface, as compared with those with anti-Lipid A antibodies, could hardly be explained by the existence of a single LPS receptor, and suggested the presence, on the macrophage surface, of different LPS-binding sites that recognize different substructures or spatial configurations of the lipid moiety of endotoxins.
Tahri-Jouti
M A
MA
1116 du Centre National de la Recherche Scientifique, Université de Paris-Sud, Orsay, France.
Mondange
M
M
Le Dur
A
A
Auzanneau
F I
FI
Charon
D
D
Girard
R
R
Chaby
R
R
D000818:Animals; D000911:Antibodies, Monoclonal; D001667:Binding, Competitive; D001886:Bordetella pertussis / Q000276:immunology; D043182:Carboxylesterase; D002265:Carboxylic Ester Hydrolases; D005260:Female; D008050:Lipid A / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000378:metabolism*; D008264:Macrophages / Q000378:metabolism*; D008297:Male; D051379:Mice; D010529:Peritoneal Cavity / Q000166:cytology
D000911:Antibodies, Monoclonal; D008050:Lipid A; D008070:Lipopolysaccharides; D002265:Carboxylic Ester Hydrolases; D043182:Carboxylesterase