An artificial glycoconjugate containing the bisphosphorylated glucosamine disaccharide backbone of lipid A binds lipid A monoclonal antibodies.
Monoclonal antibodies (MAbs) against lipid A, the endotoxic component of lipopolysaccharide (LPS) of gram-negative bacteria, are presently discussed as therapeutic agents against lethal gram-negative infections; however, their binding specificities are controversial. We have isolated from the LPS of Escherichia coli J-5 the 1,4'-bisphosphorylated beta 1-->6-linked glucosamine disaccharide backbone of its lipid A moiety, which was covalently linked to bovine serum albumin. It was shown by solid-phase enzyme immunoassay that one antibody (MAb A6) bound equally well to the glycoconjugate and synthetic E. coli-type lipid A over a broad range of antigen concentrations whereas two other MAbs (IC3 and S1-15) bound better to the conjugate at low antigen concentrations and better to the lipid A when high concentrations of antigen were used. This proves in a direct way that there exist lipid A MAbs with different specificities which bind to epitopes in the hydrophilic backbone of lipid A and which do not require the presence of fatty acids.
Brade
L
L
Division of Biochemical Microbiology, Forschungsinstitut Borstel, Institut für Experimentelle Biologie und Medizin, Germany.
Holst
O
O
Brade
H
H
D000911:Antibodies, Monoclonal / Q000276:immunology; D004187:Disaccharides / Q000276:immunology; D004926:Escherichia coli / Q000276:immunology; D005944:Glucosamine / Q000276:immunology; D006001:Glycoconjugates / Q000276:immunology*; D066298:In Vitro Techniques; D008050:Lipid A / Q000737:chemistry / Q000276:immunology*
D000911:Antibodies, Monoclonal; D004187:Disaccharides; D006001:Glycoconjugates; D008050:Lipid A; D005944:Glucosamine