Monoclonal anti-lipid A IgM antibodies HA-1A and E-5 recognize distinct epitopes on lipopolysaccharide and lipid A.
Specific binding of two monoclonal IgM antibodies previously investigated as therapeutic agents for treating gram-negative septic shock, HA-1A and E5, was assessed with respect to lipid A and lipopolysaccharide (LPS). Both antibodies bound to lipid A; however, binding of HA-1A was significantly greater than that of E5 to LPS derived from rough strains of bacteria. Reciprocal competitive inhibition experiments supported the concept that HA-1A and E5 bind to distinct epitopes on lipid A. Further, competitive inhibition studies using a monoclonal anti-idiotype antibody with specificity for the variable region of HA-1A suggested that HA-1A and E5 do not share a common idiotype. Finally, studies using double-stranded DNA as antigen indicated that E5 but not HA-1A will bind to DNA. Collectively, these data indicate that HA-1A and E5 are different lipid A-specific antibodies that bind to distinct epitopes on lipid A.
Fujihara
Y
Y
Department of Microbiology, Molecular Genetics, and Immunology, University of Kansas Medical Center, Kansas City 66160-7832.
Bogard
W C
WC
Lei
M G
MG
Daddona
P E
PE
Morrison
D C
DC
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity; D001667:Binding, Competitive; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000276:immunology*; D006801:Humans; D007130:Immunoglobulin Idiotypes; D007075:Immunoglobulin M / Q000276:immunology*; D008050:Lipid A / Q000276:immunology*; D008070:Lipopolysaccharides / Q000276:immunology*; D051379:Mice
D000911:Antibodies, Monoclonal; D000939:Epitopes; D007130:Immunoglobulin Idiotypes; D007075:Immunoglobulin M; D008050:Lipid A; D008070:Lipopolysaccharides