Mapping of the monoclonal antibody W6/32: sensitivity to the amino terminus of beta2-microglobulin.
The monoclonal antibody W6/32 is one of the most commonly used pan-HLA-ABC antibodies in studying human MHC I structure and function. We have discovered that the reactivity of W6/32 is absolutely sensitive to the amino terminus of human beta2-microglobulin (hbeta2m). Bacterially expressed recombinant forms of hbeta2m that have been extensively used in structural and biochemical studies of MHC I molecules often have an additional methionine at their amino terminus. Cell surface MHC I molecules reconstituted with allele-specific peptides and recombinant hbeta2m are reactive with various HLA-specific mAbs, but not W6/32. In contrast, cell surface HLA molecules reconstituted with peptide and native hbeta2m, which has no amino terminal methionine, are recognized by W6/32 as well as other HLA-specific mAbs. Thus, the specificity of W6/32 includes the amino terminus of hbeta2m.
Laboratory of Immune Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892-1152, USA.
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Shields
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Ribaudo
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D018604:Epitope Mapping; D018985:Epitopes, B-Lymphocyte / Q000276:immunology*; D015789:HLA-A2 Antigen / Q000235:genetics / Q000276:immunology*; D006801:Humans; D051379:Mice; D001613:beta 2-Microglobulin / Q000276:immunology*
D000911:Antibodies, Monoclonal; D018985:Epitopes, B-Lymphocyte; D015789:HLA-A2 Antigen; D001613:beta 2-Microglobulin