title: An HLA class I specific monoclonal antibody that fails to bind to all HLA-A antigens.
abstract: A monoclonal antibody, MHM.5, specific for HLA class I antigens, bound to lymphocytes of all donors tested and was thought to bind to a monomorphic determinant. When the antibody was used to precipitate 35S methionine labeled HLA class I molecules from lymphoid cells, which were then isoelectric focused, it was found that the HLA-A1,A2 and A3 antigens were not precipitated. Similarly, MHM.5, which is IgG1, failed to block complement mediated lysis by alloantisera specific for HLA-A1, 2 and 3, and most other HLA-A antigens. HLA-Aw24, A25, and A32, and all other HLA-B and C typing reactions tested were blocked. Thus the antibody binds to an epitope that is lacking on most A antigens, but present on Aw24, A25, A32 and all B and C locus antigens. Comparison of the published amino acid sequences of HLA-A2, A3, Aw24, A28, Cw3, B7, and B40 suggests some possible sites for this epitope.
authors.forename: S A
authors.initials: SA
authors.lastname: Ellis
authors.forename: C
authors.initials: C
authors.lastname: Taylor
authors.forename: J E
authors.initials: JE
authors.lastname: Hildreth
authors.forename: A J
authors.initials: AJ
authors.lastname: McMichael
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity; D001667:Binding, Competitive; D000939:Epitopes / Q000276:immunology / Q000302:isolation & purification; D006680:HLA Antigens / Q000276:immunology*; D015234:HLA-A Antigens; D015235:HLA-B Antigens; D015236:HLA-C Antigens; D006801:Humans; D007525:Isoelectric Focusing; D008214:Lymphocytes / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000939:Epitopes; D006680:HLA Antigens; D015234:HLA-A Antigens; D015235:HLA-B Antigens; D015236:HLA-C Antigens