title: Public antigenic determinant on a family of HLA-B molecules.
abstract: Serologic cross-reactivity among allelic gene products commonly occurs in the HLA complex, but the molecular basis of these serologic phenomena is incompletely characterized. Because of strong cross-reactivity among antigens comprising the B7 cross-reactive group (i.e., HLA-B7, Bw22, B27, B40, and Bw42) and because of the association of several antigens of this group with spondyloarthropathies, we initiated a study of the chemical basis of cross-reactivity among this group of antigens. Using classic serologic procedures, 125I-Protein A binding assay, and chemical immunoprecipitation techniques, we have defined a new antigenic determinant, tentatively designated "X", which is present on certain HLA-B molecules. By a series of sequential immunoprecipitation experiments, X was shown to be a "public" antigenic determinant distinct from the "private" determinants B7, Bw22, B27, and B40, but present on the same 44,000-dalton glycoprotein molecules. The implications of this finding regarding disease predisposition and HLA typing as a diagnostic aid are discussed.
mesh_terms: D016918:Arthritis, Reactive / Q000235:genetics; D003429:Cross Reactions; D000939:Epitopes; D006680:HLA Antigens / Q000235:genetics / Q000276:immunology*; D006650:Histocompatibility Testing; D006801:Humans; D007163:Immunosorbent Techniques; D010641:Phenotype; D013167:Spondylitis, Ankylosing / Q000235:genetics
chemical_list: D000939:Epitopes; D006680:HLA Antigens