title: Characterization of specific HLA-DQ alpha allospecificities by genomic, biochemical, and serologic analysis.
abstract: Bgl II restriction endonuclease digestion of genomic DNA from lymphoblastoid cell lines homozygous for HLA DR and DQ serological specificities, followed by hybridization with a DQ alpha cDNA probe, identified a genomic polymorphism characterized by two reciprocal patterns, one associated with DR 3, 5 and 8 and the other with DR 1, 2, 4, 7, and 9. The former pattern corresponded precisely to the reactivity of monoclonal antibody SFR20-DQ alpha 5, shown by Western blotting to react with isolated alpha-chains, but not with beta-chains. Additional variants of the DQ alpha genes were identified by using a locus-specific oligonucleotide probe for the DQ alpha gene, indicating differences among the DQ alpha 5-negative set of alleles. This analysis defines a set of DQ alpha allelic markers that are distinct from the well-established DQ serologic specificities DQw1, 2, 3 or "blank." Although most DQ alpha 5+ cells carry the DRw52 specificity associated with the DR beta 2 gene, analysis of DQ alpha polymorphisms on DR5, DQw1; DR8, DQw1; and DRw13, DQw1 cells verified that this DQ alpha family of alleles was not invariably linked to the DR beta 2 locus.
mesh_terms: D000939:Epitopes; D006681:HLA-D Antigens / Q000235:genetics*; D006683:HLA-DQ Antigens / Q000235:genetics* / Q000276:immunology; D006239:Haplotypes; D006720:Homozygote; D006801:Humans; D012150:Polymorphism, Restriction Fragment Length
chemical_list: D000939:Epitopes; D006681:HLA-D Antigens; D006683:HLA-DQ Antigens; C040626:HLA-Dx antigen