Association with beta 2-microglobulin controls the expression of transfected human class I genes.
The genes encoding HLA-B27K and HLA-B27W were transfected into murine recipient cells. A monoclonal antibody HC-10, directed against free B-locus heavy chain, was the only reagent capable of efficiently detecting the HLA-B27 heavy chains in detergent lysates. These heavy chains were devoid of sialic acid. Trace amounts of HLA-B27 could be isolated with the anti-HLA-A,-B antibody W6/32, which reacts with the heavy chain beta 2-microglobulin complex. In marked contrast, HLA-A2 and -B7 genes, when transfected, yielded easily detectable amounts of antigen precipitable with W6/32, which carried the usual complement of sialic acids. Because the alpha 3 domains of HLA-B27 and HLA-B7 and the more COOH-terminal portions are identical in amino acid sequence, structural elements in the polymorphic alpha 1 and alpha 2 domains must control association of heavy chain with beta 2-microglobulin. Introduction of a human beta 2-microglobulin gene into L cells transfected with the HLA-B27 gene rescued the expression of HLA-B27 at the cell surface, as evidenced by reactivity with W6/32, surface staining, and the presence of sialic acid on the heavy chain.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D005347:Fibroblasts / Q000378:metabolism; D005786:Gene Expression Regulation; D005796:Genes; D006680:HLA Antigens / Q000096:biosynthesis / Q000235:genetics*; D015789:HLA-A2 Antigen; D015796:HLA-B27 Antigen; D015793:HLA-B7 Antigen; D006801:Humans; D007122:Immunoelectrophoresis; D007739:L Cells / Q000378:metabolism; D051379:Mice; D019158:N-Acetylneuraminic Acid; D011499:Protein Processing, Post-Translational; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics*; D012794:Sialic Acids / Q000032:analysis; D014162:Transfection; D001613:beta 2-Microglobulin / Q000235:genetics / Q000276:immunology*
D000911:Antibodies, Monoclonal; D006680:HLA Antigens; D015789:HLA-A2 Antigen; D015796:HLA-B27 Antigen; D015793:HLA-B7 Antigen; D011994:Recombinant Proteins; D012794:Sialic Acids; D001613:beta 2-Microglobulin; D019158:N-Acetylneuraminic Acid