[Detection of hybrid DQ molecules by the use of T cell clone and 2D-gel analyses].
The HLA-D region incorporates three subregions, DR, DQ and DP, encoding for three sets of Ia molecules. Whereas DR antigens consist of a constant alpha chain and an extremely polymorphic beta chain, both of alpha and beta chain of DQ antigens show moderate polymorphism. This indicated us the existence of hybrid HLA-DQ molecules in HLA-D heterozygous cells, resulting from the association of an alpha chain and a beta chain encoded by genes located on the two separate haplotypes. In this report, hybrid DQ antigens were demonstrated by using cytotoxic T cell-clone. A cytotoxic T cell clone, which was generated by mixed lymphocyte reaction against a lymphoblastoid B cell line, EBV-Fuk (HLA-DR1/4, DQw1/Wa), recognized only heterogenous lymphoblastoid B cell lines (HLA-DR1/4, DQw1/Wa). Cytotoxic T cell clone, however, didn't react with B cell lines which are homozygous for HLA-DR1, DQw1 or DR4/DQWa. This suggests the T cell clone recognized the hybrid DQ molecules expressed only on heterozygous cell lines. Further confirmation was obtained by inhibition test using monoclonal antibody and biochemically by 2-D gel analyses. Biological significance of hybrid DQ antigens were discussed.
D000911:Antibodies, Monoclonal; D002478:Cells, Cultured; D002999:Clone Cells; D003601:Cytotoxicity Tests, Immunologic; D004587:Electrophoresis, Agar Gel; D006681:HLA-D Antigens / Q000032:analysis*; D006683:HLA-DQ Antigens / Q000032:analysis*; D006801:Humans; D006824:Hybridization, Genetic; D013602:T-Lymphocytes, Cytotoxic
D000911:Antibodies, Monoclonal; D006681:HLA-D Antigens; D006683:HLA-DQ Antigens