title: DQw3 variants defined by cloned alloreactive T cells.
abstract: The polymorphism of HLA class II molecules expressing the serologically defined alloantigen DQw3 was studied using cloned proliferative T lymphocytes. Two clones, IG9 and IC3, were selectively primed against DQw3-associated determinants and tested against a panel of 92 HLA-D homozygous cells. Both clones were specific for DQw3, but each showed a distinct response pattern. Clone IG9 recognized a DQw3-associated determinant expressed on a subset of DR4 and DR5 haplotypes and on all DRw6, 7, w8, and w9 haplotypes tested. In contrast, clone IC3 recognized a distinct DQw3-associated determinant expressed only on a subset of DR4 haplotypes. In monoclonal antibody inhibition experiments, anti-DQ, but not anti-DR or anti-DP antibodies, blocked reactivity of both clones IG9 and IC3, further demonstrating that the determinants defined by these clones are associated with DQ molecules. In DNA hybridization studies using a DQ beta probe, a correlation was observed between restriction site polymorphisms in the DQ beta gene, designated DQw"3.1" and "3.2," and the expression of the T-cell-defined IG9 and IC3 determinants. It is, thus, possible to demonstrate by cloned T-cell reactivity functionally relevant recognition sites on DQw3+ molecules that are associated with structural polymorphisms defined by molecular and genomic analysis.
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D002460:Cell Line; D002999:Clone Cells / Q000276:immunology; D000939:Epitopes / Q000276:immunology; D006681:HLA-D Antigens / Q000276:immunology*; D006683:HLA-DQ Antigens / Q000276:immunology*; D006239:Haplotypes; D006801:Humans; D066298:In Vitro Techniques; D007959:Lymphocyte Culture Test, Mixed; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000939:Epitopes; D006681:HLA-D Antigens; D006683:HLA-DQ Antigens; C051569:HLA-DQ3 antigen