Analysis of HLA-DQ molecules with a monoclonal antibody detecting a DQ polymorphism absent from DQW1 homozygous cells.
We have produced a monoclonal antibody detecting an HLA class II determinant absent from DR1,2,W6, and W10 (DQW1) homozygous B lymphoblastoid cell lines (BLCL). The antibody, SFR16-PI.2, immunoprecipitates molecules with electrophoretic mobilities of DQ (DS/DC) molecules from DR7 homozygous cell lines. SFR16-PI.2 binds more sets of class II molecules from internally labeled DR7 homozygous cell membranes than from externally labeled extracts from the same cell line. Depletion of DR molecules from internally-labeled membranes indicates that SFR16-PI.2, in addition to reacting with DQ molecules, also reacts with an epitope on a biosynthetic intermediate of DR molecules, which is lost on the mature DR molecule. SFR16-PI.2-reactive molecules were examined on a DR5 homozygous cell line, where they could be compared to those isolated by two other monoclonal antibodies with DQ specificity, namely IVD12 and Leu-10. All three monoclonal antibodies isolated two sets of DQ molecules with varying degrees of affinity for one of the molecules. The serological and biochemical data presented suggest that SFR16-PI.2 detects the alternate alleles of the locus encoding DQW1.
D000483:Alleles; D000911:Antibodies, Monoclonal; D002478:Cells, Cultured; D011232:Chemical Precipitation; D006683:HLA-DQ Antigens; D006579:Heterozygote; D000949:Histocompatibility Antigens Class II / Q000235:genetics / Q000276:immunology*; D006801:Humans; D007526:Isoelectric Point; D008970:Molecular Weight; D011110:Polymorphism, Genetic
D000911:Antibodies, Monoclonal; D006683:HLA-DQ Antigens; D000949:Histocompatibility Antigens Class II