A subset of HLA-DR9 molecules is detected by a polymorphic monoclonal antibody on lymphoblastoid cell lines but not on peripheral blood lymphocytes.
Some mAbs recognizing polymorphic epitopes of HLA-DR molecules exhibit striking differences of reactivity with the same HLA-DR molecules expressed by different cell types. In this study, we investigated the basis for the differential reactivity of the polymorphic anti-DR mAb OHA TM901 with HLA-DR9 molecules expressed by human PBLs or LCLs. By immunoprecipitation experiments we showed that OHA TM901 recognizes a subset of HLA-DR9 molecules from LCLs. This subset corresponds to HLA-DR9 molecules containing immature-type oligosaccharides. The absence of OHA TM901 reactivity with HLA-DR9 PBLs, as revealed by cytofluorometry analysis, suggests that this subset is either not expressed or expressed at a very low level on PBLs. These results indicate that overexpression of HLA-DR molecules in immortalized LCLs could lead to cell-surface expression of underglycosylated forms which are generally not found on the cell surface of PBLs.
Cayrol
C
C
Center of Immunopathology and Human Genetics, CIGH-CNRS UPR 8291, Toulouse, France.
Tkaczuk
J
J
Sommer
E
E
Cambon-Thomsen
A
A
D000911:Antibodies, Monoclonal / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology; D001773:Blood Cells; D002461:Cell Line, Transformed; D000939:Epitopes / Q000276:immunology; D006684:HLA-DR Antigens / Q000032:analysis* / Q000737:chemistry / Q000145:classification / Q000276:immunology; D059810:HLA-DR Serological Subtypes; D006801:Humans; D016131:Lymphocyte Subsets / Q000276:immunology*; D009439:Neuraminidase / Q000494:pharmacology; D009844:Oligosaccharides / Q000032:analysis; D012794:Sialic Acids / Q000032:analysis
D000911:Antibodies, Monoclonal; D000939:Epitopes; D006684:HLA-DR Antigens; D059810:HLA-DR Serological Subtypes; C038988:HLA-DR9 antigen; D009844:Oligosaccharides; D012794:Sialic Acids; D009439:Neuraminidase