Glycosylation of human leukocyte locus A molecules is dependent on the cell type.
Peripheral blood monocytes and B cells were isolated from a normal donor, and a portion of the B cells was transformed by the Epstein-Barr virus (EBV). Human leukocyte locus A (HLA) class-I and class-II molecules were immunoprecipitated by specific monoclonal antibodies after cell labeling with [3H]mannose. Glycopeptides of HLA molecules were obtained by pronase digestion and were analysed by lectin-affinity chromatography. Complex structures were hydrazinolysed, and their sialic acid content was analysed by ion-exchange chromatography, whereas the high-mannose structures were separated by HPLC. In normal cells, class-I antigens bear principally fucosylated biantennary structures while HLA-DR class-II antigens bear bi-, tri- and tetra-antennary structures and high-mannose structures. HLA antigens are more sialylated on normal B cells than on normal monocytes. An EBV cell line had a very different pattern of HLA-antigen glycosylation when compared with the original B cells. In the transformed cells, the fractions containing biantennary structures are largely decreased. In contrast, an increase of the tri- and tetra-antennary structure fractions is noticed, particularly in class-II molecules, while both triantennary and high-mannose structures are increased in class-I molecules. Moreover, when compared to normal B cells, the complex structures of class-I antigens in the EBV-transformed B-cell line are undersialylated while they are oversialylated in the case of the class-II molecules.
Merlu
B
B
Unité 180 de l'INSERM, Paris, France.
Neel
D
D
Goussault
Y
Y
Charron
D J
DJ
D000911:Antibodies, Monoclonal / Q000032:analysis; D000918:Antibody Specificity; D002472:Cell Transformation, Viral; D002846:Chromatography, Affinity; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D006020:Glycopeptides / Q000032:analysis*; D006031:Glycosylation; D006680:HLA Antigens / Q000032:analysis*; D004854:Herpesvirus 4, Human / Q000378:metabolism*; D006801:Humans; D006868:Hydrolysis; D037102:Lectins; D008358:Mannose / Q000032:analysis; D009000:Monocytes / Q000032:analysis / Q000187:drug effects* / Q000276:immunology; D019158:N-Acetylneuraminic Acid; D009844:Oligosaccharides / Q000032:analysis; D010641:Phenotype; D011402:Pronase; D012794:Sialic Acids / Q000032:analysis; D013601:T-Lymphocytes / Q000032:analysis / Q000187:drug effects* / Q000276:immunology; D014764:Viral Proteins / Q000494:pharmacology*
D000911:Antibodies, Monoclonal; D006020:Glycopeptides; D006680:HLA Antigens; D037102:Lectins; D009844:Oligosaccharides; D012794:Sialic Acids; D014764:Viral Proteins; D011402:Pronase; D019158:N-Acetylneuraminic Acid; D008358:Mannose