title: Activated T-lymphocytes express class I molecules which are hyposialylated compared to other lymphocyte populations.
abstract: Various H-2 and Qa/Tla region encoded class I glycoproteins expressed on the surface of resting and activated T- and B-lymphocytes were compared by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). The isoelectrophoretic patterns of the H-2K, H-2D, Qa-2 and Qa-1 molecules isolated from activated T-lymphocytes were more isoelectrically heterogeneous and/or possessed species with a more basic pI than the same molecules isolated from resting T- and B-cells or activated B-lymphocytes. The differences in charge heterogeneity of class I molecules between activated T-cells and the other cell subpopulations were abolished by treatment with: (1) endoglycosidase F which removes N-linked oligosaccharides from glycoproteins, and (2) neuraminidase which removes sialic acids from carbohydrate side chains. Thus, the increased charged heterogeneity of class I molecules expressed by activated T-cells is due to altered sialylation of their N-linked oligosaccharides. These results indicate that a mechanism exists, upon activation of T-lymphocytes, for alteration (desialylation) of the carbohydrate moieties of class I molecules.
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D002462:Cell Membrane / Q000276:immunology; D002478:Cells, Cultured; D004591:Electrophoresis, Polyacrylamide Gel; D006023:Glycoproteins / Q000276:immunology; D006026:Glycoside Hydrolases / Q000276:immunology; D007106:Immune Sera / Q000276:immunology; D008213:Lymphocyte Activation; D008285:Major Histocompatibility Complex; D051379:Mice; D008815:Mice, Inbred Strains; D009439:Neuraminidase; D009844:Oligosaccharides / Q000276:immunology; D012794:Sialic Acids / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism
chemical_list: D006023:Glycoproteins; D007106:Immune Sera; D009844:Oligosaccharides; D012794:Sialic Acids; D006026:Glycoside Hydrolases; D009439:Neuraminidase