title: T cell clones with normal or defective O-galactosylation from a patient with permanent mixed-field polyagglutinability.
abstract: To delineate the extent of O-galactosyltransferase deficiency within the lymphoid lineage, monoclonal antibody specific for the Thomsen-Friedenreich (TF) antigen (Gal beta 1----3GalNAc alpha 1-O-Ser/Thr) and its precursor the Tn antigen (GalNAc alpha 1-O-Ser/Thr) were applied to the flow cytometric analysis of peripheral blood lymphocytes from a patient with permanent mixed-field polyagglutinability (PMFP). We show that only a minor population of 4% expressed the Tn antigen which is in contrast to 93% of the patient's erythrocytes carrying the defect. Tn+ lymphocytes mainly belonged to the CD3+ subset, but were also CD19+ or CD16+. Both Tn+ and TF+ T cell clones from patient R. R. were established and shown to belong to the CD4+ or CD8+ antigenic subset. Three glycosyltransferase activities were determined in lysates from these clones: all Tn+ clones were deficient in UDP-Gal: GalNAc alpha 1-O-Ser/Thr beta 1----3 galactosyltransferase (beta 3Gal-T) activity; by contrast this activity was present in all lysates from TF-expressing clones. UDP-GalNAc: polypeptide alpha-N-acetylgalactosaminyltransferase (GalNAc-T) and UDP-Gal: GlcNAc-R beta 1----4 galactosyl-transferase (beta 4Gal-T) exhibited similar activities in both Tn+ and TF+ T cell clones. As a consequence of defective O-galactosylation in Tn+ T cells, cell surface sialic acid of Tn+ clones was reduced by greater than 50% when compared to TF+ clones as demonstrated by sialic acid-specific labeling using fluoresceinated Limax flavus agglutinin(LA) and flow cytometry. The Tn phenotype of T cell clones was stable for more than 1 year of continuous expansion in vitro. These data demonstrate that in PMFP, T cells may also be affected by the O-galactosyltransferase deficiency which is accompanied by a substantial loss of cell surface sialic acid. However, the frequency of Tn+ lymphocytes in peripheral blood from patient R.R. was strikingly low. These T cell clones should be useful to study the defect at a genetic level and the importance of O-linked carbohydrates for proper T cell function.
authors.affiliation: Institute of Physiology, University of Zürich, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Thurnher
authors.forename: H
authors.initials: H
authors.lastname: Clausen
authors.forename: W
authors.initials: W
authors.lastname: Fierz
authors.forename: A
authors.initials: A
authors.lastname: Lanzavecchia
authors.forename: E G
authors.initials: EG
authors.lastname: Berger
mesh_terms: D000371:Agglutination; D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal / Q000276:immunology; D000951:Antigens, Neoplasm / Q000032:analysis; D000954:Antigens, Surface / Q000502:physiology; D015295:Antigens, Tumor-Associated, Carbohydrate; D018968:CD58 Antigens; D002999:Clone Cells; D004187:Disaccharides / Q000032:analysis; D004912:Erythrocytes / Q000276:immunology; D005690:Galactose / Q000378:metabolism*; D006031:Glycosylation; D016695:Glycosyltransferases / Q000032:analysis / Q000172:deficiency*; D006801:Humans; D008562:Membrane Glycoproteins / Q000502:physiology; D008969:Molecular Sequence Data; D019158:N-Acetylneuraminic Acid; D012794:Sialic Acids / Q000032:analysis; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D015295:Antigens, Tumor-Associated, Carbohydrate; D018968:CD58 Antigens; D004187:Disaccharides; D008562:Membrane Glycoproteins; D012794:Sialic Acids; C040286:Tn antigen; C016467:Thomsen-Friedenreich antigen; D016695:Glycosyltransferases; D019158:N-Acetylneuraminic Acid; D005690:Galactose