These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: T cell clones with normal or defective O-galactosylation from a patient with permanent mixed-field polyagglutinability.
    Author: Thurnher M, Clausen H, Fierz W, Lanzavecchia A, Berger EG.
    Journal: Eur J Immunol; 1992 Jul; 22(7):1835-42. PubMed ID: 1378020.
    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.
    [Abstract] [Full Text] [Related] [New Search]