Altered glycosylation of leukosialin, CD43, in HIV-1-infected cells of the CEM line.
CD43 (leukosialin, gpL115, sialophorin) is a major sialoglycoprotein widely expressed on hematopoietic cells that is defective in the congenital immunodeficiency Wiskott-Aldrich syndrome. It is thought to play an important role in cell-cell interactions and to be a costimulatory molecule for T lymphocyte activation. Using a metabolic 35SO4(2-) radiolabeling assay or biotinylation of cell surface proteins, we describe here that CD43 are sulfated molecules the glycosylation of which is altered in human immunodeficiency virus type 1 (HIV-1)-infected leukemic T cells of the CEM line. Hyposialylation of O-glycans and changed substitution on N-acetylgalactosamine residues are observed. The glycosylation defect is associated with an impairment of CD43-mediated homotypic aggregation which can be restored by resialylation. The hyposialylation of CD43 on HIV-1+ cells may explain the high prevalence of autoantibodies directed against nonsialylated CD43 that have been detected in HIV-1-infected individuals. A defect in glycosylation of important molecules such as CD43 or, as we recently described, CD45 may explain alterations of T cell functions and viability in HIV-1-infected individuals. In addition, a possible implication of hyposialylation in the HIV-1-infected cells entrapment in lymph nodes could be envisioned.
Laboratoire de Virologie, Faculté de Médecine, Hôpital de Cimiez, France.
J C
JC
Lefebvre
V
V
Giordanengo
M
M
Limouse
A
A
Doglio
M
M
Cucchiarini
F
F
Monpoux
R
R
Mariani
J F
JF
Peyron
D000911:Antibodies, Monoclonal / Q000276:immunology; D015703:Antigens, CD; D015551:Autoimmunity; D002449:Cell Aggregation; D002460:Cell Line; D006031:Glycosylation; D015497:HIV-1 / Q000502:physiology*; D006801:Humans; D051917:Leukosialin; D008970:Molecular Weight; D019158:N-Acetylneuraminic Acid; D012794:Sialic Acids / Q000378:metabolism; D012795:Sialoglycoproteins / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D013601:T-Lymphocytes / Q000276:immunology
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D051917:Leukosialin; C465014:SPN protein, human; D012794:Sialic Acids; D012795:Sialoglycoproteins; D019158:N-Acetylneuraminic Acid