Differential surface expression and possible function of 9-O- and 7-O-acetylated GD3 (CD60 b and c) during activation and apoptosis of human tonsillar B and T lymphocytes

• Published in: Glycoconjugate journal Vol. 23; no. 9; pp. 627 - 638
• Main Authors: Erdmann, Michael, Wipfler, Dirk, Merling, Anette, Cao, Yi, Claus, Christine, Kniep, Bernhard, Sadick, Haneen, Bergler, Wolfgang, Vlasak, Reinhard, Schwartz-Albiez, Reinhard
• Format: Journal Article
• Language: English
• Published: United States Springer Nature B.V 01-12-2006; Kluwer Academic Publishers-Plenum Publishers
• Subjects: Acetylation; Antigens, CD - immunology; Antigens, CD - metabolism; Apoptosis; B-Lymphocytes - immunology; B-Lymphocytes - metabolism; Cells, Cultured; Child; Epitopes; Flow Cytometry; Gangliosides - chemistry; Gangliosides - immunology; Gangliosides - metabolism; Germinal Center - cytology; Humans; Immunology; Lymphocyte Activation; Lymphocytes; Palatine Tonsil - cytology; Palatine Tonsil - immunology; Signal Transduction; T-Lymphocytes - immunology; T-Lymphocytes - metabolism
• ISSN: 0282-0080; 1573-4986
• DOI: 10.1007/s10719-006-9000-5

The disialoganglioside GD3 (CD60 a) and its O-acetylated variants have previously been described as surface molecules of human T lymphocytes of the peripheral blood system. Here we report the expression of the 9-O-, and 7-O-acetylated disialoglycans of GD3 (CD60 b and CD60 c respectively) on human tonsillar lymphocytes. CD60 b and c are surface-expressed on activated germinal centre B cells and colocalize in raft-like structures on the cell surface together with the cytoplasmic tyrosine kinase Lyn and Syk. Addition of CD60 b and c mAb together with anti-IgM/IL-4 to in vitro cultivated tonsillar B cells resulted in a costimulatory effect. During spontaneous and staurosporine-induced apoptosis a distinct population of activated annexin V+/CD60 b+/CD60 c- B cells was observed. CD60 b and c are also found on cells of the extrafollicular T cell area. On tonsillar T cells, CD60 b mAb had a costimulatory effect together with PHA while CD60 c mAb alone was sufficient to induce proliferation. In further contrast to B cells, during apoptosis a distinct CD60 b+ T cell subpopulation was not observed. Together, surface-expressed CD60 b and c are differently expressed on tonsillar B and T cells and may be involved in the regulation of activation and apoptosis of lymphocytes in secondary lymphatic tissue.