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.
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.
Erdmann
Michael
M
Tumor Immunology Program, German Cancer Research Center, D-69120, Heidelberg, Germany.
Wipfler
Dirk
D
Merling
Anette
A
Cao
Yi
Y
Claus
Christine
C
Kniep
Bernhard
B
Sadick
Haneen
H
Bergler
Wolfgang
W
Vlasak
Reinhard
R
Schwartz-Albiez
Reinhard
R
D000107:Acetylation; D015703:Antigens, CD / Q000276:immunology / Q000378:metabolism; D017209:Apoptosis; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002478:Cells, Cultured; D002648:Child; D000939:Epitopes; D005434:Flow Cytometry; D005732:Gangliosides / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism; D018858:Germinal Center / Q000166:cytology; D006801:Humans; D008213:Lymphocyte Activation; D014066:Palatine Tonsil / Q000166:cytology / Q000276:immunology*; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism
D015703:Antigens, CD; D000939:Epitopes; D005732:Gangliosides; C026226:ganglioside, GD3