Sequential shifts in the three major glycosphingolipid series are associated with B cell differentiation.
Cell surface glycolipid expression as well as total glycolipid content of various B cell lines, representative of different B cell stages, and normal B lymphocytes were examined. Glycolipids, made up of a carbohydrate chain attached to a lipid called ceramide, are classified in four main 'series'. These series are defined according to the identity and chemical bonding of the sugars closest to the ceramide moiety. The pre-B cell lines contained lacto-series type II chain-based glycolipids and II3-alpha-N-acetyl-neuraminosyllactosylceramide (GM3) ganglioside. Upon differentiation, the lacto-series synthesis was shut down whereas compounds of the globo-series appeared: resting lymphocytes and lymphoblastoid cell lines (LCL) expressed GM3, globotriaosylceramide (Gb3), and globoside (Gb4). At a later stage of B cell differentiation, biosynthesis of the ganglio-series was extended and myeloma cells expressed II3-alpha-N-acetyl-neuraminosylgangliotriosylceramide (GM2). At the cell surface, in addition to Gb3, that we previously described as specifically expressed on Burkitt's lymphoma cells and on a subset of germinal centre tonsillar B cells, two glycolipids seemed specific of certain B cell lines: Gb4 was strongly positive on six out of eight LCLs and on the low buoyant density fraction of tonsillar B lymphocytes, whereas GM2 ganglioside was only detected on the two myeloma cell lines. These results, demonstrating the stage-dependent expression of certain glycolipids, suggest that these carbohydrate molecules could play functional roles during B cell differentiation.
Wiels
J
J
Laboratoire de Biologie des Tumeurs Humaines, CNRS URA 1156, Institut Gustave Roussy, Villejuif, France.
Mangeney
M
M
Tétaud
C
C
Tursz
T
T
D000911:Antibodies, Monoclonal; D015703:Antigens, CD / Q000032:analysis; D000944:Antigens, Differentiation, B-Lymphocyte / Q000032:analysis; D000954:Antigens, Surface / Q000737:chemistry; D001402:B-Lymphocytes / Q000166:cytology / Q000378:metabolism*; D002240:Carbohydrate Sequence; D002454:Cell Differentiation; D002460:Cell Line; D006028:Glycosphingolipids / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D008969:Molecular Sequence Data
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000944:Antigens, Differentiation, B-Lymphocyte; D000954:Antigens, Surface; D006028:Glycosphingolipids