Establishment of a monoclonal antibody directed against Gb3Cer/CD77: a useful immunochemical reagent for a differentiation marker in Burkitt's lymphoma and germinal centre B cells.

A new monoclonal antibody (TU-1) directed against the Gal alpha 1-4Gal beta 1-4Glc residue of the Gb3Cer/CD77 antigen was prepared by the hybridoma technique following immunization of mice with an emulsion composed of monophosphoryl lipid A, trehalose dimycolate, and Gb3Cer isolated from porcine erythrocytes. TU-1 showed reactivity towards Gb3Cer and lyso-Gb3Cer(Gal alpha 1-4Gal beta 1-4Glc beta 1-1'Sph), although the reactivity towards lyso-Gb3Cer was about 10-fold lower than that to Gb3Cer. But it did not react with other structurally-related glycolipids, such as LacCer (Gal beta 1-4Glc beta 1-1'Cer), Gg3Cer, Gg4Cer, Gb4Cer (GalNAc beta 1-3Gal alpha 1-4Gal beta 1-4Glc beta 1-1'Cer), galactosylparagloboside (Gal alpha 1-3Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1'Cer), sulfatide (HSO3-3Gal beta 1-1'Cer), other gangliosides (GM3, GM2, GM1a, GD1a and GT1b), or P1 antigen (Gal alpha 1-4Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1'Cer) among neutral glycolipids prepared from P1 phenotype red blood cells. Furthermore, TU-1 reacted with viable lymphoma cells, such as human Burkitt lymphoma cell line, Daudi, and Epstein-Barr virus (EBV)-transformed B cells by the immunofluorescence method, and also with germinal centre B cells in human tonsil and vessel endothelial cells in human thymus histochemically. These results indicate that TU-1 is a monoclonal antibody directed against Gb3Cer/CD77 antigen and can be utilized as a diagnostic reagent for Burkitt's lymphoma and also for detection of the blood group Pk antigen in glycolipid extracts of erythrocytes.