Monoclonal antibody defining a Burkitt's lymphoma-associated antigen detects carbohydrate on neutral glycolipid

Monoclonal antibody 38.13 detects an epitope presented on Burkitt's lymphoma cells that has not been detected on other lymphoid tissues or tumors. The biochemical nature of this Burkitt's lymphoma-associated antigen was investigated by staining inhibition assays. Indirect immunofluorescence and fluorescence-activated cell sorter analysis show that antibody 38.13 reacts with a protease-resistant structure present among the hydrophobic components extracted with chloroform-methanol from the Ramos Burkitt's cell line. These components were further separated by ion-exchange chromatography and activity resides in the unbound (neutral) fraction. The staining antibody is specifically absorbed when preincubated with D-galactose, and to a lesser extent with N-acetyl-galactosamine. Therefore, 38.13 appears to recognize a determinant of carbohydrate nature, which is carried on a neutral glycolipid.