Differential expression of cell surface binding sites for cholera toxin in acute and chronic leukaemias.

Binding of purified cholera toxin to cell surface receptors has been visualized by an indirect immunofluorescence procedure. Normal nucleated cells from blood, bone marrow and lymphoid tissues, express these receptors with the possible exception of erythroid precursors. Cells from patients with chronic lymphoid or myeloid leukaemias have a normal receptor expression but acute leukaemic cells showed a marked deficiency in cholera toxin binding. Insertion of purified Gm ganglioside into membranes of acute leukaemic cells provided cellular binding sites for the toxin.