GAL-ALPHA-4GAL-BINDING ANTIBODIES - SPECIFICITY AND USE FOR THE MAPPING OF GLYCOLIPIDS OF BURKITT-LYMPHOMA AND OTHER HUMAN TUMORS

The binding of four different Gal alpha 4Gal-specific antibodies was e xamined using several natural and synthetic Gal alpha 4Gal-containing glycolipids on thin-layer chromatograms, One of the antibodies, MC2102 , bound much better to galabiosylceramide (Gal alpha(4)Ga beta(3)Cer) than to the elongated structure globotriaosylceramide (Gal alpha 4Gal beta 4Glc beta Cer, CD77), Two antibodies, 38.13 and Pk002, bound best to globotriaosylceramide but cross-reacted with the pi antigen (Gal a lpha 4Gal beta 3GlcNAc beta 3Gal beta 4Glc beta Cer). The fourth antib ody tested, P001, reacted most strongly with the P1 antigen but also t o some extent with globotriaosylceramide, None of the antibodies bound to glycolipids with Gal alpha 4Gal placed internally in the carbohydr ate chains, The synthetic Gal alpha 4Gal beta-bissulfone adecylsulfony l-2-hexadecylsulfonylmethylprop-1-yl) was bound by MC2102, Pk002, and 38.13 with a strength comparable to Gal alpha 4Gal beta Cer. A large n umber of glycolipids lacking terminal Gal alpha 4Gal were also tested, but none of the antibodies was used to investigate the presence of Ga l alpha 4Gal beta-containing glycolipids in several human and lymphoma cell line grown in nude mice. Glycolipds were also isolated from a se ries of human tumors and several of them were, by antibody binding, fo und to contain Gal alpha 4Gal beta Cer.