Fucosylated glycosphingolipids of human myeloid cells

Our efforts to determine the carbohydrate binding specificity of two myeloid-specific monoclonal antibodies (VIM-1 and VIM-10) resulted in the purification of three fucosylated glycosphingolipids from human chronic myelogenous leukemia cells. After repeated high-performance liquid chromatographic separations, two forms of fucosylated glycosphingolipids were resolved. VIM-1 and VIM-10 were found to bind to the heptaosylceramide Gal beta 1-4 (Fuc alpha 1-3)GlcNAc beta 1-3Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1Cer with the Le(x) (Lewis X) epitope, but not to either the hexaosylceramide Fuc alpha 1-2Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1-Cer or the octaosylceramide Fuc alpha 1-2Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-3Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1Cer, each with the Le(y) (Lewis Y) epitope. The latter two glycosphingolipids are the first Le(y) antigens to be purified from human leukocytes and structurally characterized. Binding studies with a range of glycosphingolipids from myeloid cells and other biological sources demonstrated that VIM-1 and VIM-10 bind to Le(x) glycosphingolipids with five or more sugar residues, but not to a glycosphingolipid (III3Fuc-nLc6Cer) with an internal Le(x) trisaccharide.