THE LIGAND RECOGNIZED BY ELAM-1 ON HL-60 CELLS IS NOT CARRIED BY N-LINKED OLIGOSACCHARIDES

The sialy Lewis-x determinant is a ligand for ELAM-1, a major adhesion molecule for HL60 cells and neutrophils. ELAM-1 expression can selectively be induced on human umbilical vein endothelial cells (HUVEC) by tumor necrosis factor, interleukin 1 and lipopolysaccharide. The determinant sialy Lewis-x is found on both glycolipids as well as on glycoproteins. Using specific inhibitors of the biosynthesis of N-linked glycosylated glycoproteins, we investigated whether N-linked glycans or their modifications are involved in ELAM-1-dependent adhesion of HL60 cells to activated HUVEC. The inhibitors of glycoprotein processing N-methyl-deoxynojirimycin, 1-deoxymannojirimycin and swainsoine did not affect ELAM-l-dependent adhesion. Complex-type N-linked glycans are not required for ELAM-l-mediated adhesion, and therefore the ligand for ELAM-l is most likely to glycolipid, or a glycoprotein carrying O-linked oligosaccharides.