J Biol Chem, Vol. 274, Issue 27, 19035-19040, July 2, 1999

In Vivo Ligand Specificity of E-selectin Binding to Multivalent Sialyl Lewis^x N-linked Oligosaccharides

From the College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109-1065

The in vivo specificity for E-selectin binding to a panel of N-linked oligosaccharides containing a clustered array of one to four sialyl Lewis^x (SLe^x; NeuAc2-3Gal[Fuc1-3]1-4GlcNAc) determinants was studied in mice. Following intraperitoneal dosing with lipopolysaccharide, radioiodinated tyrosinamide N-linked oligosaccharides were dosed i.v. and analyzed for their pharmacokinetics and biodistribution. Specific targeting was determined from the degree of SLe^x oligosaccharide targeting relative to a sialyl oligosaccharide control. Oligosaccharides targeted the kidney with the greatest selectivity after a 4-h induction period following lipopolysaccharide dosing. Unique pharmacokinetic profiles were identified for SLe^x biantennary and triantennary oligosaccharides but not for monovalent and tetraantennary SLe^x oligosaccharides or sialyl oligosaccharide controls. Biodistribution studies established that both SLe^x biantennary and triantennary oligosaccharides distributed to the kidney with 2-3-fold selectivity over sialyl oligosaccharide controls, whereas monovalent and tetraantennary SLe^x oligosaccharides failed to mediate specific kidney targeting. Simultaneous dosing of SLe^x biantennary or triantennary oligosaccharide with a mouse anti-E-selectin monoclonal antibody blocked kidney targeting, whereas co-administration with anti-P-selectin monoclonal antibody did not significantly block kidney targeting. The results suggest that SLe^x biantennary and triantennary are N-linked oligosaccharide ligands for E-selectin and implicate E-selectin as a bivalent receptor in the murine kidney endothelium.