Submitted April 3, 2008
Accepted June 13, 2008
E-selectin receptors on human leukocytes
Leonardo Nimrichter, Monica M Burdick, Kazuhiro Aoki, Wouter Laroy, Mark A Fierro, Sherry A Hudson, Christopher E Von Seggern, Robert J Cotter, Bruce S Bochner, Michael Tiemeyer, Konstantinos Konstantopoulos, and Ronald L Schnaar*
Instituto de Microbiologia Prof. Paulo de Goes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, Maryland, United States
Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, United States
Department of Pharmacology and Molecular Science, The Johns Hopkins School of Medicine, Baltimore, Maryland, United States
Department of Medicine, The Johns Hopkins School of Medicine, Baltimore, Maryland, United States
* Corresponding author; email: schnaar{at}jhu.edu.
Selectins on activated vascular endothelium mediate inflammation by binding to complementary carbohydrates on circulating neutrophils. The human neutrophil receptor for E-selectin has not been established. We report here that sialylated glycosphingolipids with 5 N acetyllactosamine (LacNAc, Gal
1-4GlcNAc1-3) repeats and 2-3 fucose residues are major functional E-selectin receptors on human neutrophils. Glycolipids were extracted from 
1010 normal peripheral blood human neutrophils. Individual glycolipid species were resolved by chromatography, adsorbed as model membrane monolayers and selectin-mediated cell tethering and rolling under fluid shear was quantified as a function of glycolipid density. E-selectin-expressing cells tethered and rolled on selected glycolipids, whereas P-selectin-expressing cells failed to interact. Quantitatively minor terminally sialylated glycosphingolipids with 5-6 LacNAc repeats and 2-3 fucose residues where highly potent E-selectin receptors, constituting >60% of the E-selectin binding activity in the extract. These glycolipids are expressed on human blood neutrophils at densities exceeding those required to support E-selectin-mediated tethering and rolling. Blocking glycosphingolipid biosynthesis in cultured human neutrophils diminished E-selectin, but not P-selectin adhesion. The data support the conclusion that on human neutrophils the glycosphingolipid NeuAc
2-3Gal1-4GlcNAc1-3[Gal1-4(Fuc1-3)GlcNAc1-3]2[Gal1-4GlcNAc1-3]2Gal1-4GlcCer (and closely related structures) are functional E selectin receptors.
