title: Differential requirements for core2 glucosaminyltransferase for endothelial L-selectin ligand function in vivo.
abstract: L-selectin is a calcium-dependent lectin on leukocytes mediating leukocyte rolling in high endothelial venules and inflamed microvessels. Many selectin ligands require modification of glycoproteins by leukocyte core2 beta1,6-N-acetylglucosaminyltransferase (Core2GlcNAcT-I). To test the role of Core2GlcNAcT-I for L-selectin ligand biosynthesis, we investigated leukocyte rolling in venules of untreated and TNF-alpha-treated cremaster muscles and in Peyer's patch high endothelial venules (HEV) of Core2GlcNAcT-I null (core2(-/-)) mice. In the presence of blocking mAbs against P- and E-selectin, L-selectin-mediated leukocyte rolling was almost completely abolished in cremaster muscle venules of core2(-/-) mice, but not littermate control mice. By contrast, leukocyte rolling in Peyer's patch HEV was not significantly different between core2(-/-) and control mice. To probe L-selectin ligands more directly, we injected L-selectin-coated beads. These beads showed no rolling in cremaster muscle venules of core2(-/-) mice, but significant rolling in controls. In Peyer's patch HEV, beads coated with a low concentration of L-selectin showed reduced rolling in core2(-/-) mice. Beads coated with a 10-fold higher concentration of L-selectin rolled equivalently in core2(-/-) and control mice. Our data show that endothelial L-selectin ligands relevant for rolling in inflamed microvessels of the cremaster muscle are completely Core2GlcNAcT-I dependent. In contrast, L-selectin ligands in Peyer's patch HEV are only marginally affected by the absence of Core2GlcNAcT-I, but are sufficiently functional to support L-selectin-dependent leukocyte rolling in Core2GlcNAcT-I-deficient mice.
authors.affiliation: Department of Biomedical Engineering, and Cardiovascular Research Center, University of Virginia, Charlottesville, VA 22908, USA.
authors.forename: M
authors.initials: M
authors.lastname: Sperandio
authors.forename: S B
authors.initials: SB
authors.lastname: Forlow
authors.forename: J
authors.initials: J
authors.lastname: Thatte
authors.forename: L G
authors.initials: LG
authors.lastname: Ellies
authors.forename: J D
authors.initials: JD
authors.lastname: Marth
authors.forename: K
authors.initials: K
authors.lastname: Ley
mesh_terms: D000818:Animals; D002465:Cell Movement / Q000235:genetics / Q000276:immunology; D004729:Endothelium, Lymphatic / Q000201:enzymology* / Q000276:immunology / Q000378:metabolism; D007249:Inflammation / Q000201:enzymology / Q000235:genetics / Q000276:immunology; D019041:L-Selectin / Q000378:metabolism / Q000502:physiology*; D007962:Leukocytes / Q000201:enzymology / Q000276:immunology / Q000378:metabolism; D008024:Ligands; D051379:Mice; D018345:Mice, Knockout; D018715:Microscopy, Video; D018482:Muscle, Skeletal / Q000098:blood supply / Q000201:enzymology / Q000276:immunology; D017351:N-Acetylglucosaminyltransferases / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D010581:Peyer's Patches / Q000166:cytology / Q000201:enzymology / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D014699:Venules / Q000201:enzymology / Q000276:immunology / Q000473:pathology
chemical_list: D008024:Ligands; D014409:Tumor Necrosis Factor-alpha; D019041:L-Selectin; D017351:N-Acetylglucosaminyltransferases; C053024:beta-1,3-galactosyl-O-glycosyl-glycoprotein beta-1,6-acetylglucosaminyl transferase