title: GMP-140 binding to neutrophils is inhibited by sulfated glycans.
abstract: GMP-140 is a 140-kDa granule membrane glycoprotein localized to the alpha-granules of platelets and the Weibel-Palade bodies of endothelial cells. Expression of GMP-140 on the activated cell surface has been shown to mediate the adhesion of thrombin-activated platelets to neutrophils and monocytes and the transient adhesion of neutrophils to endothelium. In contrast, fluid-phase GMP-140 strongly inhibits the CD18-dependent adhesion of tumor necrosis factor alpha-activated neutrophils to endothelium suggesting that GMP-140 can also serve an anti-adhesive function. In the present report, it is demonstrated that fluid-phase GMP-140 which exists predominantly as a tetramer binds to a single class of high affinity receptor on neutrophils and HL60 cells. Binding of 125I-labeled GMP-140 to neutrophils and HL60 cells and the rosetting of neutrophils and HL60 cells by thrombin-activated platelets were inhibited by EDTA, excess unlabeled fluid-phase GMP-140, Fab fragments of an affinity-purified rabbit anti-GMP-140 antibody, and by the murine anti-GMP-140 monoclonal antibody, AK 4. Both neutrophil and HL60 GMP-140 binding and platelet rosetting were strongly inhibited by heparin, fucoidin, and dextran sulfate 500,000, were partially inhibited by dextran sulfate 5,000 and lambda- and kappa-carrageenan, but were not inhibited by chondroitins 4- and 6-sulfate. Since this sulfated glycan specificity is identical to that previously reported by us for GMP-140, the present results suggest that the sulfated glycan binding site and the neutrophil receptor binding site on GMP-140 are either identical or proximal.
authors.affiliation: Department of Medicine, University of Sydney, Westmead Hospital, N.S.W., Australia.
authors.forename: M P
authors.initials: MP
authors.lastname: Skinner
authors.forename: C M
authors.initials: CM
authors.lastname: Lucas
authors.forename: G F
authors.initials: GF
authors.lastname: Burns
authors.forename: C N
authors.initials: CN
authors.lastname: Chesterman
authors.forename: M C
authors.initials: MC
authors.lastname: Berndt
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D015815:Cell Adhesion Molecules / Q000276:immunology / Q000378:metabolism; D002850:Chromatography, Gel; D006801:Humans; D009504:Neutrophils / Q000276:immunology / Q000378:metabolism*; D019007:P-Selectin; D010980:Platelet Membrane Glycoproteins / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism*; D011134:Polysaccharides / Q000494:pharmacology*; D012397:Rosette Formation; D013431:Sulfates
chemical_list: D000911:Antibodies, Monoclonal; D015815:Cell Adhesion Molecules; D019007:P-Selectin; D010980:Platelet Membrane Glycoproteins; D011134:Polysaccharides; D013431:Sulfates