GMP-140 binds to a glycoprotein receptor on human neutrophils: evidence for a lectin-like interaction.
GMP-140 is a rapidly inducible receptor for neutrophils and monocytes expressed on activated platelets and endothelial cells. It is a member of the selectin family of lectin-like cell surface molecules that mediate leukocyte adhesion. We used a radioligand binding assay to characterize the interaction of purified GMP-140 with human neutrophils. Unstimulated neutrophils rapidly bound [125I]GMP-140 at 4 degrees C, reaching equilibrium in 10-15 min. Binding was Ca2+ dependent, reversible, and saturable at 3-6 nM free GMP-140 with half-maximal binding at approximately 1.5 nM. Receptor density and apparent affinity were not altered when neutrophils were stimulated with 4 beta-phorbol 12-myristate 13-acetate. Treatment of neutrophils with proteases abolished specific binding of [125I]GMP-140. Binding was also diminished when neutrophils were treated with neuraminidase from Vibrio cholerae, which cleaves alpha 2-3-, alpha 2-6-, and alpha 2-8-linked sialic acids, or from Newcastle disease virus, which cleaves only alpha 2-3- and alpha 2-8-linked sialic acids. Binding was not inhibited by an mAb to the abundant myeloid oligosaccharide, Lex (CD15), or by the neoglycoproteins Lex-BSA and sialyl-Lex-BSA. We conclude that neutrophils constitutively express a glycoprotein receptor for GMP-140, which contains sialic acid residues that are essential for function. These findings support the concept that GMP-140 interacts with leukocytes by a lectin-like mechanism.
Moore
K L
KL
Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City.
Varki
A
A
McEver
R P
RP
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D001792:Blood Platelets / Q000502:physiology*; D015815:Cell Adhesion Molecules / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D007457:Iodine Radioisotopes; D007700:Kinetics; D037102:Lectins; D008214:Lymphocytes / Q000502:physiology; D009000:Monocytes / Q000502:physiology; D009504:Neutrophils / Q000502:physiology*; D019007:P-Selectin; D010980:Platelet Membrane Glycoproteins / Q000302:isolation & purification / Q000378:metabolism*; D011869:Radioligand Assay
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D015815:Cell Adhesion Molecules; D007457:Iodine Radioisotopes; D037102:Lectins; D019007:P-Selectin; D010980:Platelet Membrane Glycoproteins