Previous studies have demonstrated that the leukocyte integrin Mac-1 adheres to several cell surface and soluble ligands including intercellular adhesion molecule-1, fibrinogen, iC3b, and factor X. However, experiments with Mac-1-expressing transfectants, purified Mac-1, and mAbs to Mac-1 indicate the existence of additional ligands. In this paper, we demonstrate a direct interaction between Mac-1 and heparan sulfate glycans. Heparin affinity resins immunoprecipitate Mac-1, and neutrophils and transfectant cells that express Mac-1 bind to heparin and heparan sulfate, but not to other sulfated glycosaminoglycans. Inhibition studies with mAbs and chemically modified forms of heparin suggest the I domain as a recognition site on Mac-1 for heparin, and suggest that either N- or O-sulfation is sufficient for heparin to bind efficiently to Mac-1. Under conditions of continuous flow in which heparins and E-selectin are cosubstrates, neutrophils tether to E-selectin and form firm adhesions through a Mac-1-heparin interaction.
Heparin is an adhesive ligand for the leukocyte integrin Mac-1 (CD11b/CD1).
M S Diamond, R Alon, C A Parkos, M T Quinn, T A Springer; Heparin is an adhesive ligand for the leukocyte integrin Mac-1 (CD11b/CD1).. J Cell Biol 15 September 1995; 130 (6): 1473–1482. doi: https://doi.org/10.1083/jcb.130.6.1473
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