LIGAND-SPECIFICITY OF THE SELECTINS

The selectins are carbohydrate-binding cell adhesion molecules acting in the vascular system. They mediate the docking of leukocytes to the blood vessel wall and the rolling of these cells along the endothelial cell surface. These adhesion phenomena initiate the entry of leukocyt es into sites of inflammation as well as the migration of recirculatin g lymphocytes into secondary lymphoid tissues. Blocking selectin funct ion with antibodies or oligosaccharides has proven to be beneficial in various animal models of inflammation and models of ischemia/reperfus ion damage. This has raised much interest in the identification of the physiological ligands of the selectins. Several glycoprotein ligands have been identified, some of which can even be selectively isolated f rom cellular detergent extracts using a selectin as an affinity probe. Four of these ''high affinity'' ligands have been cloned. The structu ral requirements of their interaction with the selectins is discussed. (C) 1996 Wiley-Liss, Inc.