Constitutive expression of E- and P-selectin cognate ligands in human endothelial cells.

On human endothelial cells from umbilical cord (HUVEC) are present, in addition to E- and P-selectins, their cognate ligands. Differently from selectins, the ligand expression is constitutive and not modulated by interleukin-1beta. Such ligands appear to be different from the ones present in promyelocytic cells in order to promote cell adhesion to immobilized selectins. The expression of selectin-ligands on HUVEC cells suggest that selectins can participate in endothelial signalling besides their role as adhesion molecules for circulating blood cells. However, despite their role in chemotaxis, selectins do not contribute to HUVEC tube formation in Matrigel.