CONSTITUTIVE EXPRESSION OF E-SELECTIN 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 fr om selectins, the ligand expression is constitutive and not modulated by interleukin-1 beta. Such ligands appear to be different from the on es present in promyelocytic cells in order to promote cell adhesion to immobilized selectins. The expression of selectin-ligands on HUVEC ce lls suggest that selectins can participate in endothelial signalling b esides their role as adhesion molecules for circulating blood cells. H owever, despite their role in chemotaxis, selectins do not contribute to HUVEC tube formation in Matrigel.