E-selectin and ICAM-1 are incorporated into detergent-insoluble membrane domains following clustering in endothelial cells.

Here we present data supporting the role of lipid rafts in endothelial cells during leukocyte adhesion. Following adhesion of THP-1 cells or antibody-mediated clustering, both E-selectin and intercellular adhesion molecule-1 (ICAM-1) partitioned into the detergent-insoluble portion of the endothelial cellular lysate. Sucrose gradient centrifugation revealed the partitioning of clustered E-selectin and ICAM-1 with the low-density fraction where they co-fractionated with src family kinases, markers of lipid rafts. Depleting the plasma membrane of cholesterol inhibited clustering of adhesion molecules following their antibody-induced crosslinking and inhibited their association with src kinases. Thus, our data suggest that E-selectin and ICAM-1 associate with lipid rafts in human endothelial cells following leukocyte adhesion.