ICAM-1 clustering on endothelial cells recruits VCAM-1

J Biomed Biotechnol. 2010;2010:120328. doi: 10.1155/2010/120328. Epub 2010 Mar 15.

Abstract

In the initial stages of transendothelial migration, leukocytes use the endothelial integrin ligands ICAM-1 and VCAM-1 for strong adhesion. Upon adhesion of the leukocyte to endothelial ICAM-1, ICAM-1 is clustered and recruited to the adhered leukocyte, promoting strong adhesion. In this study, we provide evidence for the colocalization of VCAM-1 at sites of ICAM-1 clustering. Anti-ICAM-1 antibody-coated beads were used to selectively cluster and recruit ICAM-1 on primary human endothelial cells. In time, co-localization of ICAM-1 and VCAM-1 around the adherent beads was observed. Biochemical pull-down assays showed that ICAM-1 clustering induced its association to VCAM-1, suggesting a physical link between these two adhesion molecules. The association was partly dependent on lipid rafts as well as on F-actin and promoted adhesion. These data show that VCAM-1 can be recruited, in an integrin-independent fashion, to clustered ICAM-1 which may serve to promote ICAM-1-mediated leukocyte adhesion.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Adhesion / physiology
  • Cells, Cultured
  • Endothelial Cells / physiology*
  • Humans
  • Intercellular Adhesion Molecule-1 / metabolism*
  • Protein Binding
  • Vascular Cell Adhesion Molecule-1 / metabolism*

Substances

  • Vascular Cell Adhesion Molecule-1
  • Intercellular Adhesion Molecule-1