Regulation of leukocyte integrin function: affinity vs. avidity

J Cell Biochem. 1996 Jun 15;61(4):554-61. doi: 10.1002/(sici)1097-4644(19960616)61:4<554::aid-jcb8>3.0.co;2-n.

Abstract

Leukocytes circulate freely in the bloodstream until receiving signals which activate adhesive mechanisms essential for immune responsiveness. Key mediators of these adhesion events are heterodimeric cell surface receptors called integrins. It is now apparent that several components may contribute to successful integrin-mediated adhesion: alterations in individual receptors lead to enhanced affinity for ligand; integrin clustering causes an increase in avidity; by spreading, the adhering cell is less susceptible to shear force. Model systems have allowed us to examine the contribution of each of these factors in generating adhesion. In more physiologically relevant situations, it can now be questioned whether integrin-mediated adhesion is regulated via alterations in receptor affinity or avidity, or whether both these mechanisms are involved.

Publication types

  • Review

MeSH terms

  • Calcium / metabolism
  • Cell Adhesion / physiology*
  • Humans
  • Integrins / physiology*
  • Intercellular Adhesion Molecule-1 / metabolism
  • Leukocytes / cytology*
  • Ligands
  • Lymphocyte Function-Associated Antigen-1 / metabolism
  • Magnesium / metabolism

Substances

  • Integrins
  • Ligands
  • Lymphocyte Function-Associated Antigen-1
  • Intercellular Adhesion Molecule-1
  • Magnesium
  • Calcium