ICAM-1-independent adhesion of neutrophils to phorbol ester-stimulated human airway epithelial cells

Am J Physiol. 1999 Sep;277(3):L465-71. doi: 10.1152/ajplung.1999.277.3.L465.


Intercellular adhesion molecule-1 (ICAM-1) is the only inducible adhesion receptor for neutrophils identified in bronchial epithelial cells. We stimulated human airway epithelial cells with various agonists to evaluate whether ICAM-1-independent adhesion mechanisms could be elicited. Phorbol 12-myristate 13-acetate (PMA) stimulation of cells of the alveolar cell line A549 caused a rapid, significant increase in neutrophil adhesion from 11 +/- 3 to 49 +/- 7% (SE). A significant increase from 17 +/- 4 to 39 +/- 6% was also observed for neutrophil adhesion to PMA-stimulated human bronchial epithelial cells in primary culture. Although ICAM-1 expression was upregulated by PMA at late time points, it was not affected at 10 min when neutrophil adhesion was already clearly enhanced. Antibodies to ICAM-1 had no effect on neutrophil adhesion. In contrast, antibodies to the leukocyte integrin beta-chain CD18 totally inhibited the adhesion of neutrophils to PMA-stimulated epithelial cells. These results demonstrate that PMA stimulation of human airway epithelial cells causes an increase in neutrophil adhesion that is not dependent on ICAM-1 upregulation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bronchi / cytology
  • Bronchi / drug effects
  • Bronchi / physiology*
  • Cell Adhesion / drug effects
  • Cell Adhesion Molecules / physiology
  • Energy Metabolism / physiology
  • Epithelial Cells / drug effects
  • Epithelial Cells / physiology
  • Humans
  • Intercellular Adhesion Molecule-1 / physiology*
  • Ions
  • Metals / pharmacology
  • Neutrophils / drug effects
  • Neutrophils / physiology*
  • Protein Synthesis Inhibitors / pharmacology
  • Pulmonary Alveoli / cytology
  • Pulmonary Alveoli / drug effects
  • Pulmonary Alveoli / physiology*
  • Tetradecanoylphorbol Acetate / pharmacology*


  • Cell Adhesion Molecules
  • Ions
  • Metals
  • Protein Synthesis Inhibitors
  • Intercellular Adhesion Molecule-1
  • Tetradecanoylphorbol Acetate