A surrogate method for assessment of beta(2)-integrin-dependent adhesion of human eosinophils to ICAM-1

J Immunol Methods. 2000 Jun 23;240(1-2):157-64. doi: 10.1016/s0022-1759(00)00192-7.

Abstract

We have developed and validated an inexpensive and equivalent method for measuring eosinophil adhesion by beta(2)-integrin to endothelial ICAM-1 using bovine serum albumin (BSA) as a surrogate for the immunoglobulin supergene. The number of adherent eosinophils on BSA or ICAM-1 coated microplates was quantified by residual eosinophil peroxidase activity. Non-stimulated eosinophils did not adhere to either BSA or ICAM-1. However, after IL-5 stimulation, either BSA or ICAM-1 caused comparable and concentration-dependent adhesion of eosinophils. Eosinophil adhesion was rapid and occurred within 15 to 30 min of incubation for either BSA or ICAM-1. Preincubation of cells with CD11b or CD18 antibody specifically decreased adhesion to either BSA or ICAM-1. IL-5, PAF and fMLP all induced adhesion of eosinophils to either BSA or ICAM-1 in a concentration-dependent manner, and the optimal IL-5, fMLP and PAF concentrations for adhesion to BSA were the same as for adhesion to ICAM-1. BSA-binding was specific for beta(2)-integrin; neither alpha-CD49d mAb directed against the alpha(4)-chain or alpha-CD29 directed against the common beta(1)-chain of VLA-4 blocked adhesion to BSA or ICAM-1 controls. The protein tyrosine kinase inhibitor, genistein, the phosphatidylinositol 3-kinase (PI-3 kinase) inhibitor, wortmanin, and mitogen-activated protein kinase kinase (MEK) inhibitor, U0126, all inhibited IL-5-induced eosinophil adhesion to either BSA or ICAM-1 comparably. These results indicate that BSA is a reliable and economical surrogate ligand for ICAM-1 adhesion to beta(2)-integrin-dependent adhesion to ICAM-1. Ligation characteristics of BSA are identical to those for soluble ICAM-1, and the assay is suitable for assessment of signal transduction pathways mediating adhesion.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Androstadienes / pharmacology
  • Butadienes / pharmacology
  • CD18 Antigens / metabolism*
  • Cell Adhesion / drug effects
  • Dose-Response Relationship, Drug
  • Eosinophils / drug effects
  • Eosinophils / immunology*
  • Genistein / pharmacology
  • Humans
  • Hypersensitivity, Immediate
  • Integrins / metabolism*
  • Intercellular Adhesion Molecule-1 / metabolism*
  • Interleukin-5 / pharmacology
  • N-Formylmethionine Leucyl-Phenylalanine / pharmacology
  • Nitriles / pharmacology
  • Phosphoinositide-3 Kinase Inhibitors
  • Platelet Activating Factor / pharmacology
  • Protein Kinase Inhibitors
  • Serum Albumin, Bovine
  • Wortmannin

Substances

  • Androstadienes
  • Butadienes
  • CD18 Antigens
  • Integrins
  • Interleukin-5
  • Nitriles
  • Phosphoinositide-3 Kinase Inhibitors
  • Platelet Activating Factor
  • Protein Kinase Inhibitors
  • U 0126
  • Intercellular Adhesion Molecule-1
  • Serum Albumin, Bovine
  • N-Formylmethionine Leucyl-Phenylalanine
  • Genistein
  • Wortmannin