Dissection of the hyperadhesive phenotype of airway eosinophils in asthma

Am J Respir Cell Mol Biol. 2006 Sep;35(3):378-86. doi: 10.1165/rcmb.2006-0027OC. Epub 2006 Apr 6.


Asthma is characterized by appearance of eosinophils in the airway. Eosinophils purified from the airway 48 h after segmental antigen challenge are described as exhibiting greater adhesion to albumin-coated surfaces via an unidentified beta2 integrin and increased expression of alphaMbeta2 (CD11b/18) compared with purified blood eosinophils. We have investigated the determinants of this hyperadhesive phenotype. Airway eosinophils exhibited increased reactivity with the CBRM1/5 anti-alphaM activation-sensitive antibody as well as enhanced adhesion to VCAM-1 (CD106) and diverse ligands, including albumin, ICAM-1 (CD54), fibrinogen, and vitronectin. Purified blood eosinophils did not adhere to the latter diverse ligands. Enhanced adhesion of airway eosinophils was blocked by anti-alphaMbeta2. Podosomes, structures implicated in cell movement and proteolysis of matrix proteins, were larger and more common on airway eosinophils adherent to VCAM-1 when compared with blood eosinophils. Incubation of blood eosinophils with IL-5 replicated the phenotype of airway eosinophils. That is, IL-5 enhanced recognition of alphaM by CBRM1/5; stimulated alphaMbeta2-mediated adhesion to VCAM-1, albumin, ICAM-1, fibrinogen, and vitronectin; and increased podosome formation on VCAM-1. Thus, the hyperadhesion of airway eosinophils after antigen challenge is mediated by upregulated and activated alphaMbeta2.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies / pharmacology
  • Asthma / immunology*
  • CD18 Antigens / metabolism
  • Cell Adhesion* / drug effects
  • Eosinophils / drug effects
  • Eosinophils / immunology*
  • Fibrinogen / immunology
  • Humans
  • Intercellular Adhesion Molecule-1 / immunology
  • Interleukin-5 / pharmacology
  • Ligands
  • Macrophage-1 Antigen / analysis
  • Macrophage-1 Antigen / metabolism*
  • Phenotype
  • Respiratory System / drug effects
  • Respiratory System / immunology
  • Vascular Cell Adhesion Molecule-1 / immunology
  • Vitronectin / immunology


  • Antibodies
  • CD18 Antigens
  • Interleukin-5
  • Ligands
  • Macrophage-1 Antigen
  • Vascular Cell Adhesion Molecule-1
  • Vitronectin
  • Intercellular Adhesion Molecule-1
  • Fibrinogen