Adhesion molecules in the pathogenesis of asthma

Area of Science:

• Immunology
• Pulmonary Medicine
• Cell Biology

Background:

• Airway hyperresponsiveness (AHR) and eosinophilia are hallmarks of asthma.
• The precise mechanisms driving AHR and eosinophilia, particularly the role of cell adhesion molecules, require further elucidation.

Purpose of the Study:

• To investigate the mechanisms of airway hyperresponsiveness induction in a primate model.
• To determine the contribution of intercellular adhesion molecule-1 (ICAM-1) and endothelial-leukocyte adhesion molecule-1 (ELAM-1) to antigen-induced airway inflammation and hyperresponsiveness.

Main Methods:

• A primate antigen inhalation model was employed to study AHR.
• Monoclonal antibodies against ICAM-1 and ELAM-1 were used to assess their roles.
• In vitro and in vivo experiments examined eosinophil adhesion, molecule upregulation, and airway responses.

Main Results:

• Antigen inhalation led to prolonged airway eosinophilia and increased airway responsiveness.
• ICAM-1 was upregulated on inflamed endothelium and epithelium, partially mediating eosinophil adhesion and contributing to eosinophilia and AHR.
• ELAM-1 was upregulated on inflamed endothelium but did not significantly contribute to antigen-induced eosinophilia or AHR.

Conclusions:

• ICAM-1 is a significant mediator of antigen-induced airway eosinophilia and hyperresponsiveness.
• Antagonism of ICAM-1, but not ELAM-1, presents a potential therapeutic avenue for managing asthma-related airway inflammation and hyperresponsiveness.