Adhesion to fibronectin augments eosinophil radical oxygen products.

Fibronectin, an extracellular matrix component, is a ligand for very late activation antigen (VLA)-4, which is one of the beta 1-integrin family of molecules expressed by eosinophils. This study examined the effect of adherence to fibronectin on radical oxygen products from eosinophils. Adhesion of eosinophils to fibronectin resulted in enhancement of eosinophil production of radical oxygen species, as determined by luminol-dependent chemiluminescence of eosinophils stimulated with calcium ionophore. It was concluded that eosinophil adhesion to extracellular matrix via adhesion molecules may be important in the pathogenesis of allergic inflammation through eosinophil activation.