Recently, adhesion molecules, as well as eosinophils, have been found to play an important role in the inflammatory processes in allergic disease. We demonstrated here as below. Characteristics of adhesion molecules expression on eosinophils in
asthma, namely, high-intensity expression of adhesion molecules. Induction of adhesion molecule expression by PAF and
RANTES and in addition induction by the supernatant of mononuclear cells from mite-allergic asthmatic patients stimulated with mite-
allergen as well as with a combination of the recombinant
IL-3,
GM-CSF and
IL-5. Elevated soluble
ICAM-1 in
bronchial asthma. Moreover, the presence of a large variety of membrane receptors and the identification of cytotoxic molecules (mainly granule basic
proteins) have indicated that eosinophils should be considered as effector cells. We therefore investigated the possible release of granule
proteins in response to signaling from
ICAM-1 and its
ligands. The concentrations of
eosinophil cationic protein and
eosinophil-derived neurotoxin in supernatants of eosinophils were significantly greater (p < 0.05) in the presence of recombinant soluble
ICAM-1 than without it. These results suggest that signaling from
ICAM-1 and its
ligands might induce eosinophil activation and might be involved in degranulation of
eosinophil granule proteins. In addition,
reactive oxygen species generated by eosinophils have also been considered capable of causing airway injury at the inflamed focus. We examined the effect of recombinant soluble
ICAM-1 and its
ligands on eosinophil-induced
radical oxygen products. Recombinant soluble
ICAM-1 augmented eosinophil oxidative metabolism. It was concluded that signaling via adhesion molecules might play an important role in the pathogenesis of allergic
inflammation through activation of eosinophils, such as through an increase in oxidative metabolism or degranulation of
eosinophil granule proteins.