Abstract
Purpose: :
Maintenance of eosinophils on the conjunctival epithelium is an important feature of ocular allergic inflammation, yet the specific receptors involved have not been identified. The purpose of this study was to examine eosinophil adhesion to junctional adhesion molecules (JAM) A, B and C; and the potential role of JAM in eosinophil adhesion to conjunctival epithelial cells.
Methods: :
Peripheral blood eosinophil adhesion to recombinant JAM-A, JAM-B or JAM-C coated plates and a human conjunctival epithelial cell line (IOBA-NHC, Valladolid, Spain) were evaluated using an eosinophil peroxidase assay of adherent eosinophils. Eosinophil adhesion was stimulated with fMLP or PAF. IOBA-NHC cells were pre-treated with pro-inflammatory cytokines and/or blocking antibody to JAM-A. IOBA-NHC cells were also examined for surface expression of JAM-A and JAM-C using flow cytometry.
Results: :
Unstimulated eosinophil adhesion to recombinant JAM-A, B, or C was increased compared to uncoated wells (p<0.05). Moreover, eosinophils stimulated with fMLP or PAF were more adherent to JAM-A, B, and C than to uncoated wells (p<0.05). IOBA-NHC cells expressed JAM-A and JAM-C. Pro-inflammatory cytokine stimulation of IOBA-NHC cells enhanced eosinophil adhesion, while a blocking JAM-A antibody inhibited eosinophil adhesion to levels below that of unstimulated IOBA-NHC cells.
Conclusions: :
Eosinophil adhesion to junctional adhesion molecules is a novel finding and may provide a therapeutic target in ocular and other types of allergic inflammation.
Keywords: conjunctiva • inflammation