Abstract
Introduction: :
Purpose: :
The conjunctival epithelium forms a barrier that isolates the eye from the external environment and regulates the active and passive movement of macromolecules, bacterial components, allergens and cells through both paracellular and transcellular pathways. The purpose of this study was to develop a model to study conjunctival epithelial permeability and examine the role of the epithelial derived mediators, IL-8 and TSLP in its regulation.
Methods: :
Human conjunctival epithelial cells (IOBA-NHC cell line) were cultured (multi-layers) on cell culture inserts and stimulated with various concentrations of IL-8 or TSLP (30 min) after which horseradish peroxidase (HRP) was added to the upper compartment. Aliquots were collected from the basal compartment 60 min after HRP addition. Concentration of HRP in the basal compartment was measured fluorometrically using a commercially available kit.
Results: :
IL-8 had no effect on HRP permeability at lower concentrations, comparable to what is constitutively released from conjunctival epithelial cells in culture (around 0.5 ng/ml, n=3)). At higher concentrations (5 - 50 ng/ml, n=2 or 3) IL-8 enhanced permeability of HRP through the conjunctival epithelial multi-layers. In contrast, TSLP decreased HRP permeability at 10 ng/ml (n=3), but had no effect at higher concentrations.
Conclusions: :
Epithelial derived cytokines may play a role in maintenance of conjunctival epithelial barrier integrity and function through regulation of permeability.
Keywords: conjunctiva • cell adhesions/cell junctions • cytokines/chemokines