Abstract
Purpose :
Corneal and conjunctival epithelium tight junctions (TJs) are present between most superficial cells, and form a barrier that protects the eye from the external environment, thus regulating the passive movement of fluid, electrolytes, macromolecules, and cells through the paracellular pathway. Interferon-gamma (IFN-γ), the sole member of the type II IFN family, plays an important role in both innate and adaptive immunity. In this study, we investigated the effect of IFN-γ on the ocular-surface barrier function in cultured immortalized human corneal epithelial cells (HCLE) and conjunctival epithelial cells (HCjE).
Methods :
HCLE and HCjE were cultured on 12-mm Transwell® Inserts (Corning®) at a density of 4x104 cells/cm2. The cultured cells were then stimulated with 100ng/ml IFN-γ. Transepithelial electrical resistance (TEER) was measured before stimulation and at 24-hours post stimulation using EndOhm electrodes (World Precision Instruments). The expression of TJ-related proteins claudin (CLDN)-1, -4, and -7 was then evaluated via real-time polymerase chain reaction (PCR), western blotting, and immunohistochemistry examinations.
Results :
At 24-hours post stimulation with 100ng/ml IFN-γ, a significant TEER increase of 76.0% (P<0.01) in the HCLE and 23.0% (P<0.05) in the HCjE was observed compared with that in the control cells, and increased expression of CLDN-1, -4, and -7 mRNA and protein was also observed. Immunohistochemistry findings also revealed the increased expression of CLDN-1, -4, and-7 in both the HCLE and HCjE compared with the control cells.
Conclusions :
The findings in this study revealed that the expression of TJ-related proteins in HCLE and HCjE increased and that the ocular-surface barrier function strengthened post stimulation with IFN-γ.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.