Abstract
Purpose :
Human ocular surface is frequently exposed to various antigens or stimulations, so it is essential to keeping a balance between uncontrolled infection and autoimmune-related inflammation by activation /repression of NF-κB pathway activity. The aim of this study is to establish an experimental system to study the regulation of NF-κB activation in the context of cornea epithelial cells.
Methods :
Human corneal epithelial cells were treated by TLR2 ligand with or without ikappa-B kinase (IκK) 1 and 2 inhibitors. NF-κB activity was evaluated by Secretory alkaline phosphatase reporter assay (SEAP). IκBa phosphorylation and p65/p50 nuclear localization were examined through western blots and immunofluorescence staining respectively.
Results :
NF-κB activity in human corneal epithelial cells treated with TLR2 ligand was higher than control cells and inhibited by IκK inhibitors. The phosphorylation level of IκB-α was increased overtime with treatment, although the total IκB-α protein level remaining constant. Nuclear localization of subunit p50 and p65 was observed as early as 1.5 hours after addition of TLR2 ligand. The cytokine MCP-1 protein was detected in the culture media of cells stimulated by TLR2 ligand, and its levels were reduced in the presence of IκK inhibitors.
Conclusions :
The classical NF-κB pathway can be activated by TLR2 in human corneal epithelial cells. This cell culture system may be used to evaluate TLR-related innate defences in ocular surface diseases such as bacterial keratitis.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.