Abstract
Purpose :
Dry eye disease (DED) is a condition that currently affects over nine million people in the United States. This condition results in symptoms such as eye irritation, eye dryness, and pain in the eye. The pathogenesis of DED involves the production of proinflammatory cytokines (TNFa and IL-6) and one of the effective treatments is the use of anti-inflammatory agents. Probiotic bacteria are well known inhibitors of inflammation. The purpose of this study is to identify which Toll-like receptors (TLRs) contribute to the inflammatory response in human corneal epithelial cells (HCECs) and to determine whether the metabolites produced by Lactobacillus fermentum can suppress the activation of TLRs on HCECs to reduce inflammation.
Methods :
SV40-immortalized HCECs were cultured in DMEM/F12 medium. HCECs were pretreated with a probiotic bacteria-derived metabolite (JE) produced by Lactobacillus fermentum and subsequently exposed to TLR4 agonist (LPS) or TLR5 agonists (flagellin from Pseudomonas aeruginosa). The inflammatory cytokine IL-6 within the culture supernatants was evaluated by ELISA.
Results :
HCECs did not produce any IL-6 in response to LPS. In contrast, HCECs produced large amounts of IL-6 in response to TLR5 agonist flagellin from Pseudomonas aeruginosa. This data indicates that HCECs responded to TLRs differently. Probiotic bacteria-derived metabolite (JE) produced by Lactobacillus fermentum suppressed the TLR5 agonist-induced IL-6 production.
Conclusions :
HCECs only responded to flagellin from Pseudomonas aeruginosa but not to LPS, indicating HCECs does not respond to all TLRs. The data suggests this is a possible innate mechanism to prevent ocular inflammation. The probiotic bacteria metabolite (JE) produced by Lactobacillus fermentum can suppress production of the inflammatory cytokine (IL-6) by HCECs. This data suggests that JE has a potential to be used as an anti-ocular inflammatory agent.
This is a 2021 ARVO Annual Meeting abstract.