Abstract
Purpose :
Purpose: Toll-like receptor 3 (TLR3) and interferon-beta promoter stimulator-1 (IPS-1) are associated with antiviral responses to double-stranded (ds) RNA viruses, and contribute to innate immunity. We previously reported that TLR3 is expressed on the surface of corneal epithelial cells (CECs), and confirmed that MDA5 and RIG-I, dsRNA receptors that bind to IPS-1, are also expressed in CECs (Ueta M, et al. Prog Retin Eye Res. 2012). We also reported that TLR3 and IPS-1 signaling regulates the distribution and migration of CD11c+ cells in murine corneas (Ueta M, et al. Immunol Lett. 2019). However, the functions of TLR3 and IPS-1 in CECs and the differences in their respective roles for their common ligands remain unclear. The purpose of this present study was to elucidate the function of TLR3 and IPS-1 in CECs via comprehensive analysis of gene expression in response to polyinosinic:polycytidylic [poly(I:C)] stimulation using cultured primary murine CECs (PMCECs) derived from TLR3 and IPS-1 knock-out (KO) mice.
Methods :
Methods: PMCECs were obtained from the corneas of 4- to 6-week-old BALB/c background wild-type (WT), TLR3KO, and IPS-1KO mice, and then stimulated with or without poly(I:C) (10 μg/ml) for 6 hours. Total RNA was then extracted from the PMCECs, and comprehensive gene expression analysis was performed using the GeneChip™ (Thermo Fisher Scientific) microarray scanner system. Gene expression was further evaluated via quantitative polymerase chain reaction analysis.
Results :
Results: The expression of 121 genes was upregulated more than 2-fold in the WT PMCECs after poly(I:C) stimulation compared with those without stimulation. Gene ontology analysis showed that the upregulated genes included those associated with viral responses. Compared to the WT PMCECs, genes downregulated in the TLR3KO or IPS-1KO PMCECs also included those associated with viral responses. The genes Neurl3, Irg1, and Lipg were specifically downregulated in the TLR3KO PMCECs, while the genes Oas2, Slfn4, Trim30a, and Gbp9 were downregulated in the IPS-1KO PMCECs.
Conclusions :
Conclusions: Our findings show that murine CECs contribute to the antiviral response through TLR3 and IPS-1 signaling, thus suggesting that both immune cells and CECs play an important role in innate immunity, and that TLR3 and IPS-1 may possibly regulate genes involved in different viral response pathways.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.