Differences in gene regulation by TLR3 and IPS-1 signaling in murine corneal epithelial cells

Toll-like receptor 3 (TLR3) and interferon-beta promoter stimulator-1 (IPS-1) are associated with antiviral responses to double-stranded RNA viruses and contribute to innate immunity. We previously reported that conjunctival epithelial cell (CEC) TLR3 and IPS-1 pathways respond to the common ligand polyinosinic:polycytidylic acid (polyI:C) to regulate different gene expression patterns as well as CD11c + cell migration in murine-model corneas. However, the differences in the functions and the roles of TLR3 and IPS-1 remain unclear. In this study, we investigated the differences of TLR3 or IPS-1-induced gene expression in corneal epithelial cells (CECs) in response to polyI:C stimulation using cultured murine primary CECs (mPCECs) derived from TLR3 and IPS-1 knockout mice via comprehensive analysis. The genes associated with viral responses were upregulated in the wild-type mice mPCECs after polyI:C stimulation. Among these genes, Neurl3, Irg1, and LIPG were dominantly regulated by TLR3, while interleukin (IL)-6 and IL-15 were dominantly regulated by IPS-1. CCL5, CXCL10, OAS2, Slfn4, TRIM30α, and Gbp9 were complementarily regulated by both TLR3 and IPS-1. Our findings suggest that CECs may contribute to immune responses and that TLR3 and IPS-1 possibly have different functions in the corneal innate immune response.