Antiviral Effect of miR-146a in Epithelioma Papulosum Cyprini (EPC) Cells Against Three Fish Viruses: VHSV, IHNV and IPNV

Abstract

Many studies have demonstrated that miRNAs play a crucial role in virus-host interactions. This study aimed to investigate the antiviral effects of miR-146a in Epithelioma papulosum cyprini (EPC) cells infected with viral hemorrhagic septicemia virus (VHSV), infectious pancreatic necrosis virus (IPNV), and infectious haematopoietic necrosis virus (IHNV), which are major causes of mortality in various freshwater and marine fish worldwide. Cytopathic effects (CPE) were observed as early as 72 h post-infection in both the control group and the miR-146a inhibitor group. In contrast, CPE formation was not observed in virus-infected groups treated with the miR-146a mimic. The control and miR-146a inhibitor groups exhibited a rapid increase in viral titres after 48 h, whereas the miR-146a mimic-treated groups showed minimal viral replication at all assay time points. To further investigate the antiviral mechanism of miR-146a, we analysed the genes upregulated by miR-146a following viral stimulation. The results revealed a significant increase in the expression of genes involved in the type I interferon (IFN) response in the miR-146a mimic group. Taken together, these findings suggest that miR-146a exerts antiviral effects against VHSV, IPNV and IHNV.