Gga-miR-30d regulates infectious bronchitis virus infection by targeting USP47 in HD11 cells

Avian infectious bronchitis virus (IBV) is a coronavirus which infects chickens and causes severe economic losses to the poultry industry worldwide. MicroRNAs (miRNAs) are important intracellular regulators and play a pivotal role in viral infections. In previous studies, we have revealed that IBV infection caused a significant down-regulation of gga-miR-30d expression in chicken kidneys. In present study, we investigated the role of gga-miR-30d in the process of IBV infection of HD11 cell line in vitro. By transfecting the mimics and inhibitor of gga-miR-30d, it was found that overexpressed gga-miR-30d inhibited IBV replication. Contrarily, low-expressed gga-miR-30d promoted IBV replication. In addition, dual-luciferase reporter assays revealed that ubiquitin-specific protease 47 (USP47), a deubiquitinase-encoding gene, was a target for gga-miR-30d. This is the first study demonstrating that miRNAs regulate IBV replication by regulating the deubiquitinating enzyme (DUBs).