Chicken hnRNPK suppresses interferon production, thereby enhancing IBDV replication.

Heterogeneous ribonucleoprotein K (hnRNPK) is a well-known RNA-binding protein initially identified for its role in inhibiting the growth of various human tumors. Members of the hnRNP family have also been implicated in both interferon production and RNA virus replication. However, the role of chicken hnRNPK (chhnRNPK) in the replication of Infectious Bursal Disease Virus (IBDV) remains unclear. In this study, we identified chhnRNPK as a protein that interacts with genomic double-stranded RNA (dsRNA). Following IBDV infection, chhnRNPK was recruited to the virus replication complex in the cytoplasm. Furthermore, chhnRNPK expression inhibited dsRNA-induced interferon production, specifically at the mitochondrial antiviral signaling protein (MAVS) step. Overexpression of chhnRNPK significantly enhanced virus replication, while knockdown of chhnRNPK increased dsRNA-induced interferon production and subsequently disrupted IBDV replication. Collectively, these findings suggest that chhnRNPK promotes IBDV replication by interacting with genomic dsRNA, highlighting a novel host factor that regulates viral replication.