Blocking virus infection with BacMam virus delivery bovine interferon-α gene

Interferon-αs (IFN-αs) are crucial cytokines for inducing protective antiviral responses. The baculovirus-mediated gene transduction of mammalian cells (BacMam) is an efficient delivery tool for recombinant protein expression in mammalian cells. This study focuses on the delivery of bovine IFN-α (BoIFNα) using the BacMam system. A recombinant pACEMam1-BoIFNα bacmid was constructed, and a recombinant BacMam-BoIFNα virus was obtained. After transducing HEK293T cells with this virus, BoIFNα protein was successfully secreted into the cell supernatant, displaying antiviral activities against VSV, BPIV3, BEV, and BVDV in bovine-derived cells. Additionally, the BacMam-BoIFNα virus inhibited the replication of these viruses in MDBK cells, induced the transcription of ISGs, and the expression of M × 1 in both MDBK and BT cells. These induction effects were significantly reduced following treatment with a JAK1 inhibitor, suggesting that the BacMam-BoIFNα virus exerts antiviral activity in MDBK cells through JAK-STAT signaling pathway. Furthermore, the study found that the BacMam-BoIFNα virus significantly inhibited the replication of BPIV3 in the lung and trachea of mice. Overall, this study demonstrates that the BacMam-BoIFNα virus have antivirus activities both <i>in vitro</i> and <i>in vivo</i>, signaling through JAK-STAT pathway, and provides an efficient interferon gene delivery tool for combating bovine viral infections.