Targeted Integration of siRNA against Porcine Cytomegalovirus (PCMV) Enhances the Resistance of Porcine Cells to PCMV.

In the world's first pig-to-human cardiac cytomegalovirus (PCMV), xenotransplant and elevated levels of porcine key factors contributing to patient mortality were considered. This has renewed attention on PCMV, a virus widely prevalent in pigs. Currently, there are no effective drugs or vaccines targeting PCMV, and its high detection difficulty poses challenges for prevention and control research. In this study, antiviral small hairpin RNA (shRNA) was selected and inserted into the Rosa26 and miR-17-92 loci of pigs via a CRISPR/Cas9-mediated knock-in strategy. Further in vitro viral challenge experiments demonstrated that these genetically edited pig cells could effectively limit PCMV replication. Through this process, we constructed a PCMV-infected cell model, validated partial viral interference sites, enhanced gene knock-in efficiency, performed gene editing at two different gene loci, and ultimately demonstrated that RNA interference (RNAi) technology combined with CRISPR/Cas9 has the potential to generate pig cells with enhanced antiviral infection capabilities. This opens up possibilities for the future production of pig populations with antiviral functionalities.