Inhibition of influenza A virus proliferation in mice via universal RNA interference

Influenza A virus (IAV) is a respiratory pathogen that causes seasonal outbreaks and periodic pandemics. As frequent mutations in the IAV viral genome often render vaccines ineffective or inefficient in preventing the latest outbreak, there is a need to explore other preventive strategies to control the disease. This study sought to investigate the use of antiviral short hairpin RNA (shRNA), delivered by a recombinant adeno-associated virus (AAV), for the prevention of IAV infections. Conserved regions with less than 10 % of variation were identified from IAV genome sequences deposited in the National Center for Biotechnology Information (NCBI) database between 2000 and 2023. The shRNA targeting these conserved sequences was transcribed from the human RNA polymerase III U6 promoter in an AAV system. This study demonstrates that AAV delivery of shRNA against IAV genes encoding two of the viral RNA-dependent RNA polymerase subunits, PB1 and PB2, inhibits the replication of IAV H1N1 and H3N2 viruses in Madin-Darby canine kidney (MDCK) cells. Delivery of shPB1 to lung tissue in mice through AAV also provided effective protection against IAV infection. These results offer support for a shRNA-based strategy of influenza prevention.