Adenovirus Expressing Human Interferon Inhibits Replication of Foot and Mouth Disease Virus and Reduces Fatal Rate in Mice

Interferon is an important cytokine that plays a critical role in the initial host defense against viral infection. Recombinant human adenoviruses expressing human interferon-A (Ad-HIFNA) or pig interferon-B fused with interleukin-18 (Ad-PIFNB-IL18) were constructed and used to induce an early protective response against foot and mouth disease (FMD). To analyze the antiviral effect, bovine thyroid and porcine kidney IBRS-2 cells and ICR mice were treated with Ad-HIFNA, Ad-PIFNB-IL18, and cocktail of Ad-HIFNA and Ad-PIFNB-IL18. The survival rate of suckling mice was monitored after foot and mouth disease virus (FMDV) challenge following intra-peritoneal (IP) administration of appropriate adenovirus. Indirect antigen ELISA was performed to evaluate inhibition of FMDV replication following challenge with the FMDV O, A, or Asia 1 serotypes in vitro. These recombinant adenoviruses reduced the replication of FMDV in susceptible cells, thereby decreasing the fatality in mice, suggesting that they can be a useful control method for the early protection against FMD infection in livestock after field trial.