A recombinant adenovirus bicistronically expressing porcine interferon-α and interferon-γ enhances antiviral effects against foot-and-mouth disease virus

Foot-and-mouth disease (FMD) is a virulent and economically costly disease in domestic livestock. Since the current vaccine available against FMD provides no protection until 7 days postvaccination, the only alternative method to halt the spread of the FMD virus (FMDV) during outbreaks is by the application of anti-viral agents. The combination of recombinant adenovirus expressing type I interferon (IFN-alpha) and adenovirus expressing type II IFN (IFN-gamma) has been reported to be an effective anti-viral treatment strategy against FMDV. Nevertheless, the recombinant adenovirus mixture may be inefficient because of the low anti-viral efficiency of IFN-gamma compared to that of IFN-alpha. In this study, we generated a recombinant adenovirus co-expressing porcine IFN-alpha and IFN-gamma in tandem using an FMDV 2A sequence to mediate effective cleavage of the two proteins (referred to as Ad-porcine IFN-alpha gamma). We demonstrated that both recombinant porcine IFN-alpha and IFN-gamma were expressed and interferon stimulated gene (ISG)s related with IFN-alpha and IFN-gamma were induced in porcine kidney (IBRS-2) cells infected with Ad-porcine IFN-alpha gamma. Additionally, the anti-viral effects of Ad-porcine IFN-alpha gamma against FMDV were enhanced both in IBRS-2 cells and in CD-1 (ICR) suckling mice compared to that of adenovirus expressing only a single protein. We propose that Ad-porcine IFN-alpha gamma could be a rapid, highly efficient, convenient anti-viral agent against FMDV. (C) 2014 Elsevier B.V. All rights reserved.