Canine interferon lambda 3 expressed using an adenoviral vector effectively induces antiviral activity against canine influenza virus

Interferon-lambda (IFN-?) is a type-III IFN and is considered a candidate of antiviral therapeutics. Although the antiviral effects of IFN-? have been investigated in several studies, it has not been clinically approved as an antiviral agent. In this study, an adenoviral vector expression system employing a tetracycline-operator system was developed to control the expression of canine IFN-?3. The antiviral effects of canine IFN-?3 were determined in Madin?Darby canine kidney cells and canine tracheal epithelial cells. After transducing each cell line with recombinant adenovirus containing canine interferon lambda3 gene (Ad-caIFN?3), the mRNA-expression of interferon-stimulated genes Mx1, ISG15, and OAS1 increased significantly (P < 0.05). The replication of canine influenza virus (CIV) was significantly suppressed in Ad-caIFN?3-infected cells. These results indicate that the newly constructed adenoviral vector system could express canine IFN-?3, which could subsequently inhibit CIV replication in two canine cell lines. These data imply that the recombinant Ad-caIFN?3 can potentially be used to treat canine influenza and other viral diseases.

Automated summary

In this study, an adenoviral vector system was developed to control the expression of canine IFN-λ3 and effectively inhibit the replication of canine influenza virus in two canine cell lines. These results suggest that the recombinant adenovirus carrying canine IFN-λ3 gene has the potential to be used as a treatment for canine influenza and other viral diseases.