Development of a biotechnological process for the production of recombinant canine interferon-alpha using the baculovirus-insect cell and larvae system

Abstract

Currently, Latin America is experiencing a considerable increase in demand for veterinary products to ensure animal health. In particular, interferons (IFNs) are cytokines that play an important role in small animal clinics for the treatment of viral or oncological diseases. We developed a biotechnological process for the production of recombinant canine interferon CaIFN-α7 (rCaIFN-α7) using the baculovirus-insect cell and larvae system, and evaluated its biological activity, both antiviral and antitumor, for comparison with the veterinary interferon available on the market, feline omega interferon (rFeIFN-ω, Virbagen Omega®). Recombinant rCaIFN-α7 expressed in Sf9 cell culture was purified in a single step by immobilized metal ion chromatography, yielding 4.43 mg/l with 95% purity. The purified rCaIFN-α7 showed antiviral activity against the canine kidney cell line MDCK (NBL-2, Madin Darby canine kidney) derived from Canis lupus familiaris kidney (ATCC NBL-2) infected with Vesicular Stomatitis Virus (VSV, New Jersey strain), with a recovery of 5.34 × 107 AU/ml after purification. Furthermore, rCaIFN-α7 exhibited antitumor activity against canine mucosal melanoma cell lines Ak and Bk. In a typical scale-up process using 200 Rachiplusia nu larvae, biologically active rCaIFN-α7 was obtained, showing an antiviral titer of 4.5 × 107 AU/ml and a yield of 5.36 × 106 AU/g of larvae. This product also showed antitumor activity against canine mucosal melanoma cell line Mc and a high degree of purity from the starting sample, but a yield of 20%, probably due to aggregation or degradation events leading to a decrease in biological activity.