Comparison of antiviral activities of porcine interferon type I and type II

Abstract:

Interferons (IFNs) are natural proteins produced by wide variety of cells in response to viral infection or other biological inducers, and they execute diversified functions as antiviral defense, immune activation and cell growth regulation. Four genes encoding porcine interferons (PoIFN), PoIFN-α, PoIFN-γ, PoIFN-αγ or PoIFN-ω, were cloned and sequenced. The four types of porcine interferon genes were subcloned into the pET-His vector, and expressed in Escherichia coli Rosetta (DE3). The recombinant products were purified and renaturalized from inclusion bodies to obtain a native state of well biological activity. Antiviral activity assays for porcine interferons were performed and evaluated by standard procedures in following cell/virus test systems: Marc-145/PRRSV, Marc-145/VSV, PK-15/VSV, Vero/VSV or MDBK/VSV. The data showed that both PoIFN-α and PoIFN-αγ demonstrated significant antiviral activities, and the titer of them against PRRSV was up to 108 U/mg. PoIFN-γ had approximately half or one-thirds antiviral activity of PoIFN-α. PoIFN-ω showed inconspicuous antiviral activity.