Zhao, Kuan, Li, Xiuli, Lei, Baishi, Han, Ying, An, Tongqing, Zhang, Wuchao, Zhang, Huiwen, Li, Bosen, and Yuan, Wanzhe
Pseudorabies virus (PRV) variants have been widely prevalent since 2011, leading to substantial losses to the swine industry. Although PRV can cause cross-species transmission and induce human infection, no drugs can currently prevent PRV infection. Interferons (IFNs) and interleukin-2 (IL-2) are important cytokines that mediate several biological functions including antiviral activity and immune regulation. In this study, we expressed and purified a recombinant porcine IFN-α and IL-2 fusion protein (rPoIFNα+IL-2) , which did not show a cytotoxic effect on PK-15 cells. The antiviral activity was evaluated in PK-15 cells using the cytopathic effect inhibition method, and the results indicated that rPoIFNα+IL-2 can inhibit the replication of PRV, with an antiviral activity of approximately 104 U/mL. Moreover, the proliferation of peripheral blood mononuclear cells was enhanced by rPoIFNα+IL-2. Additionally, rPoIFNα+IL-2 substantially increased the expression of IFN-stimulated genes, including IFIT1 , ISG15 , MX1 , and OAS , which are critical for antiviral activity. Furthermore, rPoIFNα+IL-2 alleviated the clinical symptoms and reduced mortality in mice infected with PRV. Simultaneously, rPoIFNα+IL-2 increased the expression levels of IFN-γ and IL-10 and inhibited the expression of IL-1β and IL-6. Additionally, the viral DNA copies in different tissues in the rPoIFNα+IL-2-treated group were lower than those in the untreated group. These findings indicate that rPoIFNα+IL-2 may serve as an antiviral agent for the prevention and treatment of PRV infection and may expand the potential function of IFN antiviral drugs in the future. • A recombinant porcine Interferon-α and Interleukin-2 fusion protein (rPoIFNα+IL-2) was expressed and purified. • rPoIFNα+IL-2 remarkably increased expression of IFN-stimulated genes. • rPoIFNα+IL-2 substantially enhances the proliferation of PMBC. • rPoIFNα+IL-2 displayed remarkably protective effects against PRV infection in vitro and vivo. [ABSTRACT FROM AUTHOR]