Open Access

ARTICLE

Synergistic inhibition of pseudorabies virus replication by porcine alpha/beta interferon and gamma interferon in vitro

Qingxia Yao, Ping Qian, Yi Cao, Yannan He, Youhui Si, Zhuofei Xu, Huanchun Chen

Laboratory of Animal Virology, College of Veterinary Medicine, Unit of Animal Infectious Diseases, National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei Province, People’s Republic of China

* Corresponding Author: H. Chen,

European Cytokine Network 2007, 18(2), 23-29. https://doi.org/10.1684/ecn.2007.0088

Abstract

Interferon (IFN) is crucial for initiating the innate immune response and for the generation of the adaptive response. IFN, in most species, comprises IFN-alpha (IFN-α), IFN-beta (IFN-β) and IFN-gamma (IFN-γ). In this study, we compared the capacity of porcine IFN-α, -β and -γ, or a combination of them, to protect IBRS-2 cells (porcine kidney cells) from infection with pseudorabies virus (PRV). The results demonstrated that porcine IFN-β (PoIFN-β) was the most efficient of the three IFNs in conferring resistance PRV infection; 100 U/ml PoIFN-β inhibited PRV plaque formation 5.3-fold. Compared with PoIFN-β, porcine IFN-γ (PoIFN-γ) was less capable of inhibiting PRV plaque formation (3.3-fold inhibition). Porcine IFN-α (PoIFN-α) had the least capability of the three PoIFNs, and inhibited PRV plaque formation only 1.26-fold. The inhibitory capacity increased to only 2.3-fold with a treatment of 12,800 U/ml PoIFN-α. A combination of PoIFN-γ and PoIFN-α or PoIFN-β inhibited PRV plaque formation 12.8-fold or 100-fold, respectively. Treatment of IBRS-2 cells with PoIFN-α/β and PoIFN-γ inhibited PRV replication 29- or 146-fold. Additionally, real-time PCR analyses of the PRV immediate early (IE) gene revealed that IE mRNA expression was profoundly decreased in cells stimulated with PoIFN-α/β and PoIFN-γ (23.8–133.0-fold) compared with vehicle-treated cells. All the findings indicate that PoIFN-γ acts synergistically with other PoIFNs (PoIFN-α and -β) to potently inhibit PRV replication in vitro.

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Keywords

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