Interferon α (IFN-α) plays a crucial role in the host’s immune response. In this study, the amino acid sequence of porcine interferon α (PoIFN-α) was analyzed. Seven substitutions, S38F, H40Q, F43L, N78D, Y86C, S151A, and R156T, were mutated and obtained by aligning the sequences of PoIFN-α subtypes. The PoIFN-α mutants were designed, expressed, and purified in E. coli. The antiviral activities of these PoIFN-αs were measured in Vero and swine testis cells against vesicular stomatitis virus (VSV). Their inhibitory abilities on pseudorabies virus (PRV) were also examined. Commercial PoIFN-α was used as a control. We found the ideal inducer concentration of isopropyl β-d-thiogalactoside was 1 mM, and the best time-point for induction was 8 h. The PoIFN-α mutant named PoIFN-α-156s had the highest antiviral activity, which was about 200-fold more than that of PoIFN-α. PoIFN-α-156s could inhibit VSV and PRV replication in a dose-dependent manner in vitro. The half-life of PoIFN-α-156s was longer than that of PoIFN-α in mice, and the effective antiviral action was higher than PoIFN-α. Animal experiments showed that PoIFN-α-156s could decrease the viral load after infection with VSV. Overall, these results suggest that recombinant PoIFN-α-156s has the ability of antivirus, and is feasible for veterinary clinical applications and fundamental research.

干扰素α (IFN-α) 在宿主的免疫反应中起着至关重要的作用。本研究分析了猪干扰素α（PoIFN-α）的氨基酸序列。通过比对 PoIFN-α 亚型的序列，对 S38F、H40Q、F43L、N78D、Y86C、S151A 和 R156T 七个取代进行突变和获得。PoIFN-α 突变体是在大肠杆菌中设计、表达和纯化的。这些 PoIFN-α 的抗病毒活性在 Vero 和猪睾丸细胞中针对水泡性口炎病毒 (VSV) 进行了测量。还检查了它们对伪狂犬病病毒 (PRV) 的抑制能力。商业 PoIFN-α 用作对照。我们找到了理想的异丙基β- d诱导剂浓度-硫代半乳糖苷为 1 mM，诱导的最佳时间点为 8 小时。PoIFN-α突变体PoIFN-α-156s的抗病毒活性最高，是PoIFN-α的200倍左右。PoIFN-α-156s 可以在体外以剂量依赖性方式抑制 VSV 和 PRV 复制。PoIFN-α-156s在小鼠体内的半衰期长于PoIFN-α，有效抗病毒作用高于PoIFN-α。动物实验表明，PoIFN-α-156s 可降低 VSV 感染后的病毒载量。总的来说，这些结果表明重组PoIFN-α-156s具有抗病毒能力，在兽医临床应用和基础研究中是可行的。