Expression of porcine interferon-α and its bioactivity analysis in vitro and in vivo

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

Automated summary

The study analyzed the amino acid sequence of porcine interferon alpha (PoIFN-alpha) and designed mutant PoIFN-alpha-156s with high antiviral activity, which showed significant inhibition on VSV and PRV replication. The recombinant PoIFN-alpha-156s had a longer half-life and more effective antiviral action in mice, indicating its potential for veterinary clinical applications and fundamental research.