Chul Han An is aPh.D. Candidate in the Department of Bioscience and Biotechnology at Chungnam National University.
Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most economically significant pathogens in the global swine industry due to reproductive disorders and growth retardation. Current vaccines against PRRSV rely on the use of an attenuated-live virus, but these are unreliable. Thus, effective vaccines against PRRSV should be developed. Plants are being considered as a promising alternative to conventional platforms for the large-scale production of recombinant proteins such as vaccine antigens. Here, our study aims at producing subunit vaccines for a set of structural proteins of PRRSV in plants. In an effort to develop plant-based subunit vaccines against PRRSV, codon-optimized and recombinant proteins (GP4, GP5) of PRRSV as antigens were expressed using plant-based subcellular targeting systems in transgenic Arabidopsis plants. Transgenic Arabidopsis plants with high-level expression of the GP4 and GP5 proteins in ER-targeting vector systems were confirmed by Western blot analysis. For animal immunogenicity study, four-week-old PRRSV-free pigs were administrated three times using a finely ground leaf material of transgenic Arabidopsis plants. All pigs were aggressively challenged with PRRSV JA142 strain after a final administration and then immunogenicity of the GP4 and GP5 was assessed. As a result, the group of pigs fed transgenic plants expressing GP4 and GP5 antigens show that higher IFA titer and lower lung lesion scores than control in pig immune response test.