Abstract
Porcine circovirus type 2 (PCV2) is the primary cause of an emerging swine disease, postweaning multisystemic wasting syndrome, that is responsible for economic losses. To develop an effective vaccine for PCV2, we evaluated a heterologous prime-boost vaccine approach, using a gene gun-mediated naked DNA vector as a priming and modified vaccinia virus ankara (MVA) as a booster, in Balb/c mice. Three open reading frames (ORF) of PCV2 viral samples from infected pigs were amplified, and gene gun-mediated DNA priming vaccination was performed followed by boosts with MVA vectors expressing the same ORFs of PCV2. After vaccination, mice were challenged with PCV2 virus, and virus titers in the lungs and lymph nodes were measured. The combination of ORF-2 and -3 in this gene-based vaccine strategy resulted in high antibody titers and virus neutralization activity in serum, reduced PCV2 virus load, and reduced levels of apoptosis in the lungs. No cross-reaction was observed between ORF-1 and -2, but weak cross-reaction was observed between ORF-1 and -3, and between ORF-2 and -3. Following vaccination, expression of chemokines, macrophage inflammatory protein-1beta and regulated upon activation, normal T cell expressed and secreted, increased significantly. The expression of T helper 1-type cytokine (interferon-gamma) and specific lysis of PCV2-infected cells increased; concomitantly, the level of T helper 2-type cytokine (interleukin-10) decreased in test mice. The expression of tumor necrosis factor-alpha and granulocyte-macrophage colony-stimulating factor increased significantly in mice vaccinated with ORF-2/-3, and with ORF-1/-2/-3. This prime-boost vaccination strategy, using a gene gun for DNA priming and recombinant MVA for boosts, may be an attractive vaccine strategy against PCV2 infection in swine.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.