Masking effect of Hinokitiol, a woody odor, on predator odor-induced stress-related activation

Porcine circovirus type 2 (PCV2) is the primary causative agent of an economically important swine disease, now known as porcine-associated disease (PCVAD). The only structural protein of viral capsid, Cap has become the major target for development of PCV2 subunit vaccines. The purpose of this study is to express Cap of PCV2 using a recombinant pseudorabies virus (PRV) that is gE gene deficient, which is a widely used PRV marker vaccine. The recombinant PRV, gE−/PCV2cap+PRV, was constructed using homologous recombination techniques, in order to replace the upstream of the gE gene with the PCV2 cap gene. The expression of Cap during virus replication was confirmed using immunofluorescence and Western blotting analysis. The expressed Cap protein self-assembled into virus-like particles (VLPs), which was demonstrated using electromicrography. The immunization of mice or guinea pigs with purified VLPs could induce significant, specific antibody responses to PCV2 Cap. These results demonstrate an alternative to PCV2 for the development of a VLP-based subunit vaccine.