Design of a Golden Gate Cloning Plasmid for the Generation of a Chimeric Virus-Like Particle-Based Subunit Vaccine Against Porcine Circovirus Type 2.

Porcine circovirus type 2 (PCV2) is a pervasive pathogen in the swine industry, leading to a spectrum of disorders known as porcine circovirus associated diseases (PCVAD). The PCV2 Cap protein contains critical antigenic epitopes and is the primary target for vaccine development. Current vaccines include inactivated viral particles and virus-like particles (VLPs), with experimental vaccines exploring various innovative approaches. This study introduces a novel Golden Gate assembly-based, Escherichia coli expression destination plasmid, pPRSVCP-E18, designed for the in-frame insertion of short peptide-coding DNA sequences into a highly antigenic site of Papaya ringspot virus (PRSV) coat protein (CP). We successfully cloned four PCV2 Cap peptides into this plasmid, expressed the chimeric CP proteins in E. coli under flask and bioreactor conditions, and assembled them into VLPs. These VLPs, when adjuvated and administered to BALB/c mice, elicited a specific IgG response against the PCV2 Cap peptides. Our findings demonstrate the plasmid's high efficiency for Golden Gate cloning and its potential in developing subunit vaccines against PCV2, contributing to the sustainable control of PCVAD in the swine industry.