Production of Porcine Circovirus Type 2 Virus-Like Particles by an Attenuated Recombinant Pseudorabies Virus

Pseudorabies virus (PRV) and porcine circovirus type 2 (PCV2) are economically important swine viruses that cause pseudorabies (PR) and porcine circovirus-associated disease (PCVAD), respectively. Vaccination appears to be efficacious for PR eradication and control of PCVAD. Combining the PRV marker vaccine and the PCV2 immunogen in a single vaccine would reduce cost and stress on vaccination strategies. We constructed a glycoprotein E (gE)/thymidine kinase (tk) double-deletion pseudorabies virus (gE-tk-/PCV2cap+ PRV) containing PCV2 cap encoding the major capsid protein (Cap). The recombinant virus gE-tk-/PCV2cap+ PRV expressed PCV2 Cap proteins that self-assembled to form virus-like particles. Virulence of gE-tk-/PCV2cap+ PRV was completely attenuated in mice. Guinea pigs immunized with gE-tk- /PCV2cap+ PRV mounted significant antibody responses against PRV and PCV2. The recombinant virus has the potential to be developed into a candidate live, attenuated bivalent vaccine to simplify vaccination strategies.