Studies of properties of viral capsid proteins and development of recombinant vaccines and diagnostic components based on artificial viral structures

The aim of this study was to develop a system for easy production of different veterinary chimeric vaccines based on stable mouse polyomavirus (MPyV) structures. The system is designed for antigens that are problematic in production or stability. First, universal vectors for baculovirus-directed production of chimeric MPyV VLPs or pentamers based on the major capsid protein VP1 were designed to be exploited as vaccines against other pathogens. The different strategies used in this study are based on: A) exposure of selected immunogenic epitopes on the surface of MPyV VLPs by inserting them into a surface loop of the VP1 protein, B) insertion of foreign protein molecules inside the VLPs, or C) fusion of a foreign protein or its part with the C-terminus of VP1 protein, thus forming giant pentamers of a chimeric protein. Candidate vaccine antigens against porcine circovirus 2 (PCV2), the causative agent of porcine circovirus 2 systemic diseases (PCV2-SD) which causes significant economic losses in swine breeding, were prepared using the constructed vectors. All candidate vaccines induced the production of antibodies against the capsid protein of PCV2 after immunization of mice. The candidate vaccine Var C based on fusion of MPyV and PCV2 capsid proteins, is able to induce production of antibodies with..