Expression of porcine circovirus (PCV) 1 and 3 capsid proteins

• Grant number: 19/12252-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2020
• End date: February 28, 2021
• Field of knowledge: Biological Sciences - Biophysics - Molecular Biophysics
• Principal Investigator: Otavio Henrique Thiemann
• Grantee: Tamiris de Souza Rocha
• Host Institution: Instituto de Física de São Carlos (IFSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

The porcine circovirus (PCV) is the main cause of the postweaning multisystemic wasting syndrome (PMWS). Three species are currently known, named PCV1, PCV2 and more recently PCV3. PCV1 does not cause pathology in pigs, with PCV2 and PCV3 being the main etiological agents causing a severe economic impact on the world suine production. A vaccine for PCV2 prevention is available, but the onset of PCV3 and its rapid spread without a form of treatment and prevention are alarming factors. This proposal aims at the heterologous expression of the PCV1 and PCV3 capsid protein for the generation of virus-like particles (VLP). These VLPs will be employed in the structural characterization by X-ray diffraction of monocrystals and/or cryo-electron microscopy. These structures will be compared to the available structure of PCV2 (PDB accession number 3JCI and 3R0R) to determine structural differences between the species. Preliminary results were obtained, where expression in Escherichia coli cells was achieved and purification protocols are being established. This project may lead to the production of specific vaccines for the prevention of PCV3 or pluripotent vaccines against PCV2 and PCV3 infections and is of interest to national companies such as OuroFino Saúde Animal.