Journal of Vaccines & Vaccination

Efficient expression of porcine circovirus type 2 virus-like particles in Escherichia coli

15^th Annual Summit on Vaccines and Immunization

February 20-21, 2017 Berlin, Germany

Guanggang Qu

Shandong Binzhou Animal Science and Veterinary Medicine Academy, China

Scientific Tracks Abstracts: J Vaccines Vaccin

Abstract:

Porcine circovirus 2 (PCV2) is considered to be the etiologic agent responsible for porcine circovirus associated disease (PCVAD) that frequently affects growing pigs at 5-18 weeks of age and can lead to significant negative impacts on profitability of pork production. The capsid (Cap) protein of PCV2 is a major candidate antigen for development of recombinant vaccine and has been successfully used as a vaccine to control porcine circovirus associated disease (PCVAD). In our study, full-length ORF2 gene with codon-optimized for E. coli was synthesized and inserted into the PTF9 (+) expression vector to improve expression of recombinant Cap protein (rCap). A large amount of soluble rCap protein was obtained. The recombinant Cap protein expressed by Escherichia coli (E. coli) has the ability to self-assemble into virus-like particles (VLPs) in vitro; it is particularly an opportunity to develop the PCV2 VLPs vaccine in E coli. In this report, a highly soluble Cap-tag protein expressed in E coli was constructed with a p-TF9 expression vector with a fusion tag of TF9. The recombinant Cap was purified using Ni2+ affinity resins and the tag was removed by the TEV protease. Simultaneously, the whole native Cap protein was able to self-assemble into VLPs in vitro when viewed under an electron microscope. The Cap-like particles had a size and shape that resembled the authentic Cap. The result could also be applied in the large-scale production of VLPs of PCV2 and could be used as a diagnostic antigen or a potential VLP vaccine against PCV2 infection in pigs. We have, for the first time, utilized the Fh8 fusion motif to successfully express the complete Cap protein of PCV2 in E coli. After the cleavage of the fusion motif, the nCap protein self-assembled into VLPs, which can be used as a potential vaccine to protect pigs from PCV2-infection.

Biography :

Guanggang Qu is interested in Preventive Veterinary Medicine, Veterinary Biotechnology and Biological Products. He is particularly interested in developing innovated vaccines by E. coli expression system. Currently, he is an Assistant Professor at Shandong Binzhou Animal Science & Veterinary Medicine Academy and Vice Director at Shandong Binzhou Research and Development Centre of propolis vaccine for livestock and poultry. He was a Visiting Scientist at Bhabha Atomic Research Centre and at U.S. Department of Agriculture of USA from 2011 to 2013. He completed his Doctoral Degree at Jilin University, China.

Email: guanggangqu@163.com