Self-assembly of virus-like particles of porcine circovirus type 2 capsid protein expressed from Escherichia coli

Abstract

BackgroundPorcine circovirus 2 (PCV2) is a serious problem to the swine industry and can lead to significant negative impacts on profitability of pork production. Syndrome associated with PCV2 is known as porcine circovirus closely associated with post-weaning multisystemic wasting syndrome (PMWS). The capsid (Cap) protein of PCV2 is a major candidate antigen for development of recombinant vaccine and serological diagnostic method. The recombinant Cap protein has the ability to self-assemble into virus-like particles (VLPs) in vitro, it is particularly opportunity to develop the PV2 VLPs vaccine in Escherichia coli,(E.coli ), because where the cost of the vaccine must be weighed against the value of the vaccinated pig, when it was to extend use the VLPs vaccine of PCV2.ResultsIn this report, a highly soluble Cap-tag protein expressed in E.coli was constructed with a p-SMK expression vector with a fusion tag of small ubiquitin-like modifiers (SUMO). The recombinant Cap was purified using Ni2+ affinity resins, whereas the tag was used to remove the SUMO 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.Conclusionwe have, for the first time, utilized the SUMO fusion motif to successfully express the entire authentic Cap protein of PCV2 in E. coli. After the cleavage of the fusion motif, the nCap protein has the ability to self-assemble into VLPs, which can be used as as a potential vaccine to protect pigs from PCV2-infection.

Development and characterization of Rift Valley fever virus-like particles

“…Additionally, the VLP vaccine Hecolin, which was developed by Innovax Biotech (Xiamen, China) for the prevention of hepatitis E viral infection, was approved in China in 2011. In the veterinary field, market approval has been obtained for porcine circovirus type 2 VLPs (Intervet International, Netherlands) (Yin et al, 2010), whereas VLPs of other animal viruses such as those of the avian flu virus (Lee et al, 2011), foot-and-mouth disease virus (Guo et al, 2013), and bluetongue virus (Roy, 2003) have also shown the potential for commercialization. VLP vaccines for various other viruses remain under development or are currently in clinical trials (Chackerian, 2007).…”

Functional Virus-Like Particles Production Using Silkworm and Their Application in Life Science

“…In this case, in vitro assembly has yielded murine polyomavirus VP1VLPs that have a diameter of ~50 nm after GST cleavage. Porcine circovirus type 2 capsid protein fused with small ubiquitin like modifiers (SUMOs) is self-assembled in vitro after SUMO cleavage [33]. Porcine circovirus type 2-capsid protein can also be assembled in E.coli [34].…”

Two-phase flow analogy as an effective boundary condition for modelling liquids at atomistic resolution

“…As a member of the family Circoviridae, genus Circovirus, PCV2 has small nonenveloped icosahedral virus shell with a single-stranded circular DNA genome inside. The genome contains two major open-reading frames (ORFs), where ORF1 encodes the replicase proteins (Rep, Rep') and ORF2 encodes the capsid protein (Cap) [12,15,16]. The capsid protein can spontaneously assemble into empty PCV2-like particles.…”