Submitted to: Archives of Virology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/14/2005
Publication Date: 12/14/2005
Citation: Natilla, A., Hammond, R., Nemchinov, L.G. 2005.Epitope presentation system based on cucumber mosaic virus coat protein expressed from a potato virus x-based vector. Archives of Virology. 15:1373-1386. Interpretive Summary: The need for large quantities of safe and effective vaccines for human and animal diseases has prompted the development of plants which can be genetically engineered to produce certain antiviral proteins. Those proteins could then be harvested from plants and used to make vaccines. We have developed such a system for production of candidate vaccines for Newcastle Disease Virus, an economically important pathogen of poultry. Our system uses a common potato virus, which is engineered to contain and express the vaccine proteins. When the potato virus infects the plant that we are using, it begins to make copies of the protein. This system may be a valuable tool for expression of large quantities of protein foreign to the plant host, but useful as vaccines or against other microbial organisms. These results will be of interest to plant and animal researchers, and representatives of industry, academia, and government organizations with an interest in plant-based systems for production of vaccines, immunology, and veterinary health.
Technical Abstract: The Cucumber mosaic virus Ixora isolate (CMV) coat protein gene (CP) was placed under the transcriptional control of the duplicated subgenomic CP promoter of a Potato virus X (PVX)-based vector. In vitro RNA transcripts were inoculated onto Nicotiana benthamiana plants and recombinant CMV capsid proteins were identified on Western blots probed with CMV antibodies 5-7 days post-inoculation. PVX-produced CMV CP subunits were capable of assembling into virus-like particles (VLPs), which were visualized by electron microscopy. We further used the PVX/CMVCP system for transient expression of recombinant CMV CP constructs containing different neutralizing epitopes of Newcastle Disease Virus (NDV) engineered into the internal ÿH-ÿI (motif 5) loop . Both crude plant extracts and purified VLPs were immunoreactive with CMV antibodies as well as with epitope-specific antibodies to NDV, thus confirming the surface display of the engineered NDV epitope. Our study demonstrates the potential of PVX/CMVCP as an expression tool and as a presentation system for promising epitopes.