Cucumber mosaic virus as carrier of a hepatitis C virus-derived epitope

Abstract

Cucumber mosaic virus (CMV) is a three component isodiametric plant virus which is common worldwide and has an extremely wide host range. A pseudorecombinant was made, derived from the RNA3 component of the CMV-S strain, carrying the coat protein (CP) gene, and the RNA1,2 components of the CMV-D strain. This system developed mild mosaic and vein clearing in Xanthi tobacco three weeks after inoculation. The CP gene was then engineered in three different positions, to encode a Hepatitis C virus (HCV) epitope. The selected peptide was the so-called R9 mimotope, a synthetic surrogate derived from a consensus profile of many hypervariable region 1 (HVR1) sequences of the putative HCV envelope protein E2. Serum samples from 60 patients with chronic hepatitis C displayed a significant immunoreactivity to crude plant extracts infected with the chimeric CMV. These results suggest that further investigation should be made into a possible vaccine function for the CMV-HCV mimotope system.

Novel Plant Virus-Based Vaccine Induces Protective Cytotoxic T-Lymphocyte-Mediated Antiviral Immunity through Dendritic Cell Maturation

“…By genetically modifying these viruses, immunogenic peptides can be fused efficiently to the coat protein (CP) and exposed on the surfaces of the assembled plant VLPs. To date, cowpea mosaic virus, tobacco mosaic virus, alfalfa mosaic virus, potato virus C, tomato bushy stunt virus, zucchini yellow mosaic virus, and plum pox virus are all examples of plant viruses that have been produced successfully and used for the presentation of murine and human epitopes (6,7,22).…”

Development of a candidate vaccine for Newcastle disease virus by epitope display in the Cucumber mosaic virus capsid protein

“…CMV is a wide host range virus that accumulates to significant levels in infected leaves of host plants, depending on the strain of CMV and the host (Palukaitis et al 1992), and its CP has been shown to accommodate a foreign peptide fusion of 27 aa (Natilla et al 2004). As the atomic structure of CMV is known, one can design fusion proteins in which foreign peptides are exposed on the surface of the virion (Smith et al 2000).…”

“…Although addition of the F and HN epitopes does not significantly affect the overall pI of the coat protein, local changes in the loop may occur as the pI of the F epitope is 8.1, the pI of HN is 4.1, and the pI of HN2 is 3.9. Natilla et al (2004) stably expressed a 27 aa peptide epitope with a pI of 10.04 in this loop, therefore, instability of the HN epitope, and non-infectivity of the HN2 construct cannot be explained solely based on size of the insertion or charge of the epitope. Instability of epitopes in CPMV were found to occur by proteolytic cleavage (Taylor et al 1999), or amino acid changes that collectively reduced the pI of the inserted peptide (Porta et al 2003).…”

Immune Reactivity of Synthetic Peptides Originated from Hypervariable Region 1 of Hepatitis C Synthetic Consensuses with Egyptian Sera Infected with Hepatitis C Virus Type 4

“…In another study, the R9 HVR1 peptide was used for displaying on several plant viruses such as the icosahedral particles of cucumber mosaic virus [46] where it elicited a specific humoral response in rabbits [47] , and it has been expressed in tobacco mosaic virus as a C-terminal fusion with the cholera toxin B subunit, under the control of the tobacco mosaic virus subgenomic promoter [48] .…”