Scope for using plant viruses to present epitopes from animal pathogens

Abstract

Epitope presentation to the immune system for vaccination purposes can be achieved either via an inactivated or attenuated form of a pathogen or via its isolated antigenic sequences. When free, these peptides can adopt a variety of conformations, most of which will not exist in their native environment. Conjugation to carrier proteins restricts mobility of the peptides and increases their immunogenicity. A high local concentration of epitopes boosts the immune response further and can be generated by the use of self‐aggregating carriers, such as the capsid proteins of viruses. In this regard plant viruses have in recent years started to make an impact as safer alternatives to the use of bacterial and attenuated animal viruses: the latter both require propagation in costly cell‐culture systems where they can undergo reversion towards a virulent form and/or become contaminated by other pathogens. Plant virus‐based vectors can be multiplied cheaply and to high yields (exceeding 1 mg/g plant tissue) in host plants. Both helical (tobacco mosaic virus, potato virus X, alfalfa mosaic virus) and icosahedral (cowpea mosaic virus, tomato bushy stunt virus) particles have been used to express a number of animal B‐cell epitopes, whose immunogenic properties have been explored to varying degrees. © 1998 John Wiley & Sons, Ltd.

Production of Japanese Encephalitis Virus Antigens in Plants Using Bamboo Mosaic Virus-Based Vector

“…Firstly, BaMV has a narrow host range in nature, and therefore is ecologically safer for field use (Hsu and Lin, 2004), minimizing the concern for environmental contaminations. Secondly, by the incorporation of FMDV 2A peptide, BaMV-based epitope-presentation vector was stable over long-term successive passages, as opposed to the previously described systems (Porta and Lomonossoff, 1998; Porta et al, 2003; Lico et al, 2006). Thirdly, the plant, C. quinoa , used for the production of JEV subunit vaccine candidate is a widely cultivated crop (Bhargava et al, 2006), and poses minimal safety concern in animals.…”

“…However, the production of antigens using plant viral vectors is hindered by several common limitations that stem from the interference of the normal biological functions of viral proteins by the fused peptides. These problems include: (1) the reliability of epitope presentation affected by the nature and sizes of foreign peptides (e.g., Bendahmane et al, 1999; Jiang et al, 2006; Uhde-Holzem et al, 2010; Zhang et al, 2010); (2) mutual restriction between encoding recombination virus RNA and the chimeric CP (e.g., Rao, 2006; Schneemann, 2006), and virus-host interactions (e.g., Porta et al, 2003; Ahlquist et al, 2005; Chen et al, 2007); (3) the stability of the foreign fragments over long-term successive passages (e.g., Porta and Lomonossoff, 1998; Porta et al, 2003; Lico et al, 2006); (4) reduced efficiency for virion assembly caused by special structural features of the chimeric CP (e.g., Canizares et al, 2005), and (5) the changes in virion morphology and stability due to cysteine residues in the foreign peptide (e.g., Li et al, 2007). Likewise, the construct pBJ, harboring direct fusion between JEV EDIII and BaMV CP, was not infectious, and the fusion protein was not detected in inoculated plants ( Figures 1C, 2 ).…”

The Art of Engineering Viral Nanoparticles

“…The advantages of expressing such proteins in planta using viral vectors include the absence of contamination with animal products, the low production costs and the high yields. 7–11 …”

Engineering DNA Vaccines that Include Plant Virus Coat Proteins

“…ItnportantlYt plant viral CPs have been used to promote antibody responses to linked B cell epitopes in a number of models of infectious diseases (Turpen et ai., 1995;Dalsgaard et al, 1996). The ability of such proteins to selfassemble into viral-like particles in the absence of viral RNA made them the Inolecules ofchoice for multiple presentation ofdefined B cell epitopes on the surface of large particles (review: Porta and Lomonossoff, 1998). This type of chimeric ItloIecu)e induces potent immune responses, even without the addition of an adjuvant (McInerney el aI., 1999).…”