Tomato is a highly effective vehicle for expression and oral immunization with Norwalk virus capsid protein

Abstract

SummaryNorwalk virus (NV) is an important agent of epidemic gastroenteritis, and an oral subunit vaccine shows potential for protection. Recombinant Norwalk virus (rNV) capsid protein expressed in plants assembles virus-like particles (VLPs) that are orally immunogenic in mice and humans. In this article we examine rNV expression in tomato and potato using a plant-optimized gene, and test the immunogenicity of dried tomato fruit and potato tuber fed to mice. The synthetic gene increased rNV expression fourfold in tomato and potato plants, which assembled VLP. Four doses of 0.4 g freeze-dried tomato fruit containing 64 µ g rNV (40 µ g VLPs) induced NV-specific serum IgG and mucosal IgA in ≥ 80% of mice, while doses of 0.8 g elicited systemic and mucosal antibody responses in all mice. Feedings of 1 g freeze-dried potato tuber containing 120 µ g rNV (90 µ g VLPs) were required to produce 100% responsiveness. Oxidation of phenolic compounds upon rehydration of dried tuber caused significant VLP instability, thus decreasing immunogenicity. Air-dried tomato fruit stimulated stronger immune responses than freeze-dried fruit of the same mass, perhaps by limiting the destruction of plant cell matrix and membrane systems that occurs with freeze-drying. Thus, rNV in dried transgenic tomato fruit was a more potent immunogen than that in dried potato tubers, based on the total VLPs ingested. These findings support the use of stabilized, dried tomato fruit for oral delivery of subunit vaccines.

Genetic Diversity in Tomato (Solanum lycopersicum) and Its Wild Relatives

“…In the research field, transformation with Agrobacterium thumefaciens is still widely used for the functional characterization of specific genes. For instance, transformed tomato plants were produced to enable study of endotoxins genes (Zhang, Buehner et al 2006) plant disease resistance genes, abiotic stress genes or to produce molecules useful in human medicine (Sharma, Singh et al 2008).…”

High-Resolution X-Ray Structure and Functional Analysis of the Murine Norovirus 1 Capsid Protein Protruding Domain

“…Each capsid protein is divided into an N-terminal arm (N), a shell (S), and a C-terminal protruding (P) domain, with the last two domains connected by a short hinge. VP1 self-assembles into virus-like particles (VLPs) in baculovirus, mammalian, and plant expression systems (21,22,50,57,67). The S domain forms a smooth shell around the viral genome but is unable to bind to receptors (3, 55).…”

Genetic Transformation in Tomato: Novel Tools to Improve Fruit Quality and Pharmaceutical Production

“…Freeze-dried plant material could be stored for long time and consumed without cooking; in addition, this technique could allow to standardize and concentrate the plant-made vaccine. Several studies applied this technique to vaccine produced in transgenic tomato and demonstrated that freeze-dried produced stable formulations for oral delivery (Alvarez et al, 2006;Salyaev et al, 2010;Shchelkunov et al, 2006;Soria-Guerra et al, 2011;Zhang et al, 2006).…”