A tobamovirus expression vector for agroinfection of legumes and Nicotiana
JOURNAL OF BIOTECHNOLOGY
Authors: Liu, Zun; Kearney, Christopher M.
Abstract
The highest recombinant protein expression levels in plants have been achieved using tobacco mosaic virus (TMV) vectors via agroinoculation of the tobacco, Nicotiana benthamiana. These vectors have been utilized for pharmaceutical protein production and also can serve as rapid gene expression screens for proteonomics. We have constructed a similar vector based on the legume-infecting tobamovirus, sunn hemp mosaic virus (SHMV), by deleting the coat protein gene (SHMV eliminate coat protein gene or SHEC). SHEC/GFP co-agroinoculated with a 35S/p19 binary yielded 600 mu g GFP/gfw (25% TSP) in N. benthamiana. In the absence of p19. SHEC/GFP expression was nearly eliminated. SHEC also yielded strong GUS production in agroinoculated Medicago trunculata, Pinto bean, cowpea, pea and lentil even without the aid of systemic infection. A full-length version (SHAC, SHMV alternate coat protein) was created by adding to SHEC the coat protein subgenomic promoter and ORF from the tobamovirus, tobacco mild green mottle virus (TMGMV). SHAC induced a slowly developing, symptomless infection of N. benthamiana and may be of use as a virus induced gene silencing (VIGS) vector. (C) 2010 Elsevier B.V. All rights reserved.
Plant-Based Vaccines: Novel and Low-Cost Possible Route for Mediterranean Innovative Vaccination Strategies
ADVANCES IN VIRUS RESEARCH, VOL 89
Authors: Aboul-Ata, Aboul-Ata E.; Vitti, Antonella; Nuzzaci, Maria; El-Attar, Ahmad K.; Piazzolla, Giuseppina; Tortorella, Cosimo; Harandi, Ali M.; Olson, Olof; Wright, Sandra A.; Piazzolla, Pasquale
Abstract
A plant bioreactor has enormous capability as a system that supports many biological activities, that is, production of plant bodies, virus-like particles (VLPs), and vaccines. Foreign gene expression is an efficient mechanism for getting protein vaccines against different human viral and nonviral diseases. Plants make it easy to deal with safe, inexpensive, and provide trouble-free storage. The broad spectrum of safe gene promoters is being used to avoid risk assessments. Engineered virus-based vectors have no side effect. The process can be manipulated as follows: (a) retrieve and select gene encoding, use an antigenic protein from GenBank and/or from a viral-genome sequence, (b) design and construct hybrid-virus vectors (viral vector with a gene of interest) eventually flanked by plant-specific genetic regulatory elements for constitutive expression for obtaining chimeric virus, (c) gene transformation and/or transfection, for transient expression, into a plant host model, that is, tobacco, to get protocols processed positively, and then moving into edible host plants, (d) confirmation of protein expression by bioassay, PCR-associated tests (RT-PCR), Northern and Western blotting analysis, and serological assay (ELISA), (e) expression for adjuvant recombinant protein seeking better antigenicity, (f) extraction and purification of expressed protein for identification and dosing, (g) antigenicity capability evaluated using parental or oral delivery in animal models (mice and/or rabbit immunization), and (h) growing of construct-treated edible crops in protective green houses. Some successful cases of heterologous gene-expressed protein, as edible vaccine, are being discussed, that is, hepatitis C virus (HCV). R9 mimotope, also named hypervariable region 1 (HVR1), was derived from the HVR1 of HCV. It was used as a potential neutralizing epitope of HCV. The mimotope was expressed using cucumber mosaic virus coat protein (CP), alfalfa mosaic virus CP P3/RNA3, and tobacco mosaic virus (TMV) CP tobacco mild green mosaic virus (TMGMV) CP as expression vectors into tobacco plants. Expressed recombinant protein has not only been confirmed as a therapeutic but also as a diagnostic tool. Herpes simplex virus 2 (HSV-2), HSV-2 gD, and HSV-2 VP16 subunits were transfected into tobacco plants, using TMV CP TMGMV CP expression vectors.