Chloroplasts as expression platforms for plant-produced vaccines

Abstract

Production of recombinant subunit vaccines from genes incorporated in the plastid genome is advantageous because of the attainable expression level due to high transgene copy number and the absence of gene silencing; biocontainment as a consequence of maternal inheritance of plastids and no transgene presence in the pollen; and expression of multiple transgenes in prokaryotic-like operons. We discuss the core technology of plastid transformation in Chlamydomonas reinhardtii, a unicellular alga, and Nicotiana tabacum (tobacco), a flowering plant species, and demonstrate the utility of the technology for the production of recombinant vaccine antigens.

Expression of Glycosyl Hydrolases in Lignocellulosic Feedstock: An Alternative for Affordable Cellulosic Ethanol Production

“…Plastid transformation takes advantage of the large number of multi-genome plastids in a plant cell [66,67]. After integration of the desired genes into the plastid genome, genes of interest will replicate during plastid replication and cell division, resulting in the desired gene being highly transcribed and the desired protein produced at a high level.…”

Transplastomic plants for innovations in agriculture. A review

“…Alterations of the plastid genome represent a promising possibility for high-level, clean, and safe expression of proteins (and other products) in cost-effective commercial applications. The advantages and challenges of plant molecular pharming are extensively reviewed elsewhere Daniell 2006;Bock 2007Bock , 2014Verma and Daniell 2007;Chebolu and Daniell 2009;Rybicki 2009;Bock and Warzecha 2010;Cardi et al 2010;Meyers et al 2010;Wani et al 2010;Lössl and Waheed 2011;Maliga and Bock 2011;Obembe et al 2011;Scotti et al 2012;Ahmad and Mukhtar 2013). Although several plastid-derived vaccine antigenes have already been tested in animal models (Lössl and Waheed 2011), to our knowledge no transplastomic plants have been licensed for biopharmaceutical use (Section 4).…”

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

“…Another breakthrough in the field of tomato genetic transformation was the development of a system for stable genetic transformation of tomato plastids (Ruf et al, 2001). In comparison with conventional nuclear transformation, the integration of transgenes in the plastid genome presents several advantages: 1) high expression levels of recombinant proteins attainable owing to the high ploidy level of the plastid genome (up to 10,000 plastid genomes per cell); 2) efficient transgene integration since integration into the plastid genome relies on homologous recombination between the targeting regions of the transformation vector and the wild-type plastid DNA; 3) absence of epigenetic effects (gene silencing); 4) increased biosafety due to the biological containment of transgenes and recombinant products owing to maternal inheritance of plastid and plastid transgenes and absence of dispersal in the environment through the pollen; 5) possibility to express multiple transgenes from prokaryotic-like operons, thus simplifying engineering metabolic pathways (Bock & Warzecha;Cardi et al, 2010;Ruf et al, 2001;Wurbs et al, 2007). The availability of a technology for transgene expression from the tomato plastid genome opened up new possibilities for metabolic engineering and the use of plants as bioreactors for the production of pharmaceuticals (Ruf et al, 2001, Wurbs et al, 2007.…”