Title:Therapeutically Important Proteins From In Vitro Plant Tissue Culture Systems
Volume: 20
Issue: 8
Author(s): Pauline M. Doran
Affiliation:
Keywords:
Disposable bioreactor, host plant species, oral delivery, plant cell culture, protein adsorption, protein stability, proteolysis, Plant cells, Plant Tissue, biopharmaceutical
Abstract: Plant cells cultured in liquid medium in bioreactors are now being used commercially to produce biopharmaceutical proteins.
The emergence of in vitro plant cell culture as a production vehicle reflects the importance of key biosafety and biocontainment concerns
affecting the competitiveness of alternative systems such as mammalian cell culture and agriculture. Food plant species are particularly
attractive as hosts for in vitro protein production: the risk of transgene escape and food chain contamination is eliminated using containment
facilities, while regulatory approval for oral delivery of drugs may be easier than if non-edible species were used. As in whole
plants, proteolysis in cultured plant cells can lead to significant degradation of foreign proteins after synthesis; however, substantial progress
has been made to counter the destructive effects of proteases in plant systems. Although protein secretion into the culture medium is
advantageous for product recovery and purification, measures are often required to minimise extracellular protease activity and product
losses due to irreversible surface adsorption. Disposable plastic bioreactors, which are being used increasingly in mammalian cell bioprocessing,
are also being adopted for plant cell culture to allow rapid scale-up and generation of saleable product. This review examines a
range of technical and regulatory issues affecting the choice of industrial production platform for foreign proteins, and assesses progress
in the development of in vitro plant systems for biopharmaceutical production.
