The use of whole plants (N. tabacum, N. benthamiana, Lemna minor, rice cell culture, Arabidopsis thaliana, Medicago sativa, lettuce and maize) for the production of recombinant proteins has been recently a great focus of attention because of many inner advantages compared to traditional microbial and mammalian expression systems ; its includes economics, scalability and safety.
However, the difficulties to manufacture recombinant proteins in compliance with cGMP requirements (current Good Manufacturing Practices), the lack of precise control over cell culture conditions and the poor batch-to-batch product consistency remain major bottlenecks for a large adoption of whole plant expression system. That’s why several companies have decided to develop suspension plant clones, especially monoclonal BY-2 tobacco stable cell lines, also with in N. benthamiana transient expression system thanks to the use of Agrobacterium tumefaciens for transient transfection.
Nicotiana tabacum suspension cells have consequently been tested to produce monoclonal antibodies, but the yield of secreted antibodies is usually low because of post-translational proteolysis. Differences in the glycosylation pattern (in particular β1,2-xylose and α1,3-fucose) between mammalian and plants cell lines are also one of the major concerns scientists have to face when developing therapeutic antibodies expressed in plants.
AmplyCell is currently working on a promissing R&D project called Mabvert, in order to stimulate Plant cells.