Alliance will make proteins from plants

Germany's Icon Genetics and Israeli firm Protalix are to collaborate on a way of hiking protein expression in plant cells to improve their use a production vehicle for recombinant proteins.

Interest in using plants as biological production systems stems from their theoretic advantages over commonly-used systems such as Escherichia coli and yeast, including the ability to make a broader range of proteins with more complex modifications.

However, the use of plant cells has historically been held back by limitations in getting expression levels to a level that makes plant production commercially viable, and it is this obstacle that the new alliance hopes to tackle.

The two-year collaborative research programme will combine Icon's amplification technologies with Protalix' expression systems for plant cell cultures grown in bioreactors.

Icon's technology makes use of amplicon sequences from a chromosome of a plant cell to amplify the expression of the gene of interest while simultaneously shutting off other biosynthetic processes in the cell. Theoretically, this should result in the highest possible yield of the protein, as well as a higher relative yield compared to other proteins that should make separation and purification easier.

Meanwhile, Protalix' role will be to assess the capacity of the clones developed by Icon to be scaled up in its bioreactor systems, evaluating their potential for commercial scale production of biopharmaceuticals.

The Israeli company - formerly known as Metabogal - specialises in using plant cells for bioproduction, and recently signed an agreement with Ferring Pharmaceuticals to make a number of therapeutic proteins.

Protalix claims that production costs are substantially lower using its systems than for mammalian cell-based systems, as well as transgenic plant-based systems using field-grown plants.

A recent report from Bio-Era on crop biomanufacturing found that crop biomanufacturing has significant advantages in production costs over rival systems, as crops are already produced by a 'competitive and efficient agricultural-industrial complex', and the capital needed for new production capacity is much lower than for mammalian culture or fermentation.

Protalix technology is based on the use of small, disposable plastic bioreactors that can support plant cells on aqueous media consisting of highly purified water and defined inorganic nutrients. Media costs are lower than for mammalian cell culture and fermentation, and because all the components of the system are fixed it is easier to separate and purify the target protein, reducing downstream processing costs.

In addition, there are no known risks of contamination from animal, bacterial, or viral pathogens in an enclosed plant-based system, Protalix points out.