Molecular pharming: a global revolution for biotechnologies

Recombinant proteins represent important synthetic products used in different fields such as medical treatment, vaccines, diagnostic tools and enzymes for industries. For several years the production was performed using bacteria or cell cultures, which however show several limitations. For this reason, a newly emerging technique based on plants, molecular pharming, has aroused great interest. Some common disadvantages related to recombinant protein production in bacteria and cell cultures are present. Bacteria do not perform post-translation modifications and produce endotoxins that are toxic to humans. Cell cultures instead are prone to be infected by pathogens that limit protein production and the post-translation modifications are not optimal. Both techniques are very expensive, and the scale-up production is difficult to be achieved due to the limited effectiveness of equipment. Molecular pharming consists of the production of recombinant proteins in plants. This technology overcomes the problems related to the previous techniques because plants are not susceptible to animal pathogens, guarantee higher production and the process is less costly. Over the years the yield of recombinant protein produced with molecular farming has improved. It has been demonstrated that by optimizing the viral vector in the promoter, coding, and untranslated regions (UTRs) the yield of recombinant proteins improves. By using different viruses to build these ameliorated vectors, it is possible to obtain the expression of different recombinant proteins simultaneously. The same increased yield can be obtained by silencing the seed storage proteins. In this way, recombinant proteins are more produced inside the seeds, which protect proteins from degradation at atmospheric temperatures. These two approaches use Agrobacterium tumefaciens as viral vectors delivery system, but this method is limited to a narrow number of species. Nanotechnology offers the possibility to produce recombinant proteins in a plant species-independent manner, extending the possibility to express recombinant proteins in more plant species. Molecular farming may represent a new technique which has the potential to increase and ameliorate the recombinant production yield and quantity. This more effective production paves the road to wider and more accessible, also in middle-income countries, use of recombinant proteins-based therapies.