Frequently Asked Questions
Q. What is Pharma-Planta?
Pharma-Planta is a research consortium representing 39 academic and industrial institutions in Europe and South Africa. It is funded by the European Union under the Framework 6 programme for Research and Development. Its focus is the development of strategies for the production of pharmaceutical proteins in plants.
Q. What is 'molecular farming in plants'?
This can be defined as the use of agricultural plants for the production of useful molecules for non food, feed or fibre applications. In most cases, this means medically-relevant molecules such as recombinant human proteins, antibodies and vaccines, but it can also include enzymes, novel polymers and technical reagents. Plants are already grown to produce valuable molecules, including many drugs. Molecular farming is different because the plants are genetically modified to enable them to produce the molecules we want them to.
Q. What are 'recombinant human proteins'?
A lot of the proteins our bodies make have medical uses (think of insulin, which is used to treat diabetes, and growth hormone, which is used to treat growth disorders). In the past, such proteins were recovered from human cadavers or isolated from animals, but this was risky because the proteins were often contaminated with viruses and other disease-causing agents. Recombinant human proteins are produced in genetically modified cells. The human gene is transferred into these cells, and they produce the corresponding protein efficiently and safely.
Q. Why use plants?
Many pharmaceutical proteins and industrial enzymes have been produced by genetically engineered microbes and cultured mammalian cells, but these systems have two major problems. First, proteins that are made in microbes are often not exactly the same as the human counterparts, because the cells lack the ability to synthesize all the correct components. Second, mammalian cells are very expensive to grow and they still may harbour viruses. Because of this there is a severe lack of production capacity throughout the world, and expensive processing and purification methods are required to ensure the final product is free of disease-causing agents. Plants are able to produce authentic recombinant proteins, agricultural production is inexpensive and unlimited in scale, and many plants are considered to be safe based on the fact that we eat them every day without ill effects.
Q. Given these advantages, will all therapeutic proteins eventually be produced by molecular farming?
No. While many therapeutic proteins can be produced in plants, others cannot. In some cases, the proteins cannot be synthesized properly in plant tissues, while in other cases the costs are too high. Generally, the costs of production by molecular farming in plants are lower than other production systems, but the cost of recovering functional products may be too high in some cases to make production economically feasible.
Q. Are there specific advantages to producing vaccines in plants?
Yes. Vaccines produced in plants are very stable, particularly those expressed in seeds and fruits, which means that it will be far easier to store and distribute them in parts of the developing world where refrigerators and freezers are difficult to come by. Also, plants offer the perfect medium for administering oral vaccines both to adults and children.
Q. Is plant molecular farming going on already in Europe?
While there is no commercial molecular farming in Europe at the current time, there have been some field trials to study the advantages and disadvantages of different production systems.
Q. Are plants used for molecular farming safe for the environment?
There is a lot of debate, particularly in Europe, about the potential risks of genetically modified plants in the environment. An additional issue in the case of molecular farming is that the plants will contain products that may have potent pharmacological effects in humans and animals that consume them. For this reason, decisions to consider molecular farming crops for confined or unconfined release are treated very carefully, and the risks and potential impacts of all plants and their novel traits are thoroughly evaluated. The Pharma-Planta consortium works closely with regulatory bodies and other interested parties to ensure safety through rigorous research, sound scientific evidence and reasoning.
Q. Are there human health impacts of plants used for molecular farming?
Some plants used for molecular farming may produce pharmaceutical proteins that affect human health following accidental ingestion or contact with the skin. Some field tests of such plants have been carried out in confinement to ensure that the plant material does not enter human food or animal feed supplies. Occupational safety is considered in the authorization of these field trials. The health impacts of the products of molecular farming are addressed in detail through human clinical trials. This is identical to the procedures used to assess the clinical efficacy and safety of any other type of drug, and it is notable that more than 25% of our current drugs are derived from plants.