Maize, commonly called corn in the US, is the third most important cereal in the world. It has a great number of advantages for molecular agriculture such as its capacity to express recombinant proteins in the seeds, its widespread cultivation and its genetic diversity, along with being anti-allergenic and non-toxic.
Now scientists from the Universidad de Lleida (University of Lleida) have published a study (1) confirming that maize seeds are an effective and sure platform within molecular agriculture to alleviate diseases. Over the next few years AIDS could be one of the first diseases to benefit from these results, although regulations for this technology are being developed at the same time as research is being undertaken.
In March, transgenic maize became the first plant to be developed commercially for medical use. The PNAS article (2) published the following findings: a maize seed with genes from the 2G12 antibody (already known for its capacity to neutralise infection from the virus) could produce antibodies against the transmission of HIV. Researchers from the Departamento de Producción Vegetal y Ciencia
Forestal [Department of Plant Production and Forest Science] at the Universidad de Lleida, were those who actually designed this drug during an international project known as Pharma-Planta (made up of 39 European and South African teams), and headed by Paul Christou.
Currently, the same team of scientists from the Universidad de Lleida who took part in the research have made “a more practical and productive approach to evaluate the ecological and toxicological risks, in which a scientific problem refers to a significant, final evaluation, and the hypotheses of risk predict effects in which the final evaluation is not a transformed plant, but the product resulting from that plant”, Paul Christou told The Scientific Information and News Service (Servicio de Información y Noticias Científicas - SINC).
According to the researchers, the use and genetic modification of plants for the production of protein-based drugs is useful for the treatment, prevention and early detection of human and animal diseases, as well as for the production of vaccines against tuberculosis, diabetes and rabies. Paul Christou states that “In the last two decades, plants have been shown to be an excellent alternative for the production of medicines in laboratory research”.
Until now, conventional methods using microbial systems and animals have been used in the production of drugs and involve high costs and limits in terms of safety and stability. Amongst other things, excessively high prices prevent the people in most need from accessing pharmaceutical drugs, as the study shows. “Plants offer a solution to the problem because pharmacological production using maize is cheaper”, Paul Christou points out to SINC. Paul Christou is also a member of the European Union Expert Committee on Food Safety.
In addition to the price, the proteins produced in maize seeds can remain intact for many years without the need for refrigeration, thus enabling vaccines to be delivered to countries such as those situated in the Tropics and Sub-Saharan Africa.
Risks that plants can present
The risks of the open farming of plants for the production of molecules for pharmaceutical use relate to their impact on the environment through the gene flow, and their impact on the health of animals and humans through inadvertently consuming these. The research team has decided that the regulation processes “should be applied in proportion to the risks of each individual case”, as some plants farmed for the production of pharmaceutical drugs are harmless and others vary in their toxicity. In every case a level of risk acceptance has to be established in order to avoid the consequences of any possible exposure.
Paul Christou points out that “the gene flow per se should not be considered “bad” for the environment”. He asserts that should this be developed on a commercial basis (anticipated within the next five years), all pharmacological production of maize will be undertaken in specialised locations, “where any risk of gene flow will be unlikely”.
(1) Ramessar K, Sabalza M, Capell T, Christou P. “Maize plants: An ideal production platform for effective and safe molecular pharming” Plant Science 174(4): 409-419 APR 2008
(2) Koreen Ramessar, Thomas Rademacher, Markus Sack, Johannes Stadlmann, Dimitris Platis, Gabriela Stiegler, Nikos Labrou, Fritz Altmann, Julian Ma, Eva Stöger, Teresa Capell, y Paul Christou. “Cost-effective production of a vaginal protein microbicide to prevent HIV transmission” PNAS 105(10): 3727-3732 MAR 2008