GM maize to tackle HIV

The research concludes that GM maize is the most economically viable manufacturing facility for producing the large quantities of monoclonal antibodies needed to combat HIV. Previous efforts have centred upon production in mammalian cells but the lack of fermenter capacity or a cold chain in HIV-endemic areas means those most at need are likely to be excluded on economic grounds. Maize based production does not suffer from these shortcomings according to the researchers at Universitat de Lleida in Spain. Consequently they believe that transgenic maize could have a profound impact on the availability of therapeutic proteins in the developing world. The publication found maize "represents a remarkable opportunity to produce therapeutic antibodies inexpensively and on a massive scale, making it much more likely that antibody-based therapeutics could be made more widely available at a much lower cost than currently possible​." It goes on to say that HIV-endemic regions already have the infrastructure in place for large-scale cultivation and harvesting of transgenic maize. In addition the recombinant proteins which accumulate in the endosperm of the maize seeds are stable enough to not require refrigeration, negating the need for a cold chain. Some of the researchers involved in the HIV paper had previously said that maize can express virtually any protein, from "simple industrial polypeptides such as laccase, to vaccine subunits and even fully assembled complex antibodies​". This presents the possibility for widespread use of maize but the technology is not without critics. In the past some have claimed the technique produces small yields and that the biological properties of the product may not be equivalent to proteins produced in mammalian cells. However, the researchers claim that by resetting maize's methylation clock yield can be increased by 30 to 40 per cent, taking the total to an average of 75 µg per gram of dry seed weight. The antibody can then be extracted with 90 per cent efficiency. The researchers also did tests on the antibodies to investigate the validity of the bioequivalence criticism. They concluded that in functional terms maize derived antibodies displayed identical antigen-binding activity but nearly three times the efficacy in HIV-neutralization assays. The success of future research and the attitudes of regulatory bodies and the public will impact on the extent to which biomanufacturing is adopted but for now it remains an interesting alternative to traditional pharmaceutical manufacturing techniques.