Modified plants make antibodies

Antibody therapies, used to treat everything from rheumatoid arthritis to transplant rejection, are one of biotechnology's success stories. The market already exceeds $20 billion per year, and at least 150 new antibody products are in clinical development. The fine print is in the small yield and prohibitive cost: One regimen can cost a patient up to $20,000 per year. These problems stem from generating the antibodies in mammalian cell cultures, which can take a year to produce gram quantities of a protein. Researchers at Icon Genetics in Halle, Germany, a subsidiary of Bayer CropScience, have now ramped up the production process by enticing a tobacco plant relative to produce antibodies (Proc. Natl. Acad. Sci. USA, DOI: 10.1073/pnas.0606631103). Anatoli Giritch and his colleagues infect Nicotiana benthamiana leaves with two types of viral DNA, each containing one of the two genes whose consequent proteins associate to form an antibody. The plant production system is optimized by making sections of the DNA appear more plantlike, leading to gram quantities of the antibodies in just 20 days. The protocol could be used to make antibodies for "situations requiring rapid response, such as pandemic or terrorism events," the researchers note.