By Claire Ainsworth

Vast fields of maize could soon be churning out antibodies for preventing sexually transmitted diseases.

Researchers at Epicyte, a biotech company in San Diego, say their technology promises to make the mass production of therapeutic antibodies easier and cheaper. At the moment, therapeutic antibodies are produced using hamster ovary cells - an expensive method that produces limited amounts.

But Epicyte's new "plantibody" technology allows the DNA that codes for antibodies to be introduced into crop plants such as maize. The antibodies are only produced in the maize kernels, making it easy to extract them using current maize-processing methods.

Secretory antibodies are proteins of the immune system that coat the wet, warm parts of the body to protect them from attack.

Both the fight against sexually transmitted diseases, such as herpes, and effort to stop pregnancy would be helped if women's reproductive tracts were "supplemented" with appropriate antibodies.

Epicyte has now produced anti-sperm antibodies in gel form. But such products have to be made in bulk to be cost-effective.

The antibody for herpes, HX8, works by sticking to the virus and blocking its entry into cells, and has proved highly effective in animal tests.

Although condoms provide some protection against herpes infection, they are not 100 per cent reliable. But HX8 can provide protection in the vagina for 24 hours. Epicyte is also developing antibodies that block HIV transmission and the virus that causes genital warts.

The HX8 genes have already been transferred into maize, and Epicyte plans to start clinical trials of the antibody next year. Hiatt hopes plantibodies will be cheap enough for consumers to buy them over the counter. "That's the ultimate goal," he says.

New Scientist October 3, 2001

The Economist September 8, 2001 83-84