科学与发展网络(SciDev.Net)

Fields of genetically modified tobacco could produce large quantities of microbicide

Flickr/perrykm5

Scientists have developed an anti-HIV microbicide that can be mass-produced in plants — in quantities large enough to make it affordable for people in developing countries, they say.

The microbicide, which has been found to prevent HIV transmission in cells, is a combination of two promising microbicide compounds — monoclonal antibody b12 and the protein cyanovirin-N.

Together the compounds are "more potent at neutralising HIV than its single components", Amy Sexton, lead author of the study and a researcher at the University of Melbourne, Australia, told SciDev.Net.

The researchers also showed that the microbicide can be mass-produced by transferring the gene constructed for the microbicide into tobacco plant cells.

"This way the plant expresses the gene and produces the microbicide in the same way it produces its own proteins," says Sexton.

Scaling-up production simply requires growing acres of the plants from genetically modified seeds, she adds.

Microbicide gels and creams are a great hope for female-initiated protection from HIV/AIDS but so far trials have had mixed results (see Drugs may be the next frontier for HIV prevention and Anti-HIV gel fails to prevent infection).

In February this year, research suggested that the anti-HIV gel PRO 2000 might protect against infection (see Microbicide hope at last, say researchers) but the results were not completely certain. The results of a larger PRO 2000 study are due in December 2009.

"The success of microbicides depends not only on the identification of a broad-acting effective product, but also on the issue of cheap and easy production at a huge scale for global availability. We have demonstrated the potential for overcoming both of these hurdles," says Sexton.

But Morad Ahmed Morad, a professor of medicine at Tanta University, Egypt, is more cautious, saying that potential health issues such as allergic reaction to a plant-produced microbicidal cream and environmental concerns about the spread of the inserted gene to other plants need to be considered.

He adds that developing countries may not be able to produce such a microbicide themselves because its production will be controlled by patents.

The research was published online in The FASEB Journal last month (26 May).

Link to abstract in The FASEB Journal