Anti-HIV Drug from GM Tobacco

Scientists from the United Kingdom and the United States have developed transgenic tobacco plants accumulating high levels of griffithsin (GRFT), a protein that has been shown to be effective against the human immunodeficiency virus (HIV) even at picomolar concentrations. Griffithsin, first isolated from the red algae Griffithsia, can stop cell-to-cell HIV transmission by binding to the viral envelope glycoproteins.

The scientists were able to harvest 60 grams of griffithsin from Nicotana benthamiana in a greenhouse with an area of 460 square meters. They estimated that this amount of GRFT could produce roughly one million HIV microbicide doses. Other antiretroviral drugs have so far proved to be too expensive to mass produce.

The tobacco-sourced griffithsin was found to be effective against HIV strains A, B, C. Strains A and C predominate in Sub-Saharan Africa and the Indian subcontinent, regions where microbicides are mostly urgently needed. GFRT also presents an advantage over other microbicides since it does not stimulate lymphocyte proliferation.

The paper published by PNAS is available for download at http://dx.doi.org/10.1073/pnas.0901506106 An article published by Nature highlights the study. Read the article at http://dx.doi.org/10.1038/news.2009.208