March 31, 2009 -- The tobacco plant could soon redeem itself in the eyes of public health experts, say scientists who are producing huge amounts of a powerful but prohibitively expensive HIV drug inside modified tobacco leaves. "This is very significant news," said Polly Harrison, Director of the Alliance for Microbicide Development, who was not involved with the research. "So often it's difficult to make enough of a promising drug to even do laboratory studies, but here production is at a level that allows them to literally make tons of the drug," said Harrison. Scientists have known for years that the drug, known as griffithsin, protects some people from HIV infection by stopping the virus from colonizing the vaginal lining. What has prevented griffithsin from becoming a standard HIV preventive measure is the cost of producing it. Related Content:
The only known naturally occurring source of griffithsin is a red algae found off the coast of New Zealand, which grows in amounts too small to be effectively harvested. Scientists can produce larger amounts of griffithsin by genetically engineering E. coli bacteria to produce the drug, but maintaining the necessarily high temperatures, supplying the raw materials, and harvesting the drug is expensive. Now scientists have turned to a virus, the tobacco mosaic virus (TMV), that commonly infects tobacco plants. TMV is rod-shaped, about 18 nanometers wide by 200 to 300 nanometers long. Once the virus enters a plant cell, it hijacks the cell's molecular machinery. Usually the hijacked plant cells are reprogrammed to produce more virus. The scientists first mail-ordered a synthetic version of the red algae gene that produces griffithsin. They then injected that gene into the TMV, mixed it with water, and sprayed the virus over a greenhouse field of eight-inch-tall Nicotiana benthamiana, a close cousin of commercial tobacco plants that is especially susceptible to TMV. Get More NewsMouse Cloned From Long-Frozen CellResearchers create a mouse from a long-frozen cell. Will the mammoth be next?'Bubble' Could Protect AstronautsScientists say a "bubble" around a Mars-bound spaceship could protect astronauts.Big Reduction of Snowmobiles in Yellowstone ProposedA new plan would cut snowmobile use by 40 percent in Yellowstone.Microbes: Fuel of the Future?A reddish South American microbe is literally breathing fuel, say scientists.DNA Links Remains to Steve FossetDNA tests on two bones found in California confirm they are those of Steve Fossett.Women Carry More Bacteria Than MenSome bacteria prefer women, suggests a new study. But why?Ancient 'Water Monster' Facing ExtinctionA foot-long salamander that was a key part of Aztec legend is threatened by extinction.Grand Canyon's Youth ConfirmedThe Grand Canyon is millions of years younger than previously thought, argue geologists.My Take: E-Voting Not User FriendlyOpinion: Electronic voting machines don't always capture the intent of voters.SLIDE SHOW: Landscapes of TerrorWhat makes a place feel scary? There are scientific explanations.At 40, Brain and Body SlowThe part of the brain in charge of motion starts a gradual slide in middle age.Spiders, Scorpions Among World's Oldest CreaturesMany creepy crawlies have been on Earth much longer than previously believed.Blood-Sucking Vampire Bats Sing DuetsWhite-winged vampire bats "harmonize" with separated roost mates. |
advertisement
|
-
our sites
-
video
mobile
-
shop
-
stay connected
-
corporate
