Yoghurt could wax the magic wand on AIDS: Study
Some of the 'friendly bacteria' found in yoghurt have been genetically modified to release a drug that blocks HIV infection.india Updated: Jan 19, 2006 17:40 IST
Researchers have revealed that some of the 'friendly bacteria' found in yoghurt have been genetically modified to release a drug that blocks HIV infection.
Although the bacteria have only been tested in a lab dish, scientists are optimistic that the technique could provide a cheaper and more effective way of delivering drugs to fight the spread of AIDS, by getting the bugs to live right where the drugs are needed most.
The bacterium (Lactococcus lactis) the researchers have modified naturally produces lactic acid, and so is used to produce cheese and yoghurt. It is also found in some parts of the human anatomy, including the gut and the vagina, where the acid it produces damps down the growth of other, harmful bacteria. Some 'probiotic' yoghurts are loaded with such beasties with the aim of keeping consumers' guts healthy (see 'Gut Reaction').
Bharat Ramratnam, an HIV specialist at Brown Medical School, Providence, Rhode Island, and his colleagues have now altered the genetic make-up of L. lactis so that it generates cyanovirin, a drug that has prevented HIV infection in monkeys and human cells, and is on track for human trials in 2007.
Cyanovirin binds to sugar molecules attached to the HIV virus, blocking a receptor that HIV uses to infect cells. "It's basically passive immunisation," says Sean Hanniffy, a molecular biologist at the Institute of Food Research, Norwich, UK, and part of the team.
Gels containing cyanovirin could afford some protection for women against the transmission of HIV, but since the drug breaks down quickly these would have to be smeared in the vagina immediately before sex. "In some countries there's a reluctance to use these gels frequently," explains Hanniffy.
Because lactic-acid bacteria live naturally in the vagina, one application of a bacterial goop should see the modified bugs thrive there for at least a week, says Hanniffy. "The next step might be to use other bacteria that can survive for even longer," he adds.