Katie Mantell 10 September
2003 Source: SciDev.Net
Scientists have engineered bacteria that are normally present in the
vagina to attack HIV. They say their findings could lead to an effective
and cheap way of tackling the spread of the virus in both developed and
developing nations.
US researchers found that in the laboratory, a modified strain of the
lactobacillus bacteria could halve the rate at which HIV infected cells.
If the strategy works in humans, it could provide women with a safe and
long-lasting way to protect themselves from the virus, according to one of
the researchers, Peter Lee of Stanford University.
"It struck me that [HIV has] to first get through the mucous membranes
to get to its host," he says. "Essentially all mucous membranes of the
body are colonised with normal, healthy bacteria. So why not … take
advantage of these healthy bacteria to either block or inactivate viruses
before they can get into a host?"
Lactobacillus already provides some protection against vaginal
transmission of HIV. Research has shown that women with little or no
lactobacillus have a higher risk of contracting HIV than those with high
levels of the bacteria.
In this latest study, published in the Proceedings of the National
Academy of Sciences, researchers gave the bacteria an extra boost by
adding the gene for CD4, a protein that specifically latches on to HIV. In
this way, the bacteria could act as a 'trap' for the virus, preventing it
from reaching target cells in the body.
Lee says the research could lead to the creation of a small vaginal
suppository that women could use regularly to provide ongoing protection.
"It would be as discreet as can be," says Lee, adding that each dose could
last a week or longer and could be inserted at any time. Heterosexual
intercourse is the main way that HIV is transmitted, and more than 19
million women are currently infected
worldwide. |