Enhancing bacteria that already colonize humans is a completely new strategy to combat viral invasion, said Peter P. Lee, MD, assistant professor of medicine. He and his colleagues have shown that a genetically engineered strain of lactobacillus - bacteria abundantly found in healthy vaginal mucosal linings - could significantly inhibit the ability of HIV to infect cells. Their findings are published in the Sept. 8 advance online edition of the Proceedings of the National Academy of Sciences.
Lee said that if the strategy works as well in humans as it does in cells, it may someday provide women with a safe, inexpensive and long-lasting way to protect themselves from HIV, the virus that causes AIDS. Lee's work may offer a promising possibility to fortify the barrier that normally protects the vagina from foreign invaders.
"It struck me that viruses - certainly HIV, but almost all viruses - have to first get through the mucous membranes to get to the host," said Lee. "Essentially all mucous membranes of the body are colonized with normal, healthy bacteria. So why not try somehow to harness that and take advantage of these healthy bacteria to either block or inactivate viruses before they can get into a host?"
The predominant mode of HIV transmission worldwide is through heterosexual contact, with the risk of transfer from male to female far greater than the reverse. In the search for an agent to help prevent the spread of HIV, the methods have generally fallen into one of two camps:
Contact: Mitzi Baker
Stanford University Medical Center