Scientists
discover HIV weak spot

An image released Thursday by researchers at the National Institute of Allergy and Infectious Diseases reveals a vulnerability in the ever-powerful AIDS virus. Unlike the rest of the mutating virus, one key portion on the surface of HIV has been found to be stable and, more important, penetrable by the HIV-fighting antibody b12.

The finding has profound implications for developing an AIDS vaccine. "NIH researchers and their colleagues have revealed a gap in HIV's armor," said NIH director Elias A. Zerhouni in a release, "and have thereby opened a new avenue to meeting that challenge."

AIDS vaccine developers have long been frustrated by the endless ways HIV eludes natural and pharmacological-induced immune responses. Not only does HIV mutate rapidly and continuously, but the virus is coated with an impenetrable coat of sugary molecules, which block access by antibodies.

However, certain parts of the virus remain immutable in order to bind and penetrate human cells. One of these regions, gp120, protrudes from the surface of the HIV molecule and has become the hot spot for vaccines to target.

This latest study, published in the current issue of Nature, has revealed the detailed structure of HIV that's formed when the antibody b12, an effective defense against HIV, binds with the gp120 protein. Researchers hope that the image will yield information on how to best fight HIV.

Revealing a "critical area of vulnerability on the virus," study coauthor Gary Nabel told the BBC, "is certainly one of the best leads to come along in recent years." (The Advocate)