WEDNESDAY, SEPTEMBER 28, 2016

AIDS vaccine could neutralize nearly all strains of virus

A study from scientists at The Scripps Research Institute (TSRI) recently found that a vaccine or other therapy directed at a single site on a surface protein of HIV could in principle neutralize nearly all strains of the virus.

It is expected that the study will influence future designs for HIV vaccines and antibody-based therapies, Science Daily reports.

The study, which appears in the May 15 issue of Science Translational Medicine, was led by senior investigator Dennis R. Burton, a professor at TSRI and the scientific director of the International AIDS Vaccine Initiative (IAVI) Neutralizing Antibody Center. He is also scientific director of the National Institutes of Health's Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery (CHAVI-ID) on TSRI's La Jolla campus. according to Science Daily.

The HIV virus evades the human immune response system by using a strategy of covering its most exposed parts, Env structures, with antibody-resistant sugar molecules call glycans.

In the past decade, scientists have found a few accessible sites on Env that can be accessed by antibodies, thereby neutralizing a wide range of viral strains.

The study examined a specific vulnerable site on Env known as the "high-mannose patch." Some of the most effective antibodies against HIV target this site. The patch is centered on a glycan attachment point designated as N332.

HIV protects from the antibodies by mutating to shift the attachment point from N332 to an area designated as N334. Burton and his team have discovered that N332-directed antibodies can still neutralize the virus even when it shifts to N334, Science Daily reports.

"We found, for example, that if the virus tries to escape from an antibody directed at that site by eliminating one of its sugars, the antibody often can latch on to a neighboring sugar instead," Burton said, according to Science Daily.

This research sheds new light on the previous assumption that a successful HIV vaccine would have to target multiple vulnerable sites of the virus.