New Weakness Found In HIV

Scientists in La Jolla, California have found a fifth area of vulnerability in HIV that may advance the search for a vaccine.

The research was described in two papers published Thursday in the journal Immunity. It’s the latest product of a major effort by the National Institutes of Health and the International AIDS Vaccine Initiative, which funds work at TSRI. A new class of antibodies that neutralize a broad range of HIV strains provided a critical tool. The surface protein bearing the vulnerable site is typically unstable and difficult to study. Unlike previously discovered "broadly neutralizing" antibodies, these actually stabilize the protein in its fully assembled, infectious state. This makes it much easier to study the HIV surface protein. Moreover, other such vulnerable sites are likely to exist, the researchers said, and knowledge of what to look for should help. The site is the first discovered since 2009, said Andrew Ward, one of the TSRI researchers. “They’re elegant studies, as good as it gets,” said Anthony Fauci, director of the NIH's National Institute of Allergy and Infectious Diseases.

Infection Control Today has more:

The discovery is part of a large, IAVI- and NIH-sponsored effort to develop an effective vaccine against HIV. Such a vaccine would work by eliciting a strong and long-lasting immune response against vulnerable conserved sites on the virus—sites that don’t vary much from strain to strain, and that, when grabbed by an antibody, leave the virus unable to infect cells. HIV generally conceals these vulnerable conserved sites under a dense layer of difficult-to-grasp sugars and fast-mutating parts of the virus surface. Much of the antibody response to infection is directed against the fast-mutating parts and thus is only transiently effective. Prior to the new findings, scientists had been able to identify only a few different sets of “broadly neutralizing” antibodies, capable of reaching four conserved vulnerable sites on the virus. All these sites are on HIV’s only exposed surface antigen, the flower-like envelope (Env) protein (gp140) that sprouts from the viral membrane and is designed to grab and penetrate host cells.

(Tipped by JMG reader Eric)