Natural antibodies' stronger version.

• Position: HIV

Using highly potent antibodies isolated from HIV-positive people, researchers have begun to identify ways to neutralize the many possible subtypes of HIV. Now, a team led by biologists at the California Institute of Technology, Pasadena, has built upon one of these naturally occurring antibodies to create a stronger version it believes is a better candidate for clinical applications.

Advances in isolating antibodies from HIV-infected individuals have allowed for the discovery of a large number of new, broadly neutralizing anti-HIV antibodies directed against the host receptor (CD4) binding site--a functional site at the surface of the virus that allows for cell entry and infection. Using a technique known as structure-based rational design, the team modified one already known and particularly potent antibody (NIH45-46) so that it can target the binding site in a different and more powerful way.

"NIH45-46 was already one of the most broad and potent of the known anti-HIV antibodies," points out Pamela Bjorkman, professor of biology and senior author of the study. "Our new antibody is now arguably the best of the currently available, broadly neutralizing anti-HIV...