Found to eliminate almost all HIV isolates in human body.
Scientists from the National Institutes of Health have identified an antibody from an HIV-infected person that successfully neutralized 98 percent of HIV isolates tested, including 16 of 20 strains resistant to other antibodies of the same class. The potency of the antibody named N6 could lead to further research in finding out a solution to treat or prevent HIV.
The scientists, led by Mark Connors, M.D, of NIH’s National Institute of Allergy and Infectious Diseases (NIAID), also tracked the evolution of N6 over time to understand how it developed the ability to potently neutralize nearly all HIV strains. This information will help inform the design of vaccines to elicit such broadly neutralizing antibodies.
As the virus rapidly changes its surface proteins to evade recognition by the immune system, identifying broadly neutralizing antibodies against HIV was a difficult task for the scientists.
“The discovery and characterization of this antibody with exceptional breadth and potency against HIV provides an important new lead for the development of strategies to prevent and treat HIV infection,” said NIAID director Anthony S. Fauci.
N6 blocks infection by binding to a part of the HIV envelope called the CD4 binding site, preventing the virus from attaching itself to immune cells. In 2010, the scientists at NIAID’s Vaccine Research Center (VRC) had found a similar antibody called VRC01 that could stop up to 90 percent of HIV strains from infecting human cells.
“Findings from the current study showed that N6 evolved a unique mode of binding that depends less on a variable area of the HIV envelope known as the V5 region and focuses more on conserved regions, which change relatively little among HIV strains. This allows N6 to tolerate changes in the HIV envelope, including the attachment of sugars in the V5 region, a major mechanism by which HIV develops resistance to other VRC01-class antibodies,” said NIAID.
According to the scientists, N6 could pose advantages over VRC01 and may offer stronger and more durable prevention and treatment benefits.