Breakthrough antibodies neutralize most known AIDS strains

US researchers have discovered two powerful antibodies that neutralize more than 90 percent of all known strains of the HIV virus in the lab, new research released Thursday showed.

NIH-led scientists discovered the antibodies known as VRCO1 and VRCO2 that prevent most HIV strains from infecting human cells. The find is a potential breakthrough for advancing HIV vaccine design, and antibody therapy for other diseases.

The authors, whose work is published in the July 9 issue of Science, also were able to demonstrate how one of these disease-fighting proteins gets the job done.

"The discovery of these exceptionally broadly neutralizing antibodies to HIV and the structural analysis that explains how they work are exciting advances that will accelerate our efforts to find a preventive HIV vaccine for global use," said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health.

"In addition, the technique the teams used to find the new antibodies represents a novel strategy that could be applied to vaccine design for many other infectious diseases," Fauci stressed in a statement.

The team of virologists found that the two antibodies were produced naturally and found in the blood of HIV-positive people.

They were able to isolate these antibodies using a new molecular device they developed. It zeroes in on specific cells that make antibodies against HIV. The device is an HIV protein scientists modified to react only with antibodies specific to the site where the virus binds to cells it infects.

Leading two research teams were NIAID scientists Peter Kwong, Ph.D., John Mascola, MD, and Gary Nabel, MD, Ph.D.

"We have used our knowledge of the structure of a virus - in this case, the outer surface of HIV - to refine molecular tools that pinpoint the vulnerable spot on the virus and guide us to antibodies that attach to this spot, blocking the virus from infecting cells," explained Nabel.

Mascola added that: "the antibodies attach to a virtually unchanging part of the virus, and this explains why they can neutralize such an extraordinary range of HIV strains."

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