George Georgiou, a professor of engineering and molecular biosciences at the University of Texas at Austin, and his colleagues have developed a hybrid antibody that neutralized 99 percent of HIV-1 strains tested. The antibody is based on so-called "broadly-neutralizing antibodies," a group of antibodies from HIV-infected patients that are able to take down an array of rapidly mutating HIV-1 viruses.
The research was published last week in the journal Science Immunology.
The hybrid antibody binds tightly to a protein on the surface of HIV called the membrane-proximal external region (MPER). Immune B cells have the capacity to make a host of different antibodies, but in practice, only a few types actually make it into the blood stream.
According to an article in The Scientist: "In a first for the HIV field, the team also probed the donor's plasma for MPER-binding protein using a technique developed by George Georgiou, a biomedical engineer at the University of Texas at Austin, which incorporates mass spectrometry to determine the protein sequences of each antibody. This approach, Georgiou explained, enabled the team to focus on the antibodies that were actually released into the blood. 'Only a few of these memory B cells somehow are selected to be expanded greatly and produce antibodies that are present at serological levels,' he said."
Because broadly-neutralizing antibodies bind to a part of the HIV virus that resembles parts of human cells, one key challenge in converting this work into a viable therapeutic will be to engineer antibodies that the body doesn't view as a threat to itself.