By studying the early immune response to the HIV virus, scientists may have found a new avenue through which to to defeat the virus.
Barton F. Haynes, MD and John Mascola, MD are leading a research team that may have discovered a new way of looking for a vaccine toward the HIV virus. Their research involves the study of the body’s initial response towards the HIV virus and is the first time the co-evolution of virus and anti-body has been mapped in a person.
Most vaccines work by inducing an antibody response which neutralizes the virus, but due to the rapidly evolving nature of the HIV virus, most antibodies become redundant before they can eradicate the infection. By tracking the evolution of both the virus and immune response, the researchers have filled gaps in knowledge that has kept a successful vaccine from being created.
"For the first time, we have mapped not only the evolutionary pathway of the antibody, but also the evolutionary pathway of the virus, defining the sequence of events involved that induce the broadly neutralizing antibodies," says Haynes, who led the project as part of the Duke University Center for HIV/AIDS Vaccine Immunology-Immunogen Discovery consortium.
The evolutionary mapping was possible thanks to an African person whose HIV infection was detected early enough that the virus had not yet mutated. In addition, the person’s immune response produced broadly neutralizing anti-bodies, a trait which only occurs in about 20% of the population and attacks the virus in places which remain unaltered as it evolved. What the study revealed was that the broadly neutralizing antibodies were triggered by the outer layer of the viral surface glycoprotein.
The study has allowed the research team to produce a roadmap to help the development of a final, universal cure. The cure would most likely involve immunogens containing glycoprotein to produce the broad-scoped immunoresponse. "The next step is to use that information to make sequential viral envelopes and test them as experimental vaccines," Haynes said. "This is a process of discovery and we've come a long way with regard to understanding what the problem has been."