Discovering a vaccine against HIV has been a four-decade effort to elicit antibodies that can effectively fight off the virus in its different strains.
Researchers at the Scripps Research Institute (TSRI), International AIDS Vaccine Initiative (IAVI) and the Rockefeller University have developed an experimental vaccine used on mice that can stimulate the immune system activity needed to stop HIV infection, a major brekathrough in developing an effective AIDS vaccine soon.
The research, published June 18, 2015 in the journals Cell and Science, outlines the fact the the currently available vaccines use a dead or inactive version of the disease-causing microbe to trigger antibody production, but immunisations with “native” HIV proteins have failed to produce immune response due to HIV’s ability to evade detection.
So the premise for TSRI researchers was that AIDS vaccine sould consist of a series of related but slightly different proteins called immunogens to train the body to produce neutralising antibodies against HIV — a twist on the traditional “booster” shot, where a person is exposed to the same immunogen multiple times.
The scientists tested one of these proteins, an immunogen called eOD-GT8 60mer, a protein nanoparticle designed to bind and activate B cells needed to fight HIV. It was developed in the Schief lab and tested in mice by the Nemazee lab to produce antibodies that resemble human antibodies.
Using a technique called B cell sorting, the researchers showed that immunization with eOD-GT8 60mer produced antibody “precursors” with some of the traits necessary to recognize and block HIV infection. The results showed that eOD-GT8 60mer could be a good candidate to work on an effective HIV vaccine, said researchers.
“The results are pretty spectacular,” said Dennis Burton, chair of the TSRI Department of Immunology and Microbial Science and scientific director of two centers at TSRI, the IAVI Neutralizing Antibody Consortium (NAC) and the National Institutes of Health (NIH) Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery (CHAVI-ID). TSRI Professor David Nemazee, co-researcher said, “The vaccine appears to work well in our mouse model to ‘prime’ the antibody response.”
With eOD-GT8 60mer in the running as a potential contributor to an HIV vaccine, the researchers are now investigating other immunogens that could work in conjunction with it.
Schief said the Nemazee lab’s mouse models will be crucial resources for testing other engineered immunogens. He emphasized the importance of bringing different disciplines together to engineer mouse models, design antibodies and analyze results. “This was a beautiful collaboration of three labs at TSRI,” said Schief.