An experimental vaccine candidate may have the potential to stimulate the immune system to block HIV infection, according to new research published Thursday.
The findings may represent a leap forward in the effort to develop a vaccine against HIV, which has so far struggled to elicit antibodies that can effectively fight off different strains of the virus, according to three papers published in the U.S. journals Cell and Science.
"The results are pretty spectacular," Dennis Burton of the Scripps Research Institute (TSRI), who led one of the studies, said in a statement.
Currently, many vaccines use a dead or inactive version of the disease-causing microbe itself to trigger antibody production, but immunizations with "native" HIV proteins are ineffective in triggering an effective immune response, due to HIV's ability to evade detection from the immune system and mutate rapidly into new strains.
This challenge has led many researchers to believe that a successful AIDS vaccine will need to consist of a series of related, but slightly different proteins, called immunogens, to train the body to produce broadly neutralizing antibodies, a special class of immune system molecules that can bind to and neutralize a wide range of globally occurring HIV variants.
In the new studies, the researchers tested one of these potential proteins, an immunogen called eOD-GT8 60mer, a protein designed to bind and activate B cells needed to fight HIV.
Using a technique called B cell sorting, the researchers showed that immunization with eOD-GT8 60mer caused two different mouse models to produce antibody "precursors," which have some of the traits necessary to recognize and block HIV infection.
This suggested that eOD-GT8 60mer could be a good candidate to serve as the first in a series of immunizations against HIV, the researchers said.
A study published in Science showed that a laboratory-designed molecular complex similar to the part of HIV that binds to cells also triggered immune responses in rabbits and monkeys.
"Together, the three papers represent an important starting point for developing HIV vaccines that can elicit broadly neutralizing antibodies in people," the U.S. National Institutes of Health, that funded the research, said in a statement.
