AIDS vaccines might be possible as British scientists in a recent study were able to recreate a camouflage mechanism that HIV uses in order to conceal itself from the body’s immune system. The researchers should be able to use the virus’s strength and turn it into its weakness which might allow them to formulate the first ever vaccine, protecting us against HIV.
A synthetic version of the camouflage mechanism could be injected into the patients, which would teach our immune system to identify HIV and neutralize it. This idea has been devised into a candidate vaccine and is being evaluated in animals and possibly in humans within two years. The research is led by Ben Davis, Professor of Organic Chemistry at University of Oxford and is the latest breakthrough in AIDS research.
Moreover, the largest candidate vaccine trial in Thailand indicated that an agent, RV144, can reduce the chances of acquiring an HIV infection by a third. Although the results and statistical significance were small, this discovery may help us immunize people against the virus and ensures that it is possible to do so.
Another research published last month also provided some breakthrough in AIDS research as they identified two antibodies, which neutralize a wide range of HIV strains. These antibodies maybe used in designing the vaccines that are far more effective than the RV144.
However, Professor Davis offers a novel method in combating HIV through creation of improved vaccines using the field of synthetic biology. The scientists are pursuing to recreate natural molecules with slight modifications in hope that they would be pathologically useful. When HIV binds to the T-cells of the immune system, it uses a surface molecule, glycoprotein 120 (GP-120) in order to infect them. Although most of the GP-120 mutates quickly, one segment of it always remains uniform, the silent face. The silent face could be a key target for antibodies produced by vaccines. The silent face is invisible to human immune system because it is coated by sugars which are too complicated for antibodies of the immune system to distinguish and remove. “The virus uses this trick to decorate itself with what is effectively camouflage. It has a cloak of invisibility, as it were,” said Professor Davis. In most patients, as the silent face goes uncovered, the immune system does not produce antibodies against it; however, in one patient an antibody has been discovered, 2G12.
Davis’s team formulated synthetic sugars which surround the virus’s silent face and slightly altered it so that it would be easy for the immune system to identify it. Through lab tests, researchers discovered that 2G12 antibody binds to these synthetic molecules, concluding that they should prepare and teach the body to make these antibodies. “We’ve done the whole thing with chemistry,” he said. “We’ve built constructs that look like the silent face, but which the body recognizes as being unnatural. We hope it will create an immune response. We’re turning the virus’s shield into its Achilles’ heel. If we can build something that elicits antibodies towards the silent face, we could have a vaccine against HIV.”
In order to test the synthetic silent face molecules, 30 different ones have been created which are implemented in rabbits to reveal whether or not their body would encourage the production of antibodies to fight the silent face. The results should be available within three to six months.
Remaining hopeful, Professor Davis said, “As soon as one shows neutralizing properties, we hope within two years we could see it in people.”