When a person is infected with HIV, a battle begins to rage between the virus and the immune system. As the body produces new antibodies for the virus, the infection mutates always managing to stay a few steps ahead. Now, a team of scientists at Rockefeller University in New York believe that using synthetic antibodies that attach to the surface of proteins on the outer membrane of the virus offer an alternative treatment to anti-retroviral drugs currently used and could one day lead to new therapeutic vaccines.
HIV antibodies previously tested in humans had disappointing results, but the antibodies tested at Rockefeller University belong to a new generation of broadly neutralizing antibodies that could potentially fight a wide range of HIV strains.
"One antibody alone, like one drug alone, will not be sufficient to suppress viral load for a long time because resistance will arise," said Dr Marina Caskey, co-first author of the study.
"What's special about these antibodies is that they have activity against over 80 per cent of HIV strains and they are extremely potent."
The research showed that the new antibody therapy was effective against 195 of 237 strains of the virus.
In about 10 to 30 percent of sufferers, the body produces broadly neutralizing antibodies, but only after several years of infection. By that time, the virus has usually mutated and evolved rendering these powerful antibodies ineffective.
However, by isolating and cloning these antibodies, researchers are able to use them as therapeutic agents against infections that have had less time to evolve.
For the study, uninfected and HIV infected people were given a single dose of the antibody intravenously and then monitored for 56 days. At the highest dose level of 30mg per kilo of weight, all eight infected people showed a 300 fold decrease in the amount of HIV measured in their blood. Most of the participants reached their lowest viral load just one week after the treatment.
Dr. Caskey said further trials could result in the antibodies being used in conjunction with anti-retroviral drugs to maintain better control over the infection to prevent the onset of Aids.
In addition to the possibility of a new treatment, the study also raises hope for an HIV vaccine. Dr. Caskey said that if researchers can induce an uninfected person's immune system to generate these potent antibodies, it might be enough to block the HIV infection before it can be established.
