The secret to AIDS immunity may reside in the body’s own genes. Apparently, one out of every 200 people or so who get infected with HIV never comes down with AIDS. These people, known as “elite controllers,” never show any sign of disease and don’t need medication, even many years after HIV infection. Scientists figured that if they could find out what protects the elite controllers, they might be on the road to developing an effective AIDS vaccine.
Drs. Arup Chakraborty of MIT and Bruce D. Walker of Harvard University and the Ragon Institute for HIV research at Massachusetts General Hospital, put out a special call to the medical community to find research subjects, which wasn’t so easy given that controllers rarely report to a doctor’s office since they show no signs of illness. Eventually, though, they enrolled 1,100 elite controllers plus 800 people who had developed full-blown AIDS in a study, and the results are now in.
What they found wasn’t at all what they expected, according to Dr. Walker. “I actually had to pull out text books,” he says. The research team found that elite controllers have unusual genes that affect how their killer T-cells operate. Killer T-cells are specialized white blood cells that fight infection. Under normal conditions, the T-cells work together as a team to vanquish infected cells, with various T-cells attacking different components of the infected cell. The reason AIDS usually overtakes the immune system is that the virus mutates so quickly that the slow-moving swarm of T-cells can’t keep up. But in elite controllers, apparently, the killer T-cells work alone rather than in a swarm, and they become extremely aggressive in doing so. They kill the virus before it can progress. Plus, these T-cells react strongly to a broad range of targets, so they kill off mutations as soon as they develop.
The downside of this scenario is that such highly activated T-cells can turn against the victim’s own body, since the cells react to such a broad range of stimuli. And so, people with these super-aggressive T-cells have a higher incidence of autoimmune conditions. But on the other hand, the T-cells fight all manner of infection effectively — not just the AIDS virus, and so these individuals have more protection against infectious diseases like hepatitis, to mention just one.
The thing that gives hope to the researchers is the fact that normal people also have these super-aggressive, broad-spectrum killer T-cells, although in very limited numbers. This gives the scientists hope that they might be able to trigger the body to create more of these cells through a targeted vaccine. “We think they might be coaxed into action with the right vaccine,” Dr. Chakraborty said. The scientists believe that once activated, the elite cells might clone themselves and multiply fast enough to overwhelm cells infected with HIV.
“What we need to do with a vaccine is train bigger [elite] T-cell armies that will be there when a person first encounters the HIV virus,” said Dr. Walker.
Traditional methods of developing vaccines haven’t been working in the case of AIDS because of the ability of the virus to mutate so quickly, and so this discovery potentially is key. The experts contend that the best hope for an AIDS vaccine lies in studying the body’s own mechanisms for controlling the disease. “I think it’s becoming more and more apparent that conventional ways of designing vaccines are not going to work for HIV,” according to HIV vaccine specialist Helen Horton of the Seattle Biomedical Research Institute. “I think this is definitely where we need to be headed.”
Unfortunately, though, the researchers say that a vaccine still lies at least 10 years in the future. Considering that over 34 million people worldwide now have AIDS, that 2.7 million new AIDS infections occurred in 2008 alone, and that the incidence of the disease keeps increasing, this seems a very long time to wait. In the meantime, I have seen numerous examples that if you keep your immune system optimized using natural immune system boosters, it tends to keep the viral load substantially down (sometimes to undetectable levels) in HIV positive patients. And although not a cure, it’s certainly better than the alternative — at least until a functioning vaccine comes along.