A Canadian-led research team has discovered where the AIDS virus hides in the human body, work the scientists say could lead to a new way to treat the disease and perhaps even a chance to eradicate it.
Doctors can't cure patients with HIV-AIDS. The anti-viral drugs used to subdue the wily human immunodeficiency virus and limit the damage it inflicts on the immune system don't completely clear it from the body.
There are hiding places- HIV reservoirs - where the small numbers of virus lay low, ready to launch an attack. Until now, scientists didn't know where these safe havens were, but the possibilities included the brain or the kidneys.
In a paper published in the journal Nature Medicine, The University of Montreal's Rafick-Pierre Sékaly and his colleagues report that HIV finds refuge in a type of long-lived immune system cell.
They are now looking at ways to destroy them without crippling the immune system. One day, the work could lead to a cure, says Dr. Sékaly, one of Canada's top AIDS researchers.
"It really is the first clue to allow us to eradicate HIV," he says.
Recent studies have shown that even patients who took five or six anti-viral drugs at the same time could not get rid of the virus, says Jean-Pierre Routy, a hematologist at the Research Institute of the McGill University Health Centre in Montreal who is one of the co-authors of the paper.
The treatment regime known as high active antiretroviral treatment, or HAART, adds, on average, 13 years to the life expectancy of HIV-positive people, according to one study. But the virus remains present at low levels, ready to stage a comeback if they stop taking their medication.
The new findings suggest that more or stronger anti-virals aren't the answer, the researchers say, but that targeting the reservoirs is a better strategy for finding a cure for HIV-AIDS.
HIV hides in the long-lived "memory" cells that allow someone to avoid the mumps or the measles as a senior because they had it as child.
Like stem cells, these memory cells have incredible longevity. They are relatively sleepy until they encounter an old foe - a virus or other infectious agent they vanquished before - or a new disease-causing organism. Then they start to replicate so they can better defend the body against invaders. But the viruses lurking within also get a chance to reproduce.
Mark Wainberg, director of the McGill AIDS Centre, says while the work is significant, it will be hard to find and eliminate every safe-haven cell.
"They are hard to get rid of and are going to represent a challenge for us," says Dr. Wainberg, who was not part of the research team, which included a number of scientists from the United States.
Last month Dr. Sékaly announced he was moving to the United States and taking as many as 25 scientists on his team with him. He said he was leaving in part because of federal cuts in science funding, and that he hoped his departure would be a wake-up call for the government.
Dr. Sékaly is still setting up his lab in Florida, where he is scientific director of the Vaccine and Gene Therapy Institute. He is planning to move there in the fall, but he will keep a lab running at the University of Montreal.
There is no vaccine for HIV-AIDS. There were 2.7 million new infections worldwide last year, and 33 million are living with the virus.