AIDS | Discovery may lead to a new way to treat the disease, or even cure it

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The Canadian Press

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TORONTO - A Canadian-led research team has discovered where the AIDS virus hides in the human body, a finding 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 antiviral 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 small numbers of virus lay low, ready to launch an attack. Until now, scientists didn't know where these safe havens were located, 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 Sekaly and 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, said Sekaly, one of Canada's top AIDS researchers.

"It really is the first clue to allow us to eradicate HIV," he said.

Recent studies have shown that even patients who took five or six antiviral drugs at the same time could not get rid of the virus, says co-author Jean-Pierre Routy, a hematologist at the Research Institute of the McGill University Health Centre in Montreal.

The treatment regime, known as high active antiretroviral treatment or HAART, adds 13 years on average 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 patients stop taking their medication.

The new findings suggest that more or stronger antivirals 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 measles as a senior because they had the disease as a 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 that means the viruses lurking within also get a chance to reproduce.

Mark Wainberg, director of the McGill AIDS Centre, says that 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 Wainberg, who was not part of the research team, which included a number of scientists from the United States.

Last month, Sekaly announced he is moving to the United States and taking as many as 25 scientists on his team with him. He says he is leaving in part because of federal cuts in science funding, and that he hopes his departure will be a wake-up call for the government.

Sekaly 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 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 people million are living with the virus.