Scientists Find Clues to How the Body Fights Off HIV

MONDAY April 5, 2010 -- Researchers report that they've gained more insight into how the body fights off HIV, a finding that offers a possible new avenue toward a vaccine against the virus, which causes AIDS.

At the moment, there's no way to know whether the research will help scientists develop a vaccine. HIV remains an extremely stubborn enemy.

Still, the findings do give scientists an idea of how to prepare the body to meet the threat of HIV, "a possible way that one could think about the kinds of response you'd want to have on hand before a virus shows up," said study author Dr. M. Anthony Moody, chief medical officer at Duke University's Human Vaccine Institute.

The findings are reported online April 5 in the Journal of Experimental Medicine.

The study examines antibodies, the foot soldiers of the immune system that gather to fight off invaders. The researchers found four kinds of antibodies that appear to create a barrier that prevents HIV from getting into a kind of door in cells.

That door, known as a receptor, is an entry point for HIV in the vast majority of cases.

The four antibodies work differently than their counterparts because they focus on creating a barricade to protect the cells instead of doing direct battle with the virus cells, Moody said.

It's not clear if having more of these antibodies would help people do a better job of fighting off HIV. There's definite room for improvement in that area, Moody said.

"One of the fundamental problems that research in HIV has faced is that when people become infected, they don't typically mount an antibody response that's very effective at controlling a response early on," Moody said. "The response to the virus is much slower, and it's delayed and comes in stages. The kinds of antibodies that are produced do appear to have an effect, but the virus always seems to stay one step ahead."

By contrast, the body has a more effective antibody response to viruses such as influenza, he said.

The next step is to "understand even more deeply what's going on," Moody said. Another step would be to consider whether to test the antibodies in animals and people to see whether they boost their immune systems, he said.

Rowena Johnston, vice president of research with amfAR, the Foundation for AIDS Research in New York City, said the research reflects a feeling in the HIV vaccine research field that "what they need to do is go back to the drawing board."

The challenge, she said, is that many steps would be involved in getting the antibodies to protect cells against HIV. "The more steps you introduce into it, the more things that can go wrong," she said.

The research does provide more information about how the process works, she said, "but it doesn't mean the next step is voila, we have a vaccine."

More information

The U.S. Vaccine Research Center has more on research into an HIV vaccine.

Posted: April 2010


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