( the oldest (form of the) virus lives in...)Scavenger cells could be key to treating HIV-related dementia

Current antiretroviral drugs block HIV from replicating in new T cells, but don't kill the virus in infected macrophages. And the drugs cannot stop the virus from evolving into new forms, McGrath said. Because the virus mutates faster than other cells in the body, it also can develop resistance to these drugs, Salemi said.

Even the HIV already in an infected person's brain is not one single virus, but rather populations of slightly different viruses that infect different parts of the brain, the findings show.

"We agree there are different strains that populate different regions of the brain," said Francisco Gonzalez-Scarano, M.D., chairman of the University of Pennsylvania neurology department. "We've done similar studies in monkeys."

To obtain their findings, the researchers studied different regions of the brain of a person who died with HIV-associated dementia using specimens from the AIDS and Cancer Specimen Resource at UCSF. They also used a new computer-based research tool to study the results. Dubbed phylodynamic analysis, this new method links traditional ways of studying the virus to give researchers a more comprehensive understanding, which Salemi says is crucial to analyzing the ever-changing disease.

"If we really want to understand what happens to a person infected with this disease, we need to develop new tools," he said. "We can put together all these different resources and describe how the virus changes over time and try to understand why this particular damage happens"

But these results are just a first step, Salemi said. The team is now analyzing brains from 10 people, some who died with HIV-associated dementia and others who did not.

The well-known cocktail of antiretroviral drugs prescribed to most HI
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Source:University of Florida