22 June 2009

Combination approach could eradicate HIV from body

by Kate Melville

Researchers from the newly-established Vaccine and Gene Therapy Institute (VGTI), Florida and the University of Montreal have uncovered a possible method for completely eradicating HIV from the human body. The researchers made use of new information about how HIV persists in the body - even in patients receiving drug treatments - and how the virus continues to replicate itself in individuals undergoing treatment. The new findings will be published in the journal Nature Medicine.

"Current medications allow us to control HIV and limit its progression in most cases," explained VGTI's Rafick-Pierre Sékaly. "However, the medications do not eradicate the disease. Instead, the disease persists within the body - much like water in a reservoir - and is never fully destroyed. We believe our latest research may help scientists and physicians overcome this hurdle."

The research team first identified the specific cells where HIV infection persists in patients. They found that the disease is able to survive within two subsets of memory T-cells. Memory T-cells are a portion of the body's immune system and have the ability to learn, detect and attack certain types of infectious diseases. By infecting cells within the body's own immune system, HIV is able to avoid antiviral treatments that are effective in stopping HIV in other cell types in the body. In-effect, HIV uses the body's own defense system as a hideout.

The researchers were also successful in identifying how these HIV-infected memory T-cells replenish themselves. When populating T-cells, HIV does not replicate itself as it does in other cell types on the body. Instead, HIV persists in memory T-cells through cell division - a finding that holds significant implications for possibly stopping the disease.

"Based on this research, we believe one possible method for eliminating HIV in the body is to use a combined approach," explained Dr. Sékaly. "We propose the use of medications that target viral replication of HIV throughout the body, in combination with drugs that prevent infected memory T-cells from dividing. We believe that by attacking the disease in these distinct two ways at once for an extended period of time, we can eliminate the reservoirs of HIV that currently persist within the human body, leaving an individual disease-free." The next step for researchers is to begin testing their proposed treatment method using animal models and newly developed therapies.

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Source: Oregon Health & Science University