Researchers discover 'reservoir' that allows HIV to remain infectious despite treatment

May 19 2008

Researchers at Brigham Young University and the Johns Hopkins School of Medicine have discovered a human cell "reservoir," called follicular dendritic cells, that allows HIV to stay in an infectious state and not respond to antiretroviral drugs, the Deseret Morning News reports.

The research, which was funded by NIH and the American Foundation for AIDS Research, will be published in the June issue of the Journal of Virology.

According to the Morning News, researchers have long believed that there are reservoirs in the body that allow HIV to remain in an infectious state despite treatment. FDCs are the third reservoir to be identified. The other two reservoirs are macrophages and CD4+ T cells infected with a latent form of HIV. FDCs store material needed to maintain antibodies in the immune system and release proteins to trigger production of certain antibodies if they become low.

Greg Burton, professor of chemistry and biochemistry at BYU, and colleagues discovered FDCs by analyzing samples from HIV-positive people. The researchers discovered that FDCs, which are located in lymph nodes, trap HIV on their services. The trapped HIV does not show behavior -- such as replicating or mutating -- that is targeted by antiretrovirals and, therefore, is able to avoid the drugs, according to Burton.

The researchers found several forms of HIV on FDC surfaces, suggesting that the virus does not mutate but acquires new samples over time. The researchers established a time frame for each version of the virus and sequenced the individual HIV genomes from the FDCs to compare with samples from other cells. According to the study, HIV takes advantage of FDCs' ability to create new versions of the virus by staying active, avoiding treatment that could eradicate the virus and by infecting other cells.

Burton said that although FDCs can store the virus and reignite HIV infection, the cells potentially could provide scientists with the information necessary to develop treatments to target stored HIV versions on FDCs. "If we could go in and perhaps flush it from the surface of the cell, we might decrease dramatically the amount of virus that could perpetuate infection," Burton said.

The researchers added that it is possible that potential treatments derived from the research could be used to treat other conditions, such as allergy and autoimmune disease. The researchers are applying for an NIH grant to develop a way to attack HIV stored in FDCs, according to the Morning News (Collins, Deseret Morning News, 5/13).

An abstract of the study is available online.