Reservoir Allows HIV To Remain Infectious Despite Treatment

Researchersat Brigham Young University and the Johns Hopkins School of Medicine have discovered a human cell"reservoir," called follicular dendritic cells, that allows HIV tostay in an infectious state and not respond to antiretroviral drugs, the Deseret Morning News reports. The research, which wasfunded by NIH and the AmericanFoundation for AIDS Research, will be published in the June issue of the Journal of Virology.

According to the Morning News, researchers have long believed thatthere are reservoirs in the body that allow HIV to remain in an infectiousstate despite treatment. FDCs are the third reservoir to be identified. Theother two reservoirs are macrophages and CD4+ T cells infected with a latentform of HIV. FDCs store material needed to maintain antibodies in the immunesystem and release proteins to trigger production of certain antibodies if theybecome low.

Greg Burton, professor of chemistry and biochemistry at BYU, and colleaguesdiscovered FDCs by analyzing samples from HIV-positive people. The researchersdiscovered that FDCs, which are located in lymph nodes, trap HIV on theirservices. The trapped HIV does not show behavior -- such as replicating ormutating -- that is targeted by antiretrovirals and, therefore, is able toavoid the drugs, according to Burton.

The researchers found several forms of HIV on FDC surfaces, suggesting that thevirus does not mutate but acquires new samples over time. The researchersestablished a time frame for each version of the virus and sequenced theindividual HIV genomes from the FDCs to compare with samples from other cells.According to the study, HIV takes advantage of FDCs' ability to create newversions of the virus by staying active, avoiding treatment that coulderadicate 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 necessaryto develop treatments to target stored HIV versions on FDCs. "If we couldgo in and perhaps flush it from the surface of the cell, we might decreasedramatically the amount of virus that could perpetuate infection," Burtonsaid.

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

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