Wednesday, March 17, 2010

stem cells - home of hiv?

The Scientist | Human immunodeficiency virus (HIV) can infect bone marrow cells -- including, possibly, hematopoietic stem cells, according to a study published online today (March 7) in Nature Medicine.

The findings suggest the virus can hide in an inactive state for long periods of time, evading treatment, even in individuals without detectable viral loads.

"It's a little bit surprising to see that [HIV infects] progenitor cells, and [possibly] stem cells as well," said virologist Michael Bukrinsky of The George Washington University in Washington, DC, who was not involved in the research. It's a "novel and important" discovery that "will have big implications for pathogenesis of the disease and potential treatment of these patients."

Even patients who respond to highly active antiretroviral therapy (HAART) can harbor undetectably low viral loads, which can be reactivated later in life to cause a resurgence of the disease. Resting T cells can conceal such latent infections, and are the only well established and characterized HIV reservoirs. But a recent study found circulating viral genomes that differ from those found in T cells, suggesting that additional reservoirs may also exist.