One of the reasons anti-HIV medications have been unable to rid the body of HIV is that the virus lurks undetected in certain cells and body tissues, providing ample reservoirs that can quickly reseed the body when anti-HIV drugs are stopped. But researchers at the Gladstone Institute in San Francisco reported this week that for the first time they have been able to identify and study the cells serving as HIV reservoirs, University of California, San Francisco News reports. "The latent pool is considered to be the barrier to eradication," said senior study author Eric Verdin, also a faculty member at UCSF. "Our work is geared toward finding a way to obliterate this latent pool, which would take us closer to actually finding a cure for AIDS."
Reporting in the April 15 issue of the European Molecular Biology Organization Journal, the researchers say that a genetically engineered recombinant strain of HIV that carries a fluorescent green protein as a marker has allowed them to track the virus in the body, including in latently infected cells. They also discovered that during infection of latent cells, HIV inserts its genetic material into inactive DNA regions of the cells called heterochromatin, which allows the virus to effectively evade the effects of anti-HIV medications that target actively reproducing virus in infected cells. "Before, the study of latent infection was restricted to the analysis of rare cells circulating in the blood of infected patients," Verdin said. "We now have a laboratory model that we can use to delve deeply into what is going on."
The researchers are now trying to identify drugs that can activate latent cells and cause them to produce new copies of HIV, a process that would make the cells vulnerable to HIV antiretroviral medications. "Hopefully, we will be soon in a position to test some of these compounds in an animal model infected with a virus related to HIV," Verdin said. "This will allow us to determine whether the 'flushing' of latent pools is a viable therapeutic approach in HIV infection."