An anti-cancer drug could activate hidden HIV, forcing it to reveal itself.

An Aarhus University research team found the cancer drug romidepsin increased virus production in HIV-infected cells between 2.1 and 3.9 times above the average viral load in the blood in five out of six patients.

The findings were presented today at the annual international AIDS conference in Melbourne, Australia. The pilot study is a piece of a larger investigation that looks into the possibility of activating HIV in order to help the immune system better fight it.

In the past the drug panobinostat has been shown to activate HIV hidden in cells, but this is the first time the virus has been activated to levels readable by standard methods. HIV has the ability to go into a state of "hibernation"in CD4 cells, which are part of the immune system. CD4 cells cannot fight HIV, but T-cells can as long as the virus is not in hibernation. This is one of the factors that have prevented medical researchers from finding an effective cure for HIV.

The recent study shows when the virus is activated and moves into the bloodstream it leaves a sign on the outside of the infected cell it emerged from, allowing T-cells to recognize and destroy them.

The medicine was tested on six HIV-infected participants. These individuals experienced "transient fatigue and nausea" which are known side effects of romidepsin, suggesting there are no special consequences for patients with HIV.

In the future the researchers hope to discover if the total HIV reservoir is lowered when T-cells are better-able to "trace and destroy" infected CD4 cells. The body's immune system may not be enough to eliminate the virus on its own, but this method could one day be used in combination with other treatments.

The team's next steps will be to conduct a bigger trial in which researchers will combine romidepsin with a vaccine (vacc-4x) that strengthens T-cells' ability to fight HIV.