In what has been hailed as “the single most important advance” presented to the International AIDS Conference in Melbourne, Danish researchers have found a way to uncloak hidden HIV in CD4 cells.
A reservoir of the HIV virus can hide in the body for years and reactivate should a patient stop taking antiretroviral (ARV) drugs. Now, experts from Aarhus University Hospital in Denmark have discovered that an anti-cancer drug called romidepsin releases latent HIV from the infected cells.
Dubbed the “kick and kill” approach, it is hoped that once the virus is exposed it could become possible to eliminate it. “In theory,” said senior researcher Dr Ole Søgaard, “if you can activate all cells and get them killed, then you have a cured person.”
Despite excitement surrounding the finding, Dr Søgaard (pictured) stressed it was still early days. “We’re still learning about this disease and where it hides, and it is a really, really tricky disease to cure because it hides in so many places in the body,” he said. “It hides really well and can hide for an indefinite period of time.”
In the pilot study six patients — all long-term HIV and on ARV treatment — were given doses of romidepsin three times a day for two weeks. Before being administered the drug, no viral particles were detectable in the patients. “But after the dose was given we easily measured the virus being released into the plasma in five of these six patients,” said Dr Søgaard.
However, once the virus was exposed the immune system failed to attack it; researchers also found no significant reduction in the number of infected cells. As well, the virus was only visible for seven days. “It came up, then hid away again,” said Dr Søgaard, “returning back to a non-active state until the next dose of cancer drug was given. This suggests, when you do this reactivation, you also need to target and activate the immune system and teach it to recognise these cells and attack.”
Even so, experts have said that the “kick and kill” strategy is likely to have a major impact on HIV cure and treatment into the future. A new trial involving 20 patients will combine romidepsin with an experimental HIV vaccine — Vacc-4x — to see if the immune system can be stimulated to kill the virus .
BY CHRISTOPHER KELLY