A cancer drug can flush out HIV hiding in a state of hibernation in human cells, allowing it to be detected and increasing the chances a treatment for the virus can be found, Danish researchers say.
While a human immunodeficiency virus infection can be reduced to manageable levels by a cocktail of AIDS drugs, a cure to completely eradicate all traces of HIV from a patient is still out of reach.
The virus is able to remain hidden by hibernating in cells in the human immune system known as CD4 cells, only to remerge as a full-blown infection years later.
The Danish scientists say the cancer drug known as romidepsin, developed by the U.S. biotech company Celgene and used to treat a cancer known as T-cell lymphoma, can activate hibernating HIV, causing it to move out into the open in the bloodstream where it might be targeted for treatment.
The researchers are calling it the "kick and kill" approach, as senior researchers Ole Sogaard of Denmark's Aarhus University explained at the International AIDS Conference being held in Melbourne, Australia.
Using the cancer drug "you attempt to kick the latent infected cells, so the cells that have archived HIV within their own DNA, to kick these cells out of their resting stage and expose the virus on the surface of these cells so they can be killed and eliminated by the immune system," he said.
In the Danish study six patients with HIV in which the virus had been inhibited by years of anti-retroviral drug treatment were given romidepsin for 14 days.
"What we saw was a significant release of viral particles from latent re-infected cells into the plasma of these six patients despite their being on anti-retroviral treatment," Sogaard said.
The findings raise the possibility of using such an HIV activation technique in combination with experimental AIDS vaccines to improve the human immune system's ability to combat HIV, the researchers said.
T-cells are the immune system's weapon to fight such infections, but T-cells cannot tell if a CD4 cell contains "hibernating" HIV virus.
But when driven out of hiding by the cancer drug, the virus has been shown to leave a marker on the outer surface of infected CD4 cells.
That trace may someday allow T-cells strengthened by a vaccine to identify and destroy CD4 cells infected with HIV, the researchers said.
The study is one small "step in the right direction" to an eventual HIV cure, the researchers said, although they caution that years of research and experiments still lie ahead.
"There is still a long way to go and many obstacles to overcome before we can start talking about a cure against HIV," Sogaard said.
