SCIENTISTS have identified the main “fuse” that ignites the HIV virus, raising hopes of finding a cure for AIDS.
An international study has found that HIV – the virus that causes AIDS – hides in the immune system’s “helper cells”, waiting for a chance to resume its attack on the body.
The findings, reported today in the Proceedings of the National Academy of Sciences, help explain why current treatments cannot eradicate the virus despite suppressing it for years.
The researchers examined cells from eight HIV patients who had received antiviral therapy for up to 12 years. They found that the “primary barrier” to a cure was “a remarkably stable pool” of infected CD4 cells.
CD4 cells send the signals which activate other types of immune or T-cells – including the “killer” cells – when the body is attacked by a new virus or infection.
Co-author Sarah Palmer, of the Westmead Millennium Institute in Sydney, said T-cells were the fuse that ignited the “ticking time bomb” of HIV. She said it was important to know which kinds of T-cells were likely to trigger the full-blown virus.
“HIV inserts its DNA into the body and can sit in a resting phase for years before the T-cells are woken up to fight another disease. Once they wake up and replicate, they also produce HIV – and this happens time and time again in HIV patients.”
The findings suggest that antiviral therapy prevents HIV from replicating itself, forcing it to wait until the T-cells it inhabits are replicated. Starting antiviral chemotherapy within three months of infection reduces the “reservoir” of infected T-cells, the researchers found.
But Dr Palmer said a cure was preferable because the success of antiviral treatments had encouraged apathy, resulting in a rise in unsafe sex and a minor upswing in HIV infections.
“People think the medical profession can treat HIV now. But the reality is most treatment involves long-term chemotherapy and it can make the patient sick.”
She said future research would look at ways of rousing infected cells from their dormancy to “purge the virus from these cells”.