New study raises hope for HIV cure

Researchers target eradication of hiding cells A new study by scientists at the University of Illinois, United States of America, has raised hope that cure for HIV may be inching closer. The researchers, based at the university’s Chicago branch, explored how to make HIV hiding inside cells visible to the immune system. About 37 million people […]

• Researchers target eradication of hiding cells

A new study by scientists at the University of Illinois, United States of America, has raised hope that cure for HIV may be inching closer.

The researchers, based at the university’s Chicago branch, explored how to make HIV hiding inside cells visible to the immune system.

About 37 million people suffer from HIV worldwide. While a lot of advances have been made in the prevention and treatment of the disease, scientists have not found a cure for it till date.

Currently, the HIV virus can hide in such a way that it cannot be detected, thus avoiding being killed off – meaning a patient can never be considered cured.

The researchers, led by Professor Jie Liang, believe they may be able to target the virus that lies dormant in cells where it is hidden from drugs and the immune system.

They claim targeting a gene inside the brain could flush the virus out of hiding and leave it vulnerable to the immune system and drugs, thereby  ridding patients of the virus.

Even in patients deemed to have an ‘undetectable’ count of the virus, there are still traces of HIV effectively sleeping inside their bodies reports  Mail Online. These are called latent viruses and don’t cause illness but cannot be destroyed by the immune system or medicines, making HIV impossible to get rid of.

The researchers claim that hijacking the gene which brings HIV out of hiding – called Tat – could expose the virus to the immune system. This could also allow antiretroviral drugs to attack the dormant virus by forcing it out into the open, in a method known as ‘shock and kill’.

Mail Online quoted Professor Liang, a biomedical engineer, as saying it is extremely difficult to flush latently-infected cells out of their latency.

The study authors refer to it as ‘the major obstacle for the eradication of HIV infection’. No existing drugs target the Tat gene circuit.

Shock and kill treatments have been trialed on HIV patients using cancer drugs called HDAC inhibitors, such as vorinostat and panobinostat.

The authors wrote in their study, published in the journal PNAS that, they have however ‘so far failed to reduce the latent reservoir’.

The researchers studied the Tat gene under different conditions using a computer model.

Professor Liang said “by targeting the Tat gene circuit with drugs or small molecules to activate it, we would be able to cause latently-infected cells to start producing more viruses and then they can be destroyed by the immune system.

“And our results suggest new ways of targeting latent cells that may lead to the eradication of the HIV virus from a host.”

The viruses’ replication is controlled by a gene called Tat, which hijacks the cell’s machinery and causes copies of HIV to be churned out.

The immune system naturally fights this process but only when Tat is ‘turned on’ and the virus is actively replicating. When the gene is ‘turned off’, HIV lies dormant in the cell.

The Tat gene has a random chance of being active or inactive at any time and can switch from one to the other spontaneously.

“The findings of this new research are promising and it’s great to see a new mechanism for eradicating HIV being investigated,” said Terrence Higgins Trust, a spokesman for the National AIDS Trust  “But it’s important to emphasise that this is very preliminary modeling which still hasn’t made it to the lab. So while we hope the results will help us move towards finding a cure in years to come, that won’t be for a long while.”

HIV progressively damages crucial cells in the immune system, weakening the body’s ability to fight infections. It leads to AIDS  if left untreated. AIDS is the collective name for a series of deadly infections which the weakened immune system cannot tackle.