AIDS cure: Study sees advance for 'kick and kill' strategy

July 22, 2014

The elusive quest for an HIV cure received a boost at the world AIDS conference Tuesday as scientists said they had forced the virus out of a hiding place where it had lurked after being suppressed by drugs.

The experiment, carried out with six HIV-infected volunteers, is an important advance in the so-called "kick-and-kill" approach for a cure, they said.

The technique aims to force the human immunodeficiency (HIV) from its last redoubt after it is beaten back by .

These drugs can bring HIV in the blood to below detectable levels, enabling sick patients to return almost miraculously to normal life. But the therapy has to be taken every day, is costly and carries potential side effects.

If the drugs are stopped, HIV usually rebounds within a few weeks and starts once more to infect other immune cells, exposing the body to opportunistic microbes.

So scientists, for the last three years, have focused on ways to kick HIV out of its bolthole and then kill the hideaway cells.

In a presentation at the International AIDS Conference in Melbourne, researchers from Aarhus University in Denmark described a step forward in the first stage of this process.

Six patients who were on antiretrovirals took an anti-cancer drug called romidepsin, which prompted virus production in HIV-infected cells to crank up to between 2.1 and 3.9 times above normal. In five patients, the level of virus in the blood increased to measurable levels, an important threshold.

The pilot study sought only to see if it was possible to flush out the hiding virus and make it detectable.

Further work will show whether all the remaining virus was exposed this way. And a way has to be found to destroy the holdout cells where HIV reproduces after waking up.

"We have now shown that we can activate a hibernating virus with romidepsin and that the activated virus moves into the bloodstream in large amounts," said lead researcher Ole Schmeltz Sogaard.

"This is a step in the right direction but there is a long way to go and many obstacles to overcome before we can start talking about a cure against HIV."

HIV 'fingerprint'

Seen through a microscope, the reactivated virus leaves a trace on the outside of infected CD4 as it returns to the bloodstream, he said.

The hope is that this tiny smear, rather like a fingerprint at a crime scene, can be spotted by so-called killer T-cells, the immune system's heavy armour.

The researchers now hope to combine romidepsin to wake up the dormant HIV and then use a vaccine called vacc-4x to prime T-cells to recognise and then destroy the bolthole.

The six volunteers did not suffer any major side effects from romidepsin, apart from known complaints such as passing fatigue and nausea, and the lymphoma drug did not interfere with their antiretrovirals.

Cure research suffered a big disappointment in the run-up to the 2014 AIDS forum with the news that a strategic prong—delivering a powerful dose of at a very early stage of infection—is unlikely to work.

Hopes had centred on an American infant known as "the Mississippi Baby", who was born with HIV. She was given drugs immediately at birth and the treatment continued for 18 months, when physicians lost track of her.

When doctors next checked her five months later, they found no sign of the virus. Now, though, it has been found that after the child had lived for 27 months without HIV and drugs, the virus has bounced back.

Research on lab monkeys published on Sunday in the journal Nature suggests HIV's haven, formally called the reservoir, is established within days of infection.

On Monday, scientists at Temple University in Philadelphia reported using an enzyme to snip out HIV genes from infected human cells in a lab dish, a useful but still very early contribution towards a cure.

Explore further: Search for AIDS cure pushes ahead despite setbacks

Related Stories

Search for AIDS cure pushes ahead despite setbacks

July 19, 2014
Scientists on Saturday vowed to press ahead with their quest for a cure for AIDS, despite losing a veteran colleague and suffering a setback in research.

Why the immune system fails to kill HIV

July 18, 2014
Our immune system contains CD8+ T cells which protect us from various diseases such as cancer and viruses. Some of them are specifically tasked with killing cells infected with the HIV virus – and researchers from Karolinska ...

New findings show strikingly early seeding of HIV viral reservoir

July 20, 2014
The most critical barrier for curing HIV-1 infection is the presence of the viral reservoir, the cells in which the HIV virus can lie dormant for many years and avoid elimination by antiretroviral drugs. Very little has been ...

Predicting which HIV patients will respond better to future therapeutic vaccine

July 18, 2014
A new study suggests that HIV patients with a higher level of a particular biomarker, or a measurable indicator found in the blood, may respond more favourably to an experimental immune activating vaccine.

'Mississippi Baby' now has detectable HIV, researchers find

July 10, 2014
The child known as the "Mississippi baby"—an infant seemingly cured of HIV that was reported as a case study of a prolonged remission of HIV infection in The New England Journal of Medicine last fall—now has detectable ...

New drug regimen speeds TB treatment

July 21, 2014
An experimental cocktail of three drugs can dramatically shorten the time it takes to treat patients infected with TB strains that are hard to cure with conventional antibiotics, according to research presented Monday at ...

Recommended for you

Scientists capture first high-resolution image of key HIV protein transitional state

July 13, 2017
A new, three-dimensional snapshot of HIV demonstrates the radical structural transformations that enable the virus to recognize and infect host cells, according to a new study led by scientists at The Scripps Research Institute ...

Barrier to autoimmune disease may open door to HIV, study suggests

July 11, 2017
Researchers from the University of Colorado School of Medicine have discovered that a process that protects the body from autoimmune disease also prevents the immune system from generating antibodies that can neutralize the ...

Team tests best delivery mode for potential HIV vaccine

June 20, 2017
For decades, HIV has successfully evaded all efforts to create an effective vaccine but researchers at The Scripps Research Institute (TSRI) and the La Jolla Institute for Allergy and Immunology (LJI) are steadily inching ...

Mathematical modeling uncovers mysteries of HIV infection in the brain

June 19, 2017
After uncovering the progression of HIV infection in the brain thanks to a new mathematical model developed by a UAlberta research team, clinicians and researchers are developing a nasal spray to administer drugs more effectively.

Understanding HIV's persistence

June 19, 2017
Most cells in the human body have a limited lifespan, typically dying after several days or weeks. And yet, HIV-1 infected cells manage to persist in the body for decades. Current treatment for HIV is very effective at suppressing ...

Knowing HIV levels are 'undetectable' may affect sexual behavior

June 15, 2017
Understanding and responding to behavioral trends in groups that are at high risk for HIV infection is critical to the development of effective strategies that decrease HIV incidence and improve access to care. New research ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.