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

HIV-1 genetic diversity is higher in vaginal tract than in blood during early infection

January 18, 2018
A first-of-its-kind study has found that the genetic diversity of human immunodeficiency virus type 1 (HIV-1) is higher in the vaginal tract than in the blood stream during early infection. This finding, published in PLOS ...

War in Ukraine has escalated HIV spread in the country: study

January 15, 2018
Conflict in Ukraine has increased the risk of HIV outbreaks throughout the country as displaced HIV-infected people move from war-affected regions to areas with higher risk of transmission, according to analysis by scientists.

Researchers offer new model for uncovering true HIV mortality rates in Zambia

January 12, 2018
A new study that seeks to better ascertain HIV mortality rates in Zambia could provide a model for improved national and regional surveillance approaches, and ultimately, more effective HIV treatment strategies.

New drug capsule may allow weekly HIV treatment

January 9, 2018
Researchers at MIT and Brigham and Women's Hospital have developed a capsule that can deliver a week's worth of HIV drugs in a single dose. This advance could make it much easier for patients to adhere to the strict schedule ...

New long-acting, less-toxic HIV drug suppresses virus in humanized mice

January 8, 2018
A team of Yale researchers tested a new chemical compound that suppresses HIV, protects immune cells, and remains effective for weeks with a single dose. In animal experiments, the compound proved to be a promising new candidate ...

Usage remains low for pill that can prevent HIV infection

January 8, 2018
From gritty neighborhoods in New York and Los Angeles to clinics in Kenya and Brazil, health workers are trying to popularize a pill that has proven highly effective in preventing HIV but which—in their view—remains woefully ...

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.