New hope for a HIV cure? Scientists eliminate virus in 40% of mice by using a ‘kick and kill’ technique that forces it out of hiding and makes it vulnerable to injections of killer immune cells
- Patients with HIV typically take antiretrovirals to supress the virus in their body
- Such drugs do not kill the virus, however, but inhibit it at points in its ‘life cycle’
- HIV lies dormant in certain immune cells, ready to emerge if treatment ceases
- Experts led from UCLA have shown that the ‘kick and kill’ approach has promise
- After activating the hiding virus, healthy natural killer cells are used to destroy it
- The team are looking to make the treatment more effective before human tests
A ‘kick and kill’ strategy that forces the human immunodeficiency virus out of cells — leaving it vulnerable to injections of natural killer cells — offers hope of an HIV cure.
In laboratory tests on 10 mice the approach was found to eliminate the virus in 40 per cent of cases, a team from the University of California Los Angeles (UCLA) said.
According to the UN, an estimated 38 million people worldwide are presently living with HIV, with the virus having led to some 36 million deaths in recent decades.
If refined and proven safe and effective in human trials, the concept could remove the need for people with HIV to depend on ongoing courses of antiretroviral drugs.
A ‘kick and kill’ strategy that forces the human immunodeficiency virus (pictured) out of cells — thereby making it vulnerable to existing antivirals — offers hope of an HIV cure
HOW DOES THE ‘KICK AND KILL’ TECHNIQUE ELIMINATE HIV?
UCLA researchers used a strategy which they dubbed ‘kick and kill’ to eliminate HIV in 40 per cent of mice studied.
The technique was first proposed back in 2017 and works by tricking the dormant virus in the infected cells to reveal itself using a compound called ‘SUW133’, so that it can be targeted and eliminated.
The researchers then injected healthy natural killer cells along with the SUW133 that flushes HIV out of hiding, enabling them to completely clear HIV from 4 out of 10 infected mice.
With their initial study complete, the researchers are now working to refine their approach so that it succeeds in eliminating HIV in 100 per cent of mice cohorts in future experiments.
The study was undertaken by infectious disease specialist Jocelyn Kim of the UCLA and her colleagues.
‘These findings show proof-of-concept for a therapeutic strategy to potentially eliminate HIV from the body, a task that had been nearly insurmountable for many years,’ said Dr Kim.
‘The study opens a new paradigm for a possible HIV cure in the future.’
At present, people with HIV take so-called antiretroviral medications which, rather than killing the virus, act to inhibit it at various stages in its ‘life cycle’ — such as, for example, when it enters a host cell or when it churns out new copies of itself.
While this can suppress the virus to the extent that the host’s viral load becomes both undetectable and untransmissible, HIV will still remain dormant in their system, hiding out in CD4+ T cells, which normally help coordinate immune responses.
When people with HIV stop taking their antiretroviral treatment, the virus can escape from these boltholes and carry on replicating itself in the body — weakening the immune system and increasing the risk from potentially fatal cancers and infections.
The team’s strategy — which they have dubbed ‘kick and kill’, and was first proposed back in 2017 — works by tricking the dormant virus in the infected cells to reveal itself using a compound called ‘SUW133’, so that it can be targeted and eliminated.
In a previous study, which looked at HIV-infected mice whose immune systems had been altered to match those of humans, the experts found treatment with both SUW133 and antiretrovirals killed up to 25 per cent of infected cells within 24 hours.
Looking for a more effective way to eliminate the infected cells, the researchers turned instead to so-called natural killer cells, which are produced by the body’s immune system that, as their name suggests, can kill infected or tumour cells.
By injecting healthy natural killer cells along with the SUW133 that flushes HIV out of hiding, the team were able to completely clear HIV from 4 out of 10 infected mice.
The researchers were careful to analyse the mice’s spleens in particular, as this organ is known to harbour immune cells like the CD4+ T cells in which HIV can lie dormant.
With their initial study complete, the researchers are now working to refine their approach so that it succeeds in eliminating HIV in 100 per cent of mice cohorts in future experiments.
‘We will also be moving this research toward preclinical studies in nonhuman primates with the ultimate goal of testing the same approach in humans,’ Dr Kim said.
The full findings of the study were published in the journal Nature Communications.
WHY MODERN MEDS MEAN HIV IS NOT A DEATH SENTENCE
Prior to 1996, HIV was a death sentence. Then, ART (anti-retroviral therapy) was made, suppressing the virus, and meaning a person can live as long a life as anyone else, despite having HIV.
Drugs were also invented to lower an HIV-negative person’s risk of contracting the virus by 99%.
In recent years, research has shown that ART can suppress HIV to such an extent that it makes the virus untransmittable to sexual partners.
That has spurred a movement to downgrade the crime of infecting a person with HIV: it leaves the victim on life-long, costly medication, but it does not mean certain death.
Here is more about the new life-saving and preventative drugs:
1. Drugs for HIV-positive people
It suppresses their viral load so the virus is untransmittable
In 1996, anti-retroviral therapy (ART) was discovered.
The drug, a triple combination, turned HIV from a fatal diagnosis to a manageable chronic condition.
It suppresses the virus, preventing it from developing into AIDS (Acquired Immunodeficiency Syndrome), which makes the body unable to withstand infections.
After six months of religiously taking the daily pill, it suppresses the virus to such an extent that it’s undetectable.
And once a person’s viral load is undetectable, they cannot transmit HIV to anyone else, according to scores of studies including a decade-long study by the National Institutes of Health.
Public health bodies around the world now acknowledge that U=U (undetectable equals untransmittable).
2. Drugs for HIV-negative people
It is 99% effective at preventing HIV
PrEP (pre-exposure prophylaxis) became available in 2012.
This pill works like ‘the pill’ – it is taken daily and is 99 percent effective at preventing HIV infection (more effective than the contraceptive pill is at preventing pregnancy).
It consists of two medicines (tenofovir dosproxil fumarate and emtricitabine). Those medicines can mount an immediate attack on any trace of HIV that enters the person’s bloodstream, before it is able to spread throughout the body.
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