A cure for HIV has come a step closer after the discovery of a & # 39; kill switch & # 39; which stops the reproduction of infected cells.
In laboratory tests on human cells, scientists have discovered that controlling a particular molecule can clear up dormant HIV reservoirs.
The team said they have been trying to find the switch for three decades and now believe the findings could lead to a way to eradicate AIDS.
Currently, people with HIV are taking lifelong medication called antiretroviral therapy to keep the symptoms at bay. But a cure has yet to be discovered.
The virus can be reactivated if the therapy is stopped, it multiplies rapidly and increases the risk that the virus is transmitted to others or leads to AIDS.
An estimated 36.9 million people worldwide are infected with HIV, figures suggest.
A cure for HIV is one step closer after scientists use a molecular & # 39; kill switch & # 39; have found that the reproduction of infected cells stops. Stock illustration of HIV in the bloodstream
Dr. Tariq Rana, the author of the research, said: & # 39; This is one of the most important switches that the HIV field has been looking for for three decades.
& # 39; The most exciting part of this discovery has never been seen before. (It suggests) that we have a potential therapeutic target to eradicate HIV and AIDS. & # 39;
The team from the University of California, San Diego, focused on RNA molecules in the body, which are essential for the expression of genes and different biological roles in living organisms.
The team discovered that the HIV-infected cells contained a long non-coding RNA (lncRNA). In general, lncRNA & # 39; s help determine which genes in a cell & # 39; to & # 39; or & # 39; from & # 39; to be.
They genetically sequenced more than 1,100 lncRNA and found a certain type that was raised in people with HIV.
WHY IS HIV SO HARD TO CURE?
In 1995, researchers discovered why HIV manages to return even when it appears to have been defeated.
The virus buries part of itself in latent reservoirs of the body, sleeping as & # 39; backup & # 39 ;.
It was discovered in 1996 that antiretroviral therapy (ART) could suppress the virus and prevent it from re-emerging if the drug was taken religiously.
But once that blanket is lifted, the virus rebuilds itself quickly.
Despite decades of attempts, we still do not know how to reach those hidden parts of the virus.
Perhaps the most promising approach is a & # 39; shock and kill & # 39; technique – waking the virus from its hiding place and then making it disappear.
But we do not yet know how to wake it up without harming the patient.
The American team called this specific molecule HIV-1 Enhanced lncRNA – appropriately nicknamed HEAL.
The HEAL gene appears to have emerged fairly recently and regulates HIV replication in immune cells.
In experiments, the researchers have silenced HEAL or cut it from the genome of HIV-infected cells using a gene processing program called CRISPR-Cas9.
CRISPR is a relatively new tool that scientists can use to cut DNA at a specific location, permanently changing DNA and coding.
In both cases, HIV did not return after antiretroviral therapy was stopped.
Dr. Rana said: & # 39; By genetically modifying a long non-coding RNA, we prevent recurrence of HIV in T cells – a type of white blood cell – and microglia immune cells when antiretroviral treatment is removed.
& # 39; Our results suggest that HEAL plays a crucial role in HIV pathogenesis.
& # 39; Further studies are needed to explain the mechanism that leads to HEAL expression after a person is infected with HIV, but this finding can be used as a therapeutic target. & # 39;
Despite their excitement, the team quickly adds that this is a very early test, and it has not yet been performed on animals, let alone humans.
The findings are published in the journal mBio.
HIV is spread through certain body fluids, including blood, sperm, vaginal fluids and breast milk.
People with HIV who undergo effective treatment are virally suppressed and therefore unable to pass on the virus.
A crucial moment in the hunt for an HIV cure came when scientists discovered that some & # 39; elite & # 39; people contain a mutation in their genes that makes them resistant to HIV.
Doctors in China revealed in March that a bone marrow transplant from one of these people had left an HIV patient in London free of the virus for 18 months.
And a third HIV positive patient, known as the & # 39; Düsseldorf patient & # 39 ;, showed no signs of infectivity four months after treatment.
The success came 12 years after Timothy Brown, the so-called Berlin patient, underwent a similar transplant and got rid of his antiretroviral medication.
But although the cases brought new hope, the method is currently considered too dangerous to be used on a large scale.
THE DRUGS SUPPRESSING HIV AND HIV-NEGATIVE PEOPLE TO GET IT
1. Medicines for HIV-positive people
It suppresses their viral load, making the virus non-transferable
Anti-retroviral therapy (ART) was discovered in 1996.
The drug, a triple combination, changed HIV from a fatal diagnosis to a manageable chronic condition.
It suppresses the virus and prevents it from developing into AIDS (acquired immunodeficiency syndrome), making the body resistant to infections.
After religiously taking the daily pill for six months, it suppresses the virus in such a way that it is not detectable.
And once a person's viral load is undetectable, they cannot transfer HIV to anyone else, according to dozens of studies, including a ten-year study by the National Institutes of Health.
Public health institutions around the world now recognize that U = U (non-detectable equivalent to non-transferable).
2. Medicines for HIV negative people
It is 99% effective in preventing HIV
PrEP (prophylaxis before exposure) became available in 2012.
This pill works as & # 39;the pill & # 39; – it is taken daily and is 99 percent effective in preventing HIV infection (more effective than the birth control pill in preventing pregnancy).
It consists of two medicines (tenofovir dosproxil fumarate and emtricitabine). These drugs can trigger a direct attack on any trace of HIV that enters the person's bloodstream before it can spread through the body.
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