Scientists used a DNA-snipping enzyme called
Cas9 to cut out the virus. The cell’s gene
repair machinery then takes over, soldering
the loose ends of the genome back together –
resulting in a virus-free cell.
Process could also be a cure for other latent
infections, researchers say ‘It’s an exciting
discovery, but not ready to go into the clinic,’
said Dr Khalili.
Once HIV conquers a human cell, it will stay
there forever. It inserts its deadly genome
permanently into its victims’ DNA, forcing
them to require medical treatment for the rest
of their life.
But now, for the first time, researchers in
Philadelphia have found a way to completely
delete HIV from human cells by ‘snipping’
them out.
For the first time, researchers in Philadelphia
have found a way to completely delete the HIV
virus (pictured) from human cells by ‘snipping’
them out. The process could also provide a
cure for other latent infections.
The team of Temple University School of
Medicine said the breakthrough marks the
first successful attempt to eliminate latent
HIV-1 virus from human cells – and could be a
cure for other latent infections.
‘This is one important step on the path
toward a permanent cure for AIDS,’ said Kamel
Khalili, PhD, Professor and Chair of the
Department of Neuroscience at Temple.
‘It’s an exciting discovery, but it’s not yet
ready to go into the clinic. It’s a proof of
concept that we’re moving in the right
direction,’ he added,
In a study published by the Proceedings of the
National Academy of Sciences, Dr Khalili and
colleagues detail how they created molecular
tools to delete the HIV-1 proviral DNA.
Researchers based the two-part HIV-1 editor
on a system that evolved as a bacterial
defence mechanism to protect against
infection.
When deployed, a combination of a DNA-
snipping enzyme called a nuclease and a
targeting strand of RNA called a guide RNA
(gRNA) hunt down the viral genome and
remove the HIV-1 DNA.
Dr Khalili’s lab engineered a 20-nucleotide
strand of gRNA to target the HIV-1 DNA and
paired it with a DNA-sniping enzyme called
Cas9 and used to edit the human genome.
From there, the cell’s gene repair machinery
takes over, soldering the loose ends of the
genome back together – resulting in virus-free
cells.
When deployed, a combination of a DNA-
snipping enzyme called a nuclease and a
targeting strand of RNA called a guide RNA
(gRNA) hunt down the viral genome and
remove the HIV-1 DNA.
From there, the cell’s gene repair machinery
takes over, soldering the loose ends of the
genome back together – resulting in virus-free
cells.
‘Since HIV-1 is never cleared by the immune
system, removal of the virus is required in
order to cure the disease,’ explained Dr Khalili.
These molecular tools also hold promise as a
therapeutic vaccine; cells armed with the
nuclease-RNA combination proved impervious
to HIV infection.
Worldwide, more than 33 million people have
HIV, including more than 1 million in the
United States.
Every year, another 50,000 Americans contract
the virus, according to the U.S. Centers for
Disease Control and Prevention.
In the UK, around 100,000 people were living
with HIV in the UK in 2013. That’s around one
person in 665.
Although highly active antiretroviral therapy
(Haart) has controlled HIV-1 for infected
people in the developed world over the last 15
years, the virus can rage again with any
interruption in treatment.
Worldwide, more than 33 million people have
HIV, including more than 1 million in the
United States. ‘This is one important step on
the path toward a permanent cure for AIDS,’
said Kamel Khalili, PhD, Professor and Chair
of the Department of Neuroscience at Temple
‘The low level replication of HIV-1 makes
patients more likely to suffer from diseases
usually associated with ageing,’ Dr Khalili said.
These include cardiomyopathy – a weakening
of the heart muscle – bone disease, kidney
disease, and neurocognitive disorders.
‘These problems are often exacerbated by the
toxic drugs that must be taken to control the
virus,’ Dr Khalili added.
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