Genetic switch to guard against escaped ’superviruses’
2013 08 14

By Priya Shetty | NewScientist



It sounds like the plot of a Hollywood disaster movie: scientists tinker with a flu virus to make it more deadly, only for the mutant strain to escape and trigger a pandemic.

Yet flu scientists are currently at loggerheads over experiments to make the H7N9 bird influenza virus that emerged in China earlier this year even more dangerous.

Some argue that "gain of function" experiments to make the virus more infectious, more deadly and drug resistant in ferrets – the best available test animal for human flu – offer up vital information that could help us defend against a pandemic.

Other scientists are concerned that deliberately creating a supervirus could provide a weapon to bioterrorists. What’s more, they point out, existing biosafety measures – such as requiring researchers to wear special safety suits and go through decontamination chambers when leaving the lab – may not be enough to prevent the virus spreading.

Now, a team led by Benjamin tenOever, at Icahn School of Medicine at Mount Sinai, New York, has devised a genetic failsafe that would switch off mutant strains if they escaped from the lab and infected humans.

Genetic tag

tenOever’s team tweaked an H3N2 flu strain, a common cause of seasonal flu, by tagging it with a single strand of microRNA, a sequence of genetic material that when paired with a complementary sequence, can switch genes on and off.

The microRNA put into the virus is chosen so that when it is met by a matching strand in its host organism, the virus’s replication genes get shut down.

By using a microRNA that exists in human and mice lung cells but not in ferrets, tenOever and his team developed a modified virus that could replicate in ferrets during their experiments but not in mice or humans, if it ever escaped the lab.

The study comes shortly after a letter was published in Science and Nature by Ron Fouchier of the Erasmus Medical Center in Rotterdam, the Netherlands, and 23 colleagues, defending such research on the basis that the best way to prevent a worst-case scenario is to provoke one.

The letter was intended to prevent a similar furore to the one that erupted in late 2011 surrounding gain of function experiments, which Fouchier also led, on another avian influenza strain, H5N1. It resulted in the publication of the work being delayed by nine months.

tenOever says that Fouchier’s H5N1 research was key in identifying mutations that would make the bird virus start to spread between mammals. "This knowledge was critical to focus our surveillance efforts to monitor the virus and predict when the risk of disease justifies vaccine development."

Unpredictable consequences

Marc Lipsitch at the Harvard School of Public Health in Boston is unconvinced. He considers gain of function studies highly risky. And the genetic failsafe proposed by tenOever’s team may itself be volatile, he says. "Engineering the restrictive sequence is a change with unpredictable consequences, which could make experiments even harder to interpret and also provide a false sense of security".

Michael Imperiale at University of Michigan in Ann Arbor agrees. "My concern is that the microRNA target on the viral genome will just mutate in the same way that a virus develops drug resistance."

[...]

Read the full article at: newscientist.com



Tune into Red Ice Radio:

Sonia Barrett & Sharry Edwards - Hour 1 - The Business of Disease

Rudy Mazzocchi - Black Market of Human Organ Transplants

H.P. Albarelli Jr. - Germ Warfare, CIA, LSD and the Murder of Dr. Frank Olson

Peter Duesberg - The Invention of AIDS

David Icke - Swine Flu, Mass Vaccinations & G20

Dr. Leonard Horowitz - The Pharmaceutical Industry, Vaccines & Frequency 528

Rupert Sheldrake - The Science Delusion

Catherine Austine Fitts - Swine Flu, Vaccination & The Economy




Related Articles
Oops: Vial of deadly virus goes missing from secure biomedical lab
U.S. virologists intentionally engineer super-deadly pandemic flu virus
"Pandemic" Simulated Reality Show has audience participate in graphic survival scenarios (Video)
Did doctors jumpstart the HIV pandemic?
The ’False’ Pandemic: Drug Firms Cashed in on Scare over Swine Flu, Claims Euro Health Chief
DARPA to Genetically Engineer Humans by Adding a 47th Chromosome
The when and where of Y: Research on Y chromosomes uncovers new clues about human ancestry


Latest News from our Front Page

If Someone Secretly Controlled What You Say, Would Anyone Notice?
2014 10 01
The subject enters a room in which a 12-year-old boy is seated. A 20-minute conversation ensues. The subject quizzes the boy about current events and other topics to get a sense of his intelligence and personality. But the boy is not what he appears to be. Unbeknownst to the subject, the boy is wearing a radio receiver in his ear, and ...
Obama has had accurate intelligence about ISIS since BEFORE the 2012 election, says administration insider
2014 10 01
‘President Barack Obama’s intelligence briefings have provided him with specific information since before he won re-election in 2012 about the growing threat of the terror group now known alternatively as ISIS and ISIL, an administration insider told MailOnline on Monday. ‘Unless someone very senior has been shredding the president’s daily briefings and telling him that the dog ate them, highly accurate ...
Can holding a magnet against your head help defeat depression?
2014 10 01
Former GP Sue Mildred suffered from crippling depression and anxiety for 20 years. On two occasions it was so severe that she ended up in hospital, and for 15 years she was unable to work. Sue, 51, has tried antidepressants, talking therapies and, out of desperation, even ECT (electro-convulsive therapy), where an electric current is passed through the brain. This did ...
Extremists to have Facebook and Twitter vetted by anti-terror police
2014 09 30
Theresa May to announce new Extremist Disruption Orders to strengthen counter-terrorism if the Tories win the next general election Extremists will have to get posts on Facebook and Twitter approved in advance by the police under sweeping rules planned by the Conservatives. They will also be barred from speaking at public events if they represent a threat to “the functioning of democracy”, ...
Scottish Independence: Protesters demand revote
2014 09 30
Pro-independence campaigners gathered outside the Scottish Parliament for the second day in a row, this time to demand a revote of the September 18 referendum. While yesterday’s “Rally For A Revote” saw the return of Saltires and Yes banners to Holyrood, it did not match the turnout for the “Voice Of The People” rally held on Saturday, when up 3000 people ...
More News »