Stopping The Spread Of The Mutant Flu Virus
It is the perfect setting for one of Robin Cook’s genetic-experiments-gone-wrong stories.
Virus causes disease. Scientists create mutant form of virus to develop a cure. Mutant virus escapes from lab and wreaks havoc.
Only this time, scientists have figured out a way to prevent it before it actually happens.
A group of researchers have come up with a way to control mutant forms of bird flu viruses used for lab experiments so that they don’t infect humans.
The bird flu virus caused a slight scare in the 1980s when it caused millions of poultry deaths around the world. But, the real panic came when it started mutating and passing from birds to humans, with cases of deaths being reported as recently as April this year.
So far, no functioning vaccine has been developed to protect people against the virus, although clinical trials are still going on.
Despite the scare, however, bird flu hasn’t quite turned into a pandemic, yet. That’s because, although the virus can spread from birds to humans, it cannot spread easily from human to human, like the common cold.
However, last year, scientists revealed that tweaking just a few genes in the virus’ DNA can make it spread easily from one ferret to another. This caused another wave of panic that the virus could one day become contagious among humans.
Working with these mutated viruses is dangerous (requiring extensive safety protocols), but also necessary, as figuring out how the virus attacks is the first step in finding a cure.
Adding an extra bit of genetic material to the virus’ DNA, however, stops it from infecting humans and could let scientists continue to use it on lab animals safely, according to a new study by researchers at Icahn School of Medicine at Mount Sinai, New York.
The researchers found that the presence of a type of genetic material called microRNA could potentially save humans from catching the mutated virus.
Analyzing different types of microRNAs from lung cells of humans and ferrets, they zeroed in on one particular type called the miR-192 that is absent in ferrets, but present in humans. MiR-192 can bind to specific target regions in the DNA and start or stop certain processes.
When these target regions are added to the mutant virus’ DNA, miR-192 bind to them and stop the virus from making copies of itself.
The researchers exposed both ferrets and mice to this mutant virus with the added target region.
Exposed ferrets caught and spread the mutant virus to others because they had no microRNA. Mice, because they had the special microRNA, were unharmed, even when the viral dose was increased by 10 times.
Just to make sure the addition worked, the researchers also treated mice with viruses that had a scrambled target region where the miR-192 could not bind. The mice lost weight and died within 8 days.
This “containment” approach can be applied to not only the bird flu virus but also others such as the Ebola and the SARS virus, the scientists write in their Nature Biotechnology paper. The only conditions for this mechanism to work are that the lab animals selected don’t have the special microRNA – like the ferrets – and that the viruses’ DNA can be tweaked to include the target region.
Image Credit: Thinkstock.com