British researchers have found that human genes play a key role in preventing bird flu from replicating in humans.
the study, published on wednesday Naturefound that a gene called BTN3A3 helped prevent the spread of bird flu to humans, providing a potential reason why many people did not get the bird flu.
“Although this gene has been identified before, the finding that it has antiviral activity against avian influenza is novel,” said study co-author Root Root, a scientist at the University of Edinburgh’s Roslin Institute. Pinto told Global News.
“It was a ‘yes moment’… BTN3A3 inhibited the avian strain but not the human strain. This was the first discovery,” she said.
Avian influenza, also known as avian influenza, spreads primarily among wild birds such as ducks and seagulls, but can also infect domesticated birds and poultry such as chickens, turkeys and quail.
The current epidemic circulating in North and South America is known as H5N1 clade 2.3.4.4b. A record number of birds died and infected mammals such as skunks, minks and sea lions.
Although rare, the virus can be transmitted from birds to humans. In a recent Cambodian case, an 11-year-old girl who lived near a reserve reportedly died from the virus.
A team of scientists from the MRC-University of Glasgow Virus Research Center led a four-year study to unravel the mystery behind the transmission of the virus from animals to humans. They looked at over 800 human genes and compared them when infected with seasonal viruses and avian flu.
Scientists already knew that the BTN3A3 gene is present in all humans, but they didn’t know it could help protect against bird flu. The researchers found that this gene is a strong barrier against bird flu, but not against human viruses such as seasonal flu.
The gene is found primarily in the spleen, lungs and upper respiratory tract, Pinto said.
“This is important because influenza is a respiratory virus. So it makes sense that BTN3A3 is present where the virus normally infects,” she added.
The gene’s antiviral activity evolved about 40 million years ago, Pinto said. It has developed in mammals, primarily monkeys, gorillas and, of course, humans. But Pinto said the gene tends to be absent in birds.
Although cases of bird flu in humans remain rare, Shayan Sharif, professor and associate dean at the University of Guelph Ontario College of Veterinary Medicine, warned that the virus could pose a threat to humans.
“One of the great features of bird flu viruses is that they don’t normally bind very tightly to receptors in our respiratory system,” he said. “Our salvation is the fact that we don’t feed or nurture bird flu viruses.”
But that could change as the virus mutates and tries to adapt.
Sharif said they could and have evaded genes like BTN3A3, which is why studies like the University of Glasgow are “important”, he added.
“For example, if you swab birds or mammals to identify viruses and determine if they have mutations that make them resistant to human genes, you can predict that any of them will be able to replicate in humans. But,” he said.
Focus agreed.
Viruses like bird flu can easily mutate around antiviral genes such as BTN3A3 and develop resistance, she said.
But if, for example, the virus has been spreading around a poultry farm within days, or even hours, it can be sequenced.
“Then it’s very easy to sequence the virus and say, ‘This virus might have the BTN3A3 bypass mutation,'” she says. “That way, we can strengthen health and safety measures for those who deal with these viruses, such as veterinarians and farmers.”
Part of the arsenal against bird flu
While this one gene was found to have antiviral properties, Sharif said the human body has many more of these defense mechanisms.
“This is one of many other genes that determine resistance to this zoonotic agent,” he says.
But BTN3A3 is part of a larger arsenal against any flu virus, he said.
He stressed the importance of these studies, saying that despite the current “normal” phase of bird flu, there remains the possibility of another epidemic, especially in the upcoming fall and winter.
according to Canadian environmental dataSince late January, the number of bird flu cases confirmed nationwide has been on a downward trend overall.
“I don’t think there is any guarantee that the virus won’t come back. But our hope is that it won’t have too much of an impact during the fall season,” Sharif said.
“But my understanding is that the virus is not quite over yet.”
— with files from Reuters
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