Key gene blocks bird flu from spreading to humans - Roslin Institute

This is according to a new study that has found a key human gene responsible for blocking the spread of most avian flu viruses in humans.

The gene , known as BTN3A3, which is normally expressed in the human respiratory tract, provides a key human defense against avian influenza.

Through a series of extensive tests, the research team was able to show that the BTN3A3 gene is vital in protecting humans from avian flu, as most strains of the virus cannot overcome this defense.

An international study on the pandemic potential of avian influenza was led by the Center for Viral Research (CVR) at the University of Glasgow (MRC) and supported by the Roslin Institute and published in the journal Nature.

“Identifying BTN3A3-resistant variants when they first appear in birds can help prevent infection in humans,” said Ruth Maria Pinto of the Roslin Institute. “Control measures against emerging avian influenza viruses can be tailored specifically against those resistant to BTN3A3, in addition to other genetic traits known to be important in zoonotic transmission.

The team also studied avian influenza viruses that occasionally infect humans, such as H7N9, which has infected more than 1,500 people since 2013 with a 40% fatality rate.

The researchers were able to show that avian influenza viruses such as H7N9 have a genetic mutation that allows them to avoid the blocking effects of the BTN3A3 gene.

Finally, by studying the evolution of avian flu strains, the scientists were also able to show that the number of BTN3A3-resistant strains circulating in poultry increased at about the same time as side effects in humans.

By tracking the history of influenza pandemics in humans, the researchers were also able to link BTN3A3 resistance to key influenza virus types.

All human influenza pandemics, including the 1918 outbreak and the 2009 swine flu pandemic, have been caused by BTN3A3-resistant influenza viruses.

As a result, this study suggests that the presence of resistance to this gene may be a key factor in whether any influenza strain has human pandemic potential.