Scientists have discovered a key gene that blocks avian flu in humans

Scientists from University of Glasgow have discovered an important gene which block most avian flu viruses from invading the human body. According to the Nature publication, the BTN3A3 human gene which is expressed in our respiratory tracts protects against most avian flu. The gene acts as a firewall to most flu viruses and becomes activated once humans are exposed to the virus.

Spill over events where individuals get infected from animals were also investigated by the scientists. A spill over of infection between species is capable of initiating a new pandemic. The BTN3A3 gene prevented the replication of avian flu in human cells, but seasonal human flu viruses were resistant to BTN3A3 gene.

Avian flu viruses like H7N9 which infected over 1500 persons in 2013 had genetic mutations that facilitated their escape from the blocking influence of BTN3A3 gene, the study says.

Viruses, including bird flu viruses are constantly finding ways to evade the human immune defenses. By several genetic mutations, it is possible that a virus could bypass BTN3A3. This is a major concern among virologists with efforts currently ongoing to unravel the immune evading mechanisms of most viruses. The aim of the University of Glasgow scientists is to constantly evaluate and sequence the genes of all avian flus that are now circulating in birds. The sequences of the viruses will provide insight on which of the virus has the highest potential to spill over to humans.

According to University of Glasgow, “All the human influenza pandemics, including the devastating 1918-19 global flu pandemic and the swine flu pandemic in 2009 were caused by influenza viruses that were resistant to BTN3A3. As result, this study suggests that having resistance to this gene may be a key factor in whether any flu strain has human pandemic potential”

The world is currently grappling with the worst form of avian flu outbreak in history. The Avian flu virus – H5N1, is presently affecting farms all over the world and particularly in Europe where outbreaks have been reported in wild and domestic birds, and in mammals across 24 countries, a WHO report says.

The scientists concluded that “sensitivity or resistance to BTN3A3 is another factor to consider in the risk assessment of the zoonotic potential of avian influenza viruses“