Avian influenza: genetic markers identified that could guide future surveillance

Researchers at The Pirbright Institute have identified the genetic markers on avian influenza viruses that could help the viruses to jump the species barrier and cause disease in people, in collaboration with other members of the One Health Poultry Hub.

Co-investigators Professor Munir Iqbal and Dr Joshua Sealy worked with scientists at Imperial College London, the University of Glasgow and The Francis Crick Institute, to show how the genetic traits of avian influenza H9N2 viruses influence their preference for infecting bird or human cells. The paper detailing their findings is published in the Journal of Virology.

The research identifies genetic traits that alter the H9N2 haemagglutinin protein, that makes it easier for the virus to recognise and bind to different cell receptors. This is the first step of viral infection, and the general inability of avian influenza viruses to effectively bind to human receptors is a major reason why they do not, in general, jump the species barrier to people.

However, given that human infections with H9N2 have been detected on an almost monthly basis since 2015, there may be a capacity for these viruses to evolve and gain the ability to efficiently target cellular receptors in people.

This latest discovery reveals which haemagglutinin properties of existing H9N2 strains allow them to bind to human receptors more effectively. These included small genetic differences as well as the overall structure and charge of the haemagglutinin protein. These findings will help guide future avian influenza surveillance by providing the genetic markers that signify the emergence of viruses with the potential to transmit to people.

Article: Peacock, T. P., Sealy, J. E., Harvey, W. T., Benton, D. J., Reeve, R., Iqbal, M. (2020). Genetic determinants of receptor-binding preference and zoonotic potential of H9N2 avian influenza viruses. Journal of Virology, advance online publication, doi: 10.1128/JVI.01651-20

[SOURCE: The Pirbright Institute]