Our research is about understanding the evolution of human and animal influenza viruses, underpinning the work we do at the Worldwide Influenza Centre.
We focus on the changes that happen at a molecular level as flu viruses evolve. Small changes can have profound effects on a virus’s ability to infect and spread through humans or animals, so understanding the molecular basis for these changes helps us to predict how viruses will behave and how to protect ourselves from them.
We’re currently investigating the properties of haemagglutinin, a protein found on the surface of flu viruses that allows them to bind to and enter human or animal cells. After a flu virus multiplies inside a cell, it ‘buds’ from the cell, pushing through the cell membrane and stretching it like a balloon. As the virus remains attached to the surface of the cell, it uses an enzyme called neuraminidase to cut loose and escape the cell to go on and infect another cell or another individual.
Haemagglutinin’s ability to bind to host cells depends on various factors including its structure, and we’re interested in how these tie in with the activities of neuraminidase and susceptibility to antiviral medicines. As part of this, we are analysing the impact of glycosylation, a process that changes the structure of haemagglutinin by adding carbohydrates to it.
Glycosylation is a growing concern as it can protect flu from our immune systems. The immune system recognises distinctive shapes on haemagglutinin proteins, which can be obscured by carbohydrates. However, changes to haemagglutinin structure can also affect their ability to bind to host cells. We’re studying how glycosylation of emerging influenza A (H3N2) strains affects this balance between susceptibility to the immune system and ability to infect cells.