Soft palate plays important role in transmissible influenza viruses
Using ferrets as study subjects, the researchers gathered evidence that the soft palate, which is a mucous-coated soft tissue that separates the nasal cavity from the mouth, is a crucial part of how flu viruses spread via the air.
Mammals contract flu infections when a specific influenza virus protein, known as hemagglutinin, binds to molecules called sialic acid (SA). This creates chain-like proteins that accumulate in tissue within the respiratory tract. Flu viruses have adapted to mammals in such a way that the viruses prefer to bind to an SA known as alpha 2,6 SA. This is the main form that is contained within the upper respiratory tract in mammals. For example, avian flu viruses prefer to bind to alpha 2,3 SA, which is mostly found in birds.
The scientists created four mutations within the hemagglutinin gathered from flu strains involved in the 2009 influenza pandemic that was infamous for its ability to spread between people. The mutations were meant to make the virus less transmissible, but this virus spread just as well as the others.
This is how the scientists discovered the important role of the soft palate, which could help better predict when viruses are likely to cause pandemics.