Incognito influenza: Flu virus masks itself to avoid being attacked, study says

© Miguel Vidal
Influenza is apparently sneakier than believed, going incognito in the body to avoid detection by the immune system. The flu virus masks itself with a protein, allowing it to easily and quickly spread before being attacked, according to new research.

The study, conducted by researchers at Aarhus University in Denmark, found that the flu virus can circumvent the body's defense system for some time before finally being detected.

"The virus contains a protein that masks the virus entering the cell. In this way, the influenza virus can spread more easily before the immune system recognizes that it is a virus and attempts to fight it," Christian Holm, an associate professor in the Department of Biomedicine, said in a statement.

The secret weapon of the flu virus has been developed through evolution, according to the researchers, who discovered the finding after giving cells in the laboratory an evolutionary conserved influenza virus protein. The result was that the cells became poorer at defending themselves against influenza and other types of viruses.

"This indicates that the recognition mechanism in the immune system that the influenza virus evades is generally important for the body's ability to defend itself against viruses,” Holm said.

Holm and his colleagues believe the discovery could be used to develop better treatment against influenza.

“The more knowledge we have about why a virus becomes dangerous, the easier it is to develop treatments," Holm said.

But he also believes the finding could potentially help with developing treatments for autoimmune diseases such as rheumatoid arthritis and lupus. In those diseases, the immune system attacks healthy cells and tissues for an unknown reason, creating chronic inflammation.

"The protein's immunosuppressant effect can possibly be used to develop better treatments for these types of diseases, where the immune system is chronically overactive. By suppressing the immune system's reaction, the symptoms can be reduced. The results of our research can also be used to examine this in more detail," Holm said.

The research was published in the journal Nature Communications.