Influenza viruses can evade the human immune system: Study

Influenza commonly known as "flu" can hide itself undetected in an individual's body by the person's immune system, reveals a study.

The influenza virus that affects mainly the nose, throat, bronchi and occasionally lungs contains a protein that helps in outsmarting the immune system -- which can track viruses and alert the body of the entry of foreign virus into the human cells to multiply.

"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 recognises that it is a virus and attempts to fight it," said Christian Holm, associate professor at Aarhus University in Denmark.

The little protein that is able to mask the influenza virus from the immune system can be used to combat autoimmune diseases such as rheumatoid arthritis as well as the relatively rare disease lupus, which to a great extent affects young women, the researchers said in the study published in the scientific journal Nature Communications.

In these diseases, the immune system attacks healthy cells and tissues and creates 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," added Holm.

The researchers discovered the mechanism of the influenza virus to hide itself from the immune system by giving cells in the laboratory an evolutionarily conserved influenza virus protein.

The result was that the cells became poorer at defending themselves against both influenza viruses and other types of viruses indicating 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, concluded the researchers.