At a time when influenza A(H1N1) is in the news, researchers have found a reason to cheer: they have identified a cellular molecule that not only senses two common respiratory viruses but also mounts a defense to destroy them. The findings have been published online in the journal Nature Immunology.
The two respiratory viruses are influenza A (flu) and human respiratory syncytial virus (RSV).
The finding is significant as the NOD2, the cellular molecule, can be used to boost the immune system. Any therapies that come up based on the understanding of this molecule can activate the NOD2 gene during and prior to infection.
According to Santanu Bose, senior author from the University of Texas Health Science Center at San Antonio, mice that lacked this crucial molecule survived only for ten days after infection compared with up to eight weeks for mice that had the molecule.
Influenza A (flu) is common during monsoon and winter in India. Though it is self-limiting in most cases, it can be severe and even cause deaths in infants and the elderly and those with certain health conditions such as diabetes, asthma or heart disease.
According to the WHO, every year, about 3-5 million suffer from severe illness, and 2.5 lakh to 5 lakh die of flu. In the U.S. alone, according to the Centers for Disease Control and Prevention (CDC), about 2.5 lakh get hospitalised and about 35,000 die every year from flu.
Much like the case of the flu, healthy people recover from RSV in 1 to 2 weeks' time. But it can be severe in the case of the elderly and young children. RSV is the most common cause of bronchiolitis (inflammation of the small airways in the lung) and pneumonia in children under 1 year.