LONDON: Scientists behind a new study may have found the biological reason we get more respiratory illnesses in winter. It turns out the cold air itself damages the immune response occurring in the nose.
In fact, reducing the temperature inside the nose by as little as 5 degrees Celsius kills nearly 50 per cent of the billions of virus and bacteria-fighting cells in the nostrils, according to the study published in The Journal of Allergy and Clinical Immunology.
“Cold air is associated with increased viral infection because you’ve essentially lost half of your immunity just by that small drop in temperature,” said rhinologist Dr Benjamin Bleier, director of otolaryngology at Massachusetts Eye and Ear and an associate professor at Harvard Medical School in Boston.
A respiratory virus or bacteria invades the nose, the main point of entry into the body. Immediately, the front of the nose detects the germ, well before the back of the nose is aware of the intruder, the team discovered.
At that point, cells lining the nose immediately begin creating billions of simple copies of themselves called extracellular vesicles.
When under attack, the nose increases production of extracellular vesicles by 160 per cent, the study found.
There were additional differences – EV’s had many more receptors on their surface than original cells, thus boosting the virus-stopping ability of the billions of extracellular vesicles in the nose. – Agencies
