(Wired) A new study shows that as temperatures drop, nasal cells release fewer of the tiny protectors that bind and neutralize invading germs. Inside the sticky confines of the human nose, a gluey layer of mucus surrounds small hairs and cells. While this ooze may appear gross, it is teeming with important components of the immune system. After all, “the front of the nose is the area that is the first point of contact with the outside world,” says Benjamin Bleier, an otolaryngologist at Massachusetts Eye and Ear.
This precious mucus contains tiny extracellular vesicles—nano-sized lipid spheres—that may be critical to combating viruses like those that cause the common cold. In work recently published in the Journal of Allergy and Clinical Immunology, Bleier, along with Mansoor Amiji, a chemist at Northeastern University, determined that during viral infection, cells in the nose release a swarm of these vesicles to fight off pathogens. Critically, the scientists found that in colder temperatures this antiviral release is impaired—which could explain why colds and other upper respiratory infections become more common in the winter.