TASS, December 6. Biologists have found that the increase in cases of acute respiratory viral infections during the onset of cold weather is due to the fact that the low ambient temperature slows down the production of microbubbles with antiviral molecules in the cells of the nose. The Massachusetts Eye Hospital (MEE) press service announced it on Tuesday.
“Flu and cold outbreaks have traditionally been thought to occur during the cold season due to people spending more time indoors during this time, where viruses are easily spread through the air. We have revealed the biological reasons for the existence of these seasonal variations in the frequency of development of various forms of SARS, including coronavirus infection,” said Benjamin Blayer, associate professor at Harvard University (USA), quoted by the service print MEE.
Blair and colleagues discovered one of the main reasons for the increase in SARS during the onset of cold weather in a series of studies aimed at studying the innate immune system of the nose. A few years ago, scientists discovered that cells in the nose are able to recognize infections and produce large numbers of microbubbles filled with various antimicrobial molecules in response to the emergence of bacteria.
Subsequent experiments showed that these blisters spread throughout the thickness of the mucous membrane of the nose and upper respiratory tract, where they interact with microbes and slow their spread throughout the body. Having discovered this innate immunity system, American molecular biologists became interested in whether it was involved in counteracting seasonal SARS.
With this idea in mind, the scientists collected nasal tissue samples from dozens of healthy volunteers and patients undergoing various surgical procedures in Boston hospitals and monitored the response of these organisms to particles from three different viruses, two of the rhinoviruses that cause the common cold. , as well as a form of SARS.-CoV-2.
Observations by Blaer and colleagues showed that nasal cells begin producing microbubbles soon after first contact with all three respiratory pathogens. These structures contain fragments of various protein molecules that bind to the virus particles and prevent them from entering actual cells.
To do this, the scientists determined how the temperature inside a person’s nose changes during cold weather and used this information to correspondingly lower the temperature in the nutrient medium in which the collected tissue samples were stored.
Subsequent observations showed that a decrease in temperature of only five degrees Celsius led to the fact that the number of microbubbles produced by the cells of the nose decreased by about 42%, and the concentration of antiviral proteins in them decreased markedly. This, according to scientists, well explains why cold significantly increases the incidence of SARS.
