This is a surprising study, at least appearing in the mainstream research current. The mere act of breathing, according to the Harvard University study, generates mechanical forces that can kill flu bugs. The mechanism is of course, not perfect, but goes with the rest of the innate immune system, as part of natural immunity.
https://www.studyfinds.org/fight-off-viruses-by-breathing/
“How hard is it for people to fight off a virus? Scientists at Harvard University say it’s actually as easy as breathing, literally.
Their study reveals that the act of breathing generates immune responses that kill invading pathogens. In experiments, a “lung chip” that mimics the mechanical forces of breathing killed flu bugs. The discovery could lead to developing better medications for respiratory diseases, including COVID.
“This research demonstrates the importance of breathing motions for human lung function, including immune responses to infection, and shows that our Human Alveolus Chip can be used to model these responses in the deep portions of the lung, where infections are often more severe and lead to hospitalization and death,” says co-first author Dr. Haiqing Bai from Harvard’s Wyss Institute in a university release.
The alveoli are where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing in and out.
“This model can also be used for preclinical drug testing to ensure that candidate drugs actually reduce infection and inflammation in functional human lung tissue,” Dr. Bai adds.
Breathing helps to exercise the lungs
The average person will take more than 600 million breaths over the course of their life. They stretch and relax the lungs with each inhale and exhale, respectively. Those motions influence their development and vital functions. The study, published in Nature Communications, now shows breathing’s role in combating infection.”
“Mechanical breathing motions have a fundamental function in lung development and disease, but little is known about how they contribute to host innate immunity. Here we use a human lung alveolus chip that experiences cyclic breathing-like deformations to investigate whether physical forces influence innate immune responses to viral infection. Influenza H3N2 infection of mechanically active chips induces a cascade of host responses including increased lung permeability, apoptosis, cell regeneration, cytokines production, and recruitment of circulating immune cells. Comparison with static chips reveals that breathing motions suppress viral replication by activating protective innate immune responses in epithelial and endothelial cells, which are mediated in part through activation of the mechanosensitive ion channel TRPV4 and signaling via receptor for advanced glycation end products (RAGE). RAGE inhibitors suppress cytokines induction, while TRPV4 inhibition attenuates both inflammation and viral burden, in infected chips with breathing motions. Therefore, TRPV4 and RAGE may serve as new targets for therapeutic intervention in patients infected with influenza and other potential pandemic viruses that cause life-threatening lung inflammation.”