Cigarette smoking is one of the most common causes of lung diseases, including lung cancer and chronic obstructive pulmonary disease, and most demographic studies of COVID-19 patients have indicated that current smokers are at increased risk of severe infection and death. But the reasons why have not been entirely clear.
The team utilized a platform known as an air-liquid interface culture, which is grown from human airway stem cells and closely replicates how the airways behave and function in humans. The airways, which carry air breathed in from the nose and mouth to the lungs, are the body’s first line of defense against airborne []—pathogens like viruses, bacteria and smoke.
This is the part that produces mucus to trap viruses, bacteria and toxins and contains cells with finger-like projections that beat that mucus up and out of the body.
smoking resulted in more severe SARS-CoV-2 infection, at least in part, by blocking the activity of immune system messenger proteins called interferons. Interferons play a critical role in the body’s early immune response by triggering infected cells to produce proteins to attack the virus, summoning additional support from the immune system, and alerting uninfected cells to prepare to fight the virus. Cigarette smoke is known to reduce the interferon response in the airways.
— source University of California – Los Angeles Health Sciences | Nov 17, 2020