The research described in this thesis focuses on the responses of lung epithelial cells lining the airways and alveoli. In the study, the effects of viruses that cause lung infections on these... Show moreThe research described in this thesis focuses on the responses of lung epithelial cells lining the airways and alveoli. In the study, the effects of viruses that cause lung infections on these epithelial cells were mapped in detail. Combinations with exposure to cigarette smoke were also included. To do this, epithelial cells obtained from lung tissue were cultured in the lab and exposed to rhinovirus, a common cold virus, and to SARS-CoV-2, which causes COVID-19. Exposure of the epithelial cells to these viruses induces very specific reactions in the airway epithelium. These can be further affected by cigarette smoke. The results of our research have taught us more about the processes specifically involved in the different responses of the epithelium, and how external factors such as cigarette smoke influence these responses. For example, we now better understand how cigarette smoke leads to a higher infection rate of rhinovirus, and it has become clear that the response of the airway epithelium to SARS-CoV-2 differs from the response to other coronaviruses. Our findings are therefore important for a better understanding of the role of viral infections in patients with chronic obstructive pulmonary disease (COPD), and for understanding what makes SARS-CoV-2 a unique virus. Show less