Immune cell implicated in development of lung disease following viral infection Findings could help explain how asthma, COPD, severe COVID-19 are triggered Holtzman Lab A new study from Washington University School of Medicine in St. Louis implicates a type of immune cell — called a dendritic cell — in the development of chronic lung diseases that can follow after a respiratory viral infection. Shown is a stained section of mouse lung. Epithelial cells, which line the airway, are red. Dendritic cells are green. Any cell nuclei are blue. Newswise — Scientists at Washington University School of Medicine in St. Louis have implicated a type of immune cell in the development of chronic lung disease that sometimes is triggered following a respiratory viral infection. The evidence suggests that activation of this immune cell — a type of guardian cell called a dendritic cell — serves as an early switch that, when activated, sets in motion a chain of events that drives progressive lung diseases, including asthma and chronic obstructive pulmonary disease (COPD).