The lung is ventilated by thousand liters of air per day. Inevitably, the respiratory system
comes into contact with airborne microbial compounds, most of them harmless
contaminants. Airway epithelial cells are known to have innate sensor functions, thus being
able to detect microbial danger. To avoid chronic inflammation, the pulmonary system has
developed specific means to control local immune responses. Even though airway epithelial
cells can act as proinflammatory promoters, we propose that under homeostatic conditions …