Epithelial Cells of a COPD Patient (IMAGE) Washington University School of Medicine Caption This photomicrograph depicts airway epithelial cells from lung tissue of a COPD patient. The cell nuclei have been stained to reveal IL-33, a type of signaling molecule found at high levels in COPD patients. New research shows that viral infection can induce these cells to proliferate. Release of IL-33 from these cells promotes inflammatory mucus production. These findings provide insight into the mechanisms linking acute infection to chronic inflammatory lung disease. Credit Holtzman lab Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.