Human airway epithelial cells lining the conduction airways produce Clara Cell Secretory Protein (CCSP). This protein is an inhibitor of phospholipase A2 and has other immunomodulatory properties. A human airway bronchial epithelial cell line has been found to express mRNA for CCSP and to produce and secrete CCSP. CCSP secretion and levels of steady state CCSP mRNA were altered by treatment of these human airway epithelial cells with interferon-gamma in a time and dose dependent fashion. This project is completed. Two manuscripts have been published.