Stimulatory effect of inflammatory cytokines on α1-antichymotrypsin expression in human lung-derived epithelial cells

Abstract

Although it is a well known fact that hepatocytes are the primary source of plasma proteinase inhibitors, including α1-antichymotrypsin, this protein has also been detected in lung epithelial cells, which may suggest its local production. We have demonstrated that lung-derived epithelial cells are capable of synthesizing high levels of α1-antichymotrypsin. In normal bronchial epithelial cells, as well as in the HTB55 human adenocarcinoma cell line, α1-antichymotrypsin synthesis was under the control of inflammatory cytokines, of which oncostatin M was the most potent stimulator. This finding is consistent with a role for this inhibitor in protecting the lung epithelium from damage by chymotrypsin-like enzymes released from phagocytes such as neutrophils following pathogen invasion.