The regulation of CC16 in lung epithelial cells in response to Klebsiella pneumoniae

Abstract

Community-acquired pneumonia (CAP) is a common acute infectious disease among elderly people. The most common cause of CAP is Streptococcus pneumoniae, followed by Klebsiella pneumoniae etc. Clara cell secretory protein is also known as club cell secretory protein or uteroglobin. This protein appears to have a protective effect against respiratory inflammatory response. We aimed to assess the expression profile of CC16 in response to Klebsiella pneumoniae in human lung epithelial cells and to treat the infected cells with EV-CC16 and rCC16. After K. pneu infection, we found that CC16 mRNA significantly decreased in BEAS-2B cells and H358, but not A549 and H441. Different proinflammatory marker genes were elevated in these cells after K. pneu infection, including IL-1β, IL-6, IL-8 and COX-2. Treatment with EV-CC16 reduced the expressions of IL-1β, IL-6 and IL-8 in BEAS-2B but not in H358 cells. Finally, rCC16 did not show anti-inflammatory effects in lung epithelial cells.