AUTHOR=Pott Gregory , Beard Scott , Bryan Courtney , Merrick Daniel , Shapiro Leland TITLE=Alpha-1 Antitrypsin Reduces Severity of Pseudomonas Pneumonia in Mice and Inhibits Epithelial Barrier Disruption and Pseudomonas Invasion of Respiratory Epithelial Cells JOURNAL=Frontiers in Public Health VOLUME=1 YEAR=2013 URL=https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2013.00019 DOI=10.3389/fpubh.2013.00019 ISSN=2296-2565 ABSTRACT=
Nosocomial pneumonia (NP) is the third most common hospital-acquired infection and the leading cause of death due to hospital-acquired infection in the US. During pneumonia and non-pneumonia severe illness, respiratory tract secretions become enriched with the serine protease neutrophil elastase (NE). Several NE activities promote onset and severity of NP. NE in the airways causes proteolytic tissue damage, augments inflammation, may promote invasion of respiratory epithelium by bacteria, and disrupts respiratory epithelial barrier function. These NE activities culminate in enhanced bacterial replication, impaired gas exchange, fluid intrusion into the airways, and loss of bacterial containment that can result in bacteremia. Therefore, neutralizing NE activity may reduce the frequency and severity of NP. We evaluated human alpha-1 antitrypsin (AAT), the prototype endogenous NE inhibitor, as a suppressor of bacterial pneumonia and pneumonia-related pathogenesis. In AAT+/+ transgenic mice that express human AAT in lungs, mortality due to