Description
Resident stem/progenitor cells in the lung are important for tissue homeostasis and repair. However, a progenitor population for alveolar type II (ATII) cells in adult human lungs have not been identified. Here we isolated alveolar epithelial progenitor cells (AEPCs) from adult human lungs. AEPCs showed mesenchymal stem cell (MSC)-like characteristics combined with ATII cell-phenotypes. AEPCs had the capability for self-renewal and the potential to generate ATII cells in vitro. Furthermore, cells expressing similar markers were present within alveolar walls in normal lungs and these cells were significantly increased in ATII cell hyperplasias. These results suggest that adult human lungs contain a progenitor population for ATII cells.