Alveolar epithelial cell (specify type as needed: Alveolar type I epithelial cell or Alveolar type II epithelial cell) (AT1 (for Alveolar type I epithelial cell), AT2 (for Alveolar type II epithelial cell))

Alveolar epithelial cells comprise the essential lining of the distal lung air sacs (alveoli), mainly represented by type I and type II cells. Type I cells are thin and flat, forming the vast majority of the alveolar surface and enabling efficient gas exchange between air and blood. Type II cells are cuboidal and provide several critical functions, including production of pulmonary surfactant (which reduces surface tension and prevents alveolar collapse), as well as acting as progenitor cells that regenerate both AT1 and AT2 populations after injury[1][2][3][4][5]. These cells collectively maintain alveolar integrity, modulate immune and inflammatory responses, and play key roles in lung repair, especially in response to insults, infections, and diseases such as COVID-19, in which AT2 cells are major entry points for the SARS-CoV-2 virus[2][3][5].

Other names

Alveolar epithelial cellPulmonary epithelial cellType I alveolar cell (AT1)Type II alveolar cell (AT2)Alveolar pneumocyteType I pneumocyteType II pneumocyte

Enhancement of surfactant production/replacement; Modulation of epithelial repair/regeneration; Inhibition of viral entry (e.g., via ACE2 blockade on AT2 cells[2])