Establishment of pulmonary alveolar type II cell line from p53-deficient mice

We obtained a pulmonary alveolar type II epithelial cell line, MAC7, derived from the lung of p53-deficient mice (p53 -/-). When this cell line was passaged for long periods of time, the epithelial cells grew at a high rate for over 50th passage and never entered the non-growing senescent phase characteristic of the normal cells (p53 +/+). Each pulmonary epithelial outgrowth was characterized morphologically and immunocytochemically, and the growth and viability of the outgrowths were examined by MTT assay. Expression of surfactant-associated protein, SP-B, was detected, and transmission electron microscopy demonstrated a type II phenotype containing lamellar bodies and phospholipids. These findings indicate that MAC7 cells retain the morphological and physiological properties of alveolar type II epithelial cells. This cell line should be useful in experimental systems for studying lung pathology.