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

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