Fig. 1

Establishment of the reversibly immortalized mouse pulmonary alveolar cells (imPACs). A Isolation of primary mouse pulmonary alveolar cells (mPACs) from the alveoli of newborn CD1 mice. The primary PACs cells migrating out of the minced lung tissues barely survived passage 4.B A schematic representation of the reversible immortalization retroviral vector SSR #41. This vector contains a cistronic expression cassette for the expression of both hygromycin resistance and SV40 Large T-antigen (SV40 Large T, or SV40 LTA flanked with the FRT sites, which can be removed by Flippase recombinase (FLP). C Establishment of imPACs. Subconfluent mPACs were infected with the SSR#41retrovirus supernatant and selected with hygromycin B, leading to the establishment of imPACs. The mPACs and imPACs were seeded at the same density, passaged and photographed at the indicated time points. Representative images are shown. D Cell proliferation and viability assay. Subconfluent mPACs and imPACs were seeded at the same density and subjected to crystal violet staining at the indicated time points. Representative images are shown. E The crystal violet stained cells were dissolved for quantitative determination at A570 nm. “**” p < 0.01 compared that of the mPACs