Proliferation of AM after in vitro infection of AM by AdmGM-CSF and subsequent transplant of the genetically modified AM to the lung. Shown is in vitro proliferation of AM recovered by lavage 1 and 5 weeks after AM transfer. (A) Proliferation in vitro of AM recovered 1 week after transplantation. Shown is in vitro assessment of [³H]thymidine uptake over 24 and 72 hours for AM recovered from naive mice, from mice receiving intratracheal recombinant mGM-CSF (60 ng), from mice receiving AM modified with AdNull (AM Null), and from mice receiving transplanted AM modified with AdmGM-CSF (AM GM-CSF). (B) Proliferation in vitro of AM recovered by lavage 5 weeks after AM transfer. Shown is in vitro assessment of [³H]thymidine uptake over 24 and 72 hours for AM recovered from mice receiving transplanted AM modified with AdNull (AM Null) or AM modified with AdmGM-CSF (AM GM-CSF). Note that the ordinates of (A) and (B) are different; the assays performed at 1 week (A) and 5 weeks (B) are performed at different times with fresh cells; thus, the overall extent of [³H]thymidine uptake cannot be compared between the two panels. (C) Presence of Ad genome in AM 1 and 5 weeks after AM transfer. DNA was analyzed using PCR with primers to amplify Ad genome (E4), Ad genome plus mGM-CSF transgene (Ad-GM-CSF), and HK-ATPase as control. Shown is ethidium bromide staining of amplified DNA from naive control, AM Null at 1 and 5 weeks, and AM GM-CSF 1 and 5 weeks after AM transfer.