(A–C) Bacterial loads were determined in lung tissue at 24, 48 and 72 h after Spn infection (1×107 CFU/mouse) from mice exposed to AdTGFβ1 (black bars) or control vector (white bars) for 14 days (A), 21 days (B) or 28 days (C), as indicated. (D–F) BAL fluid (BALF) was collected from untreated control mice (striped bars) or at 24, 48 and 72 h after Spn infection from mice exposed to AdTGFβ1 or control vector for 14 days and numbers of macrophages (D) and neutrophils (E) as well as TNF-α protein levels (F) were determined. Data are shown as mean±SD of n=4 mice per time point and treatment group, and are representative of three independently performed experiments. Data were analysed by Mann–Whitney U test. CL, untreated control mice; CFU, colony-forming unit.