Figure 3.

Effect of a single administration of adenoviruses encoding granulocyte–macrophage colony-stimulating factor (AdGM-CSF) 1 day before infection in the murine model of progressive pulmonary tuberculosis (TB). (a) Groups of mice were treated with AdGM-CSF (black bars) or control virus Addl70-3 (white bars) 1 day before intratracheal (i.t.) infection with a high dose of Mycobacterium tuberculosis (Mtb) H37Rv; five mice were killed at each day indicated and the lungs were used to determine bacterial loads by colony-forming units (CFU). A significant CFU decrease was produced by AdGM-CSF administration. (b) The morphometry study showed a significantly lower percentage of lung surface affected by pneumonia in animals treated with AdGM-CSF. (c) The number of granulomas at days 21, 28 and 60 was significantly higher in the AdGM-CSF-treated group, as well as the granuloma size at days 60 and 120 (d). Representative histopathology of the lung from treated mice after 120 days of infection with Mtb, (e) the mouse lung treated with Addl70-3 shows extensive areas of pneumonia. (f) In contrast, mouse treated with AdGM-CSF shows scarce inflammation. (g) Small granulomas are seen in mice treated with Addl70-3. (h) In comparison, bigger granulomas are formed in mouse treated with AdGM-CSF; scale bars represent 60 μm (e) and (f), and 20 μm (g) and (h). All values of bacilli loads and histomorphometry are means ± standard deviation (s.d.) of two independent experiments with five mice per group; *P < 0·05 (466 × 771 mm; 150 × 150 DPI).