Fig 7.

Gene expression profiles of lung CD11b^pos DCs and lung permeability and bacterial loads in Flt3L-pretreated mice infected with PLY-deficient S. pneumoniae. (A) WT mice were pretreated with Flt3L for 5 days followed by mock infection (50 μl of PBS o.t.) or infection with PLY-competent or PLY-deficient S. pneumoniae. At days 1 and 3 postinfection, lung CD11b^pos DCs were purified by high-speed cell sorting and analyzed by real-time RT-PCR as outlined in Materials and Methods. Fold changes of TLR4 and iNOS mRNA levels were calculated in lung CD11b^pos DCs from Flt3L-pretreated mice infected with S. pneumoniae (S. pn. WT) and lung CD11b^pos DCs from Flt3L-pretreated mice infected with PLY-deficient S. pneumoniae (S. pn. ΔPLY), relative to Flt3L-treated, mock-infected mice. Lung permeability changes (B) and lung bacterial loads (C) were determined in WT mice pretreated with vehicle or Flt3L for 5 days followed by infection with S. pneumoniae (white bars) or PLY-deficient S. pneumoniae (black bars) for 3 days. Lung permeability values are shown in arbitrary units (AU). CFU data are pooled from CFU data determined in lung tissue homogenates and respective BAL fluids from the same mice. Data are presented as means ± SEM (n = 3 to 10 mice per group and time point). In panel A, significant decrease (*, P < 0.05) relative to CD11b^pos DCs from Flt3L-treated mice infected with S. pneumoniae at the respective time point is indicated. Significant differences relative to Flt3L-treated mice infected with S. pneumoniae (*, P < 0.05; **, P < 0.01) and significant increases relative to vehicle-treated mice infected with S. pneumoniae (++, P < 0.01) are indicated in panels B and C.