Figure 6.

The presence of IL-17 during Mtb infection in mice has adverse effects on bacterial dissemination to secondary disease sites. WT (open bars) and IL-10^−/− BALB/c (closed bars) mice were treated with anti-IL-17 Ab (or isotype control IgG) before and during infection with Mtb. Mice were killed on day 32 postinfection and the lungs were isolated, homogenized and analysed by flow cytometry on the basis of (A) GR1, CD11b expression and high side scatter in order to determine the effect of IL-17 neutralization on granulocyte levels in the lungs. Bacterial burdens were determined in the (B) lungs and (C) spleen of anti-IL-17- or isotype control-treated mice. Results are mean±SEM and are combined from two independent experiments, totalling ten mice per group except for the WT isotype-treated group in (C) where n=6 mice per group. ^*p<0.05; ^**p<0.01; ^***p<0.001 (unpaired Student's t-test).