Colonic immune cell responses following <i>A</i>. <i>butzleri</i> infection of gnotobiotic IL-10^-/- mice.

<p>Gnotobiotic IL-10^−/− mice were generated by antibiotic treatment and perorally infected either with <i>A</i>. <i>butzleri</i> strain CCUG 30485 (circles) or strain C1 (squares). Uninfected gnotobiotic IL-10^−/− mice served as negative controls (black diamonds). The average number of cells positive for <b>(A)</b> CD3 (T lymphocytes), <b>(B)</b> FOXP3 (regulatory T cells, Tregs), <b>(C)</b> B220 (B Lymphocytes) and <b>(D)</b> F4/80 (macrophages and monocytes) from at least six high power fields (HPF, 400 x magnification) per animal were determined microscopically in immunohistochemically stained colonic paraffin sections derived from mice at day six p.i. (filled symbols) and day 16 p.i. (open symbols). Numbers of analyzed animals are given in parentheses. Medians (black bars) and significance levels as determined by the Mann-Whitney U test are indicated. Data were pooled from three independent experiments (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0139402#pone.0139402.s003" target="_blank">S3 Table</a>).