Fig. 4

Colonic immune cell responses in C. jejuni strain 81–176 and/or VSL#3 associated secondary abiotic mice. Secondary abiotic mice were perorally associated either with the probiotic compound VSL#3 (+VSL; white symbols) or with C. jejuni strain 81-176 (+Cj; black symbols) on day 0. In bacterial competition experiments VSL#3 associated mice were challenged with C. jejuni strain 81–176 5 days thereafter (+VSL + Cj) or, the other way around (+Cj + VSL), C. jejuni infected mice additionally associated with the probiotic compound. The average numbers of colonic a T lymphocytes (positive for CD3), b regulatory T cells (Treg; positive for FOXP3), c B lymphocytes (positive for B220), and d macrophages and monocytes (positive for F4/80) from six high power fields (HPF, 400× magnification) per animal were determined microscopically in immunohistochemically stained colonic paraffin sections at day 21 upon initial bacterial association. Naive mice served as uninfected controls (black diamonds). Medians (black bars), numbers of analyzed animals (in parentheses) and levels of significance (p-values) determined by Mann–Whitney U test are given. Significant differences as compared to naive controls are indicated by asterisks (***p < 0.001). Data were pooled from four independent experiments