Fig. 5.

Innate immune cells in the colon of C. jejuni-infected gnotobiotic mice lacking MMP-2 or MMP-9. Gnotobiotic wildtype (WT; black circles), MMP-9^–/– (grey circles), and MMP-2^–/– (white circles) mice were perorally infected with C. jejuni strain 81-176 at days 0 and day 1. The average number of cells positive for (A) MPO7 (neutrophils) and (B) F4/80 (macrophages and monocytes) from at least six high power fields (HPF, 400× magnification) per animal were determined microscopically in immunohistochemically stained colonic paraffin sections derived from mice at day (d) 8 and day 14 postinfection (p.i.). Naive (N) mice served as uninfected controls. Medians (black bars) and significance levels as determined by the Mann–Whitney U test are indicated. Data were pooled from three independent experiments