Volume 125, Issue 1, Pages 162-177 (July 2003) Bacteroides vulgatus protects against escherichia coli-induced colitis in gnotobiotic interleukin-2-deficient mice  Marc Waidmann, Oliver Bechtold, Julia-stefanie Frick, Hans-anton Lehr, Sören Schubert, Ulrich Dobrindt, Jürgen Loeffler, Erwin Bohn, Ingo B Autenrieth  Gastroenterology  Volume 125, Issue 1, Pages 162-177 (July 2003) DOI: 10.1016/S0016-5085(03)00672-3

Figure 1 Influence of the intestinal microflora on the survival rate of IL-2−/− mice. Mice were kept under germ-free conditions (◊), or were colonized with E. coli mpk (■), B. vulgatus mpk (▵), both E. coli mpk and B. vulgatus mpk (□), or E. coli Nissle (○). Survival rate was monitored between 5 and 33 weeks of age (n = at least 11 for each group). #P < 0.01 compared with all other groups (log-rank test). Gastroenterology 2003 125, 162-177DOI: (10.1016/S0016-5085(03)00672-3)

Figure 2 Representative colonic sections of 33-week-old gnotobiotic IL-2+/+ and IL-2−/− mice. All sections were stained with H&E. (A) E. coli mpk monocolonized IL-2+/+ and (B) IL-2−/− mice; (C) B. vulgatus mpk monocolonized IL-2+/+ and (D) IL-2−/− mice; (E) co-colonization of IL-2+/+ and (F) IL-2−/− mice with E. coli mpk; and (G) B. vulgatus mpk monocolonization of IL-2+/+ and (H) IL-2−/− mice with E. coli Nissle. Sections in A, C-H show normal architecture of colonic mucosa with no significant inflammatory infiltrates and no mucosal injury. B exhibits pronounced inflammation of mucosa and submucosa with focal crypt abscesses and destruction of crypt epithelium in association with neutrophilic and mononuclear infiltrates. Original magnification, ×200. Gastroenterology 2003 125, 162-177DOI: (10.1016/S0016-5085(03)00672-3)

Figure 3 Inflammation of the colon in IL-2+/+ and IL-2−/− mice at 20 (▴) and 33 (•) weeks of age. Histology slides were scored blinded by one pathologist as described in the Materials and Methods section. Each triangle or circle represents one animal. ∗P < 0.01 compared with mice of the same colonization status (Wilcoxon test). #P < 0.01 compared with all other IL-2−/− groups. Gastroenterology 2003 125, 162-177DOI: (10.1016/S0016-5085(03)00672-3)

Figure 4 Number of bacteria (A, B. vulgatus; B, E. coli) in colonic feces of IL-2+/+ (black bars) and IL-2−/− (grey bars) SPF and gnotobiotic mice (A, B, n = 3–18 animals). Each value represents the mean log10 CFU ± SD. ∗P < 0.05 compared with SPF mice of the same haplotype (Student t test). nd, not detected. Gastroenterology 2003 125, 162-177DOI: (10.1016/S0016-5085(03)00672-3)

Figure 5 Detection of E. coli mpk and B. vulgatus mpk in transverse colon sections of 20- or 33-week-old IL-2−/− mice by FISH. All sections were counterstained with di-amino-phenylindol. l, Lumen; v, villi; c, crypts. (A) Colon from B. vulgatus mpk monocolonized mouse hybridized with probe (B) B. vulgatus-Cy3, and (C) colons from E. coli mpk monocolonized mice hybridized with probe Ent-Cy3, (D) colon from E. coli mpk/B. vulgatus mpk co-colonized mouse hybridized with probes Ent-fluorescein isothiocyanate and B. vulgatus-Cy3. Arrows indicate stained bacteria. Original magnification, 640×. Gastroenterology 2003 125, 162-177DOI: (10.1016/S0016-5085(03)00672-3)

Figure 6 (A) Adhesion of bacteria to epithelial cells. The indicated bacterial strains were centrifuged onto the cell monolayers, and the number of adherent bacteria was determined after 30 minutes of incubation. Adhesion is expressed as the percentage (means of triplicate wells ± SD) of the initial inoculum recovered and representative for 3 independent experiments. (B) Production of KC by epithelial cell monolayers on 4 hours of coculture with the indicated bacterial strains at a multiplicity of infection of 0.1 (left hatched bars), 1 (black bars), 10 (right hatched bars), and 100 (open bars). The data are representative for 4 independent experiments. (C-F) Giemsa stain of epithelial cell monolayers cocultured with bacteria for 4 hours. (C) Not infected, (D) E. coli mpk, (E) E. coli Nissle, and (F) B. vulgatus mpk. Original magnification, 20×. Gastroenterology 2003 125, 162-177DOI: (10.1016/S0016-5085(03)00672-3)

Figure 6 (A) Adhesion of bacteria to epithelial cells. The indicated bacterial strains were centrifuged onto the cell monolayers, and the number of adherent bacteria was determined after 30 minutes of incubation. Adhesion is expressed as the percentage (means of triplicate wells ± SD) of the initial inoculum recovered and representative for 3 independent experiments. (B) Production of KC by epithelial cell monolayers on 4 hours of coculture with the indicated bacterial strains at a multiplicity of infection of 0.1 (left hatched bars), 1 (black bars), 10 (right hatched bars), and 100 (open bars). The data are representative for 4 independent experiments. (C-F) Giemsa stain of epithelial cell monolayers cocultured with bacteria for 4 hours. (C) Not infected, (D) E. coli mpk, (E) E. coli Nissle, and (F) B. vulgatus mpk. Original magnification, 20×. Gastroenterology 2003 125, 162-177DOI: (10.1016/S0016-5085(03)00672-3)