Figure 3. Id2 mediates the colonization resistance against C. rodentium through IL-22 dependent regulation of microbiota.
(A) RorccreId2fl/fl (KO) and their littermate Id2fl/fl (WT) mice were infected with 2 × 109 CFU of C. rodentium. The mRNA expression of IL-22, RegIIIγ and RegIIIβ antimicrobial proteins in the colon of naive or 5 days infected mice were measured by real-time PCR. Data are representative of two independent experiments (n = 3 to 5 per group; mean ± s.e.m.).
(B, C) WT mice were injected intraperitoneally with either anti-IL-22 antibody (8E11.9, 100 μg per mouse per week, n=5) or mouse IgG control (n=5) at 3, 4, 5 weeks old. Two weeks later, 7 weeks old WT and KO mice were orally infected with low dose (5 × 106 CFU) of C. rodentium. (B) Fecal C. rodentium titers at indicated day post infection. (C) Survival rates are shown. Dash line, limit of detection. Data are representative of two independent experiments.
(D) Germ free (GF) wild type B6 mice or
(E) GF Ltbr−/− mice were colonized with the microbiota from either anti-IL-22 or mouse IgG treated WT mice by gavage of cecal material. One day later, these mice were orally inoculated with low dose (5 × 106 CFU, D; 1 × 107 CFU, E) of C. rodentium and fecal C. rodentium titers were examined at indicated day post infection. Data are representative of two (D) or three (E) independent experiments.
Each dot represents one individual mouse (B, D, E). Error bars represent SEM. **P<0.01, ***P<0.001; ns, no significant difference (Student’s t-test). nd, nondetectable. See also Figure S3.