Figure 4. IL-17 receptor signaling is critical for bacterial specific fecal IgA secretion.

(A) Fecal IgA secretion was assayed by western blots after Il17ra^fl/fl villin cre+ and littermate cre- mice were infected orally with C. rodentium for 7 days using non reducing gel (left) and reducing gel (right) (n=5 per group). (B) Anti-C. rodentium specific fecal IgA (measured by ELISA using C. rodentium extract-coated plates). Feces were collected from C. rodentium infected Il17ra^fl/fl or Il17rc^fl/fl villin cre+ and respective littermate cre- mice at serial time points post-infection. (n=4 per group). Significant differences in the area under the curve (AUC) are designated by 2-tailed Student’s t test. Values are means ± SEM. (C) C. rodentium specific IgA secreting cells in colonic lamina propria as measured by Elispot after 14 days post C. rodentium infection (n=4 per group). (D) CD138+ IgA+ cells in the B220- CD3- population collected from colonic LP, spleen and BM were measured by FACS on day 14 post C. rodentium infection in Il17ra ^fl/fl villin cre+ and littermate cre- mice. Significant differences are designated by using ANOVA followed by Tukey’s multiple comparisons test (C). Significant differences are designated by 2-tailed Student’s t test (D). *, P < 0.05; **, P < 0.01; ***, P < 0.001. Values are means ± SEM.