Figure 7: Importance of Aif1 for initiation of the mucosal IgA immune response.

(a) Quantification of total faecal IgA. Faeces were prepared from the chimeric mice indicated. Concentrations of total IgA were determined by ELISA. Data are means±s.e.m. from two independent experiments (n=8 per group). P value was determined with Student’s t-test. (b) Representative plots of bacterial flow cytometry. Faeces were collected from the chimeric mice indicated and suspended in PBS. Bacteria recognized by IgA were detected and their percentages determined. (c) The percentages determined in b are shown as means±s.e.m. from two independent experiments (n=12 per group). P value was determined with Student’s t-test. (d) Quantification of total IgA after long-term infection with Y. enterocolitica. Faeces were prepared from the indicated chimeric mice on day 28 after infection. Concentrations of total IgA were determined by ELISA. Data are means±s.e.m. from two independent experiments (n=6 per group). P value was determined with Student’s t-test. (e) Comparison of anti-Y. enterocolitica-specific IgA production after long-term infection. Serial diluted faecal extracts prepared from Y. enterocolitica-infected mice were subjected to ELISA by using Y. enterocolitica-coated plates. Data are means±s.e.m. from one experiment representative of two independent experiments (n=4 per group). *P<0.05, determined with Student’s t-test.