Figure. 3. Pathogen-specific IgG responses are required for downregulation of LEE virulence expression.
A, Production of total IgG and IgA against C. rodentium in the serum and luminal content of QM mice before (d0) and after (day 14) oral infection with C. rodentium. Dots represent individual mice. *, p<0.05; ***, p<0.001; N.S., not significant by Dunn's test. B, WT and QM mice were infected with C. rodentium and pathogen load in feces were determined over the indicated time. Dots represent individual mice and pooled 3 independent experiments. C, WT and QM mice were infected with the ler-lux C. rodentium strain for 5 or 14 days. Cecum and colonic tissues were collected at the indicated day and then washed with PBS to remove non-adherent bacteria. Bioluminescent imaging of ler expression of C. rodentium attached to the cecum (top) and colon (bottom). Results are representative of 3 independent experiments. See also Figure S3.