Fig. 2.

Fixation of C3 on fecally shed C. rodentium: Representative histograms from flow cytometry of GFP+ events in fecal bacterial isolated from mice at 15 days of infection with C. rodentium. X-axis indicates fluorescence intensity in FL-2 (log₁₀ scale); Y-axis indicates number of events. Panels A–C demonstrate staining in a representative wildtype mouse. (A) C3 and (B) C4, but not (C) MBL-C to shed GFP+CR (black plots). Staining in control antibody-deficient JhD–/– mice (white tracings) are shown. Red asterisk indicates populations where the mean fluorescence intensity between wildtype and JhD–/– mice was significant. Similar plots are shown from a representative CVF-treated mouse showing (D) C3, (E) C4, and (F) MBL-C. The bottom row of plots shows representative histograms from a C3–/– mouse reconstituted intravenously with wildtype serum containing C3. (G) C3, (H) C4, and (I) MBL-C