CR2-FH colocalized with and decreased glomerular C3b/iC3b/C3c in Cfh−/− mice. (A) Representative images of glomerular C3b/iC3b/C3c in Cfh−/− mice injected with a single dose of CR2-FH, FH(1–5), or PBS. C3b/iC3b/C3c was visualized using a rat anti-mouse C3b/iC3b/C3c monoclonal antibody (green). Alexa 594-conjugated rabbit anti-mouse FH polyclonal antibody was used to detect CR2-FH (red). CR2-FH (red) colocalized with the linear C3b/iC3b/C3c (green) staining. This linear staining was reduced in intensity in CR2-FH-injected animals compared with either the FH(1–5) or PBS group. Granular C3b/iC3b/C3c staining was demonstrable 24 and 48 hours after CR2-FH injection. Original magnification, ×40. (B) Quantitative immunofluorescence demonstrated a reduction in glomerular C3b/iC3b/C3c in the CR2-FH group compared with either the FH(1–5)- or PBS-injected mice at 2, 24, and 48 hours. Horizontal bars denote median values. *P<0.05 versus PBS. **P<0.001 versus FH(1–5) and PBS. ***P<0.001 versus FH(1–5) and P<0.01 versus PBS. Bonferroni’s Multiple Comparison Test. AFU, arbitrary fluorescent units.