Fig 2: Plasma complement profile following daily FH doses. Recombinant versions of (A, C, E) murine FH, or (B, D, F) human FH were administered IP daily to CFH-/- mice for ten days. Plots show FH (A, B), C3 (C, D) and anti-FH antibody (E, F) levels in plasma, pre-injection (P), and at 24 hours, five days, and 11 days after the first injection. The dotted line (at 165 µg/mL) is mean plasma C3 concentration in wild-type mice, *P=0.0192, **P=0.0255, ***P=0.0033 versus pre-injection values, Dunn’s Multiple Comparisons. Horizontal bars denote mean values.

Fig 3: Glomerular C3 immunostaining in CFH-/- mice following repeat dosing of FH. Animals received ten daily injections of recombinant mFH or recombinant hFH (or vehicle) and were culled at day 11. Glomerular C3 (A), C3d (B) and IgG (C) were assessed, and representative images shown. Quantitation of fluorescence intensity, in arbitrary fluorescent units, is plotted with horizontal bars denoting mean values. *P=0.0317, **P=0.0159 versus PBS, Mann-Whitney Test.

Fig 4: Desialylation of FHR-1 and FHR-3 in patient H837 by 2D-WB analysis. FHR1 and FHR3 partially purified from sp1 and sp2 from patient H837 and from a control individual were subjected to 2D-electrophoresis and Western-blot with polyclonal antibodies. The characteristic ladder of FHR-3 spots (each having different Mw and isoelectric point) appeared as a few basic spots of lower Mw in the patient sample obtained 1 day after SP-HUS diagnosis (H837 sp1), and was recovered in the sample drawn 3 months later (H837 sp2). A similar situation applies to FHR-1. The small boxes within the gel images indicate the neuraminidase activity detected in samples sp1 and sp2 from patient H837.

Fig 5: Glomerular C3 immunostaining in CFH -/- mice after mFH injection. (A) Representative images of C3 staining 24 hours after injection of FH (or vehicle) as indicated below each image. White arrow indicates tubulo-interstitial C3 staining in animals receiving mouse serum-derived FH. (B) Quantitation of fluorescence intensities expressed in arbitrary fluorescent units with horizontal bars denoting mean values. Rec. mFH, recombinant mFH.