Figure 1
Binding capacity of ultrasmall superparamagnetic iron oxides (USPIOs) conjugated to anti-C3 antibodies compared with unconjugated antibodies. Passage of USPIO-conjugated antibodies through the placenta and foetal blood–brain barrier. (ai) USPIO-conjugated anti-C3 antibodies were used to detect C3 deposition in renal glomeruli from MRL/lpr mice. USPIO-conjugated anti-C3 antibodies were used as primary antibodies and fluorescein isothiocyanate (FITC)-conjugated as secondary antibodies. Positive staining was found in the kidneys from MRL/lpr mice. (aii) Detection of C3 deposition in the kidneys from MRL/lpr mice using unlabelled anti-C3 antibodies. (bi) USPIO-conjugated anti-C3 antibodies did not bind to the kidneys from C3-deficient mice (bii) Immunohistochemical studies using unlabelled anti-C3 antibodies demonstrate the absence of C3 deposition in renal glomeruli from C3-deficient mice (C3−/−), indicating that the binding of USPIO-conjugated anti-C3 antibodies to C3 is specific. (c) Immunohistochemical studies, using FITC-conjugated anti-rat immunoglobulin G1 (IgG1) performed after the magnetic resonance imaging studies show the presence of USPIO-conjugated antiC3 antibodies in the placental labyrinth of antiphospholipid syndrome (APS) mice (c), foetal brain from APS mice (d) and in foetal brain from preterm birth mice injected with USPIO-anti-C3 (e). The respective controls are mIgG-treated mice and age-matched mice. The first and third panels (left to right) in panel c show the placenta in APS- and mIgG-treated mice. Original magnification × 40. The second and fourth panels correspond to the labyrinth area. Original magnification × 20. Microphotographs (a–e) represent one of 4–5 similar experiments. The brain diagram shows the area of the cortical brain where the microphotographs were taken. The placental diagram shows the location of the labyrinth within the mouse placenta.
