Figure 1. FXII-deficient animals are less susceptible to neuroinflammation.

(a) FXII levels in plasma, LN and CSF of naive and active EAE-induced WT animals at d_max (day 16) were analysed by ELISA. Data are given as mean±s.e.m. from three independent experiments, each with five animals per group (Student's t-test). (b) Histological analysis of spinal cord sections from the lumbar region of MOG_35–55-immunized WT animals at d_max is shown. Sections were stained for FXII (red) and nucleus (4,6-diamidino-2-phenylindole (DAPI), blue). Scale bar, 50 μm. (c) Active EAE was induced in WT and F12^−/− mice. Data are mean clinical scores±s.e.m. and mean cumulative scores±s.e.m. of WT and F12^−/− animals from three independent experiments (non-parametric Mann–Whitney U-test). For detailed animal numbers and additional information, see Supplementary Table 1. (d) Identification of inflammatory foci (left panels) and demyelination (right panels) in spinal cord sections from the lumbar region of WT and F12^−/− animals by haematoxylin and eosin (HE) or Luxol fast blue (LFB) staining. Scale bars, 100 μm. Quantification and representative histological sections from d_max of EAE are shown. Data are presented as mean±s.e.m. (n=3 slices of six mice per group, Student's t-test). Arrows indicate inflammation or demyelinated areas, respectively. (e) Mean clinical scores and mean cumulative scores±s.e.m. over time of WT or F12^−/− mice treated daily with intravenous injections of FXII (200 mg kg⁻¹ body weight) or corresponding vehicle since MOG_35–55 immunization are shown. (f) EAE development in WT and F12^−/− mice after adoptive transfer of encephalitogenic LN cells is shown. LN cells were isolated from WT or F12^−/− mice on day 12 post immunization and restimulated in vitro with 10 μg ml⁻¹ MOG_35–55 and 0.5 ng ml⁻¹ interleukin-12. After 72 h, 8.4 × 10⁶ LN cells were either transferred into WT or F12^−/− recipient mice. Mean clinical scores±s.e.m. over time of three independent experiments are given (non-parametric Mann–Whitney U-test). *P<0.05, **P<0.01, ***P<0.001; NS, not significant.