Figure 8: Increased susceptibility to CIA and autoantibody production in Eaf2−/− mice.
(a) Incidence (upper) and clinical scores (lower) of CIA in WT and Eaf2−/− mice. Seven pairs of WT and Eaf2−/− mice were injected with PBS or immunized with CII on day 0 and day 20. Incidence and clinical scores of CIA were recorded every 3 days between days 20 and 41. Open triangles, PBS-injected WT mice; open squares, PBS-injected Eaf2−/− mice; open circles, CII-immunized WT mice; solid circles, CII-immunized Eaf2−/− mice. *P<0.05 (upper panel, log-rank test; lower panel, unpaired t-test). (b) Haematoxylin and eosin (H&E) staining of ankle joints (original magnifications: left, × 40; right, × 100). Bars, 200μm. (c) Elevated levels of the CII-specific IgG, IgG1 and IgG2a Ab in Eaf2−/− mice. The red bar indicates the mean value of each group. *P<0.05, **P<0.01 (unpaired t-test) (d–f) Aged (17 month old) Eaf2−/− mice produce increased levels of anti-dsDNA Ab, rheumatoid factor (RF) and ANA. Levels of anti-dsDNA Ab (d) and RF (e). Open circle, WT; solid circle, Eaf2−/− mice. The red bar indicates the mean value of each group. Results of 5 WT and 11 Eaf2−/− mice are shown. *P<0.05 (Fisher’s exact test). (f) ANA. HEp-2 cells (obtained from RIKEN BioResource Center, Japan) were stained with sera from 5 WT and 7 Eaf2−/− mice (1:80 dilution). Of five WT mice, only one mouse produced ANA. In contrast, all 7 Eaf2−/− mice produced ANA, with six mice showing a homogenous staining pattern and one mouse a centromere pattern (P<0.05, Fisher’s exact test). Bars, 100 μm. Detailed results are shown in Supplementary Fig. 8a.
