Figure 5. Ptpra KO mice are resistant to K/BxN serum transfer arthritis.

WT and Ptpra KO littermate mice were administered 200 µl K/BxN sera at 8 weeks of age. (A) Ankle thickness was measured every 2 days (WT, n=16; KO, n=17). Mean ± SEM ankle swelling is shown. *, p<0.05, 2way ANOVA. (B) 7 days post-sera transfer, mice (n=3) were injected with intravital inflammation probe and luminescence of wrist and ankle joints was measured. Mean ± SEM luminescent counts per joint are shown. *, p<0.05, Wilcoxon matched-pairs signed rank test. (C) Histological analysis of ankles stained with H&E or Safranin-O at the end of the disease course. Left, histological scores of bone and cartilage erosions (WT, n=16; KO, n=17). Mean ± SEM is shown. *, p<0.05, Wilcoxon matched-pairs signed rank test. Right, representative images of H&E-stained (upper panels; yellow arrows indicate regions of inflammatory infiltrate) or Safranin-O-stained (lower panels; black arrows indicate regions of cartilage erosion) joints.