Figure 7
STAT1 is mainly expressed in CD11b+ cells. Cerebella and spinal cords isolated from the different groups of mice on day 14 post EAE induction were analyzed for STAT1 expression close to the inflammatory foci and in the normal appearing white or gray matter (NAW/GM). In the CNS of IFNγ-/- mice and IFNγRKO-chimeras STAT1 expression was rarely detected, while CD11b+ cells were abundant both in the cerebellum and spinal cord (A-D, I-L). STAT1 expression was readily detectable in the CNS of WT mice and WT-chimeras both within the inflammatory foci (E, G, Q and S) and in the NAW/GM (F, H, R and T). In IFNγRCNSKO mice, STAT1 expression was prominent in CD11b+ cells within the inflammatory foci (M, O), while it was rarely detected in CD11b+ cells with ramified morphology away from the inflammatory lesions (N, P). In the CNS of IFNγRperiKO mice, the majority of CD11b+ cells with amoeboid morphology (activated microglia or macrophages) in the inflammatory foci did not express STAT1 (U, W). STAT1 was mainly expressed by CD11b+ cells located in the normal appearing gray matter, exhibiting morphology similar to that of ramified microglia (V, X). Space bar = 50 μm. Inserts show selected magnified fields to confirm STAT1 upregulation. Space bar = 10 μm. Nuclei were visualized by DAPI staining. Two (out of 4-6) representative mice per set are shown.