STAT1, STAT2, MX and PKR protein expression of GFAP+ astrocytes, NogoA+ oligodendrocytes, and IBA1+ microglia/macrophages in cerebellar lesions of canine distemper virus-infected dogs. (A–C) STAT1 is expressed by astrocytes, oligodendrocytes and microglia/macrophages. (D–F) STAT2 was detected in oligodendrocytes and activated microglia/macrophages (gitter cells). (G–I) MX was found in astrocytes, oligodendrocytes and microglia/macrophages. (J–L) PKR is expressed by astrocytes and oligodendrocytes but not by microglia/macrophages. The majority of PKR+ cells in L are most likely lymphocytes. Immunofluorescence double-staining using bisbenzimide as nuclear counterstaining. Bars, 50 µm.