FIG 4.
IFNAR signaling in astrocytes mediates protection against viral encephalomyelitis. (A) IFNARfl/fl (n = 12) and mGFAPcre IFNARfl/fl (n = 14) mice infected with MHV A59 were monitored for disease progression as described in Materials and Methods and for survival rate. (B) Virus titers in brain supernatants were quantified by plaque assay (n = 4/group/time point). Titers are from one experiment representative of two independent experiments. Data for panels A and B were analyzed by the unpaired two-tailed Student t test. Asterisks indicate significance between IFNARfl/fl and mGFAPcre IFNARfl/fl mice: **, P < 0.01; ***, P < 0.001; ****, P < 0.0001. (C) Representative images of viral N protein distribution in brains from both mouse groups at day 6 p.i. detected by immunoperoxidase staining using MAb J3.3 (red chromogen; hematoxylin counterstain). Scale bars, 1 mm. Insets show the infected area or cells at higher magnifications. The arrow indicates typical neuronal morphology, and the arrowhead indicates glial morphology. Scale bars, 50 μm.