Fig. 3.

Virus infection is more widespread in the lungs of wild type mice compared with those of IFNγR^-/-mice. Whole lung sections were paraffin-embedded, stained with antibody to H1N1 virus and imaged by light microscopy or scanned for virus antigen using the NanoZoomer Digital Slide Scanner. (A) Representative lung Section 2 dpi. Arrows indicate virus antigen positive areas. (B) Map of lung sections from individual mice at 2 dpi showing sites of active virus infection. Areas positive for viral antigen are outlined in black. Images are from four individual mice. Slide bar is 1 mm. (C) Virus antigen positive areas at 2 and 4 dpi were quantitated using NDP.view software (Hamamatsu). Graph shows the percentage of total lung area positive for virus antigens per mouse with median. **p < 0.01, (taking into account total lung area imaged as a covariate, and experiment as a fixed effect). Data are from two independent experiments, n = 4 mice per group, per experiment.