Figure 8.

A–G: IFN-γ treatment protects mice from infection-induced blood vessel hyperpermeability in the lung. Virus-infected adult mice (n = 3) were injected intraperitoneally with IFN-γ or PBS and the effect of these treatments on lung blood vessel permeability was determined by using Evans blue dye extravasation. A: Blue discoloration of the lung tissue of IFN-γ- and PBS-treated mice 3 days after inoculation. The black lines indicate the areas examined in more detail in B–G. B–G: The deposition of Evans blue dye in lung tissue (pink) was examined in frozen sections of the formalin-fixed tissue by using a fluorescence microscope. Scale bars: 200 μm (B–D); 100 μm (E–G).