Chronic Heat Stress Weakened the Innate Immunity and Increased the Virulence of Highly Pathogenic Avian Influenza Virus H5N1 in Mice
Figure 4
Lung and trachea histopathology following H5N1 infection in mice. Representative lung or trachea sections from each group were stained by H&E (400×). (a) The lung lesions in the TN group of mice showed peribronchiolitis. Solid arrows indicate a reduction in the number of mucous epithelial cells in bronchioles, and unshaded arrows indicate interstitial edema and inflammatory cellular infiltration around small blood vessels and the bronchioles. (b) The tracheal lesions in the TN group of mice. Unshaded arrows indicate erythrocyte infiltration. (c) The lung lesions in the CHS group of mice showed severe alveolitis, peribronchiolitis, and bronchopneumonia. The solid arrows indicate a reduction in necrosis and the number of mucous epithelial cells in bronchioles, with unshaded arrows indicating extreme interstitial edema and vast inflammatory cellular infiltration. Triangles indicate alveolar lumens flooded with edema fluid mixed with exfoliated alveolar epithelial cells, erythrocytes, and inflammatory cells. (d) The tracheal lesions in the CHS group of mice. Solid arrows indicate exfoliation or necrosis of tracheal mucous epithelial cells, and unshaded arrows indicate erythrocytes and inflammatory cellular infiltration in the tube cavity of the trachea.
