Lung injury in C57BL/6 and BALB/c mice following H7N9 virus infection.

<p>C57BL/6 and BALB/c mice were challenged intranasally with 10⁶ TCID₅₀ of AH1/H7N9 virus and euthanized on days 0, 1, 3, 5, 7, and 14 after viral infection. (A–J) Histological changes in mouse lung tissues on days 0, 1, 3, 5, 7, and 14 postviral challenge. White and yellow arrows indicate the regeneration of pneumocytes and dissociation cells, respectively. (K) Semiquantitative assessments of lung lesions in mice on days 1, 3, 5, and 7 postviral infection (<i>n</i> = 6). The data are expressed as the mean ± SD (bar). *, **, and *** indicate <i>P</i><0.05, 0.01, and 0.001, respectively.