Nox2 activity accelerates necrotic cell death. (A–E) Mice were inoculated with PR8 and 7 d later superchallenged with MRSA. (A–C) The percentages of Nox2-positive neutrophils in blood and airways at 6 dpi after coinfection (A), in blood (B), and in airways (C) at various days after MRSA or PBS inoculation of Nox2^+/− mosaic mice (n = 5) with (+Flu) or without (−Flu) before PR8 infection. Mice were treated daily with linezolid until 24 h before harvesting the samples. (A) The gray histogram represents neutrophils in Nox2^−/− airways. ***, P < 0.001, Pearson correlation. (D and E) Annexin V and FVD staining of inflammatory monocytes and neutrophils in WT (n = 8), Nox2^−/− (KO; n = 5), and Nox2^+/− (mosaic; n = 6) mice at 6 dpi. (D) Numbers indicate the mean percentages. Coinfected mice were treated daily with gentamicin until 24 h before harvesting the samples. *, P < 0.05; **, P < 0.01; ***P < 0.001, Mann Whitney test. Data shown in B and C were combined from three independent experiments. Data shown in A, D, and E are representative of at least two independent experiments. Error bars represent SD.