Figure 3.

Deficiency of DNASE1 and DNASE1L3 does not affect NETosis or cytokine response to bacteria. Mice of the indicated genotypes were infected i.v. with 1 × 10⁷ CFU of S. aureus and sacrificed 18 or 72 h later. (A–D) Levels of the indicated cytokines in the plasma. Bars represent mean ± SEM of n = 5–9 mice per group; dotted lines represent levels in uninfected WT mice. (E–G) Frequency of neutrophils among total single cells in the blood (E) and kidneys (F), and absolute numbers of neutrophils in the kidneys (G) 72 h after infection. Symbols represent individual mice; bars represent mean ± SEM of 9–11 mice per group; dotted lines represent levels in uninfected WT mice. (H) Detection of NETs in the plasma of infected mice using ELISA for myeloperoxidase-DNA complexes. Symbols represent individual mice; bars represent the median of two to eight mice per group; bronchoalveolar lavage fluid from mice with lung neutrophilia was used as a positive control (Pos ctrl). (I–K) Mice of indicated genotypes were given two daily doses of LPS (LPS-1, LPS-2) and one dose of LPS with heat-killed E. coli (LPS-3+E. coli). (I) Animal weights during the experiment. Data represent mean ± SD of 7–10 mice per group; dotted line indicates the 20% weight loss cutoff used for endpoint criteria. (J) Animals were monitored for survival after the last injection based on >20% weight loss or signs of distress. (K) H&E-stained sections of lungs at 24 h or 40 h following LPS + E. coli injection. Images are representative of at least seven mice per group. Scale bars, 50 μm. Statistical significance was determined by Kruskal–Wallis test followed by Dunn’s multiple-comparison test for comparisons between genotypes at the same time point (A–G). Two-tailed P values <0.05 (*), <0.01 (**), <0.0001 (****); ns, not significant. Only significant differences are indicated in A–G.