Fig. 2

M2-Exos inhibit PMN recruitment and NET formation during sepsis in vivo. WT C57BL/6 mice were administered M0-Exos or M2-Exos (300 μg/mouse) derived from mouse Raw264.7 macrophages via intraperitoneal injection 1 h after surgery. Twenty-four hours after CLP, venous blood and lung tissues were harvested. a Flow cytometry detection of the percentage of systemic circulating PMNs by staining with CD11b and Gr-1. b Absolute neutrophil number in peripheral blood. c and d Ly6G⁺ cells in the lung tissues were detected by immunohistochemistry and immunofluorescence. Scale bar, 40 μm. e Representative images showing the presence of NETs (MPO, red; citrullinated H3, green) in the lung tissues. Nuclei were counterstained with DAPI (blue). Scale bar, 40 μm. f and g Quantification of dsDNA and circulating NET structures in the plasma of mice using PicoGreen fluorescent dye and MPO-DNA-ELISA, respectively. One-way analysis of variance with Tukey’s multiple comparisons test was used for the analysis. Graphs represent means ± standard deviations, n = 5–6; *P < 0.05, **P < 0.01 compared within two groups