Fig. 6

LXA4 increased by M2-Exos downregulates CXCR2 and ROS expressions in PMNs. PMNs isolated from healthy volunteers (a and b) or septic patients (d) were activated by septic plasma (SP) and then cocultured with M0/M2-Exos (100 μg/mL) derived from PBMC-differentiated macrophages for 5 h with or without BOC-2 (10 µM) incubation. c PMNs from septic patients were directly cocultured with M0/M2-Exos (100 μg/mL) for 5 h after isolation. CXCR2 (a and c) and ROS (b and d) expressions in cocultured PMNs were detected by flow cytometry. n = 4–5. e and f WT C57BL/6 mice were administered M0/M2-Exos (300 μg/mouse) derived from mouse Raw264.7 macrophages via intraperitoneal injection 1 h after CLP. To block the LXA4 receptor, mice were treated with 50 µg/kg BOC-2 i.p. 30 min before CLP. CXCR2 (e) and ROS (f) expressions in peripheral blood neutrophils were detected by flow cytometry. One-way analysis of variance with Tukey’s multiple comparisons test was used for the analysis. Graphs represent means ± standard deviations, n = 6; *P < 0.05, **P < 0.01 compared within two groups