Fig. 2

P. aeruginosa SyBV show reduced toxicity compared to natural OMV. a, b The secretion of the pro-inflammatory cytokines TNF-α (a) and IL-6 (b) from MH-S cells treated with two doses of OMV or SyBV for 24 h (n = 3 independent samples). c The relative contribution of P. aeruginosa OMV and SyBV to TLR signaling. OMV or SyBV were treated to HEK-293 cell lines overexpressing TLR and NF-ĸB reporter genes for 18 h (n = 2 independent samples), and then optical density (OD) value was measured. Data were indicated as percentage of OD of cells treated with a positive TLR agonist. Two-way ANOVA with Tukey’s post-test was used. d Study design for examining the toxicity of SyBV in mice (left panel). The same dose of OMV or SyBV (5 × 10⁹) was intraperitoneally injected into mice, and body temperature was evaluated at 6 h (right panel; n = 5 mice per group). e, f The production of TNF-α (e) and IL-6 (f) in the peritoneal fluid at 6 h (n = 5 mice per group). g, h The concentration of TNF-α (g) and IL-6 (h) in serum at 6 h (n = 5 mice per group). i, j The concentration of TNF-α (i) and IL-6 (j) measured in BAL fluid (n = 5 mice per group). All data are presented as the mean ± s.e.m. ^**P < 0.01, ^***P < 0.001 by one-way ANOVA with Tukey’s post-test