Characterization of the antibacterial effect of b-MVs. (A) Effect of various inhibitors (cytochalasin B 10μM; latrunculinA 10μM; jasplakinolide 1μM; wortmannin 300nM; all added 5 minutes before incubation), absence of glucose or presence of blocking CD18-antibodies (clone TS1/18), or 1mM EDTA or 1μM DPI or pretreatment with distilled water or with saponin (1 mg/mL) on antibacterial effect of b-MVs. Change in S aureus growth was measured after 30 minutes incubation with the indicated sample. 100% represents the initial bacterial count that did not change in the absence of nutrients, but increased during the 30 minutes incubation period when inactive or destroyed vesicles were present. It was controlled that inhibitors in the applied concentration and time as well as absence of glucose by themselves did not affect bacterial growth. Bars and points indicate mean, ± SEM, n = 4; #P < .05. (B) Proteomic analysis of the contents of PMN-derived MVs. Equal amount of total protein was analyzed in the different samples. Proteins were ranked by spectral count.³²  (C) Western blot of lactoferrin and myeloperoxidase of s-MVs and b-MVs produced by 2 × 10⁷ PMNs. Actin is shown as loading control. (D) Densitometric analysis of lactoferrin and myeloperoxidase signal related to total protein content of MVs (± SEM; n = 5); #P < .05. See also supplemental Tables 1 and 2.