Oxidized ATP, but not KN-62, prevents microvesicle shedding. Immature DCs in standard saline solution were seeded on a glass coverslip at 37°C at a concentration of 10⁵/mL and were preincubated for 2 hours with the covalent P2XR blocker oATP prior to stimulation with 100 μM BzATP or 3 mM ATP (A). Image acquisition and analysis were as in Figure 1. Blocking of P2X₇R was also run by supplementing sucrose saline solution with 100 nM KN-62 (B, ▪) or by overnight incubation of DCs with 10 μg/mL of a monoclonal anti-P2X₇R (C, ▪). The negative control was run in the presence of irrelevant mouse IgG (⊡). Bar = 10 μm. Data are averages ± SE of 3 experiments performed with cells from 3 different donors.