Platelet shedding of IL-1β–rich MPs depends on caspase-1 activation. (A) Platelets from healthy subjects were exposed to mock, infective DV-2 (DV), or heat-inactivated DV-2 (heat DV), and caspase-1 activation was evaluated through the MFI of the fluorescent probe FLICA. (B-D) Platelets were exposed to mock, DV, or heat DV in the presence or absence of the caspase-1 inhibitor YVAD. B depicts the percentage of IL-1β–expressing platelets, and panel C shows the concentration of IL-1β in the supernatant of platelets incubated in each condition. Panel D shows the percentage of IL-1β–containing MPs for each condition. The bars represent the mean ± SEM of 6 to 8 independent experiments using samples from different healthy donors. *P < .05 and **P < .01 compared with mock exposed platelets that received the same treatment (dimethylsulfoxide [DMSO] or YVAD). ^#P < .05 between DV-2–treated platelets that were incubated with YVAD or DMSO.