Vesicular transplantation of gasdermin pores propagates pyroptosis

Pyroptosis—inflammatory cell death mediated by gasdermins (GSDM)—plays crucial roles in antimicrobial defense and inflammatory diseases. Pyroptosis results in the release of proinflammatory molecules, including damage-associated molecular patterns (DAMPs). However, our understanding of the consequences of pyroptosis—especially beyond IL-1 cytokines and DAMPs—that govern inflammation is limited. Here, we show intercellular propagation of pyroptosis from dying cells to bystander cells in vitro and in vivo. We identified extracellular vesicles (EVs) released by pyroptosing cells as the propagator of lytic death to naïve cells, triggering inflammatory responses and tissue damage. Remarkably, DNA-PAINT super-resolution and immunoelectron microscopical analyses revealed the presence of GSDMD nanostructures, such as pores, on EVs released by pyroptotic cells. Importantly, the transplantation of these GSDMD pores on adjacent cells’ plasma membrane by EVs causes cell-extrinsic lysis of bystanders. Overall, our findings demonstrate that cell-to-cell vesicular transplantation of GSDMD pores disseminates pyroptosis, revealing a domino-like effect shaping disease-associated bystander cell death. To assess the biological effects of pyroptotic EVs and explore the physiological importance of bystander pyroptosis, total RNA was extracted from the spleens of Gsdmd-/- mice injected with EVs from pyropototic PBS- or dox-stimulated iBMDM-iGSDMD-NT cells. Reads in .fastq files were trimmed using cutadapt/3.5.