Gasdermin E permits interleukin-1 beta release in distinct sublytic and pyroptotic phases

Cellular inflammasome activation causes Caspase-1 cleavage of the pore-forming protein gasdermin D (GSDMD) with subsequent pyroptotic cell death and cytokine release. Here, we clarify the ambiguous role of the related family member gasdermin E (GSDME) in this process. Inflammasome stimulation in GSDMD-deficient cells led to apoptotic Caspase cleavage of GSDME. Endogenous GSDME activation permitted sublytic, continuous interleukin-1β (IL-1β) release and membrane leakage, even in GSDMD-sufficient cells, whereas ectopic expression led to Pyroptosis with GSDME oligomerization and complete liberation of IL-1β akin to GSDMD Pyroptosis. We find that NLRP3 and NLRP1 inflammasomes ultimately rely concurrently on both gasdermins for IL-1β processing and release separately from their ability to induce Cell Lysis. Our study thus identifies GSDME as a conduit for IL-1β release independent of its ability to cause cell death.

GSDMD; GSDME; IL-1; cell death; gasdermin D; gasdermin E; gasdermins; inflammasome; interleukin-1; pore-forming proteins.