Differences in gene expression between WT and IRF2 KO cells

Gasdermin-D (GSDMD) is cleaved by caspase-1/4/11 in response to canonical and non-canonical inflammasome activation. Upon cleavage, GSDMD oligomerizes and forms membrane pores, resulting in IL-1β secretion, pyroptotic cell death and inflammatory pathologies including periodic fever syndromes and septic shock – a plague on modern medicine. The transcriptional machinery that drives the expression of GSDMD is unknown. Here we show that IRF2, a member of the interferon-regulatory factor (IRF) family, is essential for the transcriptional activation of GSDMD. A forward genetic screen with ethyl-N-nitrosourea (ENU)-mutagenized mice unequivocally linked IRF2 to inflammasome signaling. Indeed, GSDMD transcript levels were highly attenuated in Irf2–/– macrophages upon Irf2 deficiency in macrophages, endothelial cells, and multiple organs, corresponding to attenuated IL-1β secretion and inhibited pyroptosis. Mechanistically, IRF2 binds a previously uncharacterized site within the GSDMD promoter to directly drive GSDMD transcription for execution of pyroptosis in response to canonical and non-canonical inflammasome activation. Our data illuminate a prominent transcriptional mechanism for the expression of GSDMD, a key mediator of inflammatory pathologies. RNA was extracted from HOXB-8 cells for the following genotypes - Irf2 wild type (Parental) and Irf2 knock out(IRF2 KO).