N-GSDMD trafficking to neutrophil organelles facilitates IL-1β release independently of plasma membrane pores and pyroptosis

作者：Mausita Karmakar, Martin Minns, Elyse Noelani Greenberg, Jose R Diaz-Aponte, Kersi Pestonjamasp, Jennifer L. Johnson, Joseph K. Rathkey, Derek W. Abbott, Kun Wang, Feng Shao, Sergio Catz, George Dubyak, Eric Pearlman · 发表于：Nature Communications · 年份：2020 · DOI：10.1038/s41467-020-16043-9 · 被引用次数：453 · 研究领域：Inflammasome and immune disorders、Heme Oxygenase-1 and Carbon Monoxide、IL-33, ST2, and ILC Pathways

Abstract Gasdermin-D (GSDMD) in inflammasome-activated macrophages is cleaved by caspase-1 to generate N-GSDMD fragments. N-GSDMD then oligomerizes in the plasma membrane (PM) to form pores that increase membrane permeability, leading to pyroptosis and IL-1β release. In contrast, we report that although N-GSDMD is required for IL-1β secretion in NLRP3-activated human and murine neutrophils, N-GSDMD does not localize to the PM or increase PM permeability or pyroptosis. Instead, biochemical and microscopy studies reveal that N-GSDMD in neutrophils predominantly associates with azurophilic granules and LC3 + autophagosomes. N-GSDMD trafficking to azurophilic granules causes leakage of neutrophil elastase into the cytosol, resulting in secondary cleavage of GSDMD to an alternatively cleaved N-GSDMD product. Genetic analyses using ATG7-deficient cells indicate that neutrophils secrete IL-1β via an autophagy-dependent mechanism. These findings reveal fundamental differences in GSDMD trafficking between neutrophils and macrophages that underlie neutrophil-specific functions during inflammasome activation.