RESUMO
Host inflammatory responses must be tightly regulated to ensure effective immunity while limiting tissue injury. IFN gamma (IFNγ) primes macrophages to mount robust inflammatory responses. However, IFNγ also induces cell death, and the pathways that regulate IFNγ-induced cell death are incompletely understood. Using genome-wide CRISPR/Cas9 screening, we identified autophagy genes as central mediators of myeloid cell survival during the IFNγ response. Hypersensitivity of autophagy gene-deficient cells to IFNγ was mediated by tumor necrosis factor (TNF) signaling via receptor interacting protein kinase 1 (RIPK1)- and caspase 8-mediated cell death. Mice with myeloid cell-specific autophagy gene deficiency exhibited marked hypersensitivity to fatal systemic TNF administration. This increased mortality in myeloid autophagy gene-deficient mice required the IFNγ receptor, and mortality was completely reversed by pharmacologic inhibition of RIPK1 kinase activity. These findings provide insight into the mechanism of IFNγ-induced cell death via TNF, demonstrate a critical function of autophagy genes in promoting cell viability in the presence of inflammatory cytokines, and implicate this cell survival function in protection against mortality during the systemic inflammatory response.
Assuntos
Autofagia/genética , Interferon gama/toxicidade , Células Mieloides/patologia , Fator de Necrose Tumoral alfa/toxicidade , Animais , Autofagia/efeitos dos fármacos , Proteína 5 Relacionada à Autofagia/metabolismo , Sistemas CRISPR-Cas/genética , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Citoproteção/efeitos dos fármacos , Genoma , Camundongos Knockout , Células Mieloides/efeitos dos fármacos , Células Mieloides/metabolismo , Células Mieloides/ultraestrutura , NF-kappa B/metabolismo , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transcriptoma/genéticaRESUMO
ABBREVIATIONS: ATG5: autophagy related 5; ATG7: autophagy related 7; ATG14: autophagy related 14; ATG16L1: autophagy related 16-like 1 (S. cerevisiae); BECN1: beclin 1, autophagy related; CASP1: caspase 1; CASP4/CASP11: caspase 4, apoptosis-related cysteine peptidase; CIM: conditionally immortalized macrophage; CLP: cecal ligation and puncture; CSS: cytokine storm syndrome; DC: dendritic cell; IFNG/IFNγ: interferon gamma; IFNGR1: interferon gamma receptor 1; ip: intraperitoneal; iv: intravenous; IL12/p70: interleukin 12, p70 heterodimer; IL18: Interleukin 18; ITGAX/CD11c: integrin alpha X; LAP: LC3-associated phagocytosis; LPS: lipopolysaccharide; LYZ2/LYSM: lysozyme 2; MAP1LC3A/LC3: microtubule-associated protein 1 light chain 3 alpha; RB1CC1/FIP200: RB1-inducible coiled-coil 1; S100A8/MRP8: S100 calcium binding protein A8 (calgranulin A); TICAM1/TRIF: TIR domain containing adaptor molecule 1; TLR4: toll-like receptor 4; TNF: tumor necrosis factor.