Similar Datasets
Project description:Human mutations in the death receptor Fas or its ligand FasL cause autoimmune lymphoproliferative syndrome (ALPS), whereas mutations in caspase-8 or its adaptor FADD â which mediate cell death downstream of Fas/FasL â cause severe immunodeficiency in addition to ALPS. Mouse models have corroborated a role for FADD-caspase-8 in promoting inflammatory responses, but the mechanisms underlying immunodeficiency remain undefined. Here, we identify NEDD4-binding protein 1 (N4BP1) as a suppressor of cytokine production that is cleaved and inactivated by caspase-8. N4BP1 deletion in mice significantly increased production of select cytokines upon Toll-like receptor (TLR) 1/2, TLR7, or TLR9 stimulation, but not upon TLR3 or TLR4 engagement. N4BP1 did not suppress TLR3 or TLR4 responses in wild-type macrophages owing to TRIF- and caspase-8-dependent cleavage of N4BP1. Notably, impaired TLR3 and TLR4 cytokine responses of caspase-8-deficient macrophages were largely rescued by co-deletion of N4BP1. Thus, persistence of intact N4BP1 in caspase-8-deficient macrophages impairs their ability to mount robust cytokine responses. Tumor necrosis factor (TNF), like TLR3 or TLR4 agonists, also induced caspase-8-dependent cleavage of N4BP1, thereby licensing TRIF-independent TLRs to produce higher levels of inflammatory cytokines. Illustrating the importance of this function of TNF in vivo, TNF blockade increased the mortality of mice infected with Streptococcus Pneumoniae, but did not do so when infected mice lacked N4BP1. Collectively, our results identify N4BP1 as a potent suppressor of cytokine responses; reveal N4BP1 cleavage by Caspase-8 as a point of signal integration during inflammation; and offer an explanation for immunodeficiency caused by FADD-caspase-8 mutations.
2020-09-09 | GSE148066 | GEO
Project description:Human mutations in the death receptor Fas or its ligand FasL cause autoimmune lymphoproliferative syndrome (ALPS), whereas mutations in caspase-8 or its adaptor FADD â which mediate cell death downstream of Fas/FasL â cause severe immunodeficiency in addition to ALPS. Mouse models have corroborated a role for FADD-caspase-8 in promoting inflammatory responses, but the mechanisms underlying immunodeficiency remain undefined. Here, we identify NEDD4-binding protein 1 (N4BP1) as a suppressor of cytokine production that is cleaved and inactivated by caspase-8. N4BP1 deletion in mice significantly increased production of select cytokines upon Toll-like receptor (TLR) 1/2, TLR7, or TLR9 stimulation, but not upon TLR3 or TLR4 engagement. N4BP1 did not suppress TLR3 or TLR4 responses in wild-type macrophages owing to TRIF- and caspase-8-dependent cleavage of N4BP1. Notably, impaired TLR3 and TLR4 cytokine responses of caspase-8-deficient macrophages were largely rescued by co-deletion of N4BP1. Thus, persistence of intact N4BP1 in caspase-8-deficient macrophages impairs their ability to mount robust cytokine responses. Tumor necrosis factor (TNF), like TLR3 or TLR4 agonists, also induced caspase-8-dependent cleavage of N4BP1, thereby licensing TRIF-independent TLRs to produce higher levels of inflammatory cytokines. Illustrating the importance of this function of TNF in vivo, TNF blockade increased the mortality of mice infected with Streptococcus Pneumoniae, but did not do so when infected mice lacked N4BP1. Collectively, our results identify N4BP1 as a potent suppressor of cytokine responses; reveal N4BP1 cleavage by Caspase-8 as a point of signal integration during inflammation; and offer an explanation for immunodeficiency caused by FADD-caspase-8 mutations.
2020-09-10 | GSE157786 | GEO
Project description:Integration of Innate Immune Signaling by 2 Caspase-8-Mediated Cleavage of N4BP1
| MSV000086111 | MassIVE
Project description:Integration of Innate 1 Immune Signaling by Caspase-8-Mediated Cleavage of N4BP1
| PRJNA662774 | ENA
Project description:Integration of Innate 1 Immune Signaling by Caspase-8-Mediated Cleavage of N4BP1 (NGS2979 RNA-seq)
| PRJNA622987 | ENA
Project description:Integration of Innate 1 Immune Signaling by Caspase-8-Mediated Cleavage of N4BP1 (NGS3269 RNA-seq)
| PRJNA662778 | ENA
Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
2013-03-29 | E-GEOD-45634 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the SubSeries listed below.
2024-04-01 | GSE218958 | GEO
Project description:Coordination among multiple signaling pathways ensures an appropriate immune response, where a signaling pathway may impair or augment another signaling pathway. Here, we report a negative feedback regulation of signaling through the key innate immune mediator MyD88 by inflammasome-activated caspase-1. NLRP3 inflammasome activation impaired agonist- or infection-induced TLR signaling and cytokine production through the proteolytic cleavage of MyD88 by caspase-1. Site-specific mutagenesis was used to identify caspase-1 cleavage site within MyD88 intermediary segment. Different cleavage site location within MyD88 defined the functional consequences of MyD88 cleavage between mouse and human cells. LPS/monosodium urate-induced mouse inflammation model corroborated the physiological role of this mechanism of regulation, that could be reversed by chemical inhibition of NLRP3. While Toll/interleukin-1 receptor (TIR) domain released by MyD88 cleavage additionally contributed to the inhibition of signaling, Waldenström's macroglobulinemia associated MyD88L265P mutation is able to evade the caspase-1-mediated inhibition of MyD88 signaling through the ability of its TIRL265P domain to recruit full length MyD88 and facilitate signaling. The characterization of this mechanism reveals an additional layer of innate immunity regulation.
| S-EPMC8767097 | biostudies-literature
Project description:DEAD (Glu-Asp-Ala-Glu) box RNA helicases have been proven to contribute to antiviral innate immunity. The DDX21 RNA helicase was identified as a nuclear protein involved in rRNA processing and RNA unwinding. DDX21 was also proven to be the scaffold protein in the complex of DDX1-DDX21-DHX36, which senses double-strand RNA and initiates downstream innate immunity. Here, we identified that DDX21 undergoes caspase-dependent cleavage after virus infection and treatment with RNA/DNA ligands, especially for RNA virus and ligands. Caspase-3/6 cleaves DDX21 at D126 and promotes its translocation from the nucleus to the cytoplasm in response to virus infection. The cytoplasmic cleaved DDX21 negatively regulates the interferon beta (IFN-β) signaling pathway by suppressing the formation of the DDX1-DDX21-DHX36 complex. Thus, our data identify DDX21 as a regulator of immune balance and most importantly uncover a potential role of DDX21 cleavage in the innate immune response to virus. IMPORTANCE Innate immunity serves as the first barrier against virus infection. DEAD (Glu-Asp-Ala-Glu) box RNA helicases, originally considered to be involved in RNA processing and RNA unwinding, have been shown to play an important role in antiviral innate immunity. The precise regulation of innate immunity is critical for the host because the aberrant production of cytokines leads to unexpected pathological consequences. Here, we identified that DDX21 was cleaved at D126 by virus infection and treatment with RNA/DNA ligands via the caspase-3/6-dependent pathway. The cytoplasmic cleaved DDX21 negatively regulates the IFN-β signaling pathway by suppressing the formation of the DDX1-DDX21-DHX36 complex. In sum, our data identify DDX21 as a regulator of immune balance and most importantly uncover a potential role of DDX21 cleavage in the innate immune response to virus.
| S-EPMC8262918 | biostudies-literature