Gene induction in STAT1-/- fibroblasts transduced with lentiviruses expressing human cGAS
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE52241 | GEO | 2013/12/01
SECONDARY ACCESSION(S): PRJNA227234
REPOSITORIES: GEO
Similar Datasets
Project description:The hypothesis tested was that lentiviral driven cGAS expression activates antiviral gene expression. Cells were transduced with lentiviruses expressing cGAS or a control (firefly luciferase). Total RNA was harvested 48 h post-transduction and processed for Illumina BeadArray.
2013-12-01 | E-GEOD-52241 | biostudies-arrayexpress
Project description:Upon recognition of aberrantly located DNA, the innate immune sensor cGAS activates STING/IRF-3-driven antiviral responses. Here we characterized the ability of a specific variant of the cGAS-encoding gene MB21D1, rs610913, to alter cGAS-mediated DNA sensing and viral infection. rs610913 is a frequent G>T polymorphism resulting in a P261H exchange in the cGAS protein. Data from the International Collaboration for the Genomics of HIV suggested that rs610913 nominally associates with HIV-1 acquisition in vivo. Molecular modeling of cGAS(P261H) hinted towards the possibility for an additional binding site for a potential cellular co-factor in cGAS dimers. However, cGAS(WT) or cGAS(P261H)-reconstituted THP-1 cGAS KO cells shared steady-state expression of interferon-stimulated genes (ISGs), as opposed to cells expressing the enzymatically inactive cGAS(G212A/S213A). Accordingly, cGAS(WT) and cGAS(P261H) cells were less susceptible to lentiviral transduction and infection with HIV-1, HSV-1, and Chikungunya virus as compared to cGAS KO- or cGAS(G212A/S213A) cells. Upon DNA challenge, innate immune activation appeared to be mildly reduced upon expression of cGAS(P261H) compared to cGAS(WT). Finally, DNA challenge of PBMCs from donors homozygously expressing rs610913 provoked a trend towards a slightly reduced type I IFN response as compared to PBMCs from GG donors. Taken together, the steady-state activity of cGAS maintains a base-line antiviral state rendering cells more refractory to ISG-sensitive viral infections. rs610913 failed to grossly differ phenotypically from the wild-type gene, suggesting that cGAS(P261H) and wild-type cGAS share a similar ability to sense viral infections in vivo.
2022-05-25 | GSE203334 | GEO
Project description:cGAS maintains basal antiviral state
| PRJNA839440 | ENA
Project description:The cytosolic DNA sensor cyclic GMP-AMP (cGAMP) synthetase (cGAS) has emerged as a fundamental component fueling the anti-pathogen immunity. Because of its pivotal role in initiating innate immune response, the activity of cGAS must be tightly fine-tuned to maintain immune homeostasis in antiviral response. Here, we reported that neddylation modification was indispensable for appropriate cGAS-STING signaling activation. Blocking neddylation pathway using neddylation inhibitor MLN4924 substantially impaired the induction of type I interferon and proinflammatory cytokines, which was selectively dependent on Nedd8 E2 enzyme Ube2m. We further found that deficiency of the Nedd8 E3 ligase Rnf111 greatly attenuated DNA-triggered cGAS activation while not affecting cGAMP induced activation of STING, demonstrating that Rnf111 was the Nedd8 E3 ligase of cGAS. We further identified Lys231 and Lys421 as the key neddylation sites in human cGAS. Mechanistically, Rnf111 interacted with and polyneddylated cGAS, which in turn promoted its dimerization and enhanced the DNA-binding ability, leading to proper cGAS-STING pathway activation. In the same line, the Ube2m or Rnf111 deficiency mice exhibited severe defects in innate immune response and were susceptible to HSV-1 infection. Collectively, our study uncovered a vital role of the Ube2m-Rnf111 neddylation axis in promoting the activity of the cGAS-STING pathway and highlighted the importance of neddylation modification in antiviral defense.
2021-02-22 | PXD024088 | Pride
Project description:Cytosolic DNA activates cyclic GMP-AMP (cGAMP) synthase (cGAS), an innate immune sensor pivotal in anti-microbial defense, senescence, auto-immunity and cancer. cGAS is considered a sequence-independent DNA sensor with limited access to nuclear DNA because of compartmentalization. However, the nuclear envelope is a dynamic barrier and cGAS is present in the nucleus. Here, we identify determinants of nuclear cGAS localization and activation. We show that nuclear-localized cGAS synthesizes cGAMP and induces innate immune activation of dendritic cells, but cGAMP levels are 200-fold lower than following transfection with exogenous DNA. Using cGAS ChIP-seq and a GFP-cGAS knock-in mouse, we find nuclear cGAS enrichment on centromeric satellite DNA, confirmed by imaging, and to a lesser extent with LINE elements. The non-enzymatic N-terminal domain of cGAS determines nucleo-cytoplasmic localization, enrichment on centromeres and activation of nuclear-localized cGAS. These results reveal a preferential functional association of nuclear cGAS with centromeres.
2019-02-27 | GSE125431 | GEO
Project description:The cyclic oligonucleotide-based anti-phage signalling system (CBASS) is a typeof innate prokaryotic immune system. Composed of a cyclic GMP-AMP synthase (cGAS) and CBASS-associated proteins, CBASS utilizes cyclic oligonucleotides to activate antiviral immunity. One major class of CBASS contains a homolog of eukaryotic ubiquitin-conjugating enzymes, which is either an E1-E2 fusion or a single E2. However, the functions of single E2s in CBASS remain elusive. Here, we report that a bacterial E2 enzyme regulates cGAS by imitating the ubiquitination cascade. This includes the processing of the cGAS C-terminus, conjugation of cGAS to a cysteine residue, ligation of cGAS to a lysine residue, cleavage of the isopeptide bond, and poly-cGASylation. The poly-cGASylation activates cGAS to produce cGAMP, which acts as an antiviral signal and leads to cell death. Thus, our findings reveal a unique regulatory role of E2 in CBASS.
2024-02-27 | PXD050178 |
Project description:Detection of viral infection by pattern-recognition receptors triggers production of interferon. Secreted interferon binds to cognate receptors, triggering JAK/STAT signaling, resulting in the transcription and production of hundreds of interferon-stimulated genes (ISGs). Our lab identified interferon alpha inducible protein 6 (IFI6) as an ISG that potently suppresses replication of viruses from the Flavivirus genus. To test whether the inhibitory effects of IFI6 were due to activating expression of other antiviral ISGs, we overexpressed IFI6 and a control vector and examined global transcription using RNA-Seq.
2018-12-01 | GSE105771 | GEO
Project description:Detection of viruses by innate immune sensors induces protective antiviral immunity. The viral DNA sensor cGAS is necessary for detection of HIV by human dendritic cells and macrophages. However, synthesis of HIV DNA during infection is not sufficient for immune activation. The capsid protein, which associates with viral DNA, has a pivotal role in enabling cGAS-mediated immune activation. We now find that NONO is an essential sensor of the HIV capsid in the nucleus. NONO protein directly binds capsid with higher affinity for weakly pathogenic HIV-2 than highly pathogenic HIV-1. Upon infection, NONO is essential for cGAS activation by HIV and cGAS association with HIV DNA in the nucleus. NONO recognizes a conserved region in HIV capsid with limited tolerance for escape mutations. Detection of nuclear viral capsid by NONO to promote DNA sensing by cGAS reveals an innate strategy to achieve distinction of viruses from self in the nucleus.
2018-09-28 | GSE109554 | GEO
Project description:The DNA sensor cGAS senses cytosolic DNA and catalyzes the production of the cyclicdinucleotide cGAMP, resulting in type I IFN responses. We addressed the functionality of cGAS-mediated DNA sensing in human and murine T-cells. Activated primary CD4+ T-cells expressed cGAS and responded robustly to plasmid DNA by upregulation of ISGs and release of bioactive interferon. In mouse T-cells, cGAS KO ablated sensing of plasmid DNA, and TREX1 KO enabled cells to sense short immunostimulatory DNA. Basal expression of IFIT1 and MX2 was downregulated and upregulated in cGAS KO and TREX1 KO T-cell lines, respectively, compared to parental cells. Despite their intact cGAS sensing pathway, human CD4+ T-cells failed to mount a reverse transcriptase (RT) inhibitor-sensitive immune response following HIV-1 infection. In contrast, infection of human T-cells with HSV-1 that is functionally deficient for the cGAS antagonist pUL41 (HSV-1ΔUL41N) resulted in a cGAS dependent type I IFN response. In accordance with our results in primary CD4+ T-cells, plasmid challenge or HSV-1ΔUL41N inoculation of representative T-cell lines provoked an entirely cGAS-dependent type I IFN response, including IRF3 phosphorylation and expression of ISGs. In contrast, no RT-dependent type I IFN response was detected following transduction of T cell lines with VSV-G-pseudotyped lentiviral or gammaretroviral particles. Together, T-cells are capable to raise a cGAS-dependent cell-intrinsic response to both plasmid DNA challenge or inoculation with HSV-1ΔUL41N. However, HIV-1 infection does not appear to trigger cGAS-mediated sensing of viral DNA in T-cells, possibly by revealing viral DNA of insufficient quantity, length, and/or accessibility to cGAS.
2020-05-19 | GSE150753 | GEO
Project description:Virus infection may induce excessive interferon (IFN) responses that can lead to host tissue injury or even death. β-arrestin 2 regulates multiple cellular events through the G protein-coupled receptor (GPCR) signaling pathways. Here we demonstrate that β-arrestin 2 also promotes virus-induced production of IFN-β and clearance of viruses in macrophages. β-arrestin 2 interacts with cyclic GMP-AMP synthase (cGAS) and increases the binding of dsDNA to cGAS to enhance cyclic GMP-AMP (cGAMP) production and the downstreatm stimulator of interferon genes (STING) and innate immune responses. Mechanistically, deacetylation of β-arrestin 2 at Lys171 facilitates the activation of the cGAS–STING signaling and the production of IFN-β. In vitro, viral infection induces the degradation of β-arrestin 2 to facilitate immune evasion, while a β-blocker, carvedilol, rescues β-arrestin 2 expression to maintain the antiviral immune response. Our results thus identify a viral immune-evasion pathway via the degradation of β-arrestin 2, and also hint that carvedilol, approved for treating heart failure, can potentially be repurposed as an antiviral drug candidate.
2020-10-22 | GSE159735 | GEO