Dataset Information

DEMETER plant DNA demethylase induces antiviral response by interferon signalling in animal cells.

ABSTRACT: DNA methylation is a prominent epigenetic modification in plants and animals regulated by similar mechanisms but the process of DNA demethylation is profoundly different. Unlike vertebrates that require a series of enzymatic conversions of 5-methylcytosine (5mC) into other bases for DNA demethylation, plants utilize the DEMETER (DME) family of 5mC DNA glycosylases to catalyze a direct removal of 5mC from DNA. Here we introduced Arabidopsis DME into human HEK-293T cells to allow direct 5mC excision, and observed that direct DNA demethylation activity was successfully implemented by DME expression. In addition, DME induced diverse cellular responses such as cell proliferation inhibition, cell cycle dysregulation and S phase arrest. Microarray and methylome analyses revealed that DME upregulated a number of genes including cell cycle components, heat shock proteins, and notably, various interferon-stimulated genes. Moreover, DME-mediated DNA demethylation activated endogenous repeat elements, which are likely to form dsRNAs as viral mimics and eventually trigger interferon cascades to establish the antiviral state. This work demonstrates that plant DNA demethylase catalyzes DNA demethylation with a bypass of initial base conversion steps, and the interferon signaling plays a pivotal role to alleviate genotoxic stresses associated with DME-induced DNA demethylation in mammalian cells.

SUBMITTER: Mok YG

PROVIDER: S-EPMC5567224 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

DEMETER plant DNA demethylase induces antiviral response by interferon signalling in animal cells.

Mok Young Geun YG Choi Ki Young KY Hong Seung Hwan SH Huh Jin Hoe JH

Scientific reports 20170822 1

DNA methylation is a prominent epigenetic modification in plants and animals regulated by similar mechanisms but the process of DNA demethylation is profoundly different. Unlike vertebrates that require a series of enzymatic conversions of 5-methylcytosine (5mC) into other bases for DNA demethylation, plants utilize the DEMETER (DME) family of 5mC DNA glycosylases to catalyze a direct removal of 5mC from DNA. Here we introduced Arabidopsis DME into human HEK-293T cells to allow direct 5mC excisi ...[more]

PMID: 28831075

Similar Datasets

Project description:Induction of interferon beta (IFN-?), IFN-stimulated genes (ISGs), and inflammatory responses is critical for control of viral infection. We recently identified an essential linkage of stimulation of the inflammatory cytokine interleukin-1? (IL-1?) and induction of ISGs that function as host restriction pathways against the emerging flavivirus West Nile virus (WNV) in vivo Here we utilized ex vivo global transcriptome analysis of primary dendritic cells, known targets of WNV replication, to define gene signatures required for this IL-1?-driven antiviral response. Dendritic cells that were deficient in IL-1 receptor signaling showed dysregulation of cell-intrinsic defense genes and loss of viral control during WNV infection. Surprisingly, we found that in wild-type cells, IL-1? treatment, in the absence of infection, drove the transcription of IFN-? and ISGs at late times following treatment. Expression of these antiviral innate immune genes was dependent on the transcription factor IFN regulatory factor 3 (IRF3) and appears to reflect a general shift in IL-1? signaling from an early inflammatory response to a late IFN-mediated response. These data demonstrate that inflammatory and antiviral signals integrate to control viral infection in myeloid cells through a process of IL-1?-to-IRF3 signaling crosstalk. Strategies to exploit these cytokines in the activation of host defense programs should be investigated as novel therapeutic approaches against individual pathogens.IMPORTANCE West Nile virus is an emerging mosquito-borne flavivirus that can result in serious illness, neuropathology, and death in infected individuals. Currently, there are no vaccines or therapies for human use against West Nile virus. Immune control of West Nile virus infection requires inflammatory and antiviral responses, though the effect that each arm of this response has on the other is unclear. The significance of our research is in defining how virus-induced inflammatory responses regulate critical antiviral immune programs for effective control of West Nile virus infection. These data identify essential mechanisms of immune control that can inform therapeutic efforts against West Nile virus, with potential efficacy against other neuroinvasive viruses.

Project description:Hepatitis C virus (HCV), a major cause of liver disease worldwide, is frequently resistant to the antiviral alpha interferon (IFN). The HCV nonstructural 5A (NS5A) protein has been implicated in HCV antiviral resistance in many studies. NS5A antagonizes the IFN antiviral response in vitro, and one mechanism is via inhibition of a key IFN-induced enzyme, the double-stranded-RNA-activated protein kinase (PKR). In the present study we determined if NS5A uses other strategies to subvert the IFN system. Expression of full-length NS5A proteins from patients who exhibited a complete response (FL-NS5A-CR) or were nonresponsive (FL-NS5A-NR) to IFN therapy in HeLa cells had no effect on IFN induction of IFN-stimulated gene factor 3 (ISGF-3). Expression of mutant NS5A proteins lacking 110 (NS5A-DeltaN110), 222 (NS5A-DeltaN222), and 334 amino-terminal amino acids and mutants lacking 117 and 230 carboxy-terminal amino acids also had no effect on ISGF-3 induction by IFN. Expression of FL-NS5A-CR and FL-NS5A-NR did not affect IFN-induced STAT-1 tyrosine phosphorylation or upregulation of PKR and major histocompatibility complex class I antigens. However, NS5A expression in human cells induced interleukin 8 (IL-8) mRNA and protein, and this effect correlated with inhibition of the antiviral effects of IFN in an in vitro bioassay. NS5A induced transcription of a reporter gene driven by the IL-8 promoter, and the first 133 bp of the IL-8 promoter made up the minimal domain required for NS5A transactivation. NS5A-DeltaN110 and NS5A-DeltaN222 stimulated the IL-8 promoter to higher levels than did the full-length NS5A protein, and this correlated with increased nuclear localization of the proteins. Additional mutagenesis of the IL-8 promoter suggested that NF-kappaB and AP-1 were important in NS5A-DeltaN222 transactivation in the presence of tumor necrosis factor alpha and that NF-IL-6 was inhibitory to this process. This study suggests that NS5A inhibits the antiviral actions of IFN by at least two mechanisms and provides the first evidence for a biological effect of the transcriptional activity of the NS5A protein. During HCV infection, viral proteins may induce chemokines that contribute to HCV antiviral resistance and pathogenesis.

Dataset Information

DEMETER plant DNA demethylase induces antiviral response by interferon signalling in animal cells.

Publications

DEMETER plant DNA demethylase induces antiviral response by interferon signalling in animal cells.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets