scholarly journals Characterization and Prediction of ISRE Binding Patterns Across Cell Types Under Type I Interferon Stimulation

2020 ◽  
Author(s):  
Sivan Leviyang

AbstractStimulation of cells by type I interferons (IFN) leads to the differential expression of 100s of genes known as interferon stimulated genes, ISGs. The collection of ISGs differentially expressed under IFN stimulation, referred to as the IFN signature, varies across cell types. Non-canonical IFN signaling has been clearly associated with variation in IFN signature across cell types, but the existence of variation in canonical signaling and its impact on IFN signatures is less clear. The canonical IFN signaling pathway involves binding of the transcription factor ISGF3 to IFN-stimulated response elements, ISREs. We examined ISRE binding patterns under IFN stimulation across six cell types using existing ChIPseq datasets available on the GEO and ENCODE databases. We find that ISRE binding is cell specific, particularly for ISREs distal to transcription start sites, potentially associated with enhancer elements, while ISRE binding in promoter regions is more conserved. Given variation of ISRE binding across cell types, we investigated associations between the cell type, homeostatic state and ISRE binding patterns. Taking a machine learning approach and using existing ATACseq and ChIPseq datasets available on GEO and ENCODE, we show that the epigenetic state of an ISRE locus at homeostasis and the DNA sequence of the ISRE locus are predictive of the ISRE’s binding under IFN stimulation in a cell type, specific manner, particularly for ISRE distal to transcription start sites.

2020 ◽  
Vol 295 (42) ◽  
pp. 14325-14342
Author(s):  
Timo Oosenbrug ◽  
Michel J. van de Graaff ◽  
Mariëlle C. Haks ◽  
Sander van Kasteren ◽  
Maaike E. Ressing

Surface-exposed Toll-like receptors (TLRs) such as TLR2 and TLR4 survey the extracellular environment for pathogens. TLR activation initiates the production of various cytokines and chemokines, including type I interferons (IFN-I). Downstream of TLR4, IFNβ secretion is only vigorously triggered in macrophages when the receptor undergoes endocytosis and switches signaling adaptor; surface TLR4 engagement predominantly induces proinflammatory cytokines via the signaling adaptor MyD88. It is unclear whether this dichotomy is generally applicable to other TLRs, cell types, or differentiation states. Here, we report that diverse TLR2 ligands induce an IFN-I response in human monocyte-like cells, but not in differentiated macrophages. This TLR2-dependent IFN-I signaling originates from the cell surface and depends on MyD88; it involves combined activation of the transcription factors IRF3 and NF-κB, driven by the kinases TBK1 and TAK1-IKKβ, respectively. TLR2-stimulated monocytes produced modest IFNβ levels that caused productive downstream signaling, reflected by STAT1 phosphorylation and expression of numerous interferon-stimulated genes. Our findings reveal that the outcome of TLR2 signaling includes an IFN-I response in human monocytes, which is lost upon macrophage differentiation, and differs mechanistically from IFN-I-induction through TLR4. These findings point to molecular mechanisms tailored to the differentiation state of a cell and the nature of receptors activated to control and limit TLR-triggered IFN-I responses.


2021 ◽  
Author(s):  
Jill E Moore ◽  
Xiao-Ou Zhang ◽  
Shaimae I Elhajjajy ◽  
Kaili Fan ◽  
Fairlie Reese ◽  
...  

Accurate transcription start site (TSS) annotations are essential for understanding transcriptional regulation and its role in human disease. Gene collections such as GENCODE contain annotations for tens of thousands of TSSs, but not all of these annotations are experimentally validated nor do they contain information on cell type-specific usage. Therefore, we sought to generate a collection of experimentally validated TSSs by integrating RNA Annotation and Mapping of Promoters for the Analysis of Gene Expression (RAMPAGE) data from 115 cell and tissue types, which resulted in a collection of approximately 50 thousand representative RAMPAGE peaks. These peaks were primarily proximal to GENCODE-annotated TSSs and were concordant with other transcription assays. Because RAMPAGE uses paired-end reads, we were then able to connect peaks to transcripts by analyzing the genomic positions of the 3' ends of read mates. Using this paired-end information, we classified the vast majority (37 thousand) of our RAMPAGE peaks as verified TSSs, updating TSS annotations for 20% of GENCODE genes. We also found that these updated TSS annotations were supported by epigenomic and other transcriptomic datasets. To demonstrate the utility of this RAMPAGE rPeak collection, we intersected it with the NHGRI/EBI GWAS catalog and identified new candidate GWAS genes. Overall, our work demonstrates the importance of integrating experimental data to further refine TSS annotations and provides a valuable resource for the biological community.


2007 ◽  
Vol 81 (16) ◽  
pp. 8656-8665 ◽  
Author(s):  
Fulvia Terenzi ◽  
Christine White ◽  
Srabani Pal ◽  
Bryan R. G. Williams ◽  
Ganes C. Sen

ABSTRACT The interferon-stimulated genes (ISGs) ISG56 and ISG54 are strongly induced in cultured cells by type I interferons (IFNs), viruses, and double-stranded RNA (dsRNA), which activate their transcription by various signaling pathways. Here we studied the stimulus-dependent induction of both genes in vivo. dsRNA, which is generated during virus infection, induced the expression of both genes in all organs examined. Induction was not seen in STAT1-deficient mice, indicating that dsRNA-induced gene expression requires endogenous IFN. We further examined the regulation of these ISGs in several organs from mice injected with dsRNA or IFN-β. Both ISG56 and ISG54 were widely expressed and at comparable levels. However, in organs isolated from mice injected with IFN-α the expression of ISG54 was reduced and more restricted in distribution compared with the expression level and distribution of ISG56. When we began to study specific cell types, splenic B cells showed ISG54 but not ISG56 expression in response to all agonists. Finally, in livers isolated from mice infected with vesicular stomatitis virus, the expression of ISG56, but not ISG54, was induced; this difference was observed at both protein and mRNA levels. These studies have revealed unexpected complexity in IFN-stimulated gene induction in vivo. For the first time we showed that the two closely related genes are expressed in a tissue-specific and inducer-specific manner. Furthermore, our findings provide the first evidence of a differential pattern of expression of ISG54 and ISG56 genes by IFN-α and IFN-β.


2017 ◽  
Vol 292 (18) ◽  
pp. 7285-7294 ◽  
Author(s):  
Gideon Schreiber

Type I interferons (IFN-1) are cytokines that affect the expression of thousands of genes, resulting in profound cellular changes. IFN-1 activates the cell by dimerizing its two-receptor chains, IFNAR1 and IFNAR2, which are expressed on all nucleated cells. Despite a similar mode of binding, the different IFN-1s activate a spectrum of activities. The causes for differential activation may stem from differences in IFN-1-binding affinity, duration of binding, number of surface receptors, induction of feedbacks, and cell type-specific variations. All together these will alter the signal that is transmitted from the extracellular domain inward. The intracellular domain binds, directly or indirectly, different effector proteins that transmit signals. The composition of effector molecules deviates between different cell types and tissues, inserting an additional level of complexity to the system. Moreover, IFN-1s do not act on their own, and clearly there is much cross-talk between the activated effector molecules by IFN-1 and other cytokines. The outcome generated by all of these factors (processing step) is an observed phenotype, which can be the transformation of the cell to an antiviral state, differentiation of the cell to a specific immune cell, senescence, apoptosis, and many more. IFN-1 activities can be divided into robust and tunable. Antiviral activity, which is stimulated by minute amounts of IFN-1 and is common to all cells, is termed robust. The other activities, which we term tunable, are cell type-specific and often require more stringent modes of activation. In this review, I summarize the current knowledge on the mode of activation and processing that is initiated by IFN-1, in perspective of the resulting phenotypes.


Author(s):  
G. Rowden ◽  
M. G. Lewis ◽  
T. M. Phillips

Langerhans cells of mammalian stratified squamous epithelial have proven to be an enigma since their discovery in 1868. These dendritic suprabasal cells have been considered as related to melanocytes either as effete cells, or as post divisional products. Although grafting experiments seemed to demonstrate the independence of the cell types, much confusion still exists. The presence in the epidermis of a cell type with morphological features seemingly shared by melanocytes and Langerhans cells has been especially troublesome. This so called "indeterminate", or " -dendritic cell" lacks both Langerhans cells granules and melanosomes, yet it is clearly not a keratinocyte. Suggestions have been made that it is related to either Langerhans cells or melanocyte. Recent studies have unequivocally demonstrated that Langerhans cells are independent cells with immune function. They display Fc and C3 receptors on their surface as well as la (immune region associated) antigens.


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 542.2-542
Author(s):  
A. Avdeeva ◽  
E. Tchetina ◽  
G. Markova ◽  
E. Nasonov

Background:Type I interferons (IFN-Is) are a group of molecules with pleiotropic effects on the immune system forming a crucial link between innate and adaptive immune responses. The type I interferon pathway has been implicated in the pathogenesis of a number of rheumatic diseases, including rheumatoid arthritis. IFN activity is usually quantified using expression of interferon-stimulated genes (ISGs) referred to as an IFN signature. Acellbia (BIOCAD) is the first Russian rituximab (RTX) biosimilar which was approved for medical use in rheumatoid arthritis (RA) patients in Russia and some CIS countries.Objectives:To evaluate the changes in expression of ISGs in patients (pts) with RA during RTX biosimilar therapyMethods:20 RA pts (18 woman, Me;IQR age 61.5(54-66.5) years, disease duration 39.5(20-84) months, mean DAS 28 5.6(4.9-6.8)) received two intravenous RTX biosimilar infusions (600 mg №2) in combination with DMARDs and glucocorticoids. Laboratory biomarkers were assessed at baseline and 24 weeks after the first infusion of RTX. 5 genes (IFI44L, MX1, IFIT 1, RSAD2, EPSTI1) were selected for evaluation of the “interferon signature” (Type I IFN gene signature – IFNGS). IFI44L and IFIT1 expression was undetectable, therefore the remaining three genes (MSX1, EPSTI1, RSAD2) were included into further analysis. IFNGS was calculated as the average expression values of the three selected genes. The control group included 20 age and gender matching healthy donors.Results:The baseline expression levels of MX1-11.48 (5.45-19.38), EPSTI1-12.83 (5.62-19.64), RSAD2-5.16 (2.73-10.4), and IFNGS-10.3 (5.18-17.12) in RA patients were significantly higher compared to healthy donors– 1,26 (0,73-1,6); 1,06 (0,81-1,48); 0,93 (0,72-1,19); 1,09 (0,92-1,42), (p<0.05, respectively). IFNGS was detected in 15 (75%) patients, and was not found in 5 (15%) patients. RTX induced reduction in disease activity, and the level of acute phase reactants (ESR, CRP) after 12 and 24 weeks of therapy, p<0.05 (fig.1). Increased RSAD 2 expression (p<0.05) and a trend to increasing IFNGS levels (p=0.06) were documented in the whole group, and also in patients with moderate treatment effects by week 24. Among patients with a good EULAR response to therapy, changes in expression were not significant (p> 0.05) (fig.1)Figure 1.Conclusion:Expression of IFN-stimulated genes was increased in RA patients compared to healthy donors. Increased RSAD2 and IFNGS expression was documented in patients with moderate effect of RTX therapy, therefore, these findings have important clinical relevance as predictors of RA clinical course which necessitates personified approach to treatment.Disclosure of Interests:None declared


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hanyu Zhang ◽  
Ruoyi Cai ◽  
James Dai ◽  
Wei Sun

AbstractWe introduce a new computational method named EMeth to estimate cell type proportions using DNA methylation data. EMeth is a reference-based method that requires cell type-specific DNA methylation data from relevant cell types. EMeth improves on the existing reference-based methods by detecting the CpGs whose DNA methylation are inconsistent with the deconvolution model and reducing their contributions to cell type decomposition. Another novel feature of EMeth is that it allows a cell type with known proportions but unknown reference and estimates its methylation. This is motivated by the case of studying methylation in tumor cells while bulk tumor samples include tumor cells as well as other cell types such as infiltrating immune cells, and tumor cell proportion can be estimated by copy number data. We demonstrate that EMeth delivers more accurate estimates of cell type proportions than several other methods using simulated data and in silico mixtures. Applications in cancer studies show that the proportions of T regulatory cells estimated by DNA methylation have expected associations with mutation load and survival time, while the estimates from gene expression miss such associations.


2021 ◽  
Author(s):  
Lauren A. Todd ◽  
Maxwell P. Bui-Marinos ◽  
Barbara A. Katzenback

Epigenetic regulators such as microRNAs are emerging as conserved regulators of innate antiviral immunity in vertebrates, yet their roles in amphibian antiviral responses remain uncharacterized. We profiled changes in microRNA expressions in the Xenopus laevis skin epithelial–like cell line Xela DS2 in response to poly(I:C) – an analogue of double-stranded viral RNA and inducer of type I interferons – or frog virus 3 (FV3), an immunoevasive virus associated with amphibian mortality events. We sequenced small RNA libraries generated from untreated, poly(I:C)–treated, and FV3–infected cells. We detected 136 known X. laevis microRNAs and discovered 133 novel X. laevis microRNAs. Sixty–five microRNAs were differentially expressed in response to poly(I:C), many of which were predicted to target regulators of antiviral pathways such as cGAS–STING, RIG–I/MDA–5, TLR signaling, and type I interferon signaling, as well as products of these pathways (NF–κB–induced and interferon-stimulated genes). In contrast, only 49 microRNAs were altered by FV3 infection, fewer of which were predicted to interact with antiviral pathways. Interestingly, poly(I:C) treatment or FV3 infection downregulated transcripts encoding factors of the host microRNA biogenesis pathway. Our study is the first to suggest that host microRNAs regulate innate antiviral immunity in frogs, and sheds light on microRNA–mediated mechanisms of immunoevasion by FV3.


2002 ◽  
Vol 368 (3) ◽  
pp. 753-760 ◽  
Author(s):  
Alexandre GARIN ◽  
Philippe PELLET ◽  
Philippe DETERRE ◽  
Patrice DEBRÉ ◽  
Christophe COMBADIÈRE

We have previously shown that reduced expression of the fractalkine receptor, CX3CR1, is correlated with rapid HIV disease progression and with reduced susceptibility to acute coronary events. In order to elucidate the mechanisms underlying transcriptional regulation of CX3CR1 expression, we structurally and functionally characterized the CX3CR1 gene. It consists of four exons and three introns spanning over 18kb. Three transcripts are produced by splicing the three untranslated exons with exon 4, which contains the complete open reading frame. The transcript predominantly found in leucocytes corresponds to the splicing of exon 2 with exon 4. Transcripts corresponding to splicing of exons 1 and 4 are less abundant in leucocytes and splicing of exons 3 and 4 are rare longer transcripts. A constitutive promoter activity was found in the regions extending upstream from untranslated exons 1 and 2. Interestingly, exons 1 and 2 enhanced the activity of their respective promoters in a cell-specific manner. These data show that the CX3CR1 gene is controlled by three distinct promoter regions, which are regulated by their respective untranslated exons and that lead to the transcription of three mature messengers. This highly complex regulation may allow versatile and precise expression of CX3CR1 in various cell types.


2021 ◽  
Author(s):  
Krystal J Vail ◽  
Bibiana Petri da Silveira ◽  
Samantha L Bell ◽  
Angela I Bordin ◽  
Noah D Cohen ◽  
...  

Rhodococcus equi is a major cause of foal pneumonia and an opportunistic pathogen in immunocompromised humans. While alveolar macrophages constitute the primary replicative niche for R. equi, little is known about how intracellular R. equi is sensed by macrophages. Here, we discovered that that in addition to previously characterized pro-inflammatory cytokines (e.g., Tnfa, Il6, Il1b), macrophages infected with R. equi induce a robust type I IFN response, including Ifnb and interferon-stimulated genes (ISGs), similar to the evolutionarily related pathogen, Mycobacterium tuberculosis. Follow up studies using a combination of mammalian and bacterial genetics, demonstrated that induction of this type I IFN expression program is largely dependent on the cGAS/STING/TBK1 axis of the cytosolic DNA surveillance pathway, suggesting that R. equi perturbs the phagosomal membrane and causes DNA release into the cytosol following phagocytosis. Consistent with this we found that a population of ~12% of R. equi phagosomes recruited the galectin-3, -8 and -9 danger receptors. Interesting, neither phagosomal damage nor induction of type I IFN required the R. equi's virulence-associated plasmid. Importantly, R. equi infection of both mice and foals stimulated ISG expression, in organs (mice) and circulating monocytes (foals). By demonstrating that R. equi activates cytosolic DNA sensing in macrophages and elicits type I IFN responses in animal models, our work provides novel insights into how R. equi engages the innate immune system and furthers our understanding how this zoonotic pathogen causes inflammation and disease.


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