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Pavan S, Olivero M, Corà D, Di Renzo MF. IRF-1 expression is induced by cisplatin in ovarian cancer cells and limits drug effectiveness. Eur J Cancer 2013; 49:964-73. [DOI: 10.1016/j.ejca.2012.09.024] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Revised: 09/11/2012] [Accepted: 09/15/2012] [Indexed: 10/27/2022]
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RNA-Seq for enrichment and analysis of IRF5 transcript expression in SLE. PLoS One 2013; 8:e54487. [PMID: 23349905 PMCID: PMC3548774 DOI: 10.1371/journal.pone.0054487] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 12/12/2012] [Indexed: 11/29/2022] Open
Abstract
Polymorphisms in the interferon regulatory factor 5 (IRF5) gene have been consistently replicated and shown to confer risk for or protection from the development of systemic lupus erythematosus (SLE). IRF5 expression is significantly upregulated in SLE patients and upregulation associates with IRF5-SLE risk haplotypes. IRF5 alternative splicing has also been shown to be elevated in SLE patients. Given that human IRF5 exists as multiple alternatively spliced transcripts with distinct function(s), it is important to determine whether the IRF5 transcript profile expressed in healthy donor immune cells is different from that expressed in SLE patients. Moreover, it is not currently known whether an IRF5-SLE risk haplotype defines the profile of IRF5 transcripts expressed. Using standard molecular cloning techniques, we identified and isolated 14 new differentially spliced IRF5 transcript variants from purified monocytes of healthy donors and SLE patients to generate an IRF5 variant transcriptome. Next-generation sequencing was then used to perform in-depth and quantitative analysis of full-length IRF5 transcript expression in primary immune cells of SLE patients and healthy donors by next-generation sequencing. Evidence for additional alternatively spliced transcripts was obtained from de novo junction discovery. Data from these studies support the overall complexity of IRF5 alternative splicing in SLE. Results from next-generation sequencing correlated with cloning and gave similar abundance rankings in SLE patients thus supporting the use of this new technology for in-depth single gene transcript profiling. Results from this study provide the first proof that 1) SLE patients express an IRF5 transcript signature that is distinct from healthy donors, 2) an IRF5-SLE risk haplotype defines the top four most abundant IRF5 transcripts expressed in SLE patients, and 3) an IRF5 transcript signature enables clustering of SLE patients with the H2 risk haplotype.
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53
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The COP9 signalosome interacts with and regulates interferon regulatory factor 5 protein stability. Mol Cell Biol 2012; 33:1124-38. [PMID: 23275442 DOI: 10.1128/mcb.00802-12] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The transcription factor interferon regulatory factor 5 (IRF5) exerts crucial functions in the regulation of host immunity against extracellular pathogens, DNA damage-induced apoptosis, death receptor signaling, and macrophage polarization. Tight regulation of IRF5 is thus warranted for an efficient response toward extracellular stressors and for limiting autoimmune and inflammatory responses. Here we report that the COP9 signalosome (CSN), a general modulator of diverse cellular and developmental processes, associates constitutively with IRF5 and promotes its protein stability. The constitutive CSN/IRF5 interaction was identified using proteomics and confirmed by endogenous immunoprecipitations. The CSN/IRF5 interaction occurred on the carboxyl and amino termini of IRF5; a single internal deletion from amino acids 455 to 466 (Δ455-466) was found to significantly reduce IRF5 protein stability. CSN subunit 3 (CSN3) was identified as a direct interacting partner of IRF5, and knockdown of this subunit with small interfering RNAs resulted in enhanced degradation. Degradation was further augmented by knockdown of CSN1 and CSN3 together. The ubiquitin E1 inhibitor UBEI-41 or the proteasome inhibitor MG132 prevented IRF5 degradation, supporting the idea that its stability is regulated by the ubiquitin-proteasome system. Importantly, activation of IRF5 by the death receptor ligand tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) resulted in enhanced degradation via loss of the CSN/IRF5 interaction. This study defines CSN to be a new interacting partner of IRF5 that controls its stability.
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Xu H, Krolikowski JG, Jones DW, Ge ZD, Pagel PS, Pritchard KA, Weihrauch D. 4F decreases IRF5 expression and activation in hearts of tight skin mice. PLoS One 2012; 7:e52046. [PMID: 23251680 PMCID: PMC3522636 DOI: 10.1371/journal.pone.0052046] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Accepted: 11/08/2012] [Indexed: 12/21/2022] Open
Abstract
The apoAI mimetic 4F was designed to inhibit atherosclerosis by improving HDL. We reported that treating tight skin (Tsk−/+) mice, a model of systemic sclerosis (SSc), with 4F decreases inflammation and restores angiogenic potential in Tsk−/+ hearts. Interferon regulating factor 5 (IRF5) is important in autoimmunity and apoptosis in immune cells. However, no studies were performed investigating IRF5 in myocardium. We hypothesize that 4F differentially modulates IRF5 expression and activation in Tsk−/+ hearts. Posterior wall thickness was significantly increased in Tsk−/+ compared to C57Bl/6J (control) and Tsk−/+ mice with 4F treatment assessed by echoradiography highlighting reduction of fibrosis in 4F treated Tsk−/+ mice. IRF5 in heart lysates from control and Tsk/+ with and without 4F treatment (sc, 1 mg/kg/d, 6–8 weeks) was determined. Phosphoserine, ubiquitin, ubiquitin K63 on IRF5 were determined on immunoprecipitates of IRF5. Immunofluorescence and TUNEL assays in heart sections were used to determine positive nuclei for IRF5 and apoptosis, respectively. Fluorescence-labeled streptavidin (SA) was used to determine endothelial cell uptake of biotinylated 4F. SA-agarose pulldown and immunoblotting for IRF5 were used to determine 4F binding IRF5 in endothelial cell cytosolic fractions and to confirm biolayer interferometry studies. IRF5 levels in Tsk−/+ hearts were similar to control. 4F treatments decrease IRF5 in Tsk−/+ hearts and decrease phosphoserine and ubiquitin K63 but increase total ubiquitin on IRF5 in Tsk−/+ compared with levels on IRF5 in control hearts. 4F binds IRF5 by mechanisms favoring association over dissociation strong enough to pull down IRF5 from a mixture of endothelial cell cytosolic proteins. IRF5 positive nuclei and apoptotic cells in Tsk−/+ hearts were increased compared with controls. 4F treatments decreased both measurements in Tsk−/+ hearts. IRF5 activation in Tsk−/+ hearts is increased. 4F treatments decrease IRF5 expression and activation in Tsk−/+ hearts by a mechanism related to 4F’s ability to bind IRF5.
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Affiliation(s)
- Hao Xu
- Division of Pediatric Surgery, Department of Surgery, Children’s Research Institute, Milwaukee, Wisconsin, United States of America
| | - John G. Krolikowski
- Division of Anesthesiology, Department of Surgery, Children’s Research Institute, Milwaukee, Wisconsin, United States of America
| | - Deron W. Jones
- Division of Pediatric Surgery, Department of Surgery, Children’s Research Institute, Milwaukee, Wisconsin, United States of America
| | - Zhi-Dong Ge
- Division of Anesthesiology, Department of Surgery, Children’s Research Institute, Milwaukee, Wisconsin, United States of America
| | - Paul S. Pagel
- The Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin, United States of America
| | - Kirkwood A. Pritchard
- Division of Pediatric Surgery, Department of Surgery, Children’s Research Institute, Milwaukee, Wisconsin, United States of America
| | - Dorothée Weihrauch
- Division of Anesthesiology, Department of Surgery, Children’s Research Institute, Milwaukee, Wisconsin, United States of America
- * E-mail:
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Hu GB, Lou HM, Dong XZ, Liu QM, Zhang SC. Characteristics of the interferon regulatory factor 5 (IRF5) and its expression in response to LCDV and poly I:C challenges in Japanese flounder, Paralichthys olivaceus. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2012; 38:377-382. [PMID: 22698613 DOI: 10.1016/j.dci.2012.06.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Revised: 05/31/2012] [Accepted: 06/05/2012] [Indexed: 06/01/2023]
Abstract
Interferon regulatory factor 5 (IRF5) has been identified as a key transcriptional mediator regulating expression of both type I interferons (IFNs) and proinflammatory cytokines. In this study, the cDNA and genomic sequences of IRF5 were isolated from Japanese flounder, Paralichthys olivaceus. The gene of Japanese flounder (Jf)IRF5 is 7326 bp long, contains 9 exons and 8 introns and encodes a putative protein of 472 amino acids. The predicted protein sequence shares 61.1-81.9% identity to fish IRF5 and possesses a DNA-binding domain (DBD), a middle region (MR), an IRF association domain (IAD), a virus activated domain (VAD) and two nuclear localization signals (NLSs) conserved in all known IRF5s. Phylogenetic analysis clustered it into the teleost IRF5 subgroup within vertebrate IRF5 group. JfIRF5 mRNA was constitutively expressed in all tissues examined, with higher levels observed in the gills and head kidney. Gene expression of JfIRF5 was analyzed over a 7-day time course in the gills, head kidney, spleen and muscle of Japanese flounders challenged with lymphocystis disease virus (LCDV) and polyinosinic:polycytidylic acid (poly I:C). The data showed that JfIRF5 expression was slightly up-regulated by LCDV, but its induction time was clearly moved up; in contrast, the induction upon poly I:C challenge started not earlier than day 2 post-injection and was stronger and more persistent with a later peak time in all four organs. The late and long-lasting inductive expression of JfIRF5 following poly I:C challenge suggests that it might be an interferon stimulated gene (ISG), the induction of which is driven by poly I:C-induced type I IFNs.
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Affiliation(s)
- Guo-Bin Hu
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
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56
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Frey B, Stache C, Rubner Y, Werthmöller N, Schulz K, Sieber R, Semrau S, Rödel F, Fietkau R, Gaipl US. Combined treatment of human colorectal tumor cell lines with chemotherapeutic agents and ionizing irradiation can in vitro induce tumor cell death forms with immunogenic potential. J Immunotoxicol 2012; 9:301-13. [PMID: 22800185 DOI: 10.3109/1547691x.2012.693547] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Chemotherapeutic agents (CT) and ionizing radiation (X-ray) induce DNA damage and primarily aim to stop the proliferation of tumor cells. However, multimodal anti-cancer therapies should finally result in tumor cell death and, best, in the induction of systemic anti-tumor immunity. Since distinct therapy-induced tumor cell death forms may create an immune activating tumor microenvironment, this study examined whether sole treatment with CT that are used in the therapy for colorectal cancer or in combination with X-ray result in colorectal tumor cell death with immunogenic potential. 5-Fluorouracil (5-FU), Oxaliplatin (Oxp), or Irinotecan (Irino) in combination with X-ray were all potent inhibitors of colorectal tumor cell colony formation. This study then examined the forms of cell death with AnnexinA5-FITC/Propidium Iodide staining. Necrosis was the prominent form of cell death induced by CT and/or X-ray. While only a combination of Irino with X-ray leads to death induction already 1 day after treatment, also the combinations of Oxp or 5-FU with X-ray and X-ray alone resulted in high necrosis rates at later time points after treatment. Inhibition of apoptosis increased the amount of necrotic tumor cells, suggesting that a programmed form of necrosis can be induced by CT + X-ray. 5-FU and Oxp alone or in combination with X-ray and Irino plus X-ray were most effective in increasing the expression of RIP, IRF-5, and p53, proteins involved in necrotic and apoptotic cell death pathways. All treatments further resulted in the release of the immune activating danger signals high-mobility group box 1 (HMGB1) and heat shock protein 70 (HSP70). The supernatants of the treated tumor cells induced maturation of dendritic cells. It is, therefore, concluded that combination of CT with X-ray is capable of inducing in vitro cell death forms of colorectal tumors with immunogenic potential.
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Affiliation(s)
- Benjamin Frey
- Department of Radiation Oncology, University Hospital Erlangen, Friedrich-Alexander University of Erlangen-Nürnberg, Germany
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Stone RC, Feng D, Deng J, Singh S, Yang L, Fitzgerald-Bocarsly P, Eloranta ML, Rönnblom L, Barnes BJ. Interferon regulatory factor 5 activation in monocytes of systemic lupus erythematosus patients is triggered by circulating autoantigens independent of type I interferons. ACTA ACUST UNITED AC 2012; 64:788-98. [PMID: 21968701 DOI: 10.1002/art.33395] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE Genetic variants of interferon regulatory factor 5 (IRF-5) are associated with susceptibility to systemic lupus erythematosus (SLE). IRF-5 regulates the expression of proinflammatory cytokines and type I interferons (IFNs) believed to be involved in the pathogenesis of SLE. The aim of this study was to determine the activation status of IRF-5 by assessing its nuclear localization in the immune cells of SLE patients and healthy donors, and to identify SLE-associated triggers of IRF-5 activation. METHODS IRF-5 nuclear localization in subpopulations of peripheral blood mononuclear cells from 14 genotyped SLE patients and 11 healthy controls was assessed using imaging flow cytometry. The activation and function of IRF-5 were examined after ex vivo stimulation of healthy donor monocytes with SLE serum or components of SLE serum. Cellular localization was determined by ImageStream flow cytometry, and cytokine expression was analyzed by quantitative polymerase chain reaction and enzyme-linked immunosorbent assay. RESULTS IRF-5 was activated in a cell type-specific manner; monocytes from SLE patients had constitutively elevated levels of nuclear IRF-5, as compared to natural killer cells and T cells. SLE serum was identified as a trigger for IRF-5 nuclear accumulation; however, neither IFNα nor SLE immune complexes could induce nuclear localization. Instead, autoantigens composed of apoptotic/necrotic material triggered IRF-5 nuclear accumulation in monocytes. Production of the cytokines IFNα, tumor necrosis factor α, and interleukin-6 in monocytes stimulated with SLE serum or autoantigens was distinct, yet showed a correlation with the kinetics of IRF-5 nuclear localization. CONCLUSION This study provides the first formal proof that IRF-5 activation is altered in the monocytes of SLE patients, which can be attributed, in part, to the SLE blood environment.
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Affiliation(s)
- Rivka C Stone
- University of Medicine and Dentistry of New Jersey and New Jersey Medical School-University Hospital Cancer Center, Newark, NJ 07103, USA
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58
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IRF5 promotes the proliferation of human thyroid cancer cells. Mol Cancer 2012; 11:21. [PMID: 22507190 PMCID: PMC3444366 DOI: 10.1186/1476-4598-11-21] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Accepted: 04/16/2012] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Interferon Regulatory Factor 5 is a transcription factor that regulates the expression of genes involved in the response to viral infection and in the stimulation of the immune system. Moreover, multiple studies have demonstrated that it negatively regulates cell growth and oncogenesis, favoring cell differentiation and apoptosis.Thyroid carcinoma represents 98% of all thyroid malignancies and has shown a steady increase in incidence in both the USA and western European countries. FINDINGS We investigated the expression, localization and function of IRF5 in thyroid cancer cells and found that it is highly expressed in both primary and immortalized thyroid carcinomas but not in normal thyrocytes. IRF5 levels were variably modulated by Interferon alpha but IRF5 only localized in the cytoplasmic compartment, thus failing to induce p21 expression as previously reported in different cell models. Furthermore, ectopic IRF5 increased both the proliferation rate and the clonogenic potential of malignant thyroid cells, protecting them from the cytotoxic effects of DNA-damaging agents. These results were directly attributable to IRF5, as demonstrated by the reduction in colony-forming ability of thyroid cancer cells after IRF5 silencing. An IRF5-dependent induction of endogenous B-Raf observed in all thyroid cancer cells might contribute to these unexpected effects. CONCLUSIONS These findings suggest that, in thyroid malignancies, IRF5 displays tumor-promoting rather than tumor-suppressor activities.
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59
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Chang Foreman HC, Van Scoy S, Cheng TF, Reich NC. Activation of interferon regulatory factor 5 by site specific phosphorylation. PLoS One 2012; 7:e33098. [PMID: 22412986 PMCID: PMC3297630 DOI: 10.1371/journal.pone.0033098] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Accepted: 02/09/2012] [Indexed: 12/17/2022] Open
Abstract
The cellular defense to infection depends on accurate activation of transcription factors and expression of select innate immunity genes. Interferon regulatory factor 5 (IRF5), a risk factor for systemic lupus erythematosus, is activated in response to pathogen recognition receptor engagement and downstream effector molecules. We find the nucleotide-binding oligomerization domain containing protein 2 (NOD2) receptor to be a significant activator of IRF5. Phosphorylation is key to the regulation of IRF5, but the precise phosphorylation sites in IRF5 remained to be identified. We used mass spectrometry to identify for the first time specific residues that are phosphorylated in response to TANK-binding kinase-1 (TBK-1), tumor necrosis factor receptor-associated factor 6 (TRAF6), or receptor interacting protein 2 (RIP2). RIP2, a kinase known to function downstream of NOD2, was the most effective activator of IRF5-regulated gene expression. To determine if the phosphorylated residues are required or sufficient for IRF5 activity, aspartic acid phosphomimetic substitutions or inactivating alanine substitutions were tested. Phosphorylation of carboxyl serines 451 and 462 appear the primary trigger of IRF5 function in nuclear accumulation, transcription, and apoptosis. Results indicate polyubiquitination of IRF5 does not play a major role in its transcriptional activity, and that ubiquitination and phosphorylation are independent modifications.
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Affiliation(s)
| | | | | | - Nancy C. Reich
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, United States of America
- * E-mail:
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60
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Synthetic lethality of PARP inhibition in BRCA-network disrupted tumor cells is associated with interferon pathway activation and enhanced by interferon-γ. Apoptosis 2012; 17:691-701. [DOI: 10.1007/s10495-012-0707-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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A two-marker haplotype in the IRF5 gene is associated with inflammatory bowel disease in a North American cohort. Genes Immun 2012; 13:351-5. [PMID: 22257839 DOI: 10.1038/gene.2011.90] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Interferon regulatory factor 5 (IRF5) located on human chromosome 7q32 is associated with many chronic inflammatory disorders. IRF5 is the key regulator of proinflammatory cytokines and type I interferons. We surveyed two cohorts of inflammatory bowel disease (IBD) patients from a North American Consortium. Six single-nucleotide polymorphisms and a 5-base-pair (bp) insertion-deletion (CGGGG indel)polymorphism were investigated. Cytokine secretion was measured in primary lymphocytes after toll-like receptor 9 stimulation. Two-marker haplotypes containing the pairs (rs4728142-CGGGG indel) and (CGGGG indel-rs7808907) were associated with IBD protection (P=2.89 × 10(-6), P=9.32 × 10(-4) (non-Jewish ancestry) and P=4.68 × 10(-8), P=2.50 × 10(-8) (Jewish ancestry)) and IBD risk (P=0.004, P=0.003 (Jewish ancestry), respectively. IRF5 polymorphisms were risk factors for IBD in a single cohort. Interleukin-12-p70 cytokine production was higher (P=0.04) in lymphocytes from controls with two alleles of the 5-bp insertion. IRF5 polymorphisms contribute to the risk profile for Crohn's disease and ulcerative colitis along with ancestry and NOD2 genotypes.
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Mandal P, Krueger BE, Oldenburg D, Andry KA, Beard RS, White DW, Barton ES. A gammaherpesvirus cooperates with interferon-alpha/beta-induced IRF2 to halt viral replication, control reactivation, and minimize host lethality. PLoS Pathog 2011; 7:e1002371. [PMID: 22114555 PMCID: PMC3219715 DOI: 10.1371/journal.ppat.1002371] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Accepted: 09/26/2011] [Indexed: 02/06/2023] Open
Abstract
The gammaherpesviruses, including Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV), establish latency in memory B lymphocytes and promote lymphoproliferative disease in immunocompromised individuals. The precise immune mechanisms that prevent gammaherpesvirus reactivation and tumorigenesis are poorly defined. Murine gammaherpesvirus 68 (MHV68) is closely related to EBV and KSHV, and type I (alpha/beta) interferons (IFNαβ) regulate MHV68 reactivation from both B cells and macrophages by unknown mechanisms. Here we demonstrate that IFNβ is highly upregulated during latent infection, in the absence of detectable MHV68 replication. We identify an interferon-stimulated response element (ISRE) in the MHV68 M2 gene promoter that is bound by the IFNαβ-induced transcriptional repressor IRF2 during latency in vivo. The M2 protein regulates B cell signaling to promote establishment of latency and reactivation. Virus lacking the M2 ISRE (ISREΔ) overexpresses M2 mRNA and displays uncontrolled acute replication in vivo, higher latent viral load, and aberrantly high reactivation from latency. These phenotypes of the ISREΔ mutant are B-cell-specific, require IRF2, and correlate with a significant increase in virulence in a model of acute viral pneumonia. We therefore identify a mechanism by which a gammaherpesvirus subverts host IFNαβ signaling in a surprisingly cooperative manner, to directly repress viral replication and reactivation and enforce latency, thereby minimizing acute host disease. Since we find ISREs 5′ to the major lymphocyte latency genes of multiple rodent, primate, and human gammaherpesviruses, we propose that cooperative subversion of IFNαβ-induced IRFs to promote latent infection is an ancient strategy that ensures a stable, minimally-pathogenic virus-host relationship. Herpesviruses establish life-long infection in a non-replicating state termed latency. During immune compromise, herpesviruses can reactivate and cause severe disease, including cancer. We investigated mechanisms by which interferons alpha/beta (IFNαβ), a family of antiviral immune genes, inhibit reactivation of murine gammaherpesvirus 68 (MHV68). MHV68 is related to Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus, human gammaherpesviruses associated with multiple cancers. We made the surprising discovery that during latency, MHV68 cooperates with IFNαβ to inhibit its own replication. Specifically, a viral gene required for reactivation has evolved to be directly repressed by an IFNαβ-induced transcription factor, IRF2. Once virus replication has triggered sufficient IFNαβ production, expression of this viral gene is reduced and reactivation efficiency decreases. This strategy safeguards the health of the host, since a mutant virus that cannot respond to IRF2 replicates uncontrollably and is more virulent. Viral sensing of IFNαβ is also potentially subversive, since it allows MHV68 to detect periods of localized immune quiescence during which it can reactivate and spread to a new host. Thus, we highlight a novel path of virus-host coevolution, toward cooperative subversion of the antiviral immune response. These observations may illuminate new targets for drugs to inhibit herpesvirus reactivation or eliminate herpesvirus-associated tumors.
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Affiliation(s)
- Pratyusha Mandal
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
- Department of Microbiology and Immunology, Wake Forest University School of Medicine, Winston-Salem, North Carolina, United States of America
| | - Bridgette E. Krueger
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
| | - Darby Oldenburg
- Department of Health Professions, University of Wisconsin La Crosse, La Crosse, Wisconsin, United States of America
- Rheumatology Research Laboratory, Gundersen Lutheran Medical Center, La Crosse, Wisconsin, United States of America
| | - Katherine A. Andry
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
| | - R. Suzanne Beard
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
- Department of Microbiology and Immunology, Wake Forest University School of Medicine, Winston-Salem, North Carolina, United States of America
| | - Douglas W. White
- Rheumatology Research Laboratory, Gundersen Lutheran Medical Center, La Crosse, Wisconsin, United States of America
- Department of Microbiology, University of Wisconsin La Crosse, La Crosse, Wisconsin, United States of America
| | - Erik S. Barton
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
- Department of Microbiology and Immunology, Wake Forest University School of Medicine, Winston-Salem, North Carolina, United States of America
- * E-mail:
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Bi X, Hameed M, Mirani N, Pimenta EM, Anari J, Barnes BJ. Loss of interferon regulatory factor 5 (IRF5) expression in human ductal carcinoma correlates with disease stage and contributes to metastasis. Breast Cancer Res 2011; 13:R111. [PMID: 22053985 PMCID: PMC3326553 DOI: 10.1186/bcr3053] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Revised: 07/29/2011] [Accepted: 11/04/2011] [Indexed: 01/19/2023] Open
Abstract
INTRODUCTION New signaling pathways of the interleukin (IL) family, interferons (IFN) and interferon regulatory factors (IRF) have recently been found within tumor microenvironments and in metastatic sites. Some of these cytokines stimulate while others inhibit breast cancer proliferation and/or invasion. IRFs, a family of nine mammalian transcription factors, have multiple biologic functions that when dysregulated may contribute to tumorigenesis; most well-known are their roles in regulating/initiating host immunity. Some IRF family members have been implicated in tumorigenesis yet little is still known of their expression in primary human tumors or their role(s) in disease development/progression. IRF5 is one of the newer family members to be studied and has been shown to be a critical mediator of host immunity and the cellular response to DNA damage. Here, we examined the expression of IRF5 in primary breast tissue and determined how loss of expression may contribute to breast cancer development and/or progression. METHODS Formalin-fixed paraffin-embedded archival breast tissue specimens from patients with atypical ductal hyperplasia (ADH), ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC) were examined for their expression of IRF1 and IRF5. Knockdown or overexpression of IRF5 in MCF-10A, MCF-7 and MDA-MB-231 mammary epithelial cell lines was used to examine the role of IRF5 in growth inhibition, invasion and tumorigenesis. RESULTS Analysis of IRF expression in human breast tissues revealed the unique down-regulation of IRF5 in patients with different grades of DCIS and IDC as compared to IRF1; loss of IRF5 preceded that of IRF1 and correlated with increased invasiveness. Overexpression of IRF5 in breast cancer cells inhibited in vitro and in vivo cell growth and sensitized them to DNA damage. Complementary experiments with IRF5 siRNAs made normal mammary epithelial cells resistant to DNA damage. By 3-D culture, IRF5 overexpression reverted MDA-MB-231 to normal acini-like structures; cells overexpressing IRF5 had decreased CXCR4 expression and were insensitive to SDF-1/CXCL12-induced migration. These findings were confirmed by CXCR4 promoter reporter assays. CONCLUSIONS IRF5 is an important tumor suppressor that regulates multiple cellular processes involved in the conversion of normal mammary epithelial cells to tumor epithelial cells with metastatic potential.
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Affiliation(s)
- Xiaohui Bi
- Department of Biochemistry & Molecular Biology, New Jersey Medical School, UMDNJ, Newark, NJ 07101, USA
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Wang E, Bussom S, Chen J, Quinn C, Bedognetti D, Lam W, Guan F, Jiang Z, Mark Y, Zhao Y, Stroncek DF, White J, Marincola FM, Cheng YC. Interaction of a traditional Chinese Medicine (PHY906) and CPT-11 on the inflammatory process in the tumor microenvironment. BMC Med Genomics 2011; 4:38. [PMID: 21569348 PMCID: PMC3117677 DOI: 10.1186/1755-8794-4-38] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Accepted: 05/11/2011] [Indexed: 12/18/2022] Open
Abstract
Background - Traditional Chinese Medicine (TCM) has been used for thousands of years to treat or prevent diseases, including cancer. Good manufacturing practices (GMP) and sophisticated product analysis (PhytomicsQC) to ensure consistency are now available allowing the assessment of its utility. Polychemical Medicines, like TCM, include chemicals with distinct tissue-dependent pharmacodynamic properties that result in tissue-specific bioactivity. Determining the mode of action of these mixtures was previously unsatisfactory; however, information rich RNA microarray technologies now allow for thorough mechanistic studies of the effects complex mixtures. PHY906 is a long used four herb TCM formula employed as an adjuvant to relieve the side effects associated with chemotherapy. Animal studies documented a decrease in global toxicity and an increase in therapeutic effectiveness of chemotherapy when combined with PHY906. Methods - Using a systems biology approach, we studied tumor tissue to identify reasons for the enhancement of the antitumor effect of CPT-11 (CPT-11) by PHY906 in a well-characterized pre-clinical model; the administration of PHY906 and CPT-11 to female BDF-1 mice bearing subcutaneous Colon 38 tumors. Results - We observed that 1) individually PHY906 and CPT-11 induce distinct alterations in tumor, liver and spleen; 2) PHY906 alone predominantly induces repression of transcription and immune-suppression in tumors; 3) these effects are reverted in the presence of CPT-11, with prevalent induction of pro-apoptotic and pro-inflammatory pathways that may favor tumor rejection. Conclusions - PHY906 together with CPT-11 triggers unique changes not activated by each one alone suggesting that the combination creates a unique tissue-specific response.
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Affiliation(s)
- Ena Wang
- Infectious Disease and Immunogenetics Section (IDIS), Department of Transfusion Medicine, Clinical Center and trans-NIH Center for Human Immunology (CHI), National Institutes of Health, Bethesda, Maryland 20892, USA
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Xu D, Meyer F, Ehlers E, Blasnitz L, Zhang L. Interferon regulatory factor 4 (IRF-4) targets IRF-5 to regulate Epstein-Barr virus transformation. J Biol Chem 2011; 286:18261-7. [PMID: 21454650 DOI: 10.1074/jbc.m110.210542] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The cellular interferon regulatory factor-4 (IRF-4), which is a member of IRF family, is involved in the development of multiple myeloma and Epstein-Barr virus (EBV)-mediated transformation of B lymphocytes. However, the molecular mechanism of IRF-4 in cellular transformation is unknown. We have found that knockdown of IRF-4 leads to high expression of IRF-5, a pro-apoptotic member in the IRF family. Overexpression of IRF-4 represses IRF-5 expression. Reduction of IRF-4 leads to growth inhibition, and the restoration of IRF-4 by exogenous plasmids correlates with the growth recovery and reduces IRF-5 expression. In addition, IRF-4 negatively regulates IRF-5 promoter reporter activities and binds to IRF-5 promoters in vivo and in vitro. Knockdown of IRF-5 rescues IRF-4 knockdown-mediated growth inhibition, and IRF-5 overexpression alone is sufficient to induce cellular growth inhibition of EBV-transformed cells. Therefore, IRF-5 is one of the targets of IRF-4, and IRF-4 regulates the growth of EBV-transformed cells partially through IRF-5. This work provides insight on how IRFs interact with one another to participate in viral pathogenesis and transformation.
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Affiliation(s)
- Dongsheng Xu
- School of Biological Sciences, University of Nebraska, Lincoln, Nebraska 68588, USA
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66
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Malignant potential of H22 hepatocarcinoma cells increases after recovery from IFN-γ-mediated inhibition. Cell Biol Int 2011; 35:747-54. [PMID: 21261597 DOI: 10.1042/cbi20100268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
IFN-γ (interferon γ) can effectively suppress tumours, but it has also been found to promote tumour progression. However, the underlying mechanisms by which it enhances malignancy have not been fully elucidated. By using a mouse model that expresses IFN-γ locally in muscle, we found that the growth potential of tumours was increased after a quick decrease of IFN-γ. Furthermore, the up-regulation of IRF-2 (IFN regulatory factor 2) and down-regulation of IRF-1 were also found in the tumour cells. Along these lines, IFN-γ led to down-regulated expression of cyclin-D1, Bcl-2 and Bcl-xL and up-regulated expression of p21WAF1 and Bax in tumour cells. Yet, the expression of these genes, as well as activation of ERK (extracellular signal-regulated kinase) and NF-κB (nuclear factor-κB), was also reversed shortly after a decrease in IFN-γ, all of which resulted in increase tumour cell proliferation and apoptosis resistance. These findings indicate that the malignant potential of tumour cells may be suppressed by interfering with IRF-2 signalling pathways during and after decreased IFN-γ in tumour microenvironments.
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67
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Bi X, Yang L, Mancl ME, Barnes BJ. Modulation of interferon regulatory factor 5 activities by the Kaposi sarcoma-associated herpesvirus-encoded viral interferon regulatory factor 3 contributes to immune evasion and lytic induction. J Interferon Cytokine Res 2010; 31:373-82. [PMID: 21133648 DOI: 10.1089/jir.2010.0084] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Multiple Kaposi's sarcoma-associated herpesvirus (KSHV)-encoded proteins with potential roles in KSHV-associated neoplasms have been identified. KSHV encodes 4 genes with homology to transcription factors of the interferon (IFN) regulatory factor (IRF) family. Viral IRF3 (vIRF3) is expressed in latently KSHV-infected primary effusion lymphoma (PEL) cells and was recently shown to be essential for the survival of PEL cells. The focus of this study was to determine the mechanism(s) of vIRF3 oncogenic activity contributing to KSHV-associated lymphoma. We report that vIRF3 interacts with the amino-terminal DNA binding domain of human IRF5, leading to a complex manipulation of IRF5 function. vIRF3 associated with both exogenous and endogenous IRF5, thereby inhibiting IRF5-mediated IFN promoter activation and the synthesis of biologically active type I IFNs by blocking its binding to endogenous IFNA promoters. The function of this interaction was not limited to the IFN system as IRF5-mediated cell growth regulation was significantly altered by overexpression of vIRF3 in B cells. vIRF3 prevented IRF5-mediated growth inhibition and G2/M cell cycle arrest. Important, IRF5 was upregulated by the protein kinase C agonist 12-O-tetradecanoyl-phorbol-13-acetate in BCBL1 PEL cells and interaction with vIRF3 was observed at the endogenous p21 promoter in response to 12-O-tetradecanoyl-phorbol-13-acetate, suggesting that these 2 proteins cooperate in the regulation of lytic cycle-induced G1 arrest, which is an important early step for the reactivation of KSHV. In conclusion, cellular IRF5 and vIRF3 interact, leading to the functional modulation of IRF5-mediated type I IFN expression and cell cycle regulation. These findings support an important role for vIRF3 in immune evasion and cell proliferation that likely contribute to the survival of PEL cells.
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Affiliation(s)
- Xiaohui Bi
- Department of Biochemistry and Molecular Biology, New Jersey Medical School, University of Medicine and Dentistry of New Jersey, Newark, New Jersey, USA
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68
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Combination of Ionising Irradiation and Hyperthermia Activates Programmed Apoptotic and Necrotic Cell Death Pathways in Human Colorectal Carcinoma Cells. Strahlenther Onkol 2010; 186:587-99. [DOI: 10.1007/s00066-010-2154-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Accepted: 07/05/2010] [Indexed: 01/04/2023]
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69
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Wen F, Ellingson SM, Kyogoku C, Peterson EJ, Gaffney PM. Exon 6 variants carried on systemic lupus erythematosus (SLE) risk haplotypes modulate IRF5 function. Autoimmunity 2010; 44:82-9. [PMID: 20695768 DOI: 10.3109/08916934.2010.491842] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Interferon regulatory factor 5 (IRF5) regulates innate immune responses to viral infection. IRF5 genetic variants have been shown to be strongly associated with risk for systemic lupus erythematosus (SLE). Functional roles of IRF5 exon 6 structural variants that occur as part of a SLE risk-associated haplotype, including a 30-bp in/del (in/del-10) and a 48-bp splice-site variant (SV-16), have not been established. In this study, we used IRF5-deficient cells overexpressing human IRF5 (hIRF5) variants to investigate the roles of exon 6 in/del-10 and SV-16 in regulation of the apoptosis response, nuclear translocation, and ability to transactivate IRF5 responsive cytokines. We found that expression of IRF5 isoforms including either SV-16 or in/del-10 confers ability of IRF5 to impair the apoptotic response and correlates with reduced capacity for IRF5 nuclear translocation in MEFs after a DNA-damaging stimulus treatment. Interestingly, the presence or absence of both SV-16 and in/del-10 results in abrogation of both the anti-apoptotic and enhanced nuclear translocation effects of IRF5 expression. Only cells expressing IRF5 bearing SV-16 show increased IL-6 production upon lipopolysaccharide stimulation. MEFs expressing hIRF5 variants containing in/del-10 showed no significant difference from the control; however, cells carrying hIRF5 lacking both SV-16 and in/del-10 showed reduced IL-6 production. Our overall findings suggest that exon 6 SV-16 is more potent than in/del-10 for IRF5-driven resistance to apoptosis and promotion of cytokine production; however, in/del-10 co-expression can neutralize these effects of SV-16.
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Affiliation(s)
- Feng Wen
- Arthritis and Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
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70
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Chen W, Royer WE. Structural insights into interferon regulatory factor activation. Cell Signal 2010; 22:883-7. [PMID: 20043992 PMCID: PMC2846214 DOI: 10.1016/j.cellsig.2009.12.005] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2009] [Accepted: 12/18/2009] [Indexed: 02/07/2023]
Abstract
The interferon regulatory factors (IRFs) play important roles in development of the immune system and host defense. Recent crystallographic and biochemical studies have provided insights into the mechanism of activation of IRFs by phosphorylation. The activation of a latent closed conformation of IRF in the cytoplasm is triggered by phosphorylation of Ser/Thr residues in a C-terminal region. Phosphorylation stimulates the C-terminal autoinhibitory domain to attain a highly extended conformation triggering dimerization through extensive contacts to a second subunit. Dimers are then transported into the nucleus and assemble with the coactivator CBP/p300 to activate transcription of type I interferons and other target genes. The advances made in understanding the release of inhibition after IRF dimerization have generated a detailed structural model of how IRFs signaling pathways are activated.
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Affiliation(s)
- Weijun Chen
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, USA.
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71
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Savitsky D, Tamura T, Yanai H, Taniguchi T. Regulation of immunity and oncogenesis by the IRF transcription factor family. Cancer Immunol Immunother 2010; 59:489-510. [PMID: 20049431 PMCID: PMC11030943 DOI: 10.1007/s00262-009-0804-6] [Citation(s) in RCA: 231] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Accepted: 12/01/2009] [Indexed: 02/06/2023]
Abstract
Nine interferon regulatory factors (IRFs) compose a family of transcription factors in mammals. Although this family was originally identified in the context of the type I interferon system, subsequent studies have revealed much broader functions performed by IRF members in host defense. In this review, we provide an update on the current knowledge of their roles in immune responses, immune cell development, and regulation of oncogenesis.
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Affiliation(s)
- David Savitsky
- Department of Immunology, Faculty of Medicine, Graduate School of Medicine, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-0033 Japan
| | - Tomohiko Tamura
- Department of Immunology, Faculty of Medicine, Graduate School of Medicine, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-0033 Japan
| | - Hideyuki Yanai
- Department of Immunology, Faculty of Medicine, Graduate School of Medicine, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-0033 Japan
| | - Tadatsugu Taniguchi
- Department of Immunology, Faculty of Medicine, Graduate School of Medicine, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-0033 Japan
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72
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Feng D, Stone RC, Eloranta ML, Sangster-Guity N, Nordmark G, Sigurdsson S, Wang C, Alm G, Syvänen AC, Rönnblom L, Barnes BJ. Genetic variants and disease-associated factors contribute to enhanced interferon regulatory factor 5 expression in blood cells of patients with systemic lupus erythematosus. ACTA ACUST UNITED AC 2010; 62:562-73. [PMID: 20112383 DOI: 10.1002/art.27223] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Genetic variants of the interferon (IFN) regulatory factor 5 gene (IRF5) are associated with susceptibility to systemic lupus erythematosus (SLE). The contribution of these variants to IRF-5 expression in primary blood cells of SLE patients has not been addressed, nor has the role of type I IFNs. The aim of this study was to determine the association between increased IRF-5 expression and the IRF5 risk haplotype in SLE patients. METHODS IRF-5 transcript and protein levels in 44 Swedish patients with SLE and 16 healthy controls were measured by quantitative real-time polymerase chain reaction, minigene assay, and flow cytometry. Single-nucleotide polymorphisms rs2004640, rs10954213, and rs10488631 and the CGGGG insertion/deletion were genotyped in these patients. Genotypes of these polymorphisms defined both a common risk haplotype and a common protective haplotype. RESULTS IRF-5 expression and alternative splicing were significantly up-regulated in SLE patients compared with healthy donors. Enhanced transcript and protein levels were associated with the risk haplotype of IRF5; rs10488631 displayed the only significant independent association that correlated with increased transcription from the noncoding first exon 1C. Minigene experiments demonstrated an important role for rs2004640 and the CGGGG insertion/deletion, along with type I IFNs, in regulating IRF5 expression. CONCLUSION This study provides the first formal proof that IRF-5 expression and alternative splicing are significantly up-regulated in primary blood cells of patients with SLE. Furthermore, the risk haplotype is associated with enhanced IRF-5 transcript and protein expression in patients with SLE.
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Affiliation(s)
- Di Feng
- University of Medicine and Dentistry of New Jersey, Newark, NJ, USA
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73
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Dual functions of interferon regulatory factors 7C in Epstein-Barr virus-mediated transformation of human B lymphocytes. PLoS One 2010; 5:e9459. [PMID: 20209099 PMCID: PMC2831998 DOI: 10.1371/journal.pone.0009459] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Accepted: 02/07/2010] [Indexed: 11/19/2022] Open
Abstract
Epstein-Barr virus (EBV) infection is associated with several human malignancies. Interferon (IFN) regulatory factor 7 (IRF-7) has several splicing variants, and at least the major splicing variant (IRF-7A) has oncogenic potential and is associated with EBV transformation processes. IRF-7C is an alternative splicing variant with only the DNA-binding domain of IRF-7. Whether IRF-7C is present under physiological conditions and its functions in viral transformation are unknown. In this report, we prove the existence of IRF-7C protein and RNA in certain cells under physiological conditions, and find that high levels of IRF-7C are associated with EBV transformation of human primary B cells in vitro as well as EBV type III latency. EBV latent membrane protein 1 (LMP-1) stimulates IRF-7C expression in B lymphocytes. IRF-7C has oncogenic potential in rodent cells and partially restores the growth properties of EBV-transformed cells under a growth-inhibition condition. A tumor array experiment has identified six primary tumor specimens with high levels of IRF-7C protein—all of them are lymphomas. Furthermore, we show that the expression of IRF-7C is apparently closely associated with other IRF-7 splicing variants. IRF-7C inhibits the function of IRF-7 in transcriptional regulation of IFN genes. These data suggest that EBV may use splicing variants of IRF-7 for its transformation process in two strategies: to use oncogenic properties of various IRF-7 splicing variants, but use one of its splicing variants (IRF-7C) to block the IFN-induction function of IRF-7 that is detrimental for viral transformation. The work provides a novel relation of host/virus interactions, and has expanded our knowledge about IRFs in EBV transformation.
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74
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Fan JH, Gao LB, Pan XM, Li C, Liang WB, Liu J, Li Y, Zhang L. Association between IRF-5 polymorphisms and risk of acute coronary syndrome. DNA Cell Biol 2010; 29:19-23. [PMID: 19778284 DOI: 10.1089/dna.2009.0929] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Previous studies suggested that genetic polymorphisms in interferon regulatory factor 5 (IRF-5) are implicated in the susceptibility to a range of autoimmune diseases, including rheumatoid arthritis, systemic lupus erythematosus, and inflammatory bowel disease. Recently, IRF-5 has been implicated in inflammatory processes that are associated with excessive remodeling and atherosclerosis. Our purpose was to investigate the association between the IRF-5 polymorphisms and the risk of acute coronary syndrome (ACS) in a Chinese population. The 5 bp indel (insertion/deletion) (CGGGG) polymorphism, located 64 bp upstream of the alternative exon 1a of IRF-5 gene, and the deletion of 30 bp in exon 6 of IRF-5 gene were analyzed among 148 patients with ACS and 246 controls in a Chinese population, using a polymerase chain reaction-restriction fragment length polymorphism strategy and direct sequencing. The frequencies of (CGGGG)(3)(CGGGG)(4) genotype and (CGGGG)(4) allele in ACS patients were significantly higher than those in control subjects (p = 0.018, odds ratio [OR] = 1.76, 95% confidence interval [CI]: 1.10-2.81; p = 0.028, OR = 1.62, 95% CI: 1.05-2.50, respectively). However, no significant relationship between the 30 bp exon 6 polymorphism of the IRF-5 gene and the risk of ACS was observed (p = 0.770, OR = 0.96, 95% CI: 0.72-1.28). The 5 bp indel (CGGGG) polymorphism of the IRF-5 gene may be associated with susceptibility to ACS.
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Affiliation(s)
- Jing-Han Fan
- Department of Forensic Biology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, China
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75
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Rachakatla RS, Pyle MM, Ayuzawa R, Edwards SM, Marini FC, Weiss ML, Tamura M, Troyer D. Combination Treatment of Human Umbilical Cord Matrix Stem Cell-Based Interferon-Beta Gene Therapy and 5-Fluorouracil Significantly Reduces Growth of Metastatic Human Breast Cancer in SCID Mouse Lungs. Cancer Invest 2009; 26:662-70. [DOI: 10.1080/07357900701871134] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Functional analysis of a dominant negative mutation of interferon regulatory factor 5. PLoS One 2009; 4:e5500. [PMID: 19430534 PMCID: PMC2677155 DOI: 10.1371/journal.pone.0005500] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2008] [Accepted: 04/01/2009] [Indexed: 11/19/2022] Open
Abstract
Background Interferon regulatory factor (IRF) family members have been implicated as critical transcription factors that function in immune response, hematopoietic differentiation and cell growth regulation. Activation of IRF-5 results in the production of pro-inflammatory cytokines such as TNFα, IL6 and IL12p40, as well as type I interferons. Methodology/Principal Findings In this study, we identify a G202C (position relative to translation start codon) missense-mutation transcript of IRF-5 in transformed B and T cell lines, which were either infected or non-infected by viruses, and peripheral blood from ATL or CLL patients. The mutated transcript encodes a novel protein in which the sixty-eighth amino acid, Alanine, is substituted by Proline (IRF-5P68) in the DNA binding domain of IRF-5. IRF-5P68 phenotype results in a complete loss of its DNA-binding activity and functions as a dominant negative molecule through interacting with wild type IRF-5. Co-expression of IRF-5P68 inhibits MyD88-mediated IRF-5 transactivation. Moreover, Toll-like receptor (TLR)-dependent IL6 and IL12P40 production induced by lipopolysaccharide (LPS), R837 or CpG ODN 1826 was reduced in IRF-5 (P68) expressing cells as compared to the control cells. Conclusion IRF-5P68 acts as a dominant negative regulator that interferes with IRF-5-mediated production of pro-inflammatory cytokines. The functional characterization of the novel IRF-5 mutant in transformed B and T cell lines and in ATL and CLL patients may lead to a better understanding of the role of these transcriptional regulators in hematopoietic malignancies.
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77
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Wies E, Hahn AS, Schmidt K, Viebahn C, Rohland N, Lux A, Schellhorn T, Holzer A, Jung JU, Neipel F. The Kaposi's Sarcoma-associated Herpesvirus-encoded vIRF-3 Inhibits Cellular IRF-5. J Biol Chem 2009; 284:8525-38. [PMID: 19129183 PMCID: PMC2659211 DOI: 10.1074/jbc.m809252200] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2008] [Revised: 01/07/2009] [Indexed: 12/30/2022] Open
Abstract
Kaposi's sarcoma-associated herpesvirus encodes four genes with homology to the family of interferon regulatory factors (IRFs). At least one of these viral IRFs, vIRF-3, is expressed in latently Kaposi's sarcoma-associated herpesvirus-infected primary effusion lymphoma (PEL) cells and is essential for the survival of PEL cells. We now report that vIRF-3 interacts with cellular IRF-5, thereby inhibiting binding of IRF-5 to interferon-responsive promoter elements. Consequently, vIRF-3 blocked IRF-5-mediated promoter activation. A central double helix motif present in vIRF-3 was sufficient to abrogate both DNA binding and transcriptional transactivation by IRF-5. Upon DNA damage or activation of the interferon or Toll-like receptor pathways, cytoplasmic IRF-5 has been reported to be translocated to the nucleus, which results in induction of both p53-independent apoptosis and p21-mediated cell cycle arrest. We report here that IRF-5 is present in the nuclei of PEL cells without interferon stimulation. Silencing of vIRF-3 expression in PEL cells was accompanied by increased sensitivity to interferon-mediated apoptosis and up-regulation of IRF-5 target genes. In addition, vIRF-3 antagonized IRF-5-mediated activation of the p21 promoter. The data presented here indicate that vIRF-3 contributes to immune evasion and sustained proliferation of PEL cells by releasing IRF-5 from transcription complexes.
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MESH Headings
- Active Transport, Cell Nucleus/genetics
- Active Transport, Cell Nucleus/immunology
- Amino Acid Motifs/genetics
- Amino Acid Motifs/immunology
- Apoptosis/genetics
- Apoptosis/immunology
- Cell Nucleus/genetics
- Cell Nucleus/immunology
- Cell Nucleus/metabolism
- Cyclin-Dependent Kinase Inhibitor p21/genetics
- Cyclin-Dependent Kinase Inhibitor p21/immunology
- Cyclin-Dependent Kinase Inhibitor p21/metabolism
- Gene Silencing
- Herpesvirus 8, Human/genetics
- Herpesvirus 8, Human/immunology
- Herpesvirus 8, Human/metabolism
- Humans
- Interferon Regulatory Factors/genetics
- Interferon Regulatory Factors/immunology
- Interferon Regulatory Factors/metabolism
- Lymphoma, Primary Effusion/genetics
- Lymphoma, Primary Effusion/immunology
- Lymphoma, Primary Effusion/metabolism
- Protein Binding/genetics
- Protein Binding/immunology
- Receptors, Interferon/genetics
- Receptors, Interferon/immunology
- Receptors, Interferon/metabolism
- Response Elements
- Sarcoma, Kaposi/genetics
- Sarcoma, Kaposi/immunology
- Sarcoma, Kaposi/metabolism
- Toll-Like Receptors/genetics
- Toll-Like Receptors/immunology
- Toll-Like Receptors/metabolism
- Transcriptional Activation/genetics
- Transcriptional Activation/immunology
- Tumor Suppressor Protein p53/genetics
- Tumor Suppressor Protein p53/immunology
- Tumor Suppressor Protein p53/metabolism
- Up-Regulation/genetics
- Up-Regulation/immunology
- Viral Proteins/genetics
- Viral Proteins/immunology
- Viral Proteins/metabolism
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Affiliation(s)
- Effi Wies
- Virologisches Institut, Universitätsklinikum Erlangen, D-91054 Erlangen, Germany
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Yeon SI, Youn JH, Lim MH, Lee HJ, Kim YM, Choi JE, Lee JM, Shin JS. Development of monoclonal antibodies against human IRF-5 and their use in identifying the binding of IRF-5 to nuclear import proteins karyopherin-alpha1 and -beta1. Yonsei Med J 2008; 49:1023-31. [PMID: 19108028 PMCID: PMC2628014 DOI: 10.3349/ymj.2008.49.6.1023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
PURPOSE IRF-5 is a direct transducer of virus-mediated and TLR-mediated signaling pathways for the expression of cytokines and chemokines which form homodimers or heterodimers with IRF-7. However, direct IRF-5-specific monoclonal antibodies (mAbs) are not available at present. These could be used to further evaluate the functions of IRF-5. In this study, we produced and characterized three mouse mAbs to human IRF-5. The binding of IRF-5 to nuclear import proteins was first identified using a mAb. MATERIALS AND METHODS His-tagged human IRF-5 protein spanning amino acid residues 193-257 was used as an antigen and three mAbs were produced. The mAbs were tested with ELISA, Western blot analysis (WB), immunofluorescent staining (IF), and immunoprecipitation (IP). In addition, the nuclear import protein which carried phosphorylated IRF-5 was identified using one of these mAbs. RESULTS MAbs 5IRF8, 5IRF10 and 5IRF24 which reacted with the recombinant His-IRF-5(193-257) protein were produced. All mAbs bound to human IRF-5, but not to IRF-3 or IRF-7. They could be used for WB, IF, and IP studies. The binding of phosphorylated IRF-5 to karyopherin-alpha1 and -beta1 was also identified. CONCLUSION Human IRF-5-specific mAbs are produced for studying the immunologic roles related to IRF-5. Phosphorylated IRF-5 is transported to the nucleus by binding to nuclear import proteins karyopherin-alpha1 and -beta1.
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Affiliation(s)
- Soo-In Yeon
- Department of Microbiology, Yonsei University College of Medicine, 250 Seongsanno, Seodaemun-gu, Seoul 120-752, Korea
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79
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Insights into interferon regulatory factor activation from the crystal structure of dimeric IRF5. Nat Struct Mol Biol 2008; 15:1213-20. [PMID: 18836453 DOI: 10.1038/nsmb.1496] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2008] [Accepted: 09/03/2008] [Indexed: 12/17/2022]
Abstract
Interferon regulatory factors (IRFs) are essential in the innate immune response and other physiological processes. Activation of these proteins in the cytoplasm is triggered by phosphorylation of serine and threonine residues in a C-terminal autoinhibitory region, which stimulates dimerization, transport into the nucleus, assembly with the coactivator CBP/p300 and initiation of transcription. The crystal structure of the transactivation domain of pseudophosphorylated human IRF5 strikingly reveals a dimer in which the bulk of intersubunit interactions involve a highly extended C-terminal region. The corresponding region has previously been shown to block CBP/p300 binding to unphosphorylated IRF3. Mutation of key interface residues supports the observed dimer as the physiologically activated state of IRF5 and IRF3. Thus, phosphorylation is likely to activate IRF5 and other family members by triggering conformational rearrangements that switch the C-terminal segment from an autoinihibitory to a dimerization role.
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Abstract
Patients with systemic lupus erythematosus (SLE) have an increased expression of type I interferon (IFN) regulated genes because of a continuous production of IFN-alpha. The cellular and molecular background to this IFN-alpha production has started to be elucidated during the last years, as well as the consequences for the innate and adaptive immune systems. Plasmacytoid dendritic cells (pDC) activated by immune complexes containing nucleic acids secrete type I IFN in SLE. Type I IFN causes differentiation of monocytes to myeloid-derived dendritic cell (mDC) and activation of autoreactive T and B cells. A new therapeutic option in patients with SLE is, therefore, inhibition of IFN-alpha, and recent data from a phase I clinical trial suggests that administration of neutralizing monoclonal antibodies against anti-IFN-alpha can ameliorate disease activity.
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Affiliation(s)
- L Rönnblom
- Section of Rheumatology, Department of Medical Sciences, Uppsala University, Uppsala, Sweden.
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81
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Sigurdsson S, Nordmark G, Garnier S, Grundberg E, Kwan T, Nilsson O, Eloranta ML, Gunnarsson I, Svenungsson E, Sturfelt G, Bengtsson AA, Jönsen A, Truedsson L, Rantapää-Dahlqvist S, Eriksson C, Alm G, Göring HHH, Pastinen T, Syvänen AC, Rönnblom L. A risk haplotype of STAT4 for systemic lupus erythematosus is over-expressed, correlates with anti-dsDNA and shows additive effects with two risk alleles of IRF5. Hum Mol Genet 2008; 17:2868-76. [PMID: 18579578 PMCID: PMC2525501 DOI: 10.1093/hmg/ddn184] [Citation(s) in RCA: 159] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Systemic lupus erythematosus (SLE) is the prototype autoimmune disease where genes regulated by type I interferon (IFN) are over-expressed and contribute to the disease pathogenesis. Because signal transducer and activator of transcription 4 (STAT4) plays a key role in the type I IFN receptor signaling, we performed a candidate gene study of a comprehensive set of single nucleotide polymorphism (SNPs) in STAT4 in Swedish patients with SLE. We found that 10 out of 53 analyzed SNPs in STAT4 were associated with SLE, with the strongest signal of association (P = 7.1 x 10(-8)) for two perfectly linked SNPs rs10181656 and rs7582694. The risk alleles of these 10 SNPs form a common risk haplotype for SLE (P = 1.7 x 10(-5)). According to conditional logistic regression analysis the SNP rs10181656 or rs7582694 accounts for all of the observed association signal. By quantitative analysis of the allelic expression of STAT4 we found that the risk allele of STAT4 was over-expressed in primary human cells of mesenchymal origin, but not in B-cells, and that the risk allele of STAT4 was over-expressed (P = 8.4 x 10(-5)) in cells carrying the risk haplotype for SLE compared with cells with a non-risk haplotype. The risk allele of the SNP rs7582694 in STAT4 correlated to production of anti-dsDNA (double-stranded DNA) antibodies and displayed a multiplicatively increased, 1.82-fold risk of SLE with two independent risk alleles of the IRF5 (interferon regulatory factor 5) gene.
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Affiliation(s)
- Snaevar Sigurdsson
- Molecular Medicine, Department of Medical Sciences, Uppsala University, SE-75185 Uppsala, Sweden
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82
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Tamura T, Yanai H, Savitsky D, Taniguchi T. The IRF family transcription factors in immunity and oncogenesis. Annu Rev Immunol 2008; 26:535-84. [PMID: 18303999 DOI: 10.1146/annurev.immunol.26.021607.090400] [Citation(s) in RCA: 957] [Impact Index Per Article: 59.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The interferon regulatory factor (IRF) family, consisting of nine members in mammals, was identified in the late 1980s in the context of research into the type I interferon system. Subsequent studies over the past two decades have revealed the versatile and critical functions performed by this transcription factor family. Indeed, many IRF members play central roles in the cellular differentiation of hematopoietic cells and in the regulation of gene expression in response to pathogen-derived danger signals. In particular, the advances made in understanding the immunobiology of Toll-like and other pattern-recognition receptors have recently generated new momentum for the study of IRFs. Moreover, the role of several IRF family members in the regulation of the cell cycle and apoptosis has important implications for understanding susceptibility to and progression of several cancers.
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Affiliation(s)
- Tomohiko Tamura
- Department of Immunology, Graduate School of Medicine and Faculty of Medicine, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
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83
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Epigenetic disruption of interferon-gamma response through silencing the tumor suppressor interferon regulatory factor 8 in nasopharyngeal, esophageal and multiple other carcinomas. Oncogene 2008; 27:5267-76. [PMID: 18469857 DOI: 10.1038/onc.2008.147] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
16q24 is frequently deleted in multiple tumors including cancers of nasopharynx, esophagus, breast, prostate and liver. By array comparative genomic hybridization (aCGH), we refined a 16q24 hemizygous deletion in nasopharyngeal carcinoma (NPC) cell lines. Semi-quantitative RT-PCR analysis revealed interferon regulatory factor 8 (IRF8) as the only downregulated gene within this deletion. IRF8 belongs to a family of interferon (IFN) regulatory factors that modulate various important physiologic processes including host defense, cell growth and differentiation and immune regulation. In contrast to the broad expression of IRF8 in normal adult and fetal tissues, transcriptional silencing and promoter methylation of IRF8 were frequently detected in multiple carcinoma (except for hepatocellular) cell lines (100% in NPC, 88% in esophageal and 18-78% in other carcinoma cell lines) and in a large collection of primary carcinomas (78% in NPC, 36-71% in other carcinomas). Methylation of the IRF8 promoter led to the disruption of its response to IFN-gamma stimulation. Pharmacological and genetic demethylation could restore IRF8 expression, indicating a direct epigenetic mechanism. Ectopic expression of IRF8 in tumor cells lacking its expression strongly inhibited their clonogenicity, confirming its tumor suppressor function. Thus, IRF8 was identified as a functional tumor suppressor, which is frequently silenced by epigenetic mechanism in multiple carcinomas.
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84
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Interferon regulatory factor 4 is involved in Epstein-Barr virus-mediated transformation of human B lymphocytes. J Virol 2008; 82:6251-8. [PMID: 18417578 DOI: 10.1128/jvi.00163-08] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Epstein-Barr virus (EBV) infection is associated with many human malignancies. In vitro, EBV transforms primary B lymphocytes into continuously growing lymphoblastoid cell lines. EBV latent membrane protein 1 (LMP-1) is required for EBV transformation processes. Interferon regulatory factor 4 (IRF-4) is a transcription factor and has oncogenic potential. We find that high levels of IRF-4 are associated with EBV transformation of human primary B cells in vitro and with EBV type III latency in which LMP-1 is expressed. We show that EBV LMP-1 stimulates IRF-4 expression in B lymphocytes. The stimulation of IRF-4 by LMP-1 requires signaling from LMP-1 and involves cellular NF-kappaB. The growth of EBV-transformed cells is inhibited when IRF-4 is specifically down-regulated. We further demonstrate that IRF-4 knockdown cells have lower proliferation but higher apoptotic rates than control cells. Finally, IRF-4 is expressed in significant numbers of specimens of primary central nervous system (CNS) lymphomas (12/27 [44.4%]), an EBV-associated malignancy. The association between the expression levels of LMP-1 and IRF-4 is statistically significant (P = 0.011) in these CNS lymphomas. Our data suggest that IRF-4 may be a critical factor in EBV transformation and a useful target in the therapy of EBV-mediated neoplasia.
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85
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Takaoka A, Tamura T, Taniguchi T. Interferon regulatory factor family of transcription factors and regulation of oncogenesis. Cancer Sci 2008; 99:467-78. [PMID: 18190617 PMCID: PMC11159419 DOI: 10.1111/j.1349-7006.2007.00720.x] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2007] [Revised: 11/21/2007] [Accepted: 11/25/2007] [Indexed: 01/03/2023] Open
Abstract
A family of transcription factors, the interferon regulatory factors (IRF), was identified originally in the context of the regulation of the type I interferon (IFN)-alpha/beta system. The IRF family has now expanded to nine members, and gene-disruption studies have revealed the critical involvement of these members in multiple facets of host defense systems, such as innate and adaptive immune responses and tumor suppression. In the present review article, we aim at summarizing our current knowledge of the roles of IRF in host defense, with special emphasis on their involvement in the regulation of oncogenesis.
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Affiliation(s)
- Akinori Takaoka
- Department of Immunology, Graduate School of Medicine and Faculty of Medicine, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
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86
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A cell-type-specific requirement for IFN regulatory factor 5 (IRF5) in Fas-induced apoptosis. Proc Natl Acad Sci U S A 2008; 105:2556-61. [PMID: 18268344 DOI: 10.1073/pnas.0712295105] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Apoptosis is a highly regulated process of cell suicide that occurs during development, host defense, and pathophysiology. The transcription factor IFN regulatory factor 5 (IRF5), known to be involved in the activation of innate immune responses, recently has been shown to be critical for DNA damage-induced apoptosis and tumor suppression. Here, we report on a cell-type-specific role of IRF5 in promoting apoptosis upon signaling through the death receptor Fas (CD95/APO-1/TNFRSF6). In particular, we show that mice deficient in the Irf5 gene are resistant to hepatic apoptosis and lethality in response to the in vivo administration of a Fas-activating monoclonal antibody, and that IRF5 is involved in a stage of Fas signaling that precedes the activation of caspase 8 and c-Jun N-terminal kinase (JNK). In addition to hepatocytes, IRF5 is also required for apoptosis in dendritic cells activated by hypomethylated CpG but not in thymocytes and embryonic fibroblasts in vitro. Thus, these findings reveal a cell-type-specific function for IRF5 in the complex regulatory mechanism of death-receptor-induced apoptosis.
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87
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Interferon regulatory factor 6 promotes cell cycle arrest and is regulated by the proteasome in a cell cycle-dependent manner. Mol Cell Biol 2008; 28:2235-43. [PMID: 18212048 DOI: 10.1128/mcb.01866-07] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Interferon regulatory factor 6 (IRF6) is a novel and unique member of the IRF family of transcription factors. IRF6 has not been linked to the regulatory pathways or functions associated with other IRF family members, and the regulation and function of IRF6 remain unknown. We recently identified a protein interaction between IRF6 and the tumor suppressor maspin. To gain insight into the biological significance of the maspin-IRF6 interaction, we examined the regulation and function of IRF6 in relation to maspin in normal mammary epithelial cells. Our results demonstrate that in quiescent cells, IRF6 exists primarily in a nonphosphorylated state. However, cellular proliferation leads to rapid IRF6 phosphorylation, resulting in proteasome-dependent IRF6 degradation. These data are supported in situ by the increased expression of IRF6 in quiescent, differentiated lobuloalveolar cells of the lactating mammary gland compared to its expression in proliferating ductal and glandular epithelial cells during pregnancy. Furthermore, the reexpression of IRF6 in breast cancer cells results in cell cycle arrest, and the presence of maspin augments this response. These data support a model in which IRF6, in collaboration with maspin, promotes mammary epithelial cell differentiation by facilitating entry into the G(0) phase of the cell cycle.
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88
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Ferreiro-Neira I, Calaza M, Alonso-Perez E, Marchini M, Scorza R, Sebastiani GD, Blanco FJ, Rego I, Pullmann R, Pullmann R, Kallenberg CG, Bijl M, Skopouli FN, Mavromati M, Migliaresi S, Barizzone N, Ruzickova S, Dostal C, Schmidt RE, Witte T, Papasteriades C, Kappou-Rigatou I, Endreffy E, Kovacs A, Ordi-Ros J, Balada E, Carreira P, Gomez-Reino JJ, Gonzalez A. Opposed independent effects and epistasis in the complex association of IRF5 to SLE. Genes Immun 2007; 8:429-38. [PMID: 17568788 DOI: 10.1038/sj.gene.6364407] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Genetic variation in the interferon regulatory factor 5 (IRF5) gene affects systemic lupus erythematosus (SLE) susceptibility. However, association is complex and incompletely defined. We obtained fourteen European sample collections with a total of 1383 SLE patients and 1614 controls to better define the role of the different IRF5 variants. Eleven polymorphisms were studied, including nine tag single nucleotide polymorphisms (SNPs) and two extra functional polymorphisms. Two tag SNPs showed independent and opposed associations: susceptibility (rs10488631, P<10(-17)) and protection (rs729302, P<10(-6)). Haplotype analyses showed that the susceptibility haplotype, identified by the minor allele of rs10488631, can be due to epistasis between three IRF5 functional polymorphisms. These polymorphisms determine increased mRNA expression, a splice variant with a different exon 1 and a longer proline-rich region in exon 6. This result is striking as none of the three polymorphisms had an independent effect on their own. Protection was independent of these polymorphisms and seemed to reside in the 5' side of the gene. In conclusion, our results help to understand the role of the IRF5 locus in SLE susceptibility by clearly separating protection from susceptibility as caused by independent polymorphisms. In addition, we have found evidence for epistasis between known functional polymorphisms for the susceptibility effect.
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Affiliation(s)
- I Ferreiro-Neira
- Laboratorio Investigacion 2 and Rheumatology Unit, Hospital Clinico Universitario de Santiago, Santiago de Compostela, Spain
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89
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Gruber HE, Mougeot JL, Hoelscher G, Ingram JA, Hanley EN. Microarray analysis of laser capture microdissected-anulus cells from the human intervertebral disc. Spine (Phila Pa 1976) 2007; 32:1181-7. [PMID: 17495774 DOI: 10.1097/brs.0b013e318053ec89] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Five Thompson Grade I/II discs (Group 1), 7 Grade III discs (Group 2), and 3 Grade IV discs (Group IV) were studied here in a project approved by the authors' Human Subjects Institutional Review Board. OBJECTIVES Our objective was to use laser capture microdissection (LCM) to harvest cells from the human anulus and to derive gene expression profiles using microarray analysis. SUMMARY OF BACKGROUND DATA Appropriate gene expression is essential in the intervertebral disc for maintenance of extracellular matrix (ECM), ECM remodeling, and maintenance of a viable disc cell population. During disc degeneration, cell numbers drop, making gene expression studies challenging. METHODS LCM was used to harvest cells from paraffin-embedded sections of human anulus tissue. Gene profiling used Affymetrix GeneChip Human X3P arrays. ANOVA and SAM permutation analysis were applied to dCHIP normalized, filtered, and log-transformed gene expression data ( approximately 33,500 probes), and data analyzed to identify genes that were significantly differentially expressed between the 3 groups. RESULTS We identified 47 genes that were significantly differentially expressed between the 3 groups (P < 0.001 and lowest q values). Compared with the healthiest discs (Grade I/II), 13 genes were up-regulated and 19 down-regulated in both the Grade III and the Grade IV discs. Genes with biologic significance regulated during degeneration involved cell senescence, low cell division rates, hypoxia-related genes, heat-shock protein 70 interacting protein, neuropilin 2, and interleukin-23p19 (interleukin-12 family). CONCLUSIONS Results expand our understanding of disc aging and degeneration and show that LCM is a valuable technique that can be used to collect mRNA amounts adequate for microarray analysis from the sparse cell population of the human anulus.
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Affiliation(s)
- Helen E Gruber
- Department of Orthopaedic Surgery, Carolinas Medical Center, Charlotte, NC 28232, USA.
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90
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Yanai H, Chen HM, Inuzuka T, Kondo S, Mak TW, Takaoka A, Honda K, Taniguchi T. Role of IFN regulatory factor 5 transcription factor in antiviral immunity and tumor suppression. Proc Natl Acad Sci U S A 2007; 104:3402-7. [PMID: 17360658 PMCID: PMC1805533 DOI: 10.1073/pnas.0611559104] [Citation(s) in RCA: 167] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Host defense consists of two main aspects, namely, immune response to invading pathogens and suppression of tumor development. A family of transcription factors, IFN regulatory factors (IRFs), has recently gained much attention in terms of its critical role in linking these two aspects of host defense, wherein IRF5 was previously shown to play a critical role in the induction of proinflammatory cytokines by activation of Toll-like receptors. In the present study, using IRF5 gene-targeted mice (Irf5(-/-) mice), we demonstrate another facet of the IRF5 function in the regulation of immune response and tumor suppression. We show that IRF5 is critical for antiviral immunity by showing that Irf5(-/-) mice are highly vulnerable to viral infections, accompanied by a decrease in type I IFN induction in the sera. Furthermore, we show that Irf5(-/-) fibroblasts are resistant to apoptosis upon viral infection, resulting in an enhanced viral propagation. Finally, we provide evidence that IRF5 is critical for the induction of apoptosis, but not in cell cycle arrest, in response to DNA damage and that IRF5 functions as a tumor suppressor by acting on a pathway that may be distinct from that for p53. These results, together with the dual regulation of IRF5 gene expression by IFN signaling and p53, may provide a new link in the transcriptional network underlying antiviral immunity and tumor suppression.
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Affiliation(s)
- Hideyuki Yanai
- *Department of Immunology, Graduate School of Medicine and Faculty of Medicine, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hui-min Chen
- *Department of Immunology, Graduate School of Medicine and Faculty of Medicine, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
- Department of Veterinary Internal Medicine, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan; and
| | - Takayuki Inuzuka
- *Department of Immunology, Graduate School of Medicine and Faculty of Medicine, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Seiji Kondo
- Campbell Family Institute of Breast Cancer Research, University of Toronto, University Avenue, Room 7-411, Toronto, ON, Canada M5G 2M9
| | - Tak W. Mak
- Campbell Family Institute of Breast Cancer Research, University of Toronto, University Avenue, Room 7-411, Toronto, ON, Canada M5G 2M9
| | - Akinori Takaoka
- *Department of Immunology, Graduate School of Medicine and Faculty of Medicine, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Kenya Honda
- *Department of Immunology, Graduate School of Medicine and Faculty of Medicine, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Tadatsugu Taniguchi
- *Department of Immunology, Graduate School of Medicine and Faculty of Medicine, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
- To whom correspondence should be addressed. E-mail:
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91
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Cheng TF, Brzostek S, Ando O, Van Scoy S, Kumar KP, Reich NC. Differential activation of IFN regulatory factor (IRF)-3 and IRF-5 transcription factors during viral infection. THE JOURNAL OF IMMUNOLOGY 2006; 176:7462-70. [PMID: 16751392 DOI: 10.4049/jimmunol.176.12.7462] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Members of the IFN regulatory factor (IRF) family regulate gene expression critical to immune response, hemopoiesis, and proliferation. Although related by homology at their N-terminal DNA-binding domain, they display individual functional properties. The distinct properties result from differences in regulated expression, response to activating signals, and interaction with DNA regulatory elements. IRF-3 is expressed ubiquitously and is activated by serine phosphorylation in response to viral infection or TLR signaling. Evidence indicates that the kinases TANK-binding kinase 1 and inhibitor of NF-kappaB kinase-epsilon specifically phosphorylate and thereby activate IRF-3. We evaluated the contribution of another member of the IRF family, IRF-5, during viral infection since prior studies provided varied results. Analysis of phosphorylation, nuclear translocation, dimerization, binding to CREB-binding protein, recognition of DNA, and induction of gene expression were used comparatively with IRF-3 as a measure of IRF-5 activation. IRF-5 was not activated by viral infection; however, expression of TANK-binding kinase 1 or inhibitor of NF-kappaB kinase-epsilon did provide clear activation of IRF-5. IRF-5 is therefore distinct in its activation profile from IRF-3. However, similar to the biological effects of IRF-3 activation, a constitutively active mutation of IRF-5 promoted apoptosis. The apoptosis was inhibited by expression of Bcl-x(L) but not a dominant-negative mutation of the Fas-associated death domain. These studies support the distinct activation profiles of IRF-3 in comparison to IRF-5, but reveal a potential shared biological effect.
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Affiliation(s)
- Tsu-Fan Cheng
- Department of Molecular Genetics and Microbiology, Stony Brook University, NY 11794, USA
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92
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Hu G, Barnes BJ. Interferon regulatory factor-5-regulated pathways as a target for colorectal cancer therapeutics. Expert Rev Anticancer Ther 2006; 6:775-84. [PMID: 16759167 DOI: 10.1586/14737140.6.5.775] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Colorectal cancer is the second most common cause of cancer-related death. A significant obstacle to successful management of patients with colorectal cancer is intrinsic drug resistance or, in patients who initially responded to chemotherapy, acquired drug resistance. Failure in normal apoptotic pathways often contributes to resistance to anticancer drugs or radiotherapy. As a result, the identification of genes that control cell death and apoptosis has come to the forefront of cancer research, leading to new targets and novel therapeutic strategies in the treatment of colorectal cancer. To this effect, the authors have recently identified a new apoptotic signaling pathway that occurs through the transcription factor interferon regulatory factor-5. Here, the different strategies for targeting the interferon regulatory factor-5 signaling pathway in colorectal cancer are discussed. These strategies can be applied to a new generation of cytotoxic agents, as well as to novel biological compounds that are directed at inducing and/or activating interferon regulatory factor-5 or key components of this pathway.
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Affiliation(s)
- Goudong Hu
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
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