scholarly journals Interferon Regulatory Factor 1 Protects against Chikungunya Virus-Induced Immunopathology by Restricting Infection in Muscle Cells

2017 ◽  
Vol 91 (22) ◽  
Author(s):  
Sharmila Nair ◽  
Subhajit Poddar ◽  
Raeann M. Shimak ◽  
Michael S. Diamond
Keyword(s):  
Chikungunya Virus ◽  
Muscle Cells ◽  
Interferon Regulatory Factor ◽  
Ross River Virus ◽  
Type I ◽  
Type Ii ◽  
Regulatory Factor ◽  
Interferon Regulatory Factor 1 ◽  
Ifn Γ

ABSTRACT The innate immune system protects cells against viral pathogens in part through the autocrine and paracrine actions of alpha/beta interferon (IFN-α/β) (type I), IFN-γ (type II), and IFN-λ (type III). The transcription factor interferon regulatory factor 1 (IRF-1) has a demonstrated role in shaping innate and adaptive antiviral immunity by inducing the expression of IFN-stimulated genes (ISGs) and mediating signals downstream of IFN-γ. Although ectopic expression experiments have suggested an inhibitory function of IRF-1 against infection of alphaviruses in cell culture, its role in vivo remains unknown. Here, we infected Irf1 −/− mice with two distantly related arthritogenic alphaviruses, chikungunya virus (CHIKV) and Ross River virus (RRV), and assessed the early antiviral functions of IRF-1 prior to induction of adaptive B and T cell responses. IRF-1 expression limited CHIKV-induced foot swelling in joint-associated tissues and prevented dissemination of CHIKV and RRV at early time points. Virological and histological analyses revealed greater infection of muscle tissues in Irf1 −/− mice than in wild-type mice. The antiviral actions of IRF-1 appeared to be independent of the induction of type I IFN or the effects of type II and III IFNs but were associated with altered local proinflammatory cytokine and chemokine responses and differential infiltration of myeloid cell subsets. Collectively, our in vivo experiments suggest that IRF-1 restricts CHIKV and RRV infection in stromal cells, especially muscle cells, and that this controls local inflammation and joint-associated swelling. IMPORTANCE Interferon regulatory factor 1 (IRF-1) is a transcription factor that regulates the expression of a broad range of antiviral host defense genes. In this study, using Irf1 −/− mice, we investigated the role of IRF-1 in modulating pathogenesis of two related arthritogenic alphaviruses, chikungunya virus and Ross River virus. Our studies show that IRF-1 controlled alphavirus replication and swelling in joint-associated tissues within days of infection. Detailed histopathological and virological analyses revealed that IRF-1 preferentially restricted CHIKV infection in cells of nonhematopoietic lineage, including muscle cells. The antiviral actions of IRF-1 resulted in decreased local inflammatory responses in joint-associated tissues, which prevented immunopathology.

scholarly journals Interferon Regulatory Factor 1 and Type I Interferon Cooperate To Control Acute Gammaherpesvirus Infection

2016 ◽  
Vol 91 (1) ◽  
Author(s):  
Wadzanai P. Mboko ◽  
Michaela M. Rekow ◽  
Mitchell P. Ledwith ◽  
Philip T. Lange ◽  
Kaitlin E. Schmitz ◽  
...  
Keyword(s):  
Type I Interferon ◽  
Acute Infection ◽  
Interferon Regulatory Factor ◽  
Host Immune System ◽  
Type I ◽  
Type I Ifn ◽  
Regulatory Factor ◽  
Interferon Regulatory Factor 1

ABSTRACT Gammaherpesviruses are ubiquitous pathogens that establish lifelong infection in >95% of adults worldwide and are associated with a variety of malignancies. Coevolution of gammaherpesviruses with their hosts has resulted in an intricate relationship between the virus and the host immune system, and perturbation of the virus-host balance results in pathology. Interferon regulatory factor 1 (IRF-1) is a tumor suppressor that is also involved in the regulation of innate and adaptive immune responses. Here, we show that type I interferon (IFN) and IRF-1 cooperate to control acute gammaherpesvirus infection. Specifically, we demonstrate that a combination of IRF-1 and type I IFN signaling ensures host survival during acute gammaherpesvirus infection and supports IFN gamma-mediated suppression of viral replication. Thus, our studies reveal an intriguing cross talk between IRF-1 and type I and II IFNs in the induction of the antiviral state during acute gammaherpesvirus infection. IMPORTANCE Gammaherpesviruses establish chronic infection in a majority of adults, and this long-term infection is associated with virus-driven development of a range of malignancies. In contrast, a brief period of active gammaherpesvirus replication during acute infection of a naive host is subclinical in most individuals. Here, we discovered that a combination of type I interferon (IFN) signaling and interferon regulatory factor 1 (IRF-1) expression is required to ensure survival of a gammaherpesvirus-infected host past the first 8 days of infection. Specifically, both type I IFN receptor and IRF-1 expression potentiated antiviral effects of type II IFN to restrict gammaherpesvirus replication in vivo, in the lungs, and in vitro, in primary macrophage cultures.

scholarly journals Reduced Incidence and Severity of Antigen-induced Autoimmune Diseases in Mice Lacking Interferon Regulatory Factor-1

1997 ◽  
Vol 185 (2) ◽  
pp. 231-238 ◽  
Author(s):  
Yoshifumi Tada ◽  
Alexandra Ho ◽  
Toshifumi Matsuyama ◽  
Tak W. Mak
Keyword(s):  
Type Ii Collagen ◽  
Interferon Regulatory Factor ◽  
Type I Interferons ◽  
Type I ◽  
Type Ii ◽  
Regulatory Factor ◽  
Interferon Regulatory Factor 1 ◽  
Lymph Node Cells ◽  
Oxide Synthase

Interferon regulatory factor-1 (IRF-1) is a transcription factor that regulates interferon-induced genes and type I interferons. Recently, studies of IRF-1-deficient mice have revealed that IRF-1 regulates the induction of molecules that play important roles in inflammation, such as inducible nitric oxide synthase (iNOS) and interleukin-1β-converting enzyme (ICE). To study the role of IRF-1 in autoimmunity, we investigated type II collagen-induced arthritis (CIA), and experimental allergic encephalomyelitis (EAE), in mice lacking IRF-1. The incidence and severity of CIA were significantly decreased in IRF-1−/− mice compared with IRF-1+/− mice, as was the production of interferon (IFN)-γ in lymph node cells. Both IRF-1+/− and IRF-1−/− mice exhibited mild and transient disease after adoptive transfer of a type II collagen (CII)-specific T cell line together with sera from arthritic mice, but the IRF-1−/− mice were less severely affected than the IRF-1+/− mice. In addition, the incidence of EAE in IRF-1−/− mice was decreased as compared with IRF-1+/− mice. Reverse transcription polymerase chain reaction showed that IRF-1 mRNA was constitutively expressed in the spinal cords of IRF-1+/− mice, and was upregulated in mice with clinical EAE. Expression of iNOS was also detected in inflamed spinal cords. These results suggest that IRF-1 plays a key role in promoting inflammation and autoimmunity in CIA and EAE animal models.

scholarly journals Identification of Feline Interferon Regulatory Factor 1 as an Efficient Antiviral Factor against the Replication of Feline Calicivirus and Other Feline Viruses

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Yongxiang Liu ◽  
Xiaoxiao Liu ◽  
Hongtao Kang ◽  
Xiaoliang Hu ◽  
Jiasen Liu ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Viral Infections ◽  
Interferon Regulatory Factor ◽  
Feline Calicivirus ◽  
Type I ◽  
Norwalk Virus ◽  
Regulatory Factor ◽  
Feline Panleukopenia Virus ◽  
Protein Levels ◽  
Interferon Regulatory Factor 1

Interferons (IFNs) can inhibit most, if not all, viral infections by eliciting the transcription of hundreds of interferon-stimulated genes (ISGs). Feline calicivirus (FCV) is a highly contagious pathogen of cats and a surrogate for Norwalk virus. Interferon efficiently inhibits the replication of FCV, but the mechanism of the antiviral activity is poorly understood. Here, we evaluated the anti-FCV activity of ten ISGs, whose antiviral activities were previously reported. The results showed that interferon regulatory factor 1 (IRF1) can significantly inhibit the replication of FCV, whereas the other ISGs tested in this study failed. Further, we found that IRF1 was localized in the nucleus and efficiently activated IFN-β and the ISRE promoter. IRF1 can trigger the production of endogenous interferon and the expression of ISGs, suggesting that IRF1 can positively regulate IFN signalling. Importantly, the mRNA and protein levels of IRF1 were reduced upon FCV infection, which may be a new strategy for FCV to evade the innate immune system. Finally, the antiviral activity of IRF1 against feline panleukopenia virus, feline herpesvirus, and feline infectious peritonitis virus was demonstrated. These data indicate that feline IRF1 plays an important role in regulating the host type I IFN response and inhibiting feline viral infections.

Structure and regulation of the human interferon regulatory factor 1 (IRF-1) and IRF-2 genes: implications for a gene network in the interferon system

1994 ◽  
Vol 14 (2) ◽  
pp. 1500-1509
Author(s):  
H Harada ◽  
E Takahashi ◽  
S Itoh ◽  
K Harada ◽  
T A Hori ◽  
...  
Keyword(s):  
Gene Network ◽  
Interferon Regulatory Factor ◽  
Chromosomal Mapping ◽  
Human Interferon ◽  
Type I ◽  
Regulatory Factor ◽  
Nf Kappa B ◽  
Interferon Regulatory Factor 1 ◽  
Two Factors ◽  
Dna Binding Factors

Interferon regulatory factor 1 (IRF-1) and IRF-2 are structurally similar DNA-binding factors which were originally identified as regulators of the type I interferon (IFN) system; the former functions as a transcriptional activator, and the latter represses IRF-1 function by competing for the same cis elements. More recent studies have revealed new roles of the two factors in the regulation of cell growth; IRF-1 and IRF-2 manifest antioncogenic and oncogenic activities, respectively. In this study, we determined the structures and chromosomal locations of the human IRF-1 and IRF-2 genes and further characterized the promoters of the respective genes. Comparison of exon-intron organization of the two genes revealed a common evolutionary structure, notably within the exons encoding the N-terminal portions of the two factors. We confirmed the chromosomal mapping of the human IRF-1 gene to 5q31.1 and newly assigned the IRF-2 gene to 4q35.1, using fluorescence in situ hybridization. The 5' regulatory regions of both genes contain highly GC-rich sequences and consensus binding sequences for several known transcription factors, including NF-kappa B. Interestingly, one IRF binding site was found within the IRF-2 promoter, and expression of the IRF-2 gene was affected by both transient and stable IRF-1 expression. In addition, one potential IFN-gamma-activated sequence was found within the IRF-1 promoter. Thus, these results may shed light on the complex gene network involved in regulation of the IFN system.

scholarly journals Pulmonary Inflammation Induced by Pseudomonas aeruginosa Lipopolysaccharide, Phospholipase C, and Exotoxin A: Role of Interferon Regulatory Factor 1

2002 ◽  
Vol 70 (3) ◽  
pp. 1352-1358 ◽  
Author(s):  
Catharina W. Wieland ◽  
Britta Siegmund ◽  
Giorgio Senaldi ◽  
Michael L. Vasil ◽  
Charles A. Dinarello ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Pulmonary Inflammation ◽  
Interferon Regulatory Factor ◽  
Cell Infiltration ◽  
Exotoxin A ◽  
Regulatory Factor ◽  
Interferon Regulatory Factor 1 ◽  
Tnf Α ◽  
Ifn Γ

ABSTRACT Chronic pulmonary infection with Pseudomonas aeruginosa is common in cystic fibrosis (CF) patients. P. aeruginosa lipopolysaccharide (LPS), phosholipase C (PLC), and exotoxin A (ETA) were evaluated for their ability to induce pulmonary inflammation in mice following intranasal inoculation. Both LPS and PLC induced high levels of tumor necrosis factor alpha (TNF-α), interleukin 1β (IL-1β), IL-6, gamma interferon (IFN-γ), MIP-1α and MIP-2 in the lungs but did not affect IL-18 levels. ETA did not induce TNF-α and was a weak inducer of IL-1β, IL-6, macrophage inflammatory protein 1α (MIP-1α), and MIP-2. Remarkably, ETA reduced constitutive lung IL-18 levels. LPS was the only factor inducing IFN-γ. LPS, PLC, and ETA all induced cell infiltration in the lungs. The role of interferon regulatory factor-1 (IRF-1) in pulmonary inflammation induced by LPS, PLC, and ETA was evaluated. When inoculated with LPS, IRF-1 gene knockout (IRF-1 KO) mice produced lower levels of TNF-α, IL-1β, and IFN-γ than did wild-type (WT) mice. Similarly, a milder effect of ETA on IL-1β and IL-18 was observed for IRF-1 KO than for WT mice. In contrast, the cytokine response to PLC did not differ between WT and IRF-1 KO mice. Accordingly, LPS and ETA, but not PLC, induced expression of IRF-1 mRNA. IRF-1 deficiency had no effect on MIP-1α and MIP-2 levels and on cell infiltration induced by LPS, PLC, or ETA. Flow cytometric evaluation of lung mononuclear cells revealed strongly reduced percentages of CD8+ and NK cells in IRF-1 KO mice compared to percentages observed for WT mice. These data indicate that different virulence factors from P. aeruginosa induce pulmonary inflammation in vivo and that IRF-1 is involved in some of the cytokine responses to LPS and ETA.

scholarly journals Interferon Regulatory Factor IRF-7 Induces the Antiviral Alpha Interferon Response and Protects against Lethal West Nile Virus Infection

2008 ◽  
Vol 82 (17) ◽  
pp. 8465-8475 ◽  
Author(s):  
Stephane Daffis ◽  
Melanie A. Samuel ◽  
Mehul S. Suthar ◽  
Brian C. Keller ◽  
Michael Gale ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Cortical Neurons ◽  
Interferon Regulatory Factor ◽  
Interferon Response ◽  
Type I ◽  
Type I Ifn ◽  
Regulatory Factor ◽  
West Nile

ABSTRACT Type I interferon (IFN-α/β) comprises a family of immunomodulatory cytokines that are critical for controlling viral infections. In cell culture, many RNA viruses trigger IFN responses through the binding of RNA recognition molecules (RIG-I, MDA5, and TLR-3) and induction of interferon regulatory factor IRF-3-dependent gene transcription. Recent studies with West Nile virus (WNV) have shown that type I IFN is essential for restricting infection and that a deficiency of IRF-3 results in enhanced lethality. However, IRF-3 was not required for optimal systemic IFN production in vivo or in vitro in macrophages. To begin to define the transcriptional factors that regulate type I IFN after WNV infection, we evaluated IFN induction and virus control in IRF-7−/− mice. Compared to congenic wild-type mice, IRF-7−/− mice showed increased lethality after WNV infection and developed early and elevated WNV burdens in both peripheral and central nervous system tissues. As a correlate, a deficiency of IRF-7 blunted the systemic type I IFN response in mice. Consistent with this, IFN-α gene expression and protein production were reduced and viral titers were increased in IRF-7−/− primary macrophages, fibroblasts, dendritic cells, and cortical neurons. In contrast, in these cells the IFN-β response remained largely intact. Our data suggest that the early protective IFN-α response against WNV occurs through an IRF-7-dependent transcriptional signal.

Cytokine-inducible CD40 expression in human endothelial cells is mediated by interferon regulatory factor-1

Blood ◽  
2002 ◽  
Vol 99 (2) ◽  
pp. 520-525 ◽  
Author(s):  
Andreas H. Wagner ◽  
Matthias Gebauer ◽  
Beatrix Pollok-Kopp ◽  
Markus Hecker
Keyword(s):  
Endothelial Cells ◽  
De Novo ◽  
Cd40 Ligand ◽  
Interferon Regulatory Factor ◽  
Regulatory Factor ◽  
De Novo Synthesis ◽  
Human Endothelial Cells ◽  
Interferon Regulatory Factor 1 ◽  
Ifn Γ ◽  
Cd40 Expression

Abstract Given the significance of CD40–CD40 ligand interactions in chronic inflammatory diseases including atherosclerosis, the transcriptional regulation of CD40 expression as a potential therapeutic target was investigated in human umbilical vein cultured endothelial cells. Exposure to interferon-γ (IFN-γ) plus tumor necrosis factor-α resulted in a marked synergistic de novo expression of CD40, which, according to electrophoretic mobility shift analysis, was attributable to activation of the transcription factors nuclear factor-κB (NF-κB), signal transducer and activator of transcription-1 (STAT-1), and interferon regulatory factor-1 (IRF-1). Subsequent time-course studies revealed that de novo synthesis of IRF-1 preceded that of CD40. Decoy oligodeoxynucleotide (ODN) neutralization of STAT-1 or IRF-1, but not of NF-κB, inhibited cytokine-stimulated CD40 expression by 60% at both the mRNA and protein levels, and this effect was mimicked by antisense ODN blockade of IRF-1 synthesis. In contrast, CD40 expression in response to IFN-γ stimulation was sensitive to neutralization of STAT-1 only. These findings suggest that depending on the cytokine composition, CD40 expression in human endothelial cells under proinflammatory conditions is governed by STAT-1 either directly or indirectly through de novo synthesis of IRF-1. Moreover, decoy ODN neutralization of these transcription factors may provide a novel therapeutic option for interfering with CD40–CD40 ligand-mediated inflammatory responses in vivo.

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