scholarly journals Crucial Role of Interferon Consensus Sequence Binding Protein, but neither of Interferon Regulatory Factor 1 nor of Nitric Oxide Synthesis for Protection Against Murine Listeriosis

1997 ◽  
Vol 185 (5) ◽  
pp. 921-932 ◽  
Author(s):  
Thomas Fehr ◽  
Gabriele Schoedon ◽  
Bernhard Odermatt ◽  
Thomas Holtschke ◽  
Markus Schneemann ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Binding Protein ◽  
Consensus Sequence ◽  
Interferon Regulatory Factor ◽  
Regulatory Factor ◽  
Oxygen Intermediates ◽  
Ifn Γ ◽  
Effector Mechanisms

Listeria monocytogenes is widely used as a model to study immune responses against intracellular bacteria. It has been shown that neutrophils and macrophages play an important role to restrict bacterial replication in the early phase of primary infection in mice, and that the cytokines interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α) are essential for protection. However, the involved signaling pathways and effector mechanisms are still poorly understood. This study investigated mouse strains deficient for the IFN-dependent transcription factors interferon consensus sequence binding protein (ICSBP), interferon regulatory factor (IRF)1 or 2 for their capacity to eliminate Listeria in vivo and in vitro and for production of inducible reactive nitrogen intermediates (RNI) or reactive oxygen intermediates (ROI) in macrophages. ICSBP−/− and to a lesser degree also IRF2−/− mice were highly susceptible to Listeria infection. This correlated with impaired elimination of Listeria from infected peritoneal macrophage (PEM) cultures stimulated with IFN-γ in vitro; in addition these cultures showed reduced and delayed oxidative burst upon IFN-γ stimulation, whereas nitric oxide production was normal. In contrast, mice deficient for IRF1 were not able to produce nitric oxide, but they efficiently controlled Listeria in vivo and in vitro. These results indicate that (a) the ICSBP/IRF2 complex is essential for IFN-γ–mediated protection against Listeria and that (b) ROI together with additional still unknown effector mechanisms may be responsible for the anti-Listeria activity of macrophages, whereas IRF1-induced RNI are not limiting.

scholarly journals Cooperation between Reactive Oxygen and Nitrogen Intermediates in Killing of Rhodococcus equi by Activated Macrophages

2000 ◽  
Vol 68 (6) ◽  
pp. 3587-3593 ◽  
Author(s):  
Patricia A. Darrah ◽  
Mary K. Hondalus ◽  
Quiping Chen ◽  
Harry Ischiropoulos ◽  
David M. Mosser
Keyword(s):  
Nitric Oxide ◽  
Prolonged Exposure ◽  
Rhodococcus Equi ◽  
Activated Macrophages ◽  
Intracellular Killing ◽  
Oxygen Intermediates ◽  
Bacterial Killing ◽  
Ifn Γ

ABSTRACT Rhodococcus equi is a facultative intracellular bacterium of macrophages which can infect immunocompromised humans and young horses. In the present study, we examine the mechanism of host defense against R. equi by using a murine model. We show that bacterial killing is dependent upon the presence of gamma interferon (IFN-γ), which activates macrophages to produce reactive nitrogen and oxygen intermediates. These two radicals combine to form peroxynitrite (ONOO−), which kills R. equi. Mice deficient in the production of either the high-output nitric oxide pathway (iNOS−/−) or the oxidative burst (gp91 phox−/− ) are more susceptible to lethalR. equi infection and display higher bacterial burdens in their livers, spleens, and lungs than wild-type mice. These in vivo observations, which implicate both nitric oxide (NO) and superoxide (O2 −) in bacterial killing, were reexamined in cell-free radical-generating assays. In these assays, R. equi remains fully viable following prolonged exposure to high concentrations of either nitric oxide or superoxide, indicating that neither compound is sufficient to mediate bacterial killing. In contrast, brief exposure of bacteria to ONOO− efficiently kills virulent R. equi. The intracellular killing of bacteria in vitro by activated macrophages correlated with the production of ONOO− in situ. Inhibition of nitric oxide production by activated macrophages by usingN G-monomethyl-l-arginine blocks their production of ONOO− and weakens their ability to control rhodococcal replication. These studies indicate that peroxynitrite mediates the intracellular killing of R. equiby IFN-γ-activated macrophages.

scholarly journals Lack of Interferon Consensus Sequence Binding Protein (ICSBP) Transcripts in Human Myeloid Leukemias

Blood ◽  
1998 ◽  
Vol 91 (1) ◽  
pp. 22-29 ◽  
Author(s):  
Manuel Schmidt ◽  
Stefan Nagel ◽  
Jutta Proba ◽  
Christian Thiede ◽  
Markus Ritter ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Binding Protein ◽  
Consensus Sequence ◽  
Inverse Correlation ◽  
Myelogenous Leukemia ◽  
Leukemic Cells ◽  
Myeloid Leukemias ◽  
Ifn Γ

Interferon consensus sequence binding protein (ICSBP) was first identified as a transcription factor of the interferon (IFN) regulatory factor family (IRF) which regulates expression of IFN-dependent genes by binding to DNA at specific sites, IFN-stimulated responsive elements. Analysis of ICSBP-deficient mice showed hematologic alterations similar to chronic myelogenous leukemia (CML) in humans and suggested a novel role for ICSBP in regulating proliferation and differentiation of hematopoietic progenitor cells. Here we show that ICSBP-mRNA expression is impaired in human myeloid leukemias: 27 of 34 CML patients (79%) and 21 of 32 patients with acute myeloid leukemia (AML) (66%) showed very low or absent transcript numbers of ICSBP. In contrast, only 2 of 33 normal volunteers (6%) showed low transcription of ICSBP(P < .0001 both for CML and AML values). The lack of expression was not associated with lack of lymphatic cells, which normally have been shown to express ICSBP at the highest level. More detailed analysis showed an absence of ICSBP-mRNA also in sorted B cells derived from CML patients. To analyze whetherICSBP may be induced in leukemic cells, ex vivoexperiments using a known inducer of ICSBP, IFN-γ, were performed. Ex vivo treatment of primary CML cells using IFN-γ resulted in induction of ICSBP transcripts. Furthermore, samples of CML patients during IFN-α treatment were analyzed. In 11 of 12 CML patients ICSBP-mRNA was inducible upon in vivo treatment with IFN-α, but decreased with progression of CML. Stable transfection of K-562 cell line with ICSBP led to no difference in bcr-abl expression in vitro, although two patients showed an inverse correlation between bcr-abl andICSBP in vivo. These data suggest that lack of ICSBPmay have an important role also in human myeloid leukemogenesis.

scholarly journals Lack of Interferon Consensus Sequence Binding Protein (ICSBP) Transcripts in Human Myeloid Leukemias

Blood ◽  
1998 ◽  
Vol 91 (1) ◽  
pp. 22-29 ◽  
Author(s):  
Manuel Schmidt ◽  
Stefan Nagel ◽  
Jutta Proba ◽  
Christian Thiede ◽  
Markus Ritter ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Binding Protein ◽  
Consensus Sequence ◽  
Inverse Correlation ◽  
Myelogenous Leukemia ◽  
Leukemic Cells ◽  
Myeloid Leukemias ◽  
Ifn Γ

Abstract Interferon consensus sequence binding protein (ICSBP) was first identified as a transcription factor of the interferon (IFN) regulatory factor family (IRF) which regulates expression of IFN-dependent genes by binding to DNA at specific sites, IFN-stimulated responsive elements. Analysis of ICSBP-deficient mice showed hematologic alterations similar to chronic myelogenous leukemia (CML) in humans and suggested a novel role for ICSBP in regulating proliferation and differentiation of hematopoietic progenitor cells. Here we show that ICSBP-mRNA expression is impaired in human myeloid leukemias: 27 of 34 CML patients (79%) and 21 of 32 patients with acute myeloid leukemia (AML) (66%) showed very low or absent transcript numbers of ICSBP. In contrast, only 2 of 33 normal volunteers (6%) showed low transcription of ICSBP(P < .0001 both for CML and AML values). The lack of expression was not associated with lack of lymphatic cells, which normally have been shown to express ICSBP at the highest level. More detailed analysis showed an absence of ICSBP-mRNA also in sorted B cells derived from CML patients. To analyze whetherICSBP may be induced in leukemic cells, ex vivoexperiments using a known inducer of ICSBP, IFN-γ, were performed. Ex vivo treatment of primary CML cells using IFN-γ resulted in induction of ICSBP transcripts. Furthermore, samples of CML patients during IFN-α treatment were analyzed. In 11 of 12 CML patients ICSBP-mRNA was inducible upon in vivo treatment with IFN-α, but decreased with progression of CML. Stable transfection of K-562 cell line with ICSBP led to no difference in bcr-abl expression in vitro, although two patients showed an inverse correlation between bcr-abl andICSBP in vivo. These data suggest that lack of ICSBPmay have an important role also in human myeloid leukemogenesis.

scholarly journals Interferon Consensus Sequence Binding Protein–deficient Mice Display Impaired Resistance to Intracellular Infection Due to a Primary Defect in Interleukin 12 p40 Induction

1997 ◽  
Vol 186 (9) ◽  
pp. 1523-1534 ◽  
Author(s):  
Tanya Scharton-Kersten ◽  
Cristina Contursi ◽  
Atsuko Masumi ◽  
Alan Sher ◽  
Keiko Ozato
Keyword(s):  
Transcription Factor ◽  
Binding Protein ◽  
Consensus Sequence ◽  
Gene Activation ◽  
Interleukin 12 ◽  
Primary Defect ◽  
Ifn Γ ◽  
Deficient Mice

Mice lacking the transcription factor interferon consensus sequence binding protein (ICSBP), a member of the interferon regulatory factor family of transcription proteins, were infected with the intracellular protozoan, Toxoplasma gondii. ICSBP-deficient mice exhibited unchecked parasite replication in vivo and rapidly succumbed within 14 d after inoculation with an avirulent Toxoplasma strain. In contrast, few intracellular parasites were observed in wild-type littermates and these animals survived for at least 60 d after infection. Analysis of cytokine synthesis in vitro and in vivo revealed a major deficiency in the expression of both interferon (IFN)-γ and interleukin (IL)-12 p40 in the T. gondii exposed ICSBP−/− animals. In related experiments, macrophages from uninfected ICSBP−/− mice were shown to display a selective impairment in the mRNA expression of IL-12 p40 but not IL-1α, IL-1β, IL-1Ra, IL-6, IL-10, or TNF-α in response to live parasites, parasite antigen, lipopolysaccharide, or Staphylococcus aureus. This selective defect in IL-12 p40 production was observed regardless of whether the macrophages had been primed with IFN-γ. We hypothesize that the impaired synthesis of IL-12 p40 in ICSBP−/− animals is the primary lesion responsible for the loss in resistance to T. gondii because IFN-γ–induced parasite killing was unimpaired in vitro and, more importantly, administration of exogenous IL-12 in vivo significantly prolonged survival of the infected mice. Together these findings implicate ICSBP as a major transcription factor which directly or indirectly regulates IL-12 p40 gene activation and, as a consequence, IFN-γ–dependent host resistance.

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.

scholarly journals Interferon consensus sequence-binding protein, a member of the interferon regulatory factor family, suppresses interferon-induced gene transcription.

1993 ◽  
Vol 13 (1) ◽  
pp. 588-599 ◽  
Author(s):  
N Nelson ◽  
M S Marks ◽  
P H Driggers ◽  
K Ozato
Keyword(s):  
Major Histocompatibility Complex ◽  
Retinoic Acid ◽  
Major Histocompatibility Complex Class ◽  
Binding Protein ◽  
Consensus Sequence ◽  
Interferon Regulatory Factor ◽  
Chloramphenicol Acetyltransferase ◽  
Complex Class ◽  
Regulatory Factor ◽  
Histocompatibility Complex

We previously isolated a cDNA clone encoding interferon consensus sequence-binding protein (ICSBP), a member of the interferon regulatory factor (IRF) family, that binds to the interferon (IFN)-stimulated response element (ISRE) of many IFN-regulated genes. In this investigation, we studied the functional role of ICSBP by transient cotransfection of ICSBP cDNA with IFN-responsive reporter genes into the human embryonal carcinoma cell line N-Tera2. These cells were shown not to express ICSBP or IRF-2, thus allowing functional analysis of transfected cDNAs. Cotransfection of ICSBP into cells treated with retinoic acid or any of the IFNs (alpha, beta, or gamma) repressed expression of a chloramphenicol acetyltransferase reporter driven by the major histocompatibility complex class I gene promoter. Similarly, ICSBP repressed expression of chloramphenicol acetyltransferase reporters driven by the ISREs of the 2'-5' oligoadenylate synthetase, guanylate-binding protein, and ISG-15 genes in IFN-treated cells. The repression was dependent on the presence of the ISRE in the reporter. Deletion analysis showed that the putative N-terminal DNA binding domain of ICSBP by itself is capable of mediating the repression. Using the same cotransfection conditions as for ICSBP, a similar repression of these reporters was observed with IRF-2. Finally, ICSBP repressed the IRF-1-mediated induction of major histocompatibility complex class I and IFN-beta reporters in the absence of IFN or retinoic acid. Taken together, these results suggest that ICSBP is a negative regulatory factor capable of repressing transcription of target genes induced by IFN, retinoic acid, or IRF-1.

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.

Sign in / Sign up

Export Citation Format

Share Document