scholarly journals A cytomegaloviral protein reveals a dual role for STAT2 in IFN-γ signaling and antiviral responses

2005 ◽  
Vol 201 (10) ◽  
pp. 1543-1553 ◽  
Author(s):  
Albert Zimmermann ◽  
Mirko Trilling ◽  
Markus Wagner ◽  
Manuel Wilborn ◽  
Ivan Bubic ◽  
...  
Keyword(s):  
Biological Significance ◽  
Receptor Expression ◽  
Type I ◽  
Antiviral Responses ◽  
Type I Ifns ◽  
New Strategy ◽  
Infected Cells ◽  
Ifn Γ

A mouse cytomegalovirus (MCMV) gene conferring interferon (IFN) resistance was identified. This gene, M27, encodes a 79-kD protein that selectively binds and down-regulates for signal transducer and activator of transcription (STAT)-2, but it has no effect on STAT1 activation and signaling. The absence of pM27 conferred MCMV susceptibility to type I IFNs (α/β), but it had a much more dramatic effect on type II IFNs (γ) in vitro and in vivo. A comparative analysis of M27+ and M27− MCMV revealed that the antiviral efficiency of IFN-γ was partially dependent on the synergistic action of type I IFNs that required STAT2. Moreover, STAT2 was directly activated by IFN-γ. This effect required IFN receptor expression and was independent of type I IFNs. IFN-γ induced increasing levels of tyrosine-phosphorylated STAT2 in M27− MCMV-infected cells that were essential for the antiviral potency of IFN-γ. pM27 represents a new strategy for simultaneous evasions from types I and II IFNs, and it documents an unknown biological significance for STAT2 in antiviral IFN-γ responses.

scholarly journals HIV-Infected Macrophages Are Infected and Killed by the Interferon-Sensitive Rhabdovirus MG1

2021 ◽  
Vol 95 (9) ◽  
Author(s):  
Teslin S. Sandstrom ◽  
Nischal Ranganath ◽  
Stephanie C. Burke Schinkel ◽  
Syim Salahuddin ◽  
Oussama Meziane ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Oncolytic Viruses ◽  
Type I Interferons ◽  
Viral Reservoir ◽  
Type I ◽  
Antiviral Signaling ◽  
Infected Cells ◽  
Hiv 1

ABSTRACT The use of unique cell surface markers to target and eradicate HIV-infected cells has been a longstanding objective of HIV-1 cure research. This approach, however, overlooks the possibility that intracellular changes present within HIV-infected cells may serve as valuable therapeutic targets. For example, the identification of dysregulated antiviral signaling in cancer has led to the characterization of oncolytic viruses capable of preferentially killing cancer cells. Since impairment of cellular antiviral machinery has been proposed as a mechanism by which HIV-1 evades immune clearance, we hypothesized that HIV-infected macrophages (an important viral reservoir in vivo) would be preferentially killed by the interferon-sensitive oncolytic Maraba virus MG1. We first showed that HIV-infected monocyte-derived macrophages (MDM) were more susceptible to MG1 infection and killing than HIV-uninfected cells. As MG1 is highly sensitive to type I interferons (IFN-I), we then investigated whether we could identify IFN-I signaling differences between HIV-infected and uninfected MDM and found evidence of impaired IFN-α responsiveness within HIV-infected cells. Finally, to assess whether MG1 could target a relevant, primary cell reservoir of HIV-1, we investigated its effects in alveolar macrophages (AM) obtained from effectively treated individuals living with HIV-1. As observed with in vitro-infected MDM, we found that HIV-infected AM were preferentially eliminated by MG1. In summary, the oncolytic rhabdovirus MG1 appears to preferentially target and kill HIV-infected cells via impairment of antiviral signaling pathways and may therefore provide a novel approach to an HIV-1 cure. IMPORTANCE Human immunodeficiency virus type 1 (HIV-1) remains a treatable, but incurable, viral infection. The establishment of viral reservoirs containing latently infected cells remains the main obstacle in the search for a cure. Cure research has also focused on only one cellular target of HIV-1 (the CD4+ T cell) while largely overlooking others (such as macrophages) that contribute to HIV-1 persistence. In this study, we address these challenges by describing a potential strategy for the eradication of HIV-infected macrophages. Specifically, we show that an engineered rhabdovirus—initially developed as a cancer therapy—is capable of preferential infection and killing of HIV-infected macrophages, possibly via the same altered antiviral signaling seen in cancer cells. As this rhabdovirus is currently being explored in phase I/II clinical trials, there is potential for this approach to be readily adapted for use within the HIV-1 cure field.

scholarly journals Transcriptional role of p53 in interferon-mediated antiviral immunity

2008 ◽  
Vol 205 (8) ◽  
pp. 1929-1938 ◽  
Author(s):  
César Muñoz-Fontela ◽  
Salvador Macip ◽  
Luis Martínez-Sobrido ◽  
Lauren Brown ◽  
Joseph Ashour ◽  
...  
Keyword(s):  
Tumor Suppressor ◽  
Viral Replication ◽  
Viral Infections ◽  
Suppressor Gene ◽  
Central Component ◽  
Type I ◽  
Infected Cells

Tumor suppressor p53 is activated by several stimuli, including DNA damage and oncogenic stress. Previous studies (Takaoka, A., S. Hayakawa, H. Yanai, D. Stoiber, H. Negishi, H. Kikuchi, S. Sasaki, K. Imai, T. Shibue, K. Honda, and T. Taniguchi. 2003. Nature. 424:516–523) have shown that p53 is also induced in response to viral infections as a downstream transcriptional target of type I interferon (IFN) signaling. Moreover, many viruses, including SV40, human papillomavirus, Kaposi's sarcoma herpesvirus, adenoviruses, and even RNA viruses such as polioviruses, have evolved mechanisms designated to abrogate p53 responses. We describe a novel p53 function in the activation of the IFN pathway. We observed that infected mouse and human cells with functional p53 exhibited markedly decreased viral replication early after infection. This early inhibition of viral replication was mediated both in vitro and in vivo by a p53-dependent enhancement of IFN signaling, specifically the induction of genes containing IFN-stimulated response elements. Of note, p53 also contributed to an increase in IFN release from infected cells. We established that this p53-dependent enhancement of IFN signaling is dependent to a great extent on the ability of p53 to activate the transcription of IFN regulatory factor 9, a central component of the IFN-stimulated gene factor 3 complex. Our results demonstrate that p53 contributes to innate immunity by enhancing IFN-dependent antiviral activity independent of its functions as a proapoptotic and tumor suppressor gene.

scholarly journals Impairment of the DeISGylation Activity of Foot-and-Mouth Disease Virus Lpro Causes Attenuation In Vitro and In Vivo

2020 ◽  
Vol 94 (13) ◽  
Author(s):  
Gisselle N. Medina ◽  
Paul Azzinaro ◽  
Elizabeth Ramirez-Medina ◽  
Joseph Gutkoska ◽  
Ying Fang ◽  
...  
Keyword(s):  
Disease Virus ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Type I ◽  
Mouth Disease Virus ◽  
Foot And Mouth ◽  
Infected Cells ◽  
Viral Attenuation

ABSTRACT Foot-and-mouth disease virus (FMDV) leader proteinase (Lpro) affects several pathways of the host innate immune response. Previous studies in bovine cells demonstrated that deletions (leaderless [LLV]) or point mutations in Lpro result in increased expression of interferon (IFN) and IFN-stimulated genes (ISGs), including, among others, the ubiquitin-like protein modifier ISG15 and the ubiquitin specific peptidase USP18. In addition to its conventional papain-like protease activity, Lpro acts as a deubiquitinase (DUB) and deISGylase. In this study, we identified a conserved residue in Lpro that is involved in its interaction with ISG15. Mutation W105A rendered Escherichia coli-expressed Lpro unable to cleave the synthetic substrate pro-ISG15 while preserving cellular eIF4G cleavage. Interestingly, mutant FMDV W105A was viable. Overexpression of ISG15 and the ISGylation machinery in porcine cells resulted in moderate inhibition of FMDV replication, along with a decrease of the overall state of ISGylation in wild-type (WT)-infected cells. In contrast, reduced deISGylation was observed upon infection with W105A and leaderless virus. Reduction in the levels of deubiquitination was also observed in cells infected with the FMDV LproW105A mutant. Surprisingly, similarly to WT, infection with W105A inhibited IFN/ISG expression despite displaying an attenuated phenotype in vivo in mice. Altogether, our studies indicate that abolishing/reducing the deISGylase/DUB activity of Lpro causes viral attenuation independently of its ability to block the expression of IFN and ISG mRNA. Furthermore, our studies highlight the potential of ISG15 to be developed as a novel biotherapeutic molecule against FMD. IMPORTANCE In this study, we identified an aromatic hydrophobic residue in foot-and-mouth disease virus (FMDV) leader proteinase (Lpro) (W105) that is involved in the interaction with ISG15. Mutation in Lpro W105 (A12-LproW105A) resulted in reduced deISGylation in vitro and in porcine-infected cells. Impaired deISGylase activity correlated with viral attenuation in vitro and in vivo and did not affect the ability of Lpro to block expression of type I interferon (IFN) and other IFN-stimulated genes. Moreover, overexpression of ISG15 resulted in the reduction of FMDV viral titers. Thus, our study highlights the potential use of Lpro mutants with modified deISGylase activity for development of live attenuated vaccine candidates, and ISG15 as a novel biotherapeutic against FMD.

scholarly journals pDC Activation by TLR7/8 Ligand CL097 Compared to TLR7 Ligand IMQ or TLR9 Ligand CpG

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Jing Wu ◽  
Shuang Li ◽  
Tete Li ◽  
Xinping Lv ◽  
Mingyou Zhang ◽  
...  
Keyword(s):  
Type I Interferons ◽  
Phenotypic Change ◽  
Type I ◽  
Antitumor Effects ◽  
Tlr9 Ligand ◽  
New Strategy ◽  
Cytotoxic Molecules ◽  
Tlr7 Ligand

Plasmacytoid dendritic cells (pDCs) express high levels of the toll-like receptors (TLRs) TLR7 and TLR9. In response to TLR7 and TLR9 ligands, pDCs are primary producers of type I interferons. Our previous study demonstrated that pDCs activated by the TLR7 ligand imiquimod (IMQ) and the TLR9 ligand CpG A can kill breast cancer cells in vitro and inhibit tumor growth in vivo. Moreover, we observed a distinctive morphological, phenotypic change in pDCs after activation by IMQ and CpG A. However, the effect of other TLR7 and TLR9 ligands on pDCs remains less understood. In this study, we treat pDCs with the TLR7 ligand IMQ, TLR7/8 ligands (CL097 and CL075), and three TLR9 ligands (different types of CpGs). The size of pDCs increased significantly after activation by TLR7, or TLR7/8 ligands. TLR7, TLR7/8, and TLR9 ligands similarly modulated cytokine release, as well as protein expression of pDC markers, costimulatory molecules, and cytotoxic molecules. Interestingly, TLR7/8 ligands, especially CL097, induced stronger responses. These results are relevant to the further study of the role and mechanism of pDC-induced antitumor effects and may aid in the development of a new strategy for future tumor immunotherapy.

Inhibition of Angiogenesis by Type I Interferons in Models of Kaposi'S Sarcoma

1999 ◽  
Vol 14 (4) ◽  
pp. 257-262 ◽  
Author(s):  
C. Marchisone ◽  
R. Benelli ◽  
A. Albini ◽  
L. Santi ◽  
D. M. Noonan
Keyword(s):  
Kaposi's Sarcoma ◽  
Kaposi’S Sarcoma ◽  
Inhibitory Effect ◽  
Type I Interferons ◽  
Endothelial Cell Migration ◽  
Type I ◽  
Type I Ifns ◽  
Hiv 1

Kaposi's Sarcoma (KS) is a pathology which occurs with increased frequency and in a particularly aggressive form in AIDS patients. The HIV-1 Tat protein appears to be an important co-factor in the induction of the extensive neo-vascularization associated with AIDS-KS. Tat acts as a chemoattractant for endothelial cells in vitro, inducing both chemotactic and invasive responses. Several clinical trials have been performed testing the effectiveness of diverse biological agents in therapy of KS, among these the type I interferons. Type I IFNs have diverse biological functions besides their anti-viral activity, including anti-angiogenic properties. We have shown that IFNα and IFNβ are potent inhibitors of both primary and immortalized endothelial cell migration and morphogenesis in vitro as well as neo-angiogenesis induced by HIV-1 Tat in vivo. The inhibitory effect of IFN class I on HIV-Tat associated angiogenesis further supports its use as a therapy for epidemic Kaposi's sarcoma. The use of recombinant IFNs at the levels required to obtain a therapeutic effect are associated with side effects and toxicity, therefore we are now developing a gene therapy approach for constant and local delivery type I IFNs.

scholarly journals Rotavirus Degrades Multiple Interferon (IFN) Type Receptors To Inhibit IFN Signaling and Protects against Mortality from Endotoxin in Suckling Mice

2017 ◽  
Vol 92 (1) ◽  
Author(s):  
Adrish Sen ◽  
Ayushi Sharma ◽  
Harry B. Greenberg
Keyword(s):  
Intestinal Epithelial Cells ◽  
Degradation Pathway ◽  
Type I ◽  
Intestinal Epithelial ◽  
Genetic Ablation ◽  
Suckling Mice ◽  
Infected Cells ◽  
New Research

ABSTRACTSTAT1 phosphorylation in response to exogenous interferon (IFN) administration can be inhibited by rotaviral replication bothin vitroandin vivo. In addition many rotavirus strains are resistant to the actions of different IFN types. The regulation by rotaviruses (RVs) of antiviral pathways mediated by multiple IFN types is not well understood. In this study, we find that during infectionin vitroandin vivo, RVs significantly deplete IFN type I, II, and III receptors (IFNRs). Regulation of IFNRs occurred exclusively within RV-infected cells and could be abrogated by inhibiting the lysosomal-endosomal degradation pathway.In vitro, IFNR degradation was conserved across multiple RV strains that differ in their modes of regulating IFN induction. In suckling mice, exogenously administered type I, II, or III IFN induced phosphorylation of STAT1-Y701 within intestinal epithelial cells (IECs) of suckling mice. Murine EW strain RV infection transiently activated intestinal STAT1 at 1 day postinfection (dpi) but not subsequently at 2 to 3 dpi. In response to injection of purified IFN-α/β or -λ, IECs in EW-infected mice exhibited impaired STAT1-Y701 phosphorylation, correlating with depletion of different intestinal IFNRs and impaired IFN-mediated transcription. The ability of EW murine RV to inhibit multiple IFN types led us to test protection of suckling mice from endotoxin-mediated shock, an outcome that is dependent on the host IFN response. Compared to mortality in controls, mice infected with EW murine RV were substantially protected against mortality following parenteral endotoxin administration. These studies identify a novel mechanism of IFN subversion by RV and reveal an unexpected protective effect of RV infection on endotoxin-mediated shock in suckling mice.IMPORTANCEAntiviral functions of types I, II, and III IFNs are mediated by receptor-dependent activation of STAT1. Here, we find that RV degrades the types I, II, and III IFN receptors (IFNRs)in vitro. In a suckling mouse model, RV effectively blocked STAT1 activation and transcription following injection of different purified IFNs. This correlated with significantly decreased protein expression of intestinal types I and II IFNRs. Recent studies demonstrate that in mice lipopolysaccharide (LPS)-induced lethality is prevented by genetic ablation of IFN signaling genes such as IFNAR1 and STAT1. When suckling mice were infected with RV, they were substantially protected from lethal exposure to endotoxin. These findings provide novel insights into the mechanisms underlying rotavirus regulation of different interferons and are likely to stimulate new research into both rotavirus pathogenesis and endotoxemia.

Type I interferons produced by dendritic cells promote their phenotypic and functional activation

Blood ◽  
2002 ◽  
Vol 99 (9) ◽  
pp. 3263-3271 ◽  
Author(s):  
Maria Montoya ◽  
Giovanna Schiavoni ◽  
Fabrizio Mattei ◽  
Ion Gresser ◽  
Filippo Belardelli ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Dendritic Cells ◽  
T Cell ◽  
Bone Marrow Cells ◽  
Type I Interferons ◽  
Type I ◽  
Type I Ifn ◽  
Type I Ifns

Abstract Resting dendritic cells (DCs) are resident in most tissues and can be activated by environmental stimuli to mature into potent antigen-presenting cells. One important stimulus for DC activation is infection; DCs can be triggered through receptors that recognize microbial components directly or by contact with infection-induced cytokines. We show here that murine DCs undergo phenotypic maturation upon exposure to type I interferons (type I IFNs) in vivo or in vitro. Moreover, DCs either derived from bone marrow cells in vitro or isolated from the spleens of normal animals express IFN-α and IFN-β, suggesting that type I IFNs can act in an autocrine manner to activate DCs. Consistent with this idea, the ability to respond to type I IFN was required for the generation of fully activated DCs from bone marrow precursors, as DCs derived from the bone marrow of mice lacking a functional receptor for type I IFN had reduced expression of costimulatory and adhesion molecules and a diminished ability to stimulate naive T-cell proliferation compared with DCs derived from control bone marrow. Furthermore, the addition of neutralizing anti–IFN-α/β antibody to purified splenic DCs in vitro partially blocked the “spontaneous” activation of these cells, inhibiting the up-regulation of costimulatory molecules, secretion of IFN-γ, and T-cell stimulatory activity. These results show that DCs both secrete and respond to type I IFN, identifying type I interferons as autocrine DC activators.

In vivo administration of lentiviral vectors triggers a type I interferon response that restricts hepatocyte gene transfer and promotes vector clearance

Blood ◽  
2006 ◽  
Vol 109 (7) ◽  
pp. 2797-2805 ◽  
Author(s):  
Brian D. Brown ◽  
Giovanni Sitia ◽  
Andrea Annoni ◽  
Ehud Hauben ◽  
Lucia Sergi Sergi ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Transgene Expression ◽  
Lentiviral Vectors ◽  
Interferon Response ◽  
Type I ◽  
Nonparenchymal Cells ◽  
Antiviral Responses ◽  
Liver Gene

AbstractLiver gene transfer is a highly sought goal for the treatment of inherited and infectious diseases. Lentiviral vectors (LVs) have many desirable properties for hepatocyte-directed gene delivery, including the ability to integrate into nondividing cells. Unfortunately, upon systemic administration, LV transduces hepatocytes relatively inefficiently compared with nonparenchymal cells, and the duration of transgene expression is often limited by immune responses. Here, we investigated the role of innate antiviral responses in these events. We show that administration of LVs to mice triggers a rapid and transient IFNαβ response. This effect was dependent on functional vector particles, and in vitro challenge of antigen-presenting cells suggested that plasmacytoid dendritic cells initiated the response. Remarkably, when LVs were administered to animals that lack the capacity to respond to IFNαβ, there was a dramatic increase in hepatocyte transduction, and stable transgene expression was achieved. These findings indicate that, even in the setting of acute delivery of replication-defective vectors, IFNs effectively interfere with transduction in a cell-type–specific manner. Moreover, because disabling a single component of the innate/immune network was sufficient to establish persistent xenoantigen expression, our results raise the hope that the immunologic barriers to gene therapy are less insurmountable than expected.

scholarly journals Type-I Interferon Receptor Deficiency Reduces Lupus-like Disease in NZB Mice

2003 ◽  
Vol 197 (6) ◽  
pp. 777-788 ◽  
Author(s):  
Marie-Laure Santiago-Raber ◽  
Roberto Baccala ◽  
Katarina M. Haraldsson ◽  
Divaker Choubey ◽  
Timothy A. Stewart ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Cell ◽  
Indirect Evidence ◽  
Dendritic Cell Maturation ◽  
Type I Interferons ◽  
Type I ◽  
Type I Ifns ◽  
Common Receptor

Indirect evidence suggests that type-I interferons (IFN-α/β) play a significant role in the pathogenesis of lupus. To directly examine the contribution of these pleiotropic molecules, we created congenic NZB mice lacking the α-chain of IFN-α/βR, the common receptor for the multiple IFN-α/β species. Compared with littermate controls, homozygous IFN-α/βR-deleted NZB mice had significantly reduced anti-erythrocyte autoantibodies, erythroblastosis, hemolytic anemia, anti-DNA autoantibodies, kidney disease, and mortality. These reductions were intermediate in the heterozygous-deleted mice. The disease-ameliorating effects were accompanied by reductions in splenomegaly and in several immune cell subsets, including B-1 cells, the major producers of anti-erythrocyte autoantibodies. Decreases of B and T cell proliferation in vitro and in vivo, and of dendritic cell maturation and T cell stimulatory activity in vitro were also detected. Absence of signaling through the IFN-α/βR, however, did not affect increased basal levels of the IFN-responsive p202 phosphoprotein, encoded by a polymorphic variant of the Ifi202 gene associated with the Nba2 predisposing locus in NZB mice. The data indicate that type-I IFNs are important mediators in the pathogenesis of murine lupus, and that reducing their activity in the human counterpart may be beneficial.

ALL-associated JAK1 mutations confer hypersensitivity to the antiproliferative effect of type I interferon

Blood ◽  
2010 ◽  
Vol 115 (16) ◽  
pp. 3287-3295 ◽  
Author(s):  
Tekla Hornakova ◽  
Sabina Chiaretti ◽  
Muriel M. Lemaire ◽  
Robin Foà ◽  
Raouf Ben Abdelali ◽  
...  
Keyword(s):  
Cell Lines ◽  
Type I Interferon ◽  
Type I ◽  
Type I Ifn ◽  
Transcriptional Signature ◽  
Activating Mutations ◽  
Type I Ifns ◽  
Antitumorigenic Effect

Abstract Activating mutations in JAK1 have been reported in acute lymphoblastic leukemias (ALLs). In this study, we found a type I interferon (IFN) transcriptional signature in JAK1 mutation-positive human ALL samples. This signature was recapitulated in vitro by the expression of JAK1 mutants in BW5147 and BaF3 hematopoietic cell lines. Binding of JAK1 to the IFN receptor was essential because mutations in the FERM domain abrogated this effect. Beside the constitutive activation of the type I IFN signaling cascade, JAK1 mutations also strongly potentiated the response to IFN in vitro. Typically, the proliferation of cell lines expressing JAK1A634D was abrogated by type I IFNs. Interestingly, we found that different JAK1 mutations differentially potentiate responses to type I IFNs or to interleukin-9, another cytokine using JAK1 to mediate its effects. This suggests that the type of mutation influences the specificity of the effect on distinct cytokine receptor signaling. Finally, we also showed in an in vivo leukemia model that cells expressing JAK1A634D are hypersensitive to the antiproliferative and antitumorigenic effect of type I IFN, suggesting that type I IFNs should be considered as a potential therapy for ALL with JAK1-activating mutations.

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