scholarly journals Role of the Promyelocytic Leukemia Protein PML in the Interferon Sensitivity of Lymphocytic Choriomeningitis Virus

2001 ◽  
Vol 75 (13) ◽  
pp. 6204-6208 ◽  
Author(s):  
Mahmoud Djavani ◽  
Juan Rodas ◽  
Igor S. Lukashevich ◽  
Douglas Horejsh ◽  
Pier Paolo Pandolfi ◽  
...  
Keyword(s):  
Culture Media ◽  
Virus Production ◽  
Lymphocytic Choriomeningitis ◽  
Lymphocytic Choriomeningitis Virus ◽  
Type I ◽  
Promyelocytic Leukemia Protein ◽  
Ifn Γ ◽  
Ifn Treatment ◽  
Z Protein

ABSTRACT Lymphocytic choriomeningitis virus (LCMV) induces type I interferon (alpha and beta interferon [IFN-α and IFN-β]) upon infection and yet is sensitive to the addition of type II interferon (gamma interferon [IFN-γ]) to the culture media. This sensitivity is biologically important because it correlates inversely with the ability of certain LCMV strains to persist in mice (D. Moskophidis, M. Battegay, M. A. Bruendler, E. Laine, I. Gresser, and R. M. Zinkernagel, J. Virol. 68:1951-1955, 1994). The cellular oncoprotein PML is induced by both IFN-α/β and IFN-γ, and PML binds the LCMV Z protein and becomes redistributed within cells from nucleus to cytoplasm upon LCMV infection. In the present study, increased PML expression results in diminished LCMV replication, implicating PML in the IFN sensitivity of LCMV. Virus production in PML −/− murine embryonic fibroblasts (MEF) exceeds virus production in PML +/+ MEF, and this difference is exacerbated by IFN treatment that upregulates PML expression. IFN-γ also diminishes LCMV production in PML −/− cells; therefore, viral IFN sensitivity is not entirely due to PML. Both viral mRNA production and viral protein production decrease as PML expression increases. Here we propose that PML reduces LCMV transcription through its interaction with the Z protein.

scholarly journals Opposing roles of STAT1 and STAT3 in IL-21 function in CD4+ T cells

2015 ◽  
Vol 112 (30) ◽  
pp. 9394-9399 ◽  
Author(s):  
Chi-Keung Wan ◽  
Allison B. Andraski ◽  
Rosanne Spolski ◽  
Peng Li ◽  
Majid Kazemian ◽  
...  
Keyword(s):  
T Cells ◽  
Immune Cell ◽  
Lymphocytic Choriomeningitis ◽  
Fine Tuning ◽  
Type I ◽  
Rna Seq ◽  
Ifn Γ ◽  
And Function

IL-21 is a type I cytokine essential for immune cell differentiation and function. Although IL-21 can activate several STAT family transcription factors, previous studies focused mainly on the role of STAT3 in IL-21 signaling. Here, we investigated the role of STAT1 and show that STAT1 and STAT3 have at least partially opposing roles in IL-21 signaling in CD4+ T cells. IL-21 induced STAT1 phosphorylation, and this was augmented in Stat3-deficient CD4+ T cells. RNA-Seq analysis of CD4+ T cells from Stat1- and Stat3-deficient mice revealed that both STAT1 and STAT3 are critical for IL-21–mediated gene regulation. Expression of some genes, including Tbx21 and Ifng, was differentially regulated by STAT1 and STAT3. Moreover, opposing actions of STAT1 and STAT3 on IFN-γ expression in CD4+ T cells were demonstrated in vivo during chronic lymphocytic choriomeningitis infection. Finally, IL-21–mediated induction of STAT1 phosphorylation, as well as IFNG and TBX21 expression, were higher in CD4+ T cells from patients with autosomal dominant hyper-IgE syndrome, which is caused by STAT3 deficiency, as well as in cells from STAT1 gain-of-function patients. These data indicate an interplay between STAT1 and STAT3 in fine-tuning IL-21 actions.

scholarly journals Farnesoid X Receptor in Mice Prevents Severe Liver Immunopathology During Lymphocytic Choriomeningitis Virus Infection

2017 ◽  
Vol 41 (1) ◽  
pp. 323-338 ◽  
Author(s):  
Nadine Honke ◽  
Namir Shaabani ◽  
Cornelia Hardt ◽  
Caroline Krings ◽  
Dieter Häussinger ◽  
...  
Keyword(s):  
T Cell ◽  
Lymphocytic Choriomeningitis ◽  
Lymphocytic Choriomeningitis Virus ◽  
Farnesoid X Receptor ◽  
Toxic Effects ◽  
Type I ◽  
T Cell Exhaustion ◽  
Cell Exhaustion ◽  
Lymphocytic Choriomeningitis Virus Infection

Background: Bile acids (BAs) are steroid molecules that are synthesized in the liver. In addition to their important role as a surfactant in solubilizing lipids and promoting the absorption of lipids in the gastrointestinal tract, they act as inflammagens. The role of BAs and their receptor farnesoid X receptor (FXR) during viral infection has not been studied in detail. Methods: By using FXR-deficient mice, we investigated the role of bile acid receptor FXR during infection with lymphocytic choriomeningitis virus (LCMV). The importance of FXR in inducing IFN-I and monocytes proliferation were investigated and viral titers and T cell exhaustion were analyzed at different time points. Results: This study shows that controlled levels of BAs activate FXR in hepatocytes and FXR in response upregulates the production of type I interferon. In turn, FXR maintains BAs within a balanced range to inhibit their toxic effects. The absence of FXR results in high levels of BAs, which inhibit the proliferation of monocytes and result in a defect in viral elimination, consequently leading to T cell exhaustion. Conclusion: We found that FXR contributes to IFN-I production in hepatocytes and balances BA levels to inhibit their toxic effects on monocytes.

scholarly journals Viral coinfection promotes tuberculosis immunopathogenesis by type I IFN signaling-dependent impediment of Th1 pulmonary influx

2021 ◽  
Author(s):  
Sung Jae Shin ◽  
Tae Gun Kang ◽  
Kee Woong Kwon ◽  
Kyung Soo Kim ◽  
Insuk Lee ◽  
...  
Keyword(s):  
Lymphocytic Choriomeningitis ◽  
Type I ◽  
Type I Ifn ◽  
Th1 Cell ◽  
Type I Ifns ◽  
Immunological Mechanisms ◽  
Negative Role ◽  
Ifn Γ ◽  
Viral Coinfection

Abstract Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), is often exacerbated upon coinfection, but the underlying immunological mechanisms remain unclear. Here, to elucidate these mechanisms, we used a Mtb and lymphocytic choriomeningitis virus coinfection model. Viral coinfection significantly suppressed Mtb-specific IFN-γ production, with elevated bacterial loads and hyperinflammation in the lungs. Type I IFN signaling blockade rescued the Mtb-specific IFN-γ response and ameliorated lung immunopathology. Single-cell sequencing, tissue immunofluorescence staining, and adoptive transfer experiments revealed that type I IFN signaling produced in response to viral infection inhibited CXCL9/10 production in myeloid cells, resulting in impaired pulmonary migration of Mtb-specific CD4+ T cells from lymph nodes. Thus, virus coinfection-induced type I IFN signaling prior to the pulmonary localization of Mtb-specific Th1 cells exacerbates TB immunopathogenesis by impeding the Mtb-specific Th1 cell influx. Our study highlights another novel negative role of viral coinfection and/or type I IFNs in delaying Mtb-specific Th1 responses in the lung.

scholarly journals Novel Functions of IFI44L as a Feedback Regulator of Host Antiviral Responses

2019 ◽  
Vol 93 (21) ◽  
Author(s):  
Marta L. DeDiego ◽  
Luis Martinez-Sobrido ◽  
David J. Topham
Keyword(s):  
Immune Responses ◽  
Nuclear Factor Kappa B ◽  
Virus Production ◽  
Innate Immune ◽  
Type I ◽  
Nuclear Factor ◽  
Innate Immune Responses ◽  
Virus Infections ◽  
Nuclear Factor Kappa ◽  
Ifn Treatment

ABSTRACT We describe a novel function for the interferon (IFN)-induced protein 44-like (IFI44L) gene in negatively modulating innate immune responses induced after virus infections. Furthermore, we show that decreasing IFI44L expression impairs virus production and that IFI44L expression negatively modulates the antiviral state induced by an analog of double-stranded RNA (dsRNA) or by IFN treatment. The mechanism likely involves the interaction of IFI44L with cellular FK506-binding protein 5 (FKBP5), which in turn interacts with kinases essential for type I and III IFN responses, such as inhibitor of nuclear factor kappa B (IκB) kinase alpha (IKKα), IKKβ, and IKKε. Consequently, binding of IFI44L to FKBP5 decreased interferon regulatory factor 3 (IRF-3)-mediated and nuclear factor kappa-B (NF-κB) inhibitor (IκBα)-mediated phosphorylation by IKKε and IKKβ, respectively. According to these results, IFI44L is a good target for treatment of diseases associated with excessive IFN levels and/or proinflammatory responses and for reduction of viral replication. IMPORTANCE Excessive innate immune responses can be deleterious for the host, and therefore, negative feedback is needed. Here, we describe a completely novel function for IFI44L in negatively modulating innate immune responses induced after virus infections. In addition, we show that decreasing IFI44L expression impairs virus production and that IFI44L expression negatively modulates the antiviral state induced by an analog of dsRNA or by IFN treatment. IFI44L binds to the cellular protein FKBP5, which in turn interacts with kinases essential for type I and III IFN induction and signaling, such as the kinases IKKα, IKKβ, and IKKε. IFI44L binding to FKBP5 decreased the phosphorylation of IRF-3 and IκBα mediated by IKKε and IKKβ, respectively, providing an explanation for the function of IFI44L in negatively modulating IFN responses. Therefore, IFI44L is a candidate target for reducing virus replication.

scholarly journals Splicing factor SRSF1 limits IFN-γ production via RhoH and ameliorates experimental nephritis

Rheumatology ◽  
2020 ◽  
Vol 60 (1) ◽  
pp. 420-429
Author(s):  
Takayuki Katsuyama ◽  
Hao Li ◽  
Suzanne M Krishfield ◽  
Vasileios C Kyttaris ◽  
Vaishali R Moulton
Keyword(s):  
T Cells ◽  
T Cell ◽  
Molecular Mechanisms ◽  
Elevated Serum ◽  
Splicing Factor ◽  
Type I ◽  
Human T Cells ◽  
Experimental Nephritis ◽  
Ifn Γ

Abstract Objective CD4 T helper 1 (Th1) cells producing IFN-γ contribute to inflammatory responses in the pathogenesis of SLE and lupus nephritis. Moreover, elevated serum type II IFN levels precede the appearance of type I IFNs and autoantibodies in patient years before clinical diagnosis. However, the molecules and mechanisms that control this inflammatory response in SLE remain unclear. Serine/arginine-rich splicing factor 1 (SRSF1) is decreased in T cells from SLE patients, and restrains T cell hyperactivity and systemic autoimmunity. Our objective here was to evaluate the role of SRSF1 in IFN-γ production, Th1 differentiation and experimental nephritis. Methods T cell-conditional Srsf1-knockout mice were used to study nephrotoxic serum-induced nephritis and evaluate IFN-γ production and Th1 differentiation by flow cytometry. RNA sequencing was used to assess transcriptomics profiles. RhoH was silenced by siRNA transfections in human T cells by electroporation. RhoH and SRSF1 protein levels were assessed by immunoblots. Results Deletion of Srsf1 in T cells led to increased Th1 differentiation and exacerbated nephrotoxic serum nephritis. The expression levels of RhoH are decreased in Srsf1-deficient T cells, and silencing RhoH in human T cells leads to increased production of IFN-γ. Furthermore, RhoH expression was decreased and directly correlated with SRSF1 in T cells from SLE patients. Conclusion Our study uncovers a previously unrecognized role of SRSF1 in restraining IFN-γ production and Th1 differentiation through the control of RhoH. Reduced expression of SRSF1 may contribute to pathogenesis of autoimmune-related nephritis through these molecular mechanisms.

scholarly journals Role of Macrophage Inflammatory Protein-1α in T-Cell-Mediated Immunity to Viral Infection

2003 ◽  
Vol 77 (22) ◽  
pp. 12378-12384 ◽  
Author(s):  
Andreas N. Madsen ◽  
Anneline Nansen ◽  
Jan P. Christensen ◽  
Allan R. Thomsen
Keyword(s):  
T Cell ◽  
Lymphocytic Choriomeningitis ◽  
Lymphocytic Choriomeningitis Virus ◽  
Effector T Cells ◽  
Cell Mediated Immunity ◽  
Inflammatory Protein ◽  
Specific Effector ◽  
Macrophage Inflammatory Protein ◽  
Deficient Mice

ABSTRACT The immune response to lymphocytic choriomeningitis virus in mice lacking macrophage inflammatory protein-1α (MIP-1α) was evaluated. Generation of virus-specific effector T cells is unimpaired in MIP-1α-deficient mice. Furthermore, MIP-1α is not required for T-cell-mediated virus control or virus-induced T-cell-dependent inflammation. Thus, MIP-1α is not mandatory for T-cell-mediated antiviral immunity.

scholarly journals Critical Role for Alpha/Beta and Gamma Interferons in Persistence of Lymphocytic Choriomeningitis Virus by Clonal Exhaustion of Cytotoxic T Cells

2001 ◽  
Vol 75 (18) ◽  
pp. 8407-8423 ◽  
Author(s):  
Rong Ou ◽  
Shenghua Zhou ◽  
Lei Huang ◽  
Demetrius Moskophidis
Keyword(s):  
T Cells ◽  
T Cell ◽  
Critical Role ◽  
Lymphocytic Choriomeningitis ◽  
Lymphocytic Choriomeningitis Virus ◽  
Interferon Response ◽  
Type I ◽  
T Cell Exhaustion ◽  
Cell Exhaustion ◽  
Alpha Beta

ABSTRACT Under conditions of high antigenic load during infection with invasive lymphocytic choriomeningitis virus (LCMV) strains, virus can persist by selective clonal exhaustion of antigen-specific CD8+ T cells. In this work we studied the down-regulation of the virus-specific CD8+-T-cell response during a persistent infection of adult mice, with particular emphasis on the contribution of the interferon response in promoting host defense. Studies were conducted by infecting mice deficient in receptors for type I (alpha/beta interferon [IFN-α/β]), type II (IFN-γ), and both type I and II IFNs with LCMV isolates that vary in their capacity to induce T-cell exhaustion. The main conclusions of this study are as follows. (i) IFNs play a critical role in LCMV infection by reducing viral loads in the initial stages of infection and thus modifying both the extent of CD8+-T-cell exhaustion and the course of infection. The importance of IFNs in this context varies with the biological properties of the LCMV strain. (ii) An inverse correlation exists between antigen persistence and responsiveness of virus-specific CD8+ T cells. This results in distinct programs of activation or tolerance (functional unresponsiveness and/or physical elimination of antigen-specific cells) during acute and chronic virus infections, respectively. (iii) A successful immune response associated with definitive viral clearance requires an appropriate balance between cellular and humoral components of the immune system. We discuss the role of IFNs in influencing virus-specific T cells that determine the outcome of persistent infections.

scholarly journals The CD8+ T-Cell Response to Lymphocytic Choriomeningitis Virus Involves the L Antigen: Uncovering New Tricks for an Old Virus

2007 ◽  
Vol 81 (10) ◽  
pp. 4928-4940 ◽  
Author(s):  
Maya F. Kotturi ◽  
Bjoern Peters ◽  
Fernando Buendia-Laysa ◽  
John Sidney ◽  
Carla Oseroff ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Response ◽  
Cellular Response ◽  
Lymphocytic Choriomeningitis ◽  
Lymphocytic Choriomeningitis Virus ◽  
T Cell Response ◽  
Ifn Γ ◽  
Lcmv Infection

ABSTRACT CD8+ T-cell responses control lymphocytic choriomeningitis virus (LCMV) infection in H-2b mice. Although antigen-specific responses against LCMV infection are well studied, we found that a significant fraction of the CD8+ CD44hi T-cell response to LCMV in H-2b mice was not accounted for by known epitopes. We screened peptides predicted to bind major histocompatibility complex class I and overlapping 15-mer peptides spanning the complete LCMV proteome for gamma interferon (IFN-γ) induction from CD8+ T cells derived from LCMV-infected H-2b mice. We identified 19 novel epitopes. Together with the 9 previously known, these epitopes account for the total CD8+ CD44hi response. Thus, bystander T-cell activation does not contribute appreciably to the CD8+ CD44hi pool. Strikingly, 15 of the 19 new epitopes were derived from the viral L polymerase, which, until now, was not recognized as a target of the cellular response induced by LCMV infection. The L epitopes induced significant levels of in vivo cytotoxicity and conferred protection against LCMV challenge. Interestingly, protection from viral challenge was best correlated with the cytolytic potential of CD8+ T cells, whereas IFN-γ production and peptide avidity appear to play a lesser role. Taken together, these findings illustrate that the LCMV-specific CD8+ T-cell response is more complex than previously appreciated.

scholarly journals Role of non-raft cholesterol in lymphocytic choriomeningitis virus infection via α-dystroglycan

2006 ◽  
Vol 87 (3) ◽  
pp. 673-678 ◽  
Author(s):  
Waris A. Shah ◽  
Huashan Peng ◽  
Salvatore Carbonetto
Keyword(s):  
Extracellular Matrix ◽  
Lipid Rafts ◽  
Vesicular Stomatitis Virus ◽  
Lymphocytic Choriomeningitis ◽  
Lymphocytic Choriomeningitis Virus ◽  
Ganglioside Gm1 ◽  
The Family ◽  
Lymphocytic Choriomeningitis Virus Infection ◽  
Vesicular Stomatitis

Dystroglycan (DG) is an extracellular matrix receptor necessary for the development of metazoans from flies to humans and is also an entry route for various pathogens. Lymphocytic choriomeningitis virus (LCMV), a member of the family Arenaviridae, infects by binding to α-DG. Here, the role of cholesterol lipid rafts in infection by LCMV via α-DG was investigated. The cholesterol-sequestering drugs methyl-β-cyclodextrin (MβCD), filipin and nystatin inhibited the infectivity of LCMV selectively, but did not affect infection by vesicular stomatitis virus. Cholesterol loading after depletion with MβCD restored infectivity to control levels. DG was not found in lipid rafts identified with the raft marker ganglioside GM1. Treatment with MβCD, however, enhanced the solubility of DG. This may reflect the association of DG with cholesterol outside lipid rafts and suggests that association of DG with non-raft cholesterol is critical for infection by LCMV through α-DG.

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