DOCSLIB.ORG

Lack of Response to Exogenous Interferon-Α in the Liver of HCV Chronically Infected Chimpanzees

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Lack of Response to Exogenous Interferon-Α in the Liver of HCV Chronically Infected Chimpanzees NIH Public Access Author Manuscript Hepatology. Author manuscript; available in PMC 2008 May 19. NIH-PA Author ManuscriptPublished NIH-PA Author Manuscript in final edited NIH-PA Author Manuscript form as: Hepatology. 2007 October ; 46(4): 999±1008. Lack of Response to Exogenous Interferon-α in the Liver of HCV Chronically Infected Chimpanzees Robert E. Lanford1,2, Bernadette Guerra1, Catherine B. Bigger3, Helen Lee1, Deborah Chavez1, and Kathleen M. Brasky2 1 Department of Virology and Immunology, Southwest Foundation for Biomedical Research, 7620 NW Loop 410, San Antonio, TX 78227 2 Southwest National Primate Research Center, 7620 NW Loop 410, San Antonio, TX 78227 3 Children's Research Institute, Columbus, OH 45205 Abstract The mechanism of the interferon-alpha (IFNα)-induced antiviral response is not completely understood. We recently examined the transcriptional response to IFNα in uninfected chimpanzees. The transcriptional response to IFNα in the liver and peripheral blood mononuclear cells (PBMC) was rapidly induced but was also rapidly down-regulated, with most IFNα stimulated genes (ISGs) returning to baseline within 24 hr. We have extended these observations to include chimpanzees chronically infected with hepatitis C virus (HCV). Remarkably, using total genome microarray analysis, almost no induction of ISG transcripts was observed in the liver of chronically infected animals following IFNα dosing, while the response in PBMC was similar to that in uninfected animals. Consistent with this finding, no decrease in viral load occurred in up to 12 weeks of pegylated (peg)-IFNα therapy. The block in response to exogenous IFNα appeared to be HCV specific, since the response in an HBV infected animal was similar to that of uninfected animals. The lack of response to exogenous IFNα may be due to an already maximally induced ISG response, since HCV chronically infected chimpanzees already have a highly up-regulated hepatic ISG response. Alternatively, negative regulation may block the response to exogenous IFNα, yet does not prevent the continued response to endogenous ISG stimuli. The IFNα response in HCV chronically infected chimpanzees may be mechanistically similar to the null response in the human population. Conclusion—In chimpanzees infected with HCV, the highly elevated hepatic ISG expression may prevent further induction of ISGs and antiviral efficacy following IFNα treatment. Keywords microarray; hepatitis; innate immunity; virus; antiviral Approximately 170 million people worldwide are chronically infected with HCV which frequently progresses to serious liver disease, including cirrhosis and hepatocellular carcinoma 1,2. Combination therapy with pegIFNα and ribavirin results in sustained viral clearance for approximately 40–50% and 80–90% of patients infected with genotypes 1 and 2/3, respectively 3–5. Little is understood regarding the factors leading to successful or failed viral clearance during IFNα therapy, but studies on gene expression are beginning to illustrate differences in these populations. Gene expression studies in chimpanzees with acute-resolving and chronic HCV infections have revealed elevated ISG expression in the liver, indicative of a response to Address reprint requests to: Robert E. Lanford, Department of Virology and Immunology, Southwest Foundation for Biomedical Research, 7620 NW Loop 410, San Antonio, TX 78227. Phone: (210) 258-9445 FAX: (210) 670-3329 Email: [email protected]. full names of genes indicated by gene symbols can be found at www.genecards.org. Lanford et al. Page 2 dsRNA and/or IFNα 6–8, and similar observations have been made in chronically infected humans 9,10. More recently, an inverse correlation has been observed between pretreatment 11 NIH-PA Author Manuscript NIH-PA Author Manuscripthepatic NIH-PA Author Manuscript levels for some ISG transcripts and virologic response to therapy , while a positive correlation has been observed between the magnitude of the ISG response in IFNα treated PBMC and virologic response to therapy 12. The early kinetics of viral RNA loss from the circulation during IFNα therapy suggests the presence of two phases. Phase I occurs during the first 24–48 hr and is presumably due to the decrease in secretion of new virions, while phase II kinetics vary between individuals, are predictive of the outcome of therapy, and are thought to be a measurement of loss of infected cells 13–15. Our recent data on gene expression in uninfected chimpanzees dosed with IFNα suggests that the rapid down-regulation of the IFNα-induced ISG response may be partially responsible for the rapid change in kinetics from phase I and II 16. Peak expression for most genes occurred by 4 hr after IFNα dosing and was declining or at baseline by 8hr. The transcriptional response to IFNα in vivo was largely tissue specific with significant differences in the response in liver and PBMC. Previous studies with IFNα in chimpanzees have failed to demonstrate a reduction in viral load using either traditional IFNα therapy with ribavirin, or adenovirus-based gene therapy to induce high-level expression of IFNα in the liver 17,18 (Lanford, unpublished data). Our recent studies comparing human and chimpanzee IFNα in uninfected animals indicated that IFNα from both species was equally effective with regard to ISG induction in the liver and PBMC. Thus, the reason for the lack of antiviral effect of IFNα in the chimpanzee remains unresolved. Here, we have examined human peg-IFNα in three HCV chronically infected chimpanzees and have performed total genome DNA microarray analysis to characterize changes in liver and PBMC gene expression. No decline in viral load was observed with up to 12 weeks of therapy. The induction of ISGs in PBMC from infected animals was similar to that observed in uninfected animals, while the liver of HCV infected animals was resistant to exogenous IFNα. The implications of these findings to HCV infected humans and possible mechanisms of resistance to exogenous IFNα are discussed. MATERIALS AND METHODS Chimpanzees Chimpanzees were housed at the Southwest National Primate Research Center at the Southwest Foundation for Biomedical Research. The animals were cared for in accordance with the Guide for the Care and Use of Laboratory Animals, and all protocols were approved by the Institutional Animal Care and Use Committee. Biopsies were obtained in the morning on fasting animals to avoid postprandial and diurnal changes in liver gene expression. The chimpanzees used in this study had been chronically infected for 16–28 years, had been monitored on a regular basis in recent years and had stable levels of viremia. The three HCV infected animals were 4x0081(Genotype 1b; infected in 1983 with NANB); 4 × 0119(Genotype 3a infected in 1981 with NANB contaminated factor VIII); and 4 × 0341(Genotype 1a infected in 1991 with strain HCV1). The HBV infected animal was 4 × 0139 (infected in 1979). Microarray and RT-PCR Analyses Total RNA prepared from liver and PBMC was used to perform microarray analyses 6,7 and to monitor viral and cellular transcripts by quantitative reverse transcription-PCR (RT-PCR; TaqMan) 19, as described in Supplemental Methods. Microarray analysis was performed on 71 microarrays which included a previous data set from 36 arrays from uninfected animals 16. A more comprehensive data set is available at Hepatology. Author manuscript; available in PMC 2008 May 19. Lanford et al. Page 3 http://www.sfbr.org/pages/virology/lanford including Excel versions of the Supplemental Tables that can be searched, sorted and downloaded. NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscript IFNα dosing Peg-IFNα2a (Roche; Nutely, NJ) was partially a gift of Dr. David Thomas (Johns Hopkins University) and partially purchased from a pharmacy. Chimpanzees were inoculated subcutaneously with 5 million IU of IFNα, and blood and liver samples were obtained at 2 and 4 weeks prior to dosing, at 4, 8 and 24 hr and 7 days post-inoculation. The genotype 1 animals were continued on weekly administration of peg-IFNα for 8 or 12 weeks as indicated. RESULTS Lack of antiviral response in chimpanzees to peg-IFNα In the current study, we examined the relationship of the antiviral response to peg-IFNα in HCV infected chimpanzees and the induction of gene expression in the liver and PBMC. Three chimpanzees chronically infected with HCV were dosed with peg-IFNα weekly for 1–12 weeks, and viral load was determined by quantitative RT-PCR (TaqMan). The genotype 1a chimpanzee (4 × 0341) was dosed for 12 weeks, while the genotype 1b chimpanzee (4 × 0081) was stopped at 8 weeks due to unrelated health issues, and the genotype 3a chimpanzee (4 × 0119) was given a single dose of IFNα to examine ISG induction in the liver and was only followed for 14 days. No significant decline in viral RNA was observed in the serum (Fig. 1) or liver (data not shown). Lack of IP-10 transcriptional response to IFNα in the liver of HCV infected chimpanzees To evaluate the possible reasons for failed antiviral response to IFNα in chimpanzees, the induction of IP-10 (CXCL10) transcription was examined in the liver and PBMC by quantitative RT-PCR. We have previously demonstrated that this chemokine is highly elevated during acute 7 and chronic 6 HCV infection and following IFNα dosing in uninfected chimpanzees 16, primary hepatocytes 16 and Huh7 cells 19. At 4 hr post-inoculation with peg- IFNα in an uninfected chimpanzee (4 × 0363), IP-10 transcripts were elevated by 394- and 667-fold in PBMC and liver, respectively. Similarly, in the PBMC of an HCV infected animal (4 × 0081), IP-10 transcripts were increased by 107-fold, but surprisingly no induction was observed in the liver of this animal (Fig. 2). As previously observed in uninfected chimpanzees 16, the transcriptional response to IFNα was rapidly down-regulated. IP-10 transcripts were reduced to near baseline in the liver and PBMC of uninfected animals and in PBMC of HCV infected animals by 8–24 hr post-inoculation.
Load more

Recommended publications
  • CD56+ T-Cells in Relation to Cytomegalovirus in Healthy Subjects and Kidney Transplant Patients
    CD56+ T-cells in Relation to Cytomegalovirus in Healthy Subjects and Kidney Transplant Patients Institute of Infection and Global Health Department of Clinical Infection, Microbiology and Immunology Thesis submitted in accordance with the requirements of the University of Liverpool for the degree of Doctor in Philosophy by Mazen Mohammed Almehmadi December 2014 - 1 - Abstract Human T cells expressing CD56 are capable of tumour cell lysis following activation with interleukin-2 but their role in viral immunity has been less well studied. The work described in this thesis aimed to investigate CD56+ T-cells in relation to cytomegalovirus infection in healthy subjects and kidney transplant patients (KTPs). Proportions of CD56+ T cells were found to be highly significantly increased in healthy cytomegalovirus-seropositive (CMV+) compared to cytomegalovirus-seronegative (CMV-) subjects (8.38% ± 0.33 versus 3.29%± 0.33; P < 0.0001). In donor CMV-/recipient CMV- (D-/R-)- KTPs levels of CD56+ T cells were 1.9% ±0.35 versus 5.42% ±1.01 in D+/R- patients and 5.11% ±0.69 in R+ patients (P 0.0247 and < 0.0001 respectively). CD56+ T cells in both healthy CMV+ subjects and KTPs expressed markers of effector memory- RA T-cells (TEMRA) while in healthy CMV- subjects and D-/R- KTPs the phenotype was predominantly that of naïve T-cells. Other surface markers, CD8, CD4, CD58, CD57, CD94 and NKG2C were expressed by a significantly higher proportion of CD56+ T-cells in healthy CMV+ than CMV- subjects. Functional studies showed levels of pro-inflammatory cytokines IFN-γ and TNF-α, as well as granzyme B and CD107a were significantly higher in CD56+ T-cells from CMV+ than CMV- subjects following stimulation with CMV antigens.
    [Show full text]
  • Identification and Expression of the Laboratory of Genetics and Physiology 2 Gene in Common Carp Cyprinus Carpio
    Journal of Fish Biology (2014) doi:10.1111/jfb.12541, available online at wileyonlinelibrary.com Identification and expression of the laboratory of genetics and physiology 2 gene in common carp Cyprinus carpio X. L. Cao*†, J. J. Chen†,Y.Cao†,G.X.Nie†,Q.Y.Wan*,L.F.Wang† and J. G. Su*‡ *College of Animal Science and Technology, Northwest A&F University, Yangling 712100, People’s Republic of China and †College of Fisheries, Henan Normal University, Xinxiang 453007, People’s Republic of China (Received 29 April 2014, Accepted 9 September 2014) In this study, a laboratory of genetics and physiology 2 gene (lgp2) from common carp Cyprinus car- pio was isolated and characterized. The full-length complementary (c)DNA of lgp2 was 3061 bp and encoded a polypeptide of 680 amino acids, with an estimated molecular mass of 77 341⋅2Daanda predicted isoelectric point of 6⋅53. The predicted protein included four main overlapping structural domains: a conserved restriction domain of bacterial type III restriction enzyme, a DEAD–DEAH box helicase domain, a helicase super family C-terminal domain and a regulatory domain. Real-time quantitative polymerase chain reaction (PCR) showed widespread expression of lgp2, mitochondrial antiviral signalling protein (mavs) and interferon transcription factor 3 (irf3) in tissues of nine organs. lgp2, mavs and irf3 expression levels were significantly induced in all examined organs by infec- tion with koi herpesvirus (KHV). lgp2, mavs and irf3 messenger (m)RNA levels were significantly up-regulated in vivo after KHV infection, and lgp2 transcripts were also significantly enhanced in vitro after stimulation with synthetic, double-stranded RNA polyinosinic polycytidylic [poly(I:C)].
    [Show full text]
  • Pattern Recognition Receptors in Health and Diseases
    Signal Transduction and Targeted Therapy www.nature.com/sigtrans REVIEW ARTICLE OPEN Pattern recognition receptors in health and diseases Danyang Li1,2 and Minghua Wu1,2 Pattern recognition receptors (PRRs) are a class of receptors that can directly recognize the specific molecular structures on the surface of pathogens, apoptotic host cells, and damaged senescent cells. PRRs bridge nonspecific immunity and specific immunity. Through the recognition and binding of ligands, PRRs can produce nonspecific anti-infection, antitumor, and other immunoprotective effects. Most PRRs in the innate immune system of vertebrates can be classified into the following five types based on protein domain homology: Toll-like receptors (TLRs), nucleotide oligomerization domain (NOD)-like receptors (NLRs), retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs), C-type lectin receptors (CLRs), and absent in melanoma-2 (AIM2)-like receptors (ALRs). PRRs are basically composed of ligand recognition domains, intermediate domains, and effector domains. PRRs recognize and bind their respective ligands and recruit adaptor molecules with the same structure through their effector domains, initiating downstream signaling pathways to exert effects. In recent years, the increased researches on the recognition and binding of PRRs and their ligands have greatly promoted the understanding of different PRRs signaling pathways and provided ideas for the treatment of immune-related diseases and even tumors. This review describes in detail the history, the structural characteristics, ligand recognition mechanism, the signaling pathway, the related disease, new drugs in clinical trials and clinical therapy of different types of PRRs, and discusses the significance of the research on pattern recognition mechanism for the treatment of PRR-related diseases.
    [Show full text]
  • Innate Immune System of Mallards (Anas Platyrhynchos)
    Anu Helin Linnaeus University Dissertations No 376/2020 Anu Helin Eco-immunological studies of innate immunity in Mallards immunity innate of studies Eco-immunological List of papers Eco-immunological studies of innate I. Chapman, J.R., Hellgren, O., Helin, A.S., Kraus, R.H.S., Cromie, R.L., immunity in Mallards (ANAS PLATYRHYNCHOS) Waldenström, J. (2016). The evolution of innate immune genes: purifying and balancing selection on β-defensins in waterfowl. Molecular Biology and Evolution. 33(12): 3075-3087. doi:10.1093/molbev/msw167 II. Helin, A.S., Chapman, J.R., Tolf, C., Andersson, H.S., Waldenström, J. From genes to function: variation in antimicrobial activity of avian β-defensin peptides from mallards. Manuscript III. Helin, A.S., Chapman, J.R., Tolf, C., Aarts, L., Bususu, I., Rosengren, K.J., Andersson, H.S., Waldenström, J. Relation between structure and function of three AvBD3b variants from mallard (Anas platyrhynchos). Manuscript I V. Chapman, J.R., Helin, A.S., Wille, M., Atterby, C., Järhult, J., Fridlund, J.S., Waldenström, J. (2016). A panel of Stably Expressed Reference genes for Real-Time qPCR Gene Expression Studies of Mallards (Anas platyrhynchos). PLoS One. 11(2): e0149454. doi:10.1371/journal. pone.0149454 V. Helin, A.S., Wille, M., Atterby, C., Järhult, J., Waldenström, J., Chapman, J.R. (2018). A rapid and transient innate immune response to avian influenza infection in mallards (Anas platyrhynchos). Molecular Immunology. 95: 64-72. doi:10.1016/j.molimm.2018.01.012 (A VI. Helin, A.S., Wille, M., Atterby, C., Järhult, J., Waldenström, J., Chapman, N A S J.R.
    [Show full text]
  • Manifests Disparate Antiviral Responses Loss of Dexd/H Box
    Loss of DExD/H Box RNA Helicase LGP2 Manifests Disparate Antiviral Responses Thiagarajan Venkataraman, Maikel Valdes, Rachel Elsby, Shigeru Kakuta, Gisela Caceres, Shinobu Saijo, Yoichiro This information is current as Iwakura and Glen N. Barber of September 25, 2021. J Immunol 2007; 178:6444-6455; ; doi: 10.4049/jimmunol.178.10.6444 http://www.jimmunol.org/content/178/10/6444 Downloaded from References This article cites 46 articles, 19 of which you can access for free at: http://www.jimmunol.org/content/178/10/6444.full#ref-list-1 http://www.jimmunol.org/ Why The JI? Submit online. • Rapid Reviews! 30 days* from submission to initial decision • No Triage! Every submission reviewed by practicing scientists • Fast Publication! 4 weeks from acceptance to publication by guest on September 25, 2021 *average Subscription Information about subscribing to The Journal of Immunology is online at: http://jimmunol.org/subscription Permissions Submit copyright permission requests at: http://www.aai.org/About/Publications/JI/copyright.html Email Alerts Receive free email-alerts when new articles cite this article. Sign up at: http://jimmunol.org/alerts The Journal of Immunology is published twice each month by The American Association of Immunologists, Inc., 1451 Rockville Pike, Suite 650, Rockville, MD 20852 Copyright © 2007 by The American Association of Immunologists All rights reserved. Print ISSN: 0022-1767 Online ISSN: 1550-6606. The Journal of Immunology Loss of DExD/H Box RNA Helicase LGP2 Manifests Disparate Antiviral Responses Thiagarajan Venkataraman,1* Maikel Valdes,1* Rachel Elsby,* Shigeru Kakuta,† Gisela Caceres,* Shinobu Saijo,† Yoichiro Iwakura,† and Glen N. Barber2* The DExD/H box RNA helicase retinoic acid-inducible gene I (RIG-I) and the melanoma differentiation-associated gene 5 (MDA5) are key intracellular receptors that recognize virus infection to produce type I IFN.
    [Show full text]
  • Review Article Collaboration of Toll-Like and RIG-I-Like Receptors in Human Dendritic Cells: Triggering Antiviral Innate Immune Responses
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by University of Debrecen Electronic Archive Am J Clin Exp Immunol 2013;2(3):195-207 www.ajcei.us /ISSN:2164-7712/AJCEI1309001 Review Article Collaboration of Toll-like and RIG-I-like receptors in human dendritic cells: tRIGgering antiviral innate immune responses Attila Szabo, Eva Rajnavolgyi Department of Immunology, University of Debrecen Medical and Health Science Center, Debrecen, Hungary Received September 24, 2013; Accepted October 8, 2013; Epub October 16, 2013; Published October 30, 2013 Abstract: Dendritic cells (DCs) represent a functionally diverse and flexible population of rare cells with the unique capability of binding, internalizing and detecting various microorganisms and their components. However, the re- sponse of DCs to innocuous or pathogenic microbes is highly dependent on the type of microbe-associated molecu- lar patterns (MAMPs) recognized by pattern recognition receptors (PRRs) that interact with phylogenetically con- served and functionally indispensable microbial targets that involve both self and foreign structures such as lipids, carbohydrates, proteins, and nucleic acids. Recently, special attention has been drawn to nucleic acid receptors that are able to evoke robust innate immune responses mediated by type I interferons and inflammatory cytokine production against intracellular pathogens. Both conventional and plasmacytoid dendritic cells (cDCs and pDCs) ex- press specific nucleic acid recognizing receptors, such as members of the membrane Toll-like receptor (TLR) and the cytosolic RIG-I-like receptor (RLR) families. TLR3, TLR7/TLR8 and TLR9 are localized in the endosomal membrane and are specialized for the recognition of viral double-stranded RNA, single-stranded RNA, and nonmethylated DNA, respectively whereas RLRs (RIG-I, MDA5, and LGP2) are cytosolic proteins that sense various viral RNA species.
    [Show full text]
  • RIG-I-Like Receptors: Their Regulation and Roles in RNA Sensing
    REVIEWS RIG- I- like receptors: their regulation and roles in RNA sensing Jan Rehwinkel 1 ✉ and Michaela U. Gack 2 ✉ Abstract | Retinoic acid- inducible gene I (RIG- I)- like receptors (RLRs) are key sensors of virus infection, mediating the transcriptional induction of type I interferons and other genes that collectively establish an antiviral host response. Recent studies have revealed that both viral and host- derived RNAs can trigger RLR activation; this can lead to an effective antiviral response but also immunopathology if RLR activities are uncontrolled. In this Review , we discuss recent advances in our understanding of the types of RNA sensed by RLRs in the contexts of viral infection, malignancies and autoimmune diseases. We further describe how the activity of RLRs is controlled by host regulatory mechanisms, including RLR-interacting proteins, post- translational modifications and non- coding RNAs. Finally , we discuss key outstanding questions in the RLR field, including how our knowledge of RLR biology could be translated into new therapeutics. Toll- like receptors Type I interferons are highly potent cytokines that were Their expression is rapidly induced by several innate (TLRs). A family of initially identified for their essential role in antiviral immune signalling pathways. These signalling events are membrane- bound innate defence1,2. They shape both innate and adaptive immune typically initiated by proteins called nucleic acid sensors immune receptors that responses and induce the expression of restriction fac- that monitor cells for unusual nucleic acids. For example, recognize various bacterial or virus- derived pathogen- tors, which are proteins that directly interfere with a step it is an indispensable step in the life cycle of any virus 3 associated molecular patterns.
    [Show full text]
  • Landscape of Innate Immune System Transcriptome and Acute T Cell–Mediated Rejection of Human Kidney Allografts
    Landscape of innate immune system transcriptome and acute T cell–mediated rejection of human kidney allografts Franco B. Mueller, … , Manikkam Suthanthiran, Thangamani Muthukumar JCI Insight. 2019;4(13):e128014. https://doi.org/10.1172/jci.insight.128014. Research Article Immunology Transplantation Acute rejection of human allografts has been viewed mostly through the lens of adaptive immunity, and the intragraft landscape of innate immunity genes has not been characterized in an unbiased fashion. We performed RNA sequencing of 34 kidney allograft biopsy specimens from 34 adult recipients; 16 were categorized as Banff acute T cell–mediated rejection (TCMR) and 18 as normal. Computational analysis of intragraft mRNA transcriptome identified significantly higher abundance of mRNA for pattern recognition receptors in TCMR compared with normal biopsies, as well as increased expression of mRNAs for cytokines, chemokines, interferons, and caspases. Intragraft levels of calcineurin mRNA were higher in TCMR biopsies, suggesting underimmunosuppression compared with normal biopsies. Cell-type- enrichment analysis revealed higher abundance of dendritic cells and macrophages in TCMR biopsies. Damage- associated molecular patterns, the endogenous ligands for pattern recognition receptors, as well markers of DNA damage were higher in TCMR. mRNA expression patterns supported increased calcium flux and indices of endoplasmic, cellular oxidative, and mitochondrial stress were higher in TCMR. Expression of mRNAs in major metabolic pathways was decreased in TCMR. Our global and unbiased transcriptome profiling identified heightened expression of innate immune system genes during an episode of TCMR in human kidney allografts. Find the latest version: https://jci.me/128014/pdf RESEARCH ARTICLE Landscape of innate immune system transcriptome and acute T cell–mediated rejection of human kidney allografts Franco B.
    [Show full text]
  • Virus Sensor RIG-I Represses RNA Interference by Interacting with TRBP Through LGP2 in Mammalian Cells
    G C A T T A C G G C A T genes Article Virus Sensor RIG-I Represses RNA Interference by Interacting with TRBP through LGP2 in Mammalian Cells Tomoko Takahashi 1 , Yuko Nakano 1, Koji Onomoto 2, Mitsutoshi Yoneyama 2 and Kumiko Ui-Tei 1,3,* 1 Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan; [email protected] (T.T.); [email protected] (Y.N.) 2 Division of Molecular Immunology, Medical Mycology Research Center, Chiba University, Chiba 260-8673, Japan; [email protected] (K.O.); [email protected] (M.Y.) 3 Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8561, Japan * Correspondence: [email protected]; Tel.: +81-3-5841-3043 Received: 22 September 2018; Accepted: 17 October 2018; Published: 19 October 2018 Abstract: Exogenous double-stranded RNAs (dsRNAs) similar to viral RNAs induce antiviral RNA silencing or RNA interference (RNAi) in plants or invertebrates, whereas interferon (IFN) response is induced through activation of virus sensor proteins including Toll like receptor 3 (TLR3) or retinoic acid-inducible gene I (RIG-I) like receptors (RLRs) in mammalian cells. Both RNA silencing and IFN response are triggered by dsRNAs. However, the relationship between these two pathways has remained unclear. Laboratory of genetics and physiology 2 (LGP2) is one of the RLRs, but its function has remained unclear. Recently, we reported that LGP2 regulates endogenous microRNA-mediated RNA silencing by interacting with an RNA silencing enhancer, TAR-RNA binding protein (TRBP).
    [Show full text]
  • Loss of Dexd/H Box RNA Helicase LGP2 Manifests Disparate Antiviral Responses
    The Journal of Immunology Loss of DExD/H Box RNA Helicase LGP2 Manifests Disparate Antiviral Responses Thiagarajan Venkataraman,1* Maikel Valdes,1* Rachel Elsby,* Shigeru Kakuta,† Gisela Caceres,* Shinobu Saijo,† Yoichiro Iwakura,† and Glen N. Barber2* The DExD/H box RNA helicase retinoic acid-inducible gene I (RIG-I) and the melanoma differentiation-associated gene 5 (MDA5) are key intracellular receptors that recognize virus infection to produce type I IFN. A third helicase gene, Lgp2, is homologous to Rig-I and Mda5 but lacks a caspase activation and recruitment domain. We generated Lgp2-deficient mice and report that the loss of this gene greatly sensitizes cells to cytosolic polyinosinic/polycytidylic acid-mediated induction of type I IFN. However, negative feedback inhibition of IFN-␤ transcription was found to be normal in the absence of LGP2, indicating that LGP2 is not the primary negative regulator of type I IFN production. Our data further indicate that Lgp2؊/؊ mice exhibited resistance to lethal vesicular stomatitis virus infection, a virus whose replicative RNA intermediates are recognized specif- ically by RIG-I rather than by MDA5 to trigger the production of type I IFN. However, mice lacking LGP2 were observed to exhibit a defect in type I IFN production in response to infection by the encephalomyocarditis virus, the replication of which activates MDA5-dependent innate immune responses. Collectively, our data indicate a disparate regulatory role for LGP2 in the triggering of innate immune signaling pathways following RNA virus infection. The Journal of Immunology, 2007, 178: 6444–6455. ellular detection of pathogenic microbes and activation of TNFR-associated kinase 6 (11–14).
    [Show full text]
  • Chemico-Biological Interactions 196 (2012) 89–95
    Chemico-Biological Interactions 196 (2012) 89–95 Contents lists available at ScienceDirect Chemico-Biological Interactions journal homepage: www.elsevier.com/locate/chembioint Exposure to sodium tungstate and Respiratory Syncytial Virus results in hematological/immunological disease in C57BL/6J mice ⇑ Cynthia D. Fastje a, , Kevin Harper a, Chad Terry a, Paul R. Sheppard b, Mark L. Witten a,1 a Steele Children’s Research Center, PO Box 245073, University of Arizona, Tucson, AZ 85724-5073, USA b Laboratory of Tree-Ring Research, PO Box 210058, University of Arizona, Tucson, AZ 85721-0058, USA article info abstract Article history: The etiology of childhood leukemia is not known. Strong evidence indicates that precursor B-cell Acute Available online 1 May 2011 Lymphoblastic Leukemia (Pre-B ALL) is a genetic disease originating in utero. Environmental exposures in two concurrent, childhood leukemia clusters have been profiled and compared with geographically Keywords: similar control communities. The unique exposures, shared in common by the leukemia clusters, have Tungsten been modeled in C57BL/6 mice utilizing prenatal exposures. This previous investigation has suggested Respiratory Syncytial Virus in utero exposure to sodium tungstate (Na2WO4) may result in hematological/immunological disease Childhood leukemia through genes associated with viral defense. The working hypothesis is (1) in addition to spontaneously and/or chemically generated genetic lesions forming pre-leukemic clones, in utero exposure to Na2WO4 increases genetic susceptibility to viral influence(s); (2) postnatal exposure to a virus possessing the 1FXXKXFXXA/V9 peptide motif will cause an unnatural immune response encouraging proliferation in the B-cell precursor compartment. This study reports the results of exposing C57BL/6J mice to Na2WO4 3 in utero via water (15 ppm, ad libetum) and inhalation (mean concentration PM5 3.33 mg/m ) and to Respiratory Syncytial Virus (RSV) within 2 weeks of weaning.
    [Show full text]
  • LGP2 Is a Positive Regulator of RIG-I– and MDA5-Mediated Antiviral Responses
    LGP2 is a positive regulator of RIG-I– and MDA5-mediated antiviral responses Takashi Satoha,1, Hiroki Katoa,1,2, Yutaro Kumagaia, Mitsutoshi Yoneyamab,c, Shintaro Satoa,3, Kazufumi Matsushitaa, Tohru Tsujimurad, Takashi Fujitab, Shizuo Akiraa,4, and Osamu Takeuchia aLaboratory of Host Defense, WPI Immunology Frontier Research Center, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan; bDepartment of Genetics and Molecular Biology, Institute for Virus Research, and Laboratory of Molecular Cell Biology, Graduate School of Biostudies, Kyoto University, Kyoto 606-8507, Japan; cPRESTO, Japan Science and Technology Agency, Saitama, Japan; and dDepartment of Pathology, Hyogo College of Medicine, Hyogo 663-8501, Japan Contributed by Shizuo Akira, November 10, 2009 (sent for review October 30, 2009) RNA virus infection is recognized by retinoic acid-inducible gene (RIG)- the RIG-I helicase domain has the ability to unwind dsRNA, this I–like receptors (RLRs), RIG-I, and melanoma differentiation–associated activity is not correlated with the level of IFN production (14). gene 5 (MDA5) in the cytoplasm. RLRs are comprised of N-terminal A recent report proposed that the RIG-I ATPase activity is required caspase-recruitment domains (CARDs) and a DExD/H-box helicase do- for translocation of RIG-I on dsRNA (15). The N-terminal CARDs main. The third member of the RLR family, LGP2, lacks any CARDs and of RIG-I and MDA5 trigger intracellular signaling pathways via was originally identified as a negative regulator of RLR signaling. In IFN-β promoter stimulator (IPS)–1 (also known as MAVS, VISA, the present study, we generated mice lacking LGP2 and found that or CARDIF), an adaptor molecule possessing an N-terminal LGP2 was required for RIG-I– and MDA5-mediated antiviral responses.
    [Show full text]