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Ramanathan P, Tigabu B, Santos RI, Ilinykh PA, Kuzmina N, Vogel OA, Thakur N, Ahmed H, Wu C, Amarasinghe GK, Basler CF, Bukreyev A. Ebolavirus Species-Specific Interferon Antagonism Mediated by VP24. Viruses 2023; 15:1075. [PMID: 37243162 PMCID: PMC10222226 DOI: 10.3390/v15051075] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 04/24/2023] [Indexed: 05/28/2023] Open
Abstract
Members of the Ebolavirus genus demonstrate a marked differences in pathogenicity in humans with Ebola (EBOV) being the most pathogenic, Bundibugyo (BDBV) less pathogenic, and Reston (RESTV) is not known to cause a disease in humans. The VP24 protein encoded by members of the Ebolavirus genus blocks type I interferon (IFN-I) signaling through interaction with host karyopherin alpha nuclear transporters, potentially contributing to virulence. Previously, we demonstrated that BDBV VP24 (bVP24) binds with lower affinities to karyopherin alpha proteins relative to EBOV VP24 (eVP24), and this correlated with a reduced inhibition in IFN-I signaling. We hypothesized that modification of eVP24-karyopherin alpha interface to make it similar to bVP24 would attenuate the ability to antagonize IFN-I response. We generated a panel of recombinant EBOVs containing single or combinations of point mutations in the eVP24-karyopherin alpha interface. Most of the viruses appeared to be attenuated in both IFN-I-competent 769-P and IFN-I-deficient Vero-E6 cells in the presence of IFNs. However, the R140A mutant grew at reduced levels even in the absence of IFNs in both cell lines, as well as in U3A STAT1 knockout cells. Both the R140A mutation and its combination with the N135A mutation greatly reduced the amounts of viral genomic RNA and mRNA suggesting that these mutations attenuate the virus in an IFN-I-independent attenuation. Additionally, we found that unlike eVP24, bVP24 does not inhibit interferon lambda 1 (IFN-λ1), interferon beta (IFN-β), and ISG15, which potentially explains the lower pathogenicity of BDBV relative to EBOV. Thus, the VP24 residues binding karyopherin alpha attenuates the virus by IFN-I-dependent and independent mechanisms.
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Affiliation(s)
- Palaniappan Ramanathan
- Department of Pathology, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
- Galveston National Laboratory, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
| | - Bersabeh Tigabu
- Department of Pathology, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
- Galveston National Laboratory, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
| | - Rodrigo I. Santos
- Department of Pathology, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
- Galveston National Laboratory, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
| | - Philipp A. Ilinykh
- Department of Pathology, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
- Galveston National Laboratory, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
| | - Natalia Kuzmina
- Department of Pathology, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
- Galveston National Laboratory, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
| | - Olivia A. Vogel
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Naveen Thakur
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Hamza Ahmed
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Chao Wu
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Gaya K. Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Christopher F. Basler
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Alexander Bukreyev
- Department of Pathology, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
- Galveston National Laboratory, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
- Department of Microbiology & Immunology, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
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Type I and Type II Interferon Antagonism Strategies Used by Paramyxoviridae: Previous and New Discoveries, in Comparison. Viruses 2022; 14:v14051107. [PMID: 35632848 PMCID: PMC9145045 DOI: 10.3390/v14051107] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 05/15/2022] [Accepted: 05/18/2022] [Indexed: 02/04/2023] Open
Abstract
Paramyxoviridae is a viral family within the order of Mononegavirales; they are negative single-strand RNA viruses that can cause significant diseases in both humans and animals. In order to replicate, paramyxoviruses–as any other viruses–have to bypass an important protective mechanism developed by the host’s cells: the defensive line driven by interferon. Once the viruses are recognized, the cells start the production of type I and type III interferons, which leads to the activation of hundreds of genes, many of which encode proteins with the specific function to reduce viral replication. Type II interferon is produced by active immune cells through a different signaling pathway, and activates a diverse range of genes with the same objective to block viral replication. As a result of this selective pressure, viruses have evolved different strategies to avoid the defensive function of interferons. The strategies employed by the different viral species to fight the interferon system include a number of sophisticated mechanisms. Here we analyzed the current status of the various strategies used by paramyxoviruses to subvert type I, II, and III interferon responses.
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Siering O, Cattaneo R, Pfaller CK. C Proteins: Controllers of Orderly Paramyxovirus Replication and of the Innate Immune Response. Viruses 2022; 14:v14010137. [PMID: 35062341 PMCID: PMC8778822 DOI: 10.3390/v14010137] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 01/07/2022] [Accepted: 01/09/2022] [Indexed: 01/07/2023] Open
Abstract
Particles of many paramyxoviruses include small amounts of proteins with a molecular weight of about 20 kDa. These proteins, termed “C”, are basic, have low amino acid homology and some secondary structure conservation. C proteins are encoded in alternative reading frames of the phosphoprotein gene. Some viruses express nested sets of C proteins that exert their functions in different locations: In the nucleus, they interfere with cellular transcription factors that elicit innate immune responses; in the cytoplasm, they associate with viral ribonucleocapsids and control polymerase processivity and orderly replication, thereby minimizing the activation of innate immunity. In addition, certain C proteins can directly bind to, and interfere with the function of, several cytoplasmic proteins required for interferon induction, interferon signaling and inflammation. Some C proteins are also required for efficient virus particle assembly and budding. C-deficient viruses can be grown in certain transformed cell lines but are not pathogenic in natural hosts. C proteins affect the same host functions as other phosphoprotein gene-encoded proteins named V but use different strategies for this purpose. Multiple independent systems to counteract host defenses may ensure efficient immune evasion and facilitate virus adaptation to new hosts and tissue environments.
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Affiliation(s)
- Oliver Siering
- Division of Veterinary Medicine, Paul-Ehrlich-Institute, 63225 Langen, Germany;
| | - Roberto Cattaneo
- Department of Molecular Medicine, Mayo Clinic, Rochester, MN 55906, USA
- Correspondence: (R.C.); (C.K.P.)
| | - Christian K. Pfaller
- Division of Veterinary Medicine, Paul-Ehrlich-Institute, 63225 Langen, Germany;
- Correspondence: (R.C.); (C.K.P.)
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Lal S, Raffel C. Protocols to Manufacture an Oncolytic Measles Virus-Sensitive Immunocompetent Mouse Model of Medulloblastoma. Methods Mol Biol 2022; 2423:165-177. [PMID: 34978698 DOI: 10.1007/978-1-0716-1952-0_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Oncolytic virotherapy translational research in the current era is heavily focused on the interaction of the immune system and tumor microenvironment with oncolytic viruses. Preclinical xenograft studies using human cells in immunodeficient mouse models does not serve this purpose. As a consequence, developing syngeneic immunocompetent murine cancer models sensitive to infection and growth of specific oncolytic viruses is required. The group 3 subtype of medulloblastoma, among the four molecular subgroups-WNT, SHH, Group 3, and Group 4, has the worst prognosis and the poorest outcome. Sadly, current treatments cause long-term toxicity and morbidity to survivors adversely affecting their quality of life. Alternate effective therapy with less side effects is urgently needed. We have shown that oncolytic measles virus (MV) is effective against localized as well as CSF-disseminated medulloblastoma in immunodeficient mouse models. To study the interaction of immune system with oncolytic measles virotherapy, we have developed a murine group 3 medulloblastoma cell line (CSCG) that is infectible by MV, is killed by MV, allows replication of MV, and is tumorigenic in the brain of syngeneic transgenic immune-competent mice. Intratumoral injection of MV results in significant prolongation of survival in mice bearing CSCG tumors in the brain. This model provides the first suitable platform to examine therapeutic regimens of MV therapy for MB tumors in the presence of intact immune system. Here, we describe our lab protocols to develop this cell line and the mouse model.
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Affiliation(s)
- Sangeet Lal
- Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA.
| | - Corey Raffel
- Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
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Kitagawa Y, Yamaguchi M, Kohno M, Sakai M, Itoh M, Gotoh B. Respirovirus C protein inhibits activation of type I interferon receptor-associated kinases to block JAK-STAT signaling. FEBS Lett 2019; 594:864-877. [PMID: 31705658 DOI: 10.1002/1873-3468.13670] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 10/22/2019] [Accepted: 10/31/2019] [Indexed: 12/31/2022]
Abstract
Respirovirus C protein blocks the type I interferon (IFN)-stimulated activation of the JAK-STAT pathway. It has been reported that C protein inhibits IFN-α-stimulated tyrosine phosphorylation of STATs, but the underlying mechanism is poorly understood. Here, we show that the C protein of Sendai virus (SeV), a member of the Respirovirus genus, binds to the IFN receptor subunit IFN-α/β receptor subunit (IFNAR)2 and inhibits IFN-α-stimulated tyrosine phosphorylation of the upstream receptor-associated kinases, JAK1 and TYK2. Analysis of various SeV C mutant (Cm) proteins demonstrates the importance of the inhibitory effect on receptor-associated kinase phosphorylation for blockade of JAK-STAT signaling. Furthermore, this inhibitory effect and the IFNAR2 binding capacity are observed for all the respirovirus C proteins examined. Our results suggest that respirovirus C protein inhibits activation of the receptor-associated kinases JAK1 and TYK2 possibly through interaction with IFNAR2.
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Affiliation(s)
- Yoshinori Kitagawa
- Division of Microbiology and Infectious Diseases, Department of Pathology, Shiga University of Medical Science, Otsu, Japan
| | - Mayu Yamaguchi
- Division of Microbiology and Infectious Diseases, Department of Pathology, Shiga University of Medical Science, Otsu, Japan
| | - Miki Kohno
- Division of Microbiology and Infectious Diseases, Department of Pathology, Shiga University of Medical Science, Otsu, Japan.,Nagahama Institute of Bio-Science and Technology, Nagahama, Japan
| | - Madoka Sakai
- Division of Microbiology and Infectious Diseases, Department of Pathology, Shiga University of Medical Science, Otsu, Japan.,Nagahama Institute of Bio-Science and Technology, Nagahama, Japan
| | - Masae Itoh
- Nagahama Institute of Bio-Science and Technology, Nagahama, Japan
| | - Bin Gotoh
- Division of Microbiology and Infectious Diseases, Department of Pathology, Shiga University of Medical Science, Otsu, Japan
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Lal S, Carrera D, Phillips JJ, Weiss WA, Raffel C. An oncolytic measles virus-sensitive Group 3 medulloblastoma model in immune-competent mice. Neuro Oncol 2019; 20:1606-1615. [PMID: 29912438 DOI: 10.1093/neuonc/noy089] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Background Oncolytic measles virus (MV) is effective in xenograft models of many tumor types in immune-compromised mice. However, no murine cell line exists that is tumorigenic, grows in immune-competent mice, and is killed by MV. The lack of such a model prevents an examination of the effect of the immune system on MV oncotherapy. Methods Cerebellar stem cells from human CD46-transgenic immunocompetent mice were transduced to express Sendai virus C-protein, murine C-Myc, and Gfi1b proteins. The resultant cells were injected into the brain of NSG mice, and a cell line, called CSCG, was prepared from the resulting tumor. Results CSCG cells are highly proliferative, and express stem cell markers. These cells are permissive for replication of MV and are killed by the virus in a dose- and time-dependent manner. CSCG cells form aggressive tumors that morphologically resemble medulloblastoma when injected into the brains of immune-competent mice. On the molecular level, CSCG tumors overexpress natriuretic peptide receptor 3 and gamma-aminobutyric acid type A receptor alpha 5, markers of Group 3 medulloblastoma. A single intratumoral injection of MV‒green fluorescent protein resulted in complete tumor regression and prolonged survival of animals compared with treatments with phosphate buffered saline (P = 0.0018) or heat-inactivated MV (P = 0.0027). Conclusions This immune-competent model provides the first platform to test therapeutic regimens of oncolytic MV for Group 3 medulloblastoma in the presence of anti-measles immunity. The strategy presented here can be used to make MV-sensitive murine models of any human tumor for which the driving mutations are known.
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Affiliation(s)
- Sangeet Lal
- Department of Neurological Surgery, Brain Tumor Research Center, Helen Diller Family Comprehensive Cancer Center, University of California San Francisco (UCSF), San Francisco, California
| | - Diego Carrera
- Department of Neurological Surgery, Brain Tumor Research Center, Helen Diller Family Comprehensive Cancer Center, University of California San Francisco (UCSF), San Francisco, California
| | - Joanna J Phillips
- Department of Neurological Surgery, Brain Tumor Research Center, Helen Diller Family Comprehensive Cancer Center, University of California San Francisco (UCSF), San Francisco, California
| | - William A Weiss
- Department of Neurology, Pediatrics, and Neurological Surgery and Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, California
| | - Corey Raffel
- Department of Neurological Surgery, Brain Tumor Research Center, Helen Diller Family Comprehensive Cancer Center, University of California San Francisco (UCSF), San Francisco, California
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Zhang Y, Mao D, Keeler SP, Wang X, Wu K, Gerovac BJ, Shornick LL, Agapov EV, Holtzman MJ. Respiratory Enterovirus (like Parainfluenza Virus) Can Cause Chronic Lung Disease if Protection by Airway Epithelial STAT1 Is Lost. THE JOURNAL OF IMMUNOLOGY 2019; 202:2332-2347. [PMID: 30804041 DOI: 10.4049/jimmunol.1801491] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 02/11/2019] [Indexed: 12/11/2022]
Abstract
Epithelial barrier cells are proposed to be critical for host defense, and airway epithelial cell capacity for IFN signal transduction is presumed to protect against respiratory viral infection. However, it has been difficult to fully test these concepts given the absence of tools to analyze IFN signaling specific to airway epithelial cells in vivo. To address these issues, we generated a new line of transgenic mice with Cre-driver genes (Foxj1 and Scgb1a1) for a floxed-Stat1 allele (designated Foxj1-Scgb1a1-Cre-Stat1f/f mice) to target the master IFN signal regulator STAT1 in airway epithelial cells and tested these mice for control of infection because of mouse parainfluenza (Sendai) virus and human enterovirus D68 (EV-D68). Indeed, both types of infections showed increases in viral titers and severity of acute illness in Foxj1-Scgb1a1-Cre-Stat1f/f mice and conventional Stat1-/- mice compared with wild-type mice. In concert, the chronic lung disease that develops after Sendai virus infection was also increased in Foxj1-Scgb1a1-Cre-Stat1f/f and Stat1-/ - mice, marked by airway and adjacent parenchymal immune cell infiltration and mucus production for at least 7 wk postinfection. Unexpectedly, relatively mild EV-D68 infection also progressed to chronic lung disease in Foxj1-Scgb1a1-Cre-Stat1f/f and Stat1 -/- mice but was limited (like viral replication) to airways. The results thereby provide proof-of-concept for a critical role of barrier epithelial cells in protection from acute illness and chronic disease after viral infection and suggest a specific role for airway epithelial cells given the limitation of EV-D68 replication and acute and chronic manifestations of disease primarily to airway tissue.
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Affiliation(s)
- Yong Zhang
- Pulmonary and Critical Care Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - Dailing Mao
- Pulmonary and Critical Care Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - Shamus P Keeler
- Pulmonary and Critical Care Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - Xinyu Wang
- Pulmonary and Critical Care Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - Kangyun Wu
- Pulmonary and Critical Care Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - Benjamin J Gerovac
- Pulmonary and Critical Care Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - Laurie L Shornick
- Pulmonary and Critical Care Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - Eugene V Agapov
- Pulmonary and Critical Care Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - Michael J Holtzman
- Pulmonary and Critical Care Medicine, Washington University School of Medicine, St. Louis, MO 63110
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Wei W, Kong W. Identification of key genes and signaling pathways during Sendai virus infection in vitro. Braz J Microbiol 2019; 50:13-22. [PMID: 30637656 DOI: 10.1007/s42770-018-0021-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 05/18/2018] [Indexed: 11/30/2022] Open
Abstract
Sendai virus (SeV) has been used as a model strain to reveal molecular features of paramyxovirus biology. In this study, we comprehensively analyzed the gene profiling of murine macrophages and airway epithelial cells in response to SeV using gene expression data. The significantly differentially expressed genes (DEGs) were screened by GEO2R. Gene ontology (GO) and pathway enrichment analyses were performed by DAVID. The protein-protein interaction (PPI) map of DEGs was constructed by STRING. The modules of PPI network are produced by molecular complex detection (MCODE) plug-in of Cytoscape. In total, 241 up- and 83 downregulated DEGs were identified in airway epithelial cells while 130 up- and 148 downregulated in macrophage. Particularly, Tmem119 and Colla2 are significantly downregulated in airway epithelial cells and macrophages, respectively. Functional enrichment analysis showed that upregulated DEGs are clustered in innate immunity and inflammatory response in both cell types, whereas downregulated DEGs are involved in host metabolic pathway in airway epithelial cells. PI3K-AKT signaling pathway is downregulated in macrophages. PPI network analysis indicated that some high degree of nodes exist in both cell types, such as Stat1, Tnf, and Cxcl10. In conclusion, SeV infection can induce different host cell responses in airway epithelial cells and macrophages.
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Affiliation(s)
- Wenqiang Wei
- School of Basic Medical Sciences, Henan University, Kaifeng, 475004, China. .,Department of Physiology and Immunology Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117456, Singapore.
| | - Wanting Kong
- Department of Physiology and Immunology Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117456, Singapore
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Yoshida A, Kawabata R, Honda T, Sakai K, Ami Y, Sakaguchi T, Irie T. A Single Amino Acid Substitution within the Paramyxovirus Sendai Virus Nucleoprotein Is a Critical Determinant for Production of Interferon-Beta-Inducing Copyback-Type Defective Interfering Genomes. J Virol 2018; 92:e02094-17. [PMID: 29237838 PMCID: PMC5809723 DOI: 10.1128/jvi.02094-17] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 12/06/2017] [Indexed: 12/12/2022] Open
Abstract
One of the first defenses against infecting pathogens is the innate immune system activated by cellular recognition of pathogen-associated molecular patterns (PAMPs). Although virus-derived RNA species, especially copyback (cb)-type defective interfering (DI) genomes, have been shown to serve as real PAMPs, which strongly induce interferon-beta (IFN-β) during mononegavirus infection, the mechanisms underlying DI generation remain unclear. Here, for the first time, we identified a single amino acid substitution causing production of cbDI genomes by successful isolation of two distinct types of viral clones with cbDI-producing and cbDI-nonproducing phenotypes from the stock Sendai virus (SeV) strain Cantell, which has been widely used in a number of studies on antiviral innate immunity as a representative IFN-β-inducing virus. IFN-β induction was totally dependent on the presence of a significant amount of cbDI genome-containing viral particles (DI particles) in the viral stock, but not on deficiency of the IFN-antagonistic viral accessory proteins C and V. Comparison of the isolates indicated that a single amino acid substitution found within the N protein of the cbDI-producing clone was enough to cause the emergence of DI genomes. The mutated N protein of the cbDI-producing clone resulted in a lower density of nucleocapsids than that of the DI-nonproducing clone, probably causing both production of the DI genomes and their formation of a stem-loop structure, which serves as an ideal ligand for RIG-I. These results suggested that the integrity of mononegaviral nucleocapsids might be a critical factor in avoiding the undesirable recognition of infection by host cells.IMPORTANCE The type I interferon (IFN) system is a pivotal defense against infecting RNA viruses that is activated by sensing viral RNA species. RIG-I is a major sensor for infection with most mononegaviruses, and copyback (cb)-type defective interfering (DI) genomes have been shown to serve as strong RIG-I ligands in real infections. However, the mechanism underlying production of cbDI genomes remains unclear, although DI genomes emerge as the result of an error during viral replication with high doses of viruses. Sendai virus has been extensively studied and is unique in that its interaction with innate immunity reveals opposing characteristics, such as high-level IFN-β induction and strong inhibition of type I IFN pathways. Our findings provide novel insights into the mechanism of production of mononegaviral cbDI genomes, as well as virus-host interactions during innate immunity.
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Affiliation(s)
- Asuka Yoshida
- Department of Virology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Ryoko Kawabata
- Department of Virology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Tomoyuki Honda
- Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Kouji Sakai
- Department of Virology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Yasushi Ami
- Division of Experimental Animal Research, National Institute of Infectious Diseases, Tokyo, Japan
| | - Takemasa Sakaguchi
- Department of Virology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Takashi Irie
- Department of Virology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
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Oda K, Oda T, Matoba Y, Sato M, Irie T, Sakaguchi T. Structural analysis of the STAT1:STAT2 heterodimer revealed the mechanism of Sendai virus C protein-mediated blockade of type 1 interferon signaling. J Biol Chem 2017; 292:19752-19766. [PMID: 28978648 DOI: 10.1074/jbc.m117.786285] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 09/28/2017] [Indexed: 11/06/2022] Open
Abstract
Sendai virus (SeV), which causes respiratory diseases in rodents, possesses the C protein that blocks the signal transduction of interferon (IFN), thereby escaping from host innate immunity. We previously demonstrated by using protein crystallography that two molecules of Y3 (the C-terminal half of the C protein) can bind to the homodimer of the N-terminal domain of STAT1 (STAT1ND), elucidating the mechanism of inhibition of IFN-γ signal transduction. SeV C protein also blocks the signal transduction of IFN-α/β by inhibiting the phosphorylation of STAT1 and STAT2, although the mechanism for the inhibition is unclear. Therefore, we sought to elucidate the mechanism of inhibition of the IFN signal transduction via STAT1 and STAT2. Small angle X-ray scattering analysis indicated that STAT1ND associates with the N-terminal domain of STAT2 (STAT2ND) with the help of a Gly-rich linker. We generated a linker-less recombinant protein possessing a STAT1ND:STAT2ND heterodimeric structure via an artificial disulfide bond. Analytical size-exclusion chromatography and surface plasmon resonance revealed that one molecule of Y3 can associate with a linker-less recombinant protein. We propose that one molecule of C protein associates with the STAT1:STAT2 heterodimer, inducing a conformational change to an antiparallel form, which is easily dephosphorylated. This suggests that association of C protein with the STAT1ND:STAT2ND heterodimer is an important factor to block the IFN-α/β signal transduction.
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Affiliation(s)
| | - Takashi Oda
- the Structural Biology Laboratory, Graduate School of Medical Life Science, Yokohama City University, Yokohama 230-0045, Japan
| | - Yasuyuki Matoba
- Microbiology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8551 and
| | - Mamoru Sato
- the Structural Biology Laboratory, Graduate School of Medical Life Science, Yokohama City University, Yokohama 230-0045, Japan
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Lo MK, Søgaard TM, Karlin DG. Evolution and structural organization of the C proteins of paramyxovirinae. PLoS One 2014; 9:e90003. [PMID: 24587180 PMCID: PMC3934983 DOI: 10.1371/journal.pone.0090003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 01/24/2014] [Indexed: 12/21/2022] Open
Abstract
The phosphoprotein (P) gene of most Paramyxovirinae encodes several proteins in overlapping frames: P and V, which share a common N-terminus (PNT), and C, which overlaps PNT. Overlapping genes are of particular interest because they encode proteins originated de novo, some of which have unknown structural folds, challenging the notion that nature utilizes only a limited, well-mapped area of fold space. The C proteins cluster in three groups, comprising measles, Nipah, and Sendai virus. We predicted that all C proteins have a similar organization: a variable, disordered N-terminus and a conserved, α-helical C-terminus. We confirmed this predicted organization by biophysically characterizing recombinant C proteins from Tupaia paramyxovirus (measles group) and human parainfluenza virus 1 (Sendai group). We also found that the C of the measles and Nipah groups have statistically significant sequence similarity, indicating a common origin. Although the C of the Sendai group lack sequence similarity with them, we speculate that they also have a common origin, given their similar genomic location and structural organization. Since C is dispensable for viral replication, unlike PNT, we hypothesize that C may have originated de novo by overprinting PNT in the ancestor of Paramyxovirinae. Intriguingly, in measles virus and Nipah virus, PNT encodes STAT1-binding sites that overlap different regions of the C-terminus of C, indicating they have probably originated independently. This arrangement, in which the same genetic region encodes simultaneously a crucial functional motif (a STAT1-binding site) and a highly constrained region (the C-terminus of C), seems paradoxical, since it should severely reduce the ability of the virus to adapt. The fact that it originated twice suggests that it must be balanced by an evolutionary advantage, perhaps from reducing the size of the genetic region vulnerable to mutations.
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Affiliation(s)
- Michael K. Lo
- Centers for Disease Control and Prevention, Viral Special Pathogens Branch, Atlanta, Georgia, United States of America
| | - Teit Max Søgaard
- Division of Structural Biology, Oxford University, Oxford, United Kingdom
| | - David G. Karlin
- Division of Structural Biology, Oxford University, Oxford, United Kingdom
- Department of Zoology, University of Oxford, Oxford, United Kingdom
- * E-mail:
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Role of interferon regulatory factor 3-mediated apoptosis in the establishment and maintenance of persistent infection by Sendai virus. J Virol 2012; 87:16-24. [PMID: 23077293 DOI: 10.1128/jvi.01853-12] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Infection of cultured cells by paramyxoviruses causes cell death, mediated by a newly discovered apoptotic pathway activated by virus infection. The key proapoptotic protein in this pathway is interferon regulatory factor 3 (IRF-3), which upon activation by virus infection binds BAX, translocates it to mitochondria, and triggers apoptosis. When IRF-3-knockdown cells were infected with Sendai virus (SeV), persistent infection (PI) was established. The PI cells produced infectious SeV continuously and constitutively expressed many innate immune genes. Interferon signaling was blocked in these cells. The elevated levels of IRF-3-driven genes in the PI cells indicated that the amount of residual IRF-3 activated by endogenous SeV was high enough to drive the transcriptional effects of IRF-3 but too low to trigger its apoptotic activity. We confirmed this IRF-3 threshold idea by generating a tetracycline (Tet)-inducible cell line for IRF-3 expression, which enabled us to express various levels of IRF-3. PI could be established in the Tet-off cell line, and as expected, when doxycycline was withdrawn, the cells underwent apoptosis. Finally, we tested for PI establishment in 12 mouse embryo fibroblasts by natural selection. Eleven lines became persistently infected; although seven out of them had low IRF-3 levels, four did not. When one of the latter four was further analyzed, we observed that it expressed a very low level of caspase 3, the final executor protease of the apoptotic pathway. These results demonstrated that SeV PI can arise from infection of normal wild-type cells, but only if they can find a way to impair the IRF-3-dependent apoptotic pathway.
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13
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Nonstructural Nipah virus C protein regulates both the early host proinflammatory response and viral virulence. J Virol 2012; 86:10766-75. [PMID: 22837207 DOI: 10.1128/jvi.01203-12] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Nipah virus (NiV) is a highly pathogenic, negative-strand RNA paramyxovirus that has recently emerged from flying foxes to cause serious human disease. We have analyzed the role of the nonstructural NiV C protein in viral immunopathogenesis using recombinant virus lacking the expression of NiV C (NiVΔC). While wild-type NiV was highly pathogenic in the hamster animal model, NiVΔC was strongly attenuated. Replication of NiVΔC was followed by the production of NiV-specific antibodies and associated with higher recruitment of inflammatory cells and less intensive histopathological lesions in different organs than in wild-type-NiV-infected animals. To analyze the molecular basis of NiVΔC attenuation, we studied early changes in gene expression in infected primary human endothelial cells, a major cellular target of NiV infection. The transcriptomic approach revealed the striking difference between wild-type and mutant NiV in the expression of genes involved in immunity, with the particularly interesting differential patterns of proinflammatory cytokines. Compared to wild-type virus, NiVΔC induced increased expression of interleukin 1 beta (IL-1β), IL-8, CXCL2, CXCL3, CXCL6, CCL20, and beta interferon. Furthermore, the expression of NiV C in stably transfected cells decreased the production of the same panel of cytokines, revealing a role of the C protein in the regulation of cytokine balance. Together, these results suggest that NiV C regulates expression of proinflammatory cytokines, therefore providing a signal responsible for the coordination of leukocyte recruitment and the chemokine-induced immune response and controlling the lethal outcome of the infection.
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14
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Bowick GC, Airo AM, Bente DA. Expression of interferon-induced antiviral genes is delayed in a STAT1 knockout mouse model of Crimean-Congo hemorrhagic fever. Virol J 2012; 9:122. [PMID: 22713837 PMCID: PMC3489622 DOI: 10.1186/1743-422x-9-122] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Accepted: 06/19/2012] [Indexed: 01/14/2023] Open
Abstract
Background Crimean Congo hemorrhagic fever (CCHF) is a tick-borne hemorrhagic zoonosis associated with high mortality. Pathogenesis studies and the development of vaccines and antivirals against CCHF have been severely hampered by the lack of suitable animal model. We recently developed and characterized a mature mouse model for CCHF using mice carrying STAT1 knockout (KO). Findings Given the importance of interferons in controlling viral infections, we investigated the expression of interferon pathway-associated genes in KO and wild-type (WT) mice challenged with CCHF virus. We expected that the absence of the STAT1 protein would result in minimal expression of IFN-related genes. Surprisingly, the KO mice showed high levels of IFN-stimulated gene expression, beginning on day 2 post-infection, while in WT mice challenged with virus the same genes were expressed at similar levels on day 1. Conclusions We conclude that CCHF virus induces similar type I IFN responses in STAT1 KO and WT mice, but the delayed response in the KO mice permits rapid viral dissemination and fatal illness.
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Affiliation(s)
- Gavin C Bowick
- Department of Microbiology & Immunology, Center for Biodefense and Emerging Infectious Diseases, Sealy Center for Vaccine Development, Institute for Human Infections & Immunity, Galveston, TX, USA
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15
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Wells G, Addington-Hall M, Malur AG. Mutations within the human parainfluenza virus type 3 (HPIV 3) C protein affect viral replication and host interferon induction. Virus Res 2012; 167:385-90. [PMID: 22634035 DOI: 10.1016/j.virusres.2012.05.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Revised: 05/09/2012] [Accepted: 05/15/2012] [Indexed: 10/28/2022]
Abstract
Human parainfluenza virus type 3 (HPIV 3) encodes a multifunctional C protein that is capable of inhibiting viral replication and counteracting the host interferon (IFN) signaling pathway. We recently demonstrated that the C protein is phosphorylated both in vitro and in vivo and mutations within the phosphorylation sites exhibit differential inhibitory activities in vitro. In this study, we report for the first time the successful recovery of mutant HPIV 3 viruses containing mutations within the C protein. Three mutant viruses, Cm-1, Cm-3 and Cm-4, harboring individual mutations of S7, S47T48 and S81 residues, respectively, were examined for their replication profiles and their ability to abrogate host IFN induction. Viral transcription was similar for all viruses; however Cm-3 displayed a relatively higher replication. Infection of cells with Cm-1 and Cm-3 led to the activation of IFN regulatory transcription factor 3 (IRF-3) and subsequent increase in IFN-β mRNA levels as determined by immunofluorescence assay and RT-PCR analyses, respectively. Moreover, Cm-3 was able to partially resist the interferon induced antiviral state in Vero cells. Taken together, these results suggest that mutations within the C protein differentially affect viral replication and host interferon induction.
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Affiliation(s)
- Greg Wells
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, 600 Moye Boulevard, Greenville, NC 27834, USA
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16
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Interaction between innate immunity and porcine reproductive and respiratory syndrome virus. Anim Health Res Rev 2012; 12:149-67. [PMID: 22152291 DOI: 10.1017/s1466252311000144] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Innate immunity provides frontline antiviral protection and bridges adaptive immunity against virus infections. However, viruses can evade innate immune surveillance potentially causing chronic infections that may lead to pandemic diseases. Porcine reproductive and respiratory syndrome virus (PRRSV) is an example of an animal virus that has developed diverse mechanisms to evade porcine antiviral immune responses. Two decades after its discovery, PRRSV is still one of the most globally devastating viruses threatening the swine industry. In this review, we discuss the molecular and cellular composition of the mammalian innate antiviral immune system with emphasis on the porcine system. In particular, we focus on the interaction between PRRSV and porcine innate immunity at cellular and molecular levels. Strategies for targeting innate immune components and other host metabolic factors to induce ideal anti-PRRSV protection are also discussed.
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17
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Virus-driven conditional expression of an interferon antagonist as a tool to circumvent host restriction. Proc Natl Acad Sci U S A 2011; 108:17239-40. [DOI: 10.1073/pnas.1114431108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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18
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Sato H, Yoneda M, Honda T, Kai C. Recombinant vaccines against the mononegaviruses--what we have learned from animal disease controls. Virus Res 2011; 162:63-71. [PMID: 21982973 PMCID: PMC7114506 DOI: 10.1016/j.virusres.2011.09.038] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Accepted: 09/28/2011] [Indexed: 11/30/2022]
Abstract
The mononegaviruses include a number of highly contagious and severe disease-causing viruses of both animals and humans. For the control of these viral diseases, development of vaccines, either with classical methods or with recombinant DNA virus vectors, has been attempted over the years. Recently reverse genetics of mononegaviruses has been developed and used to generate infectious viruses possessing genomes derived from cloned cDNA in order to study the consequent effects of viral gene manipulations on phenotype. This technology allows us to develop novel candidate vaccines. In particular, a variety of different attenuation strategies to produce a range of attenuated mononegavirus vaccines have been studied. In addition, because of their ideal nature as live vaccines, recombinant mononegaviruses expressing foreign proteins have also been produced with the aim of developing multivalent vaccines against more than one pathogen. These recombinant mononegaviruses are currently under evaluation as new viral vectors for vaccination. Reverse genetics could have great potential for the preparation of vaccines against many mononegaviruses.
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Affiliation(s)
- Hiroki Sato
- Laboratory Animal Research Center/International Research Center for Infectious Diseases, Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan.
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19
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Pasieka TJ, Collins L, O'Connor MA, Chen Y, Parker ZM, Berwin BL, Piwnica-Worms DR, Leib DA. Bioluminescent imaging reveals divergent viral pathogenesis in two strains of Stat1-deficient mice, and in αßγ interferon receptor-deficient mice. PLoS One 2011; 6:e24018. [PMID: 21915277 PMCID: PMC3168466 DOI: 10.1371/journal.pone.0024018] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Accepted: 08/03/2011] [Indexed: 01/14/2023] Open
Abstract
Pivotal components of the IFN response to virus infection include the IFN receptors (IFNR), and the downstream factor signal transducer and activator of transcription 1 (Stat1). Mice deficient for Stat1 and IFNR (Stat1(-/-) and IFNαßγR(-/-) mice) lack responsiveness to IFN and exhibit high sensitivity to various pathogens. Here we examined herpes simplex virus type 1 (HSV-1) pathogenesis in Stat1(-/-) mice and in IFNαßγR(-/-) mice following corneal infection and bioluminescent imaging. Two divergent and paradoxical patterns of infection were observed. Mice with an N-terminal deletion in Stat1 (129Stat1(-/-) (N-term)) had transient infection of the liver and spleen, but succumbed to encephalitis by day 10 post-infection. In stark contrast, infection of IFNαßγR(-/-) mice was rapidly fatal, with associated viremia and fulminant infection of the liver and spleen, with infected infiltrating cells being primarily of the monocyte/macrophage lineage. To resolve the surprising difference between Stat1(-/-) and IFNαßγR(-/-) mice, we infected an additional Stat1(-/-) strain deleted in the DNA-binding domain (129Stat1(-/-) (DBD)). These 129Stat1(-/-) (DBD) mice recapitulated the lethal pattern of liver and spleen infection seen following infection of IFNαßγR(-/-) mice. This lethal pattern was also observed when 129Stat1(-/-) (N-term) mice were infected and treated with a Type I IFN-blocking antibody, and immune cells derived from 129Stat1(-/-) (N-term) mice were shown to be responsive to Type I IFN. These data therefore show significant differences in viral pathogenesis between two commonly-used Stat1(-/-) mouse strains. The data are consistent with the hypothesis that Stat1(-/-) (N-term) mice have residual Type I IFN receptor-dependent IFN responses. Complete loss of IFN signaling pathways allows viremia and rapid viral spread with a fatal infection of the liver. This study underscores the importance of careful comparisons between knockout mouse strains in viral pathogenesis, and may also be relevant to the causation of HSV hepatitis in humans, a rare but frequently fatal infection.
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Affiliation(s)
- Tracy Jo Pasieka
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Lynne Collins
- BRIGHT Institute, Molecular Imaging Center, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Megan A. O'Connor
- Department of Microbiology and Immunology, Dartmouth Medical School, Lebanon, New Hampshire, United States of America
| | - Yufei Chen
- Department of Microbiology and Immunology, Dartmouth Medical School, Lebanon, New Hampshire, United States of America
| | - Zachary M. Parker
- Department of Microbiology and Immunology, Dartmouth Medical School, Lebanon, New Hampshire, United States of America
| | - Brent L. Berwin
- Department of Microbiology and Immunology, Dartmouth Medical School, Lebanon, New Hampshire, United States of America
| | - David R. Piwnica-Worms
- BRIGHT Institute, Molecular Imaging Center, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - David A. Leib
- Department of Microbiology and Immunology, Dartmouth Medical School, Lebanon, New Hampshire, United States of America
- * E-mail:
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20
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Expression of the Sendai (murine parainfluenza) virus C protein alleviates restriction of measles virus growth in mouse cells. Proc Natl Acad Sci U S A 2011; 108:15384-9. [PMID: 21896767 DOI: 10.1073/pnas.1107382108] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Measles virus (MV), a human pathogen, uses the signaling lymphocyte activation molecule (SLAM) or CD46 as an entry receptor. Although several transgenic mice expressing these receptors have been generated as small animal models for measles, these mice usually have to be made defective in IFN-α/β signaling to facilitate MV replication. Similarly, when functional receptors are expressed by transfection, mouse cells do not allow MV growth as efficiently as primate cells. In this study, we demonstrate that MV efficiently grows in SLAM-expressing mouse cells in which the Sendai virus (SeV) C protein is transiently expressed. We developed a SLAM-expressing mouse cell line whose genome also encodes the SeV C protein downstream of the sequence flanked with loxP sequences. When this cell line was infected with the recombinant MV expressing the Cre recombinase, the SeV C protein was readily expressed. Importantly, the Cre recombinase-encoding MV grew in this cell line much more efficiently than it did in the parental cell. The minigenome assay demonstrated that the SeV C protein does not modulate MV RNA synthesis. Analyses using the mutant proteins with the defined functional defects revealed that the IFN-antagonist function, but not the budding-accelerating function, of the SeV C protein was critical for supporting efficient MV growth in mouse cells. Our results indicate that insufficient IFN antagonism can be an important determinant of the host range of viruses, and the system described here may be useful to overcome the species barrier of other human viruses.
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21
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Ye J, Maniatis T. Negative regulation of interferon-β gene expression during acute and persistent virus infections. PLoS One 2011; 6:e20681. [PMID: 21677781 PMCID: PMC3108996 DOI: 10.1371/journal.pone.0020681] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2011] [Accepted: 05/06/2011] [Indexed: 01/19/2023] Open
Abstract
The production of type I interferons (IFNs) in response to viral infections is critical for antiviral immunity. However, IFN production is transient, and continued expression can lead to inflammatory or autoimmune diseases. Thus, understanding the mechanisms underlying the negative regulation of IFN expression could lead to the development of novel therapeutic approaches to the treatment of these diseases. We report that the transcription factor IRF3 plays a central role in the negative regulation of interferon-β (IFNβ) expression during both acute and persistent (chronic) virus infections. We show that the degradation of IRF3 during acute infections, rather than the activation of transcriptional repressors, leads to the down regulation of IFNβ expression. We also show that the block to IFNβ expression in mouse embryonic fibroblasts that are persistently infected with Sendai virus (SeV) correlates with the absence of transcriptionally active IRF3. Remarkably, ongoing protein synthesis and viral replication are required to maintain repression of the IFNβ gene in persistently infected cells, as the gene can be activated by the protein synthesis inhibitor cycloheximide, or by the antiviral drug ribavirin. Finally, we show that the SeV V protein inhibits IRF3 activity in persistently infected cells. Thus, in conjunction with the known interference with STAT1 by the SeV C protein, both IFN activation and its signaling pathways are blocked in persistently infected cells. We conclude that the transcription factor IRF3 is targeted for turnover and inactivation through distinct mechanisms from both the host cells and virus, leading to the inhibition of IFNβ gene expression during acute and persistent viral infections. These observations show that IRF3 plays a critical role, not only in the activation of the IFNβ gene, but also in the controlling the duration of its expression. (284 words)
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Affiliation(s)
- Junqiang Ye
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | - Tom Maniatis
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, United States of America
- * E-mail:
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22
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Irie T, Nagata N, Igarashi T, Okamoto I, Sakaguchi T. Conserved charged amino acids within Sendai virus C protein play multiple roles in the evasion of innate immune responses. PLoS One 2010; 5:e10719. [PMID: 20502666 PMCID: PMC2873429 DOI: 10.1371/journal.pone.0010719] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Accepted: 04/27/2010] [Indexed: 12/24/2022] Open
Abstract
One of the accessory proteins of Sendai virus (SeV), C, translated from an alternate reading frame of P/V mRNA has been shown to function at multiple stages of infection in cell cultures as well as in mice. C protein has been reported to counteract signal transduction by interferon (IFN), inhibit apoptosis induced by the infection, enhance the efficiency of budding of viral particles, and regulate the polarity of viral genome-length RNA synthesis to maximize production of infectious particles. In this study, we have generated a series of SeV recombinants containing substitutions of highly conserved, charged residues within the C protein, and characterized them together with previously-reported C′/C(−), 4C(−), and F170S recombinant viruses in infected cell cultures in terms of viral replication, cytopathogenicity, and antagonizing effects on host innate immunity. Unexpectedly, the amino acid substitutions had no or minimal effect on viral growth and viral RNA synthesis. However, all the substitutions of charged amino acids resulted in the loss of a counteracting effect against the establishment of an IFN-α-mediated anti-viral state. Infection by the virus (Cm2′) containing mutations at K77 and D80 induced significant IFN-β production, severe cytopathic effects, and detectable amounts of viral dsRNA production. In addition to the Cm2′ virus, the virus containing mutations at E114 and E115 did not inhibit the poly(I:C)-triggered translocation of cellular IRF-3 to the nucleus. These results suggest that the C protein play important roles in viral escape from induction of IFN-β and cell death triggered by infection by means of counteracting the pathway leading to activation of IRF-3 as well as of minimizing viral dsRNA production.
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Affiliation(s)
- Takashi Irie
- Department of Virology, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan.
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23
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Harrison MS, Sakaguchi T, Schmitt AP. Paramyxovirus assembly and budding: building particles that transmit infections. Int J Biochem Cell Biol 2010; 42:1416-29. [PMID: 20398786 DOI: 10.1016/j.biocel.2010.04.005] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2010] [Revised: 04/05/2010] [Accepted: 04/07/2010] [Indexed: 01/16/2023]
Abstract
The paramyxoviruses define a diverse group of enveloped RNA viruses that includes a number of important human and animal pathogens. Examples include human respiratory syncytial virus and the human parainfluenza viruses, which cause respiratory illnesses in young children and the elderly; measles and mumps viruses, which have caused recent resurgences of disease in developed countries; the zoonotic Hendra and Nipah viruses, which have caused several outbreaks of fatal disease in Australia and Asia; and Newcastle disease virus, which infects chickens and other avian species. Like other enveloped viruses, paramyxoviruses form particles that assemble and bud from cellular membranes, allowing the transmission of infections to new cells and hosts. Here, we review recent advances that have improved our understanding of events involved in paramyxovirus particle formation. Contributions of viral matrix proteins, glycoproteins, nucleocapsid proteins, and accessory proteins to particle formation are discussed, as well as the importance of host factor recruitment for efficient virus budding. Trafficking of viral structural components within infected cells is described, together with mechanisms that allow for the selection of specific sites on cellular membranes for the coalescence of viral proteins in preparation of bud formation and virion release.
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Affiliation(s)
- Megan S Harrison
- Department of Veterinary and Biomedical Sciences, and Center for Molecular Immunology and Infectious Disease, The Pennsylvania State University, University Park, PA 16802, United States
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24
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Zhang Y, Song L, Zhao J, Wang L, Kong P, Liu L, Wang M, Qiu L. Protective immunity induced by CpG ODNs against white spot syndrome virus (WSSV) via intermediation of virus replication indirectly in Litopenaeus vannamei. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2010; 34:418-424. [PMID: 19963004 DOI: 10.1016/j.dci.2009.11.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2009] [Revised: 11/30/2009] [Accepted: 11/30/2009] [Indexed: 05/28/2023]
Abstract
The worldwide shrimp culture is beset with diseases mainly caused by white spot syndrome virus (WSSV) and suffered huge economic losses, which bring out an urgent need to develop the novel strategies to better protect shrimps against WSSV. In the present study, CpG-rich plasmid pUC57-CpG, plasmid pUC57 and PBS were employed to pretreat shrimps comparatively to evaluate the protective effects of CpG ODNs on shrimps against WSSV. The survival rates, WSSV copy numbers, and antiviral associated factors (Dicer, Argonaute, STAT and ROS) were detected in Litopenaeus vannamei. There were higher survival proportion, lower WSSV copy numbers, and higher mRNA expression of Dicer and STAT in pUC57-CpG-pretreatment shrimps than those in pUC57- and PBS-pretreatment shrimps after WSSV infection. The Argonaute mRNA expression in pUC57-CpG-, pUC57- and PBS-pretreatment shrimps after WSSV infection was significantly higher than that of shrimps post PBS stimulation on the first day. The ROS levels in pUC57-CpG-pretreatment shrimps post secondary stimulation of PBS were significantly higher than those post WSSV infection on the first day. These results together demonstrated that pUC57-CpG induced partial protective immunity in shrimps against WSSV via intermediation of virus replication indirectly and could be used as a potential candidate in the development of therapeutic agents for disease control of WSSV in L. vannamei.
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Affiliation(s)
- Ying Zhang
- The Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Rd., Qingdao, Shandong 266071, China
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25
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Simon A, Moritoh K, Torigoe D, Asano A, Sasaki N, Agui T. Multigenic control of resistance to Sendai virus infection in mice. INFECTION GENETICS AND EVOLUTION 2009; 9:1253-9. [DOI: 10.1016/j.meegid.2009.08.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2009] [Revised: 08/13/2009] [Accepted: 08/18/2009] [Indexed: 10/20/2022]
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26
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Differential regulation of type I interferon and epidermal growth factor pathways by a human Respirovirus virulence factor. PLoS Pathog 2009; 5:e1000587. [PMID: 19806178 PMCID: PMC2736567 DOI: 10.1371/journal.ppat.1000587] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2009] [Accepted: 08/24/2009] [Indexed: 01/10/2023] Open
Abstract
A number of paramyxoviruses are responsible for acute respiratory infections in children, elderly and immuno-compromised individuals, resulting in airway inflammation and exacerbation of chronic diseases like asthma. To understand the molecular pathogenesis of these infections, we searched for cellular targets of the virulence protein C of human parainfluenza virus type 3 (hPIV3-C). We found that hPIV3-C interacts directly through its C-terminal domain with STAT1 and GRB2, whereas C proteins from measles or Nipah viruses failed to do so. Binding to STAT1 explains the previously reported capacity of hPIV3-C to block type I interferon signaling, but the interaction with GRB2 was unexpected. This adaptor protein bridges Epidermal Growth Factor (EGF) receptor to MAPK/ERK pathway, a signaling cascade recently found to be involved in airway inflammatory response. We report that either hPIV3 infection or transient expression of hPIV3-C both increase cellular response to EGF, as assessed by Elk1 transactivation and phosphorylation levels of ERK1/2, 40S ribosomal subunit protein S6 and translation initiation factor 4E (eIF4E). Furthermore, inhibition of MAPK/ERK pathway with U0126 prevented viral protein expression in infected cells. Altogether, our data provide molecular basis to explain the role of hPIV3-C as a virulence factor and determinant of pathogenesis and demonstrate that Paramyxoviridae have evolved a single virulence factor to block type I interferon signaling and to boost simultaneous cellular response to growth factors. Respiroviruses are important pathogens responsible for acute respiratory tract infections associated with severe airway inflammation in children, elderly and immuno-compromised individuals. Their RNA genome encodes for structural proteins that compose viral particles, but also for virulence factors that alter cell biology to enhance virus replication and spreading. Among them, the C protein plays a critical role by blocking cellular response to type I interferons, the main antiviral cytokines secreted during virus infections. To provide molecular basis to this activity, we found that the C protein of human parainfluenza virus type 3 (hPIV3-C), the most frequent human Respirovirus, interacts with STAT1, a key component of type I interferon receptor complex. But hPIV3-C was also found to interact with GRB2, an adaptor molecule involved in cellular response to Epidermal Growth Factor (EGF), and to enhance cell response to this cytokine. This pathway increases protein translation, promotes cell survival and contributes to airway inflammation and mucus secretion. Thus, our findings show that hPIV3-C not only inhibits the antiviral response but also stimulates cellular response to EGF, which benefits virus replication and induces an excessive inflammation of airways during infection.
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Mao H, Chattopadhyay S, Banerjee AK. N-terminally truncated C protein, CNDelta25, of human parainfluenza virus type 3 is a potent inhibitor of viral replication. Virology 2009; 394:143-8. [PMID: 19747707 DOI: 10.1016/j.virol.2009.08.026] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2009] [Revised: 07/06/2009] [Accepted: 08/18/2009] [Indexed: 11/27/2022]
Abstract
The C protein of human parainfluenza virus type 3 (HPIV3) is a multifunctional accessory protein that inhibits viral transcription and interferon (IFN) signaling. In the present study, we found that removal of N-terminal 25 or 50 amino acid residues from the C protein (CNDelta25 or CNDelta50) totally abolished viral RNA synthesis in the HPIV3 minigenome system. Further N-terminal or C-terminal deletion impaired the inhibitory ability of CNDelta25 and CNDelta50. Subsequent mutagenesis analysis suggested that the N-terminal-charged amino acid residues (K3, K6, K12, E16, and R24) contribute to the higher inhibition caused by CNDelta25 than the C protein. Consistent with viral RNA synthesis inhibition, the growth of HPIV3 was significantly decreased by 5 logs in HeLa-derived cell line expressing CNDelta25. Interestingly, replication of respiratory syncytial virus (RSV), another important respiratory tract pathogen, was also strongly inhibited in the presence of CNDelta25. These findings provide a promising potential to use CNDelta25 as an antiviral agent against the clinically important respiratory tract diseases caused by HPIV3 and RSV.
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Affiliation(s)
- Hongxia Mao
- Virology Section, Department of Molecular Genetics, Lerner Research Institute, Cleveland Clinic Foundation, NN1-06, 9500 Euclid Avenue, Cleveland, OH 44195, USA
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Konno H, Yamamoto T, Yamazaki K, Gohda J, Akiyama T, Semba K, Goto H, Kato A, Yujiri T, Imai T, Kawaguchi Y, Su B, Takeuchi O, Akira S, Tsunetsugu-Yokota Y, Inoue JI. TRAF6 establishes innate immune responses by activating NF-kappaB and IRF7 upon sensing cytosolic viral RNA and DNA. PLoS One 2009; 4:e5674. [PMID: 19479062 PMCID: PMC2682567 DOI: 10.1371/journal.pone.0005674] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2008] [Accepted: 05/05/2009] [Indexed: 12/24/2022] Open
Abstract
Background In response to viral infection, the innate immune system recognizes viral nucleic acids and then induces production of proinflammatory cytokines and type I interferons (IFNs). Toll-like receptor 7 (TLR7) and TLR9 detect viral RNA and DNA, respectively, in endosomal compartments, leading to the activation of nuclear factor κB (NF-κB) and IFN regulatory factors (IRFs) in plasmacytoid dendritic cells. During such TLR signaling, TNF receptor-associated factor 6 (TRAF6) is essential for the activation of NF-κB and the production of type I IFN. In contrast, RIG-like helicases (RLHs), cytosolic RNA sensors, are indispensable for antiviral responses in conventional dendritic cells, macrophages, and fibroblasts. However, the contribution of TRAF6 to the detection of cytosolic viral nucleic acids has been controversial, and the involvement of TRAF6 in IRF activation has not been adequately addressed. Principal Findings Here we first show that TRAF6 plays a critical role in RLH signaling. The absence of TRAF6 resulted in enhanced viral replication and a significant reduction in the production of IL-6 and type I IFNs after infection with RNA virus. Activation of NF-κB and IRF7, but not that of IRF3, was significantly impaired during RLH signaling in the absence of TRAF6. TGFβ-activated kinase 1 (TAK1) and MEKK3, whose activation by TRAF6 during TLR signaling is involved in NF-κB activation, were not essential for RLH-mediated NF-κB activation. We also demonstrate that TRAF6-deficiency impaired cytosolic DNA-induced antiviral responses, and this impairment was due to defective activation of NF-κB and IRF7. Conclusions/Significance Thus, TRAF6 mediates antiviral responses triggered by cytosolic viral DNA and RNA in a way that differs from that associated with TLR signaling. Given its essential role in signaling by various receptors involved in the acquired immune system, TRAF6 represents a key molecule in innate and antigen-specific immune responses against viral infection.
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Affiliation(s)
- Hiroyasu Konno
- Division of Cellular and Molecular Biology, Department of Cancer Biology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Takuya Yamamoto
- Division of Cellular and Molecular Biology, Department of Cancer Biology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
- Department of Immunology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Kohsuke Yamazaki
- Division of Cellular and Molecular Biology, Department of Cancer Biology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Jin Gohda
- Division of Cellular and Molecular Biology, Department of Cancer Biology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Taishin Akiyama
- Division of Cellular and Molecular Biology, Department of Cancer Biology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Kentaro Semba
- Department of Life Science and Medical Bio-Science, Waseda University, Tokyo, Japan
| | - Hideo Goto
- Division of Virology, Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Atsushi Kato
- Department of Virology III, National Institute of Infectious Diseases, Tokyo, Japan
| | - Toshiaki Yujiri
- Third Department of Internal Medicine, Yamaguchi University School of Medicine, Yamaguchi, Japan
| | - Takahiko Imai
- Division of Viral Infection, Department of Infectious Disease Control, International Research Center for Infectious Diseases, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Yasushi Kawaguchi
- Division of Viral Infection, Department of Infectious Disease Control, International Research Center for Infectious Diseases, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Bing Su
- Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Osamu Takeuchi
- Laboratory of Host Defense, WPI Immunology Frontier Research Center, Osaka, Japan
| | - Shizuo Akira
- Laboratory of Host Defense, WPI Immunology Frontier Research Center, Osaka, Japan
| | | | - Jun-ichiro Inoue
- Division of Cellular and Molecular Biology, Department of Cancer Biology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
- * E-mail:
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29
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Chambers R, Takimoto T. Host specificity of the anti-interferon and anti-apoptosis activities of parainfluenza virus P/C gene products. J Gen Virol 2009; 90:1906-1915. [PMID: 19423549 DOI: 10.1099/vir.0.011700-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Human parainfluenza virus type 1 (HPIV-1) and Sendai virus (SeV) are highly homologous in structure and sequence, whilst maintaining distinct host ranges. These viruses express accessory proteins from their P/C gene that are known to have activities against innate immunity. The accessory proteins expressed from the P/C gene of these viruses are different. In addition to the nested set of C proteins, SeV expresses V protein from edited P mRNA, which is not expressed by HPIV-1. This study evaluated the host specificity and role of the P/C gene products in anti-interferon (IFN) and anti-apoptosis activity by characterizing a recombinant SeV, rSeVhP, in which the SeV P/C gene was replaced with that of HPIV-1. Unlike SeV, rSeVhP infection strongly activated IFN regulatory transcription factor (IRF)-3 and nuclear factor-kappaB, resulting in an increased level of IFN-beta induction compared with SeV in murine cells. In contrast, activation of IRF-3 was not observed in rSeVhP-infected human A549 cells. rSeVhPSV, which expressed SeV V protein from an inserted gene in rSeVhP, induced less IFN-beta than rSeVhP, suggesting that V contributes to the suppression of IFN production in murine cells. Furthermore, rSeVhP induced apoptotic cell death in murine but not in A549 cells. These data indicate the functional difference in P/C gene products from SeV and HPIV-1 in antagonizing IFN induction and apoptosis, which is likely to be one of the major factors for pathogenicity in specific hosts.
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Affiliation(s)
- Raychel Chambers
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Toru Takimoto
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA
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30
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Malur AG, Wells G, McCoy A, Banerjee AK. Evidence for phosphorylation of human parainfluenza virus type 3 C protein: mutant C proteins exhibit variable inhibitory activities in vitro. Virus Res 2009; 144:180-7. [PMID: 19410612 DOI: 10.1016/j.virusres.2009.04.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2008] [Revised: 04/16/2009] [Accepted: 04/26/2009] [Indexed: 11/16/2022]
Abstract
The P mRNA of human parainfluenza virus type 3, like other members of the subfamily Paramyxovirinae, gives rise to several polypeptides, one amongst them, the C protein, which is involved in inhibition of viral RNA synthesis as well as counteracting the host interferon signaling pathway. As a further step towards characterizing the function of C protein we present evidence to demonstrate the phosphorylation of C protein. Evidence for this observation emerged from deletion mapping studies coupled with mass spectroscopy analysis confirming residues S7, S22, S47T48 and S81 residues as the phosphorylation sites within the NH(2)-terminus of C protein. Here, we utilized a HPIV 3 minigenome replication assay and real time RT-PCR analysis to measure the relative RNA levels synthesized in the presence of mutant C proteins. Mutants S7A and S81A displayed low levels of RNA while mutant 5A that was devoid of all these phosphorylation sites exhibited high RNA level in comparison to wild type C during transcription. Interestingly, high levels of RNA were observed in the presence of S81A and mutant 5A during replication. Taken together, our results indicate that phosphorylation may differentially affect the inhibitory activity of C protein thereby regulating viral RNA synthesis.
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Affiliation(s)
- Achut G Malur
- Department of Microbiology and Immunology, Brody School of Medicine, Biotech 124, East Carolina University, 600 Moye Boulevard, Greenville, NC 27834, USA.
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31
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Davis AM, Hagan KA, Matthews LA, Bajwa G, Gill MA, Gale M, Farrar JD. Blockade of virus infection by human CD4+ T cells via a cytokine relay network. THE JOURNAL OF IMMUNOLOGY 2008; 180:6923-32. [PMID: 18453613 DOI: 10.4049/jimmunol.180.10.6923] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CD4(+) T cells directly participate in bacterial clearance through secretion of proinflammatory cytokines. Although viral clearance relies heavily on CD8(+) T cell functions, we sought to determine whether human CD4(+) T cells could also directly influence viral clearance through cytokine secretion. We found that IFN-gamma and TNF-alpha, secreted by IL-12-polarized Th1 cells, displayed potent antiviral effects against a variety of viruses. IFN-gamma and TNF-alpha acted directly to inhibit hepatitis C virus replication in an in vitro replicon system, and neutralization of both cytokines was required to block the antiviral activity that was secreted by Th1 cells. IFN-gamma and TNF-alpha also exerted antiviral effects against vesicular stomatitis virus infection, but in this case, functional type I IFN receptor activity was required. Thus, in cases of vesicular stomatitis virus infection, the combination of IFN-gamma and TNF-alpha secreted by human Th1 cells acted indirectly through the IFN-alpha/beta receptor. These results highlight the importance of CD4(+) T cells in directly regulating antiviral responses through proinflammatory cytokines acting in both a direct and indirect manner.
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Affiliation(s)
- Ann M Davis
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9093, USA
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32
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Measles virus circumvents the host interferon response by different actions of the C and V proteins. J Virol 2008; 82:8296-306. [PMID: 18562542 DOI: 10.1128/jvi.00108-08] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Measles is an acute febrile infectious disease with high morbidity and mortality. The genome of measles virus (MV), the causative agent, encodes two accessory products, V and C proteins, that play important roles in MV virulence. The V but not the C protein of the IC-B strain (a well-characterized virulent strain of MV) has been shown to block the Jak/Stat signaling pathway and counteract the cellular interferon (IFN) response. We have recently shown that a recombinant IC-B strain that lacks C protein expression replicates poorly in certain cell lines, and its growth defect is related to translational inhibition and strong IFN induction. Here, we show that the V protein of the MV IC-B strain also blocks the IFN induction pathway mediated by the melanoma differentiation-associated gene 5 product, thus actively interfering with the host IFN response at two different steps. On the other hand, the C protein per se possesses no activity to block the IFN induction pathway. Our data indicate that the C protein acts as a regulator of viral RNA synthesis, thereby acting indirectly to suppress IFN induction. Since recombinant MVs with C protein defective in modulating viral RNA synthesis or lacking C protein expression strongly stimulate IFN production, in spite of V protein production, both the C and V proteins must be required for MV to fully circumvent the host IFN response.
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Mann BA, Huang JH, Li P, Chang HC, Slee RB, O'Sullivan A, Mathur A, Yeh N, Klemsz MJ, Brutkiewicz RR, Blum JS, Kaplan MH. Vaccinia virus blocks Stat1-dependent and Stat1-independent gene expression induced by type I and type II interferons. J Interferon Cytokine Res 2008; 28:367-80. [PMID: 18593332 PMCID: PMC2987269 DOI: 10.1089/jir.2007.0113] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2007] [Accepted: 12/14/2007] [Indexed: 12/16/2022] Open
Abstract
Blocking the function of Stat (signal transducer and activator of transcription) proteins, which are critical for antiviral responses, has evolved as a common mechanism for pathogen immune evasion. The poxvirus-encoded phosphatase H1 is critical for viral replication, and may play an additional role in the evasion of host defense by dephosphorylating Stat1 and blocking interferon (IFN)-stimulated innate immune responses. Vaccinia virus (VACV) H1 can inhibit the phosphorylation of the transcription factor Stat1 after IFN-gamma stimulation of epithelial cells, greatly attenuating IFN-induced biological functions. In this study, we demonstrate that VACV infection is capable of inhibiting the phosphorylation of Stat1 and Stat2 after stimulation of fibroblasts or bone marrow-derived macrophages with either type I or type II IFNs, but did not inhibit the activation of Stat3 or Stat5 in either cell type. By using recombinant proteins for in vitro assays, we observe that variola virus H1 is more active than VACV H1, although it has similar selectivity for Stat targets. Differential effects of VACV infection were observed on the induction of IFN-stimulated genes, with complete inhibition of some genes by VACV infection, while others were less affected. Despite the IFN-gamma-induced expression of some genes in VACV-infected cells, IFN-gamma was unable to rescue the VACV-mediated inhibition of MHC class II antigen presentation. Moreover, VACV infection can affect the IFN-induced expression of Stat1-dependent and Stat1-independent genes, suggesting that the virus may target additional IFN-activated pathways. Thus, VACV targets multiple signaling pathways in the evasion of antiviral immune responses.
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Affiliation(s)
- Brandon A. Mann
- Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN
| | - Julia He Huang
- Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN
| | - Ping Li
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN
| | - Hua-Chen Chang
- Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN
| | - Roger B. Slee
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN
| | - Audrey O'Sullivan
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN
| | - Anita Mathur
- Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN
| | - Norman Yeh
- Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN
| | - Michael J. Klemsz
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN
| | - Randy R. Brutkiewicz
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN
| | - Janice S. Blum
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN
| | - Mark H. Kaplan
- Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN
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Sakaguchi T, Kato A, Kiyotani K, Yoshida T, Nagai Y. Studies on the paramyxovirus accessory genes by reverse genetics in the Sendai virus-mouse system. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2008; 84:439-451. [PMID: 19075516 PMCID: PMC3720547 DOI: 10.2183/pjab.84.439] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2008] [Accepted: 10/20/2008] [Indexed: 05/27/2023]
Abstract
Nucleotide sequencing of the entire genomes was completed in the 1980s for most members of the Paramyxoviridae. It then became a new common task with challenge for researchers in the field to establish a system to recover the virus entirely from cDNA, thereby allowing reverse genetics (free manipulation of the viral genome). Using Sendai virus, we established a system of incomparable virus recovery efficiency early on. This technology was then fully exploited in answering a series of long-held questions. In particular, two accessory genes whose functions had remained enigmatic were demonstrated to encode special functions critical in viral in vivo pathogenesis producing fatal pneumonia in mice, although dispensable in virus replication at the in vitro cellular level. Their in vivo functions were found to counteract the two respective facets of the antiviral state induced by interferons and an interferon regulatory factor 3-dependent but yet unknown effector. These achievements appear to have facilitated a scientific trend where the accessory genes are a focus of active investigation in studies on other paramyxoviruses and opened up a new common ground shared between virology and immunology.
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Affiliation(s)
- Takemasa Sakaguchi
- Department of Virology, Graduate School of Biomedical Sciences, Hiroshima University,
Japan
| | - Atsushi Kato
- Department of Virology 3, National Institute of Infectious Diseases,
Japan
| | - Katsuhiro Kiyotani
- Department of Virology, Graduate School of Biomedical Sciences, Hiroshima University,
Japan
| | - Tetsuya Yoshida
- Department of Clinical Engineering, Faculty of Health Sciences, Hiroshima International University,
Japan
| | - Yoshiyuki Nagai
- Center of Research Network for Infectious Diseases, RIKEN,
Japan
- Recipient of
Japan Academy Prize in 2008
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35
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Kumagai Y, Takeuchi O, Kato H, Kumar H, Matsui K, Morii E, Aozasa K, Kawai T, Akira S. Alveolar macrophages are the primary interferon-alpha producer in pulmonary infection with RNA viruses. Immunity 2007; 27:240-52. [PMID: 17723216 DOI: 10.1016/j.immuni.2007.07.013] [Citation(s) in RCA: 306] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2007] [Revised: 05/22/2007] [Accepted: 07/03/2007] [Indexed: 12/23/2022]
Abstract
Type I interferons (IFNs) are critical for antiviral responses. Here we generated a knockin mouse in which green fluorescence protein (GFP) was expressed under the control of the Ifna6 promoter. Virus-induced expression of GFP recapitulated various IFN-alpha subtypes. Systemic infection of the mice with Newcastle disease virus (NDV) increased GFP(+) plasmacytoid dendritic cells (pDCs) via the Toll-like receptor system, and GFP(+) conventional dendritic cells (cDCs) and macrophages via the RIG-I-like helicase system. By contrast, lung infection with NDV led to IFN-alpha production in alveolar macrophages (AMs) and cDCs, but not in pDCs. Specific depletion of AMs caused a marked defect in the initial viral elimination in the lung. pDCs produced IFN-alpha in the absence of AM-mediated viral recognition, suggesting that pDCs function when the first defense line is broken. Thus, AMs act as a type I IFN producer that is important for the initial responses to viral infection in the lung.
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Affiliation(s)
- Yutaro Kumagai
- Department of Host Defense, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan
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36
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Thakur CS, Jha BK, Dong B, Das Gupta J, Silverman KM, Mao H, Sawai H, Nakamura AO, Banerjee AK, Gudkov A, Silverman RH. Small-molecule activators of RNase L with broad-spectrum antiviral activity. Proc Natl Acad Sci U S A 2007; 104:9585-90. [PMID: 17535916 PMCID: PMC1877983 DOI: 10.1073/pnas.0700590104] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2007] [Indexed: 11/18/2022] Open
Abstract
RNase L, a principal mediator of innate immunity to viral infections in higher vertebrates, is required for a complete IFN antiviral response against certain RNA stranded viruses. dsRNA produced during viral infections activates IFN-inducible synthetases that produce 5'-phosphorylated, 2',5'-oligoadenylates (2-5A) from ATP. 2-5A activates RNase L in a wide range of different mammalian cell types, thus blocking viral replication. However, 2-5A has unfavorable pharmacologic properties; it is rapidly degraded, does not transit cell membranes, and leads to apoptosis. To obtain activators of RNase L with improved drug-like properties, high-throughput screening was performed on chemical libraries by using fluorescence resonance energy transfer. Seven compounds were obtained that activated RNase L at micromolar concentrations, and structure-activity relationship studies resulted in identification of an additional four active compounds. Two lead compounds were shown to have a similar mechanistic path toward RNase L activation as the natural activator 2-5A. The compounds bound to the 2-5A-binding domain of RNase L (as determined by surface plasmon resonance and confirmed by computational docking), and the compounds induced RNase L dimerization and activation. Interestingly, the low-molecular-weight activators of RNase L had broad-spectrum antiviral activity against diverse types of RNA viruses, including the human pathogen human parainfluenza virus type 3, yet these compounds by themselves were not cytotoxic at the effective concentrations. Therefore, these RNase L activators are prototypes for a previously uncharacterized class of broad-spectrum antiviral agents.
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Affiliation(s)
- Chandar S. Thakur
- Departments of *Cancer Biology and
- Department of Chemistry, Cleveland State University, Euclid Avenue at East 24th Street, Cleveland, OH 44115; and
| | | | | | | | | | - Hongxia Mao
- Molecular Genetics, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195
| | - Hiro Sawai
- Department of Applied Chemistry, Faculty of Engineering, Gunma University, Kiryu, Gunma 376-8515, Japan
| | - Akiko O. Nakamura
- Department of Applied Chemistry, Faculty of Engineering, Gunma University, Kiryu, Gunma 376-8515, Japan
| | - Amiya K. Banerjee
- Molecular Genetics, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195
| | - Andrei Gudkov
- Molecular Genetics, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195
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