1
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Yoneyama M, Kato H, Fujita T. Physiological functions of RIG-I-like receptors. Immunity 2024; 57:731-751. [PMID: 38599168 DOI: 10.1016/j.immuni.2024.03.003] [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] [Received: 01/20/2024] [Revised: 02/19/2024] [Accepted: 03/04/2024] [Indexed: 04/12/2024]
Abstract
RIG-I-like receptors (RLRs) are crucial for pathogen detection and triggering immune responses and have immense physiological importance. In this review, we first summarize the interferon system and innate immunity, which constitute primary and secondary responses. Next, the molecular structure of RLRs and the mechanism of sensing non-self RNA are described. Usually, self RNA is refractory to the RLR; however, there are underlying host mechanisms that prevent immune reactions. Studies have revealed that the regulatory mechanisms of RLRs involve covalent molecular modifications, association with regulatory factors, and subcellular localization. Viruses have evolved to acquire antagonistic RLR functions to escape the host immune reactions. Finally, the pathologies caused by the malfunction of RLR signaling are described.
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Affiliation(s)
- Mitsutoshi Yoneyama
- Division of Molecular Immunology, Medical Mycology Research Center, Chiba University, Chiba, Japan; Division of Pandemic and Post-disaster Infectious Diseases, Research Institute of Disaster Medicine, Chiba University, Chiba, Japan
| | - Hiroki Kato
- Institute of Cardiovascular Immunology, Medical Faculty, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Takashi Fujita
- Institute of Cardiovascular Immunology, Medical Faculty, University Hospital Bonn, University of Bonn, Bonn, Germany; Laboratory of Regulatory Information, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan.
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2
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Kitagawa Y, Tsukamoto T, Itoh M, Gotoh B. Middle East respiratory syndrome coronavirus
ORF4b
protein inhibits
TLR7
‐ and
TLR9
‐dependent alpha interferon induction. FEBS Lett 2022; 596:2538-2554. [DOI: 10.1002/1873-3468.14486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 08/14/2022] [Accepted: 08/18/2022] [Indexed: 11/07/2022]
Affiliation(s)
- Yoshinori Kitagawa
- Division of Microbiology and Infectious Diseases, Department of Pathology Shiga University of Medical Science, Seta, Otsu Shiga 520‐2192 Japan
| | - Takumi Tsukamoto
- Department of Microbiology, Faculty of Bio‐Science Nagahama institute of Bio‐Science and Technology Nagahama Shiga 526‐0829 Japan
| | - Masae Itoh
- Department of Microbiology, Faculty of Bio‐Science Nagahama institute of Bio‐Science and Technology Nagahama Shiga 526‐0829 Japan
| | - Bin Gotoh
- Division of Microbiology and Infectious Diseases, Department of Pathology Shiga University of Medical Science, Seta, Otsu Shiga 520‐2192 Japan
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3
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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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4
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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: 11] [Impact Index Per Article: 5.5] [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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5
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Iwasaki M. [Molecular basis for the multiplication of negative-strand RNA viruses: basic research and potential applications in vaccine development]. Uirusu 2022; 72:67-78. [PMID: 37899232 DOI: 10.2222/jsv.72.67] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2023]
Abstract
Viruses achieve their efficient reproduction by utilizing their limited components (nucleic acids, lipids, and proteins) and host cell machineries. A detailed understanding of virus-virus and virus-host interactions will lead to the elucidation of mechanisms underlying viral pathogenesis and the development of novel medical countermeasures. We elucidated the details of several such interactions and their roles in the multiplication of negative-strand RNA viruses, measles virus, and Lassa virus. These discoveries were harnessed to develop a novel genetic approach for the generation of live-attenuated vaccine candidates with a well-defined molecular mechanism of attenuation. This article describes our findings.
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Affiliation(s)
- Masaharu Iwasaki
- Laboratory of Emerging Viral Diseases, International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
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6
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Sakuma R, Morita N, Tanaka Y, Koide N, Komatsu T. Sendai virus C protein affects macrophage function, which plays a critical role in modulating disease severity during Sendai virus infection in mice. Microbiol Immunol 2021; 66:124-134. [PMID: 34859490 DOI: 10.1111/1348-0421.12956] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 10/28/2021] [Accepted: 11/24/2021] [Indexed: 11/29/2022]
Abstract
Sendai virus (SeV) accessory protein C limits the generation of double-stranded RNAs, defective interfering RNAs, or both, during viral transcription and replication, thereby limiting interferon-β production. Our recent in vitro analyses on murine macrophage cell lines demonstrated that this protein also contributes to restricting macrophage function, including the production of nitric oxide (NO) and inflammatory cytokines in addition to interferon-β, in infected macrophages. This study showed that depletion of airway macrophages by clodronate-loaded liposomes led to the development of severe viral pneumonia in recombinant C gene-knockout SeV (SeV∆C)-infected mice, but did not modulate disease severity in wild-type SeV-infected mice. Furthermore, the severe disease observed in macrophage-depleted, SeV∆C-infected mice was associated with exacerbated virus replication in the lungs, leading to severe airway inflammation and pulmonary edema, indicating lung injury. These results suggested that the antimacrophage activity of SeV C protein might play a critical role in modulating lung injury and associated diseases caused by SeV.
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Affiliation(s)
- Ryusuke Sakuma
- Department of Microbiology and Immunology, Aichi Medical University School of Medicine, Aichi, Japan
| | - Naoko Morita
- Department of Microbiology and Immunology, Aichi Medical University School of Medicine, Aichi, Japan
| | - Yukie Tanaka
- Department of Molecular Biology and Chemistry, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - Naoki Koide
- Department of Microbiology and Immunology, Aichi Medical University School of Medicine, Aichi, Japan
| | - Takayuki Komatsu
- Department of Microbiology and Immunology, Aichi Medical University School of Medicine, Aichi, Japan
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7
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Structural Insight into the Interaction of Sendai Virus C Protein with Alix To Stimulate Viral Budding. J Virol 2021; 95:e0081521. [PMID: 34287046 DOI: 10.1128/jvi.00815-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Sendai virus (SeV), belonging to the Respirovirus genus of the family Paramyxoviridae, harbors an accessory protein, named C protein, which facilitates the viral pathogenicity in mice. In addition, the C protein is known to stimulate the budding of virus-like particles through the binding to the host ALG-2 interacting protein X (Alix), a component of the endosomal sorting complexes required for transport (ESCRT) machinery. However, siRNA-mediated gene knockdown studies suggested that neither Alix nor C protein are related to the SeV budding. In the present study, we determined the crystal structure of a complex comprising of the C-terminal half of the C protein (Y3) and the Bro1 domain of Alix at a resolution of 2.2 Å, to investigate the role of the association in the SeV budding. The structure revealed that a novel consensus sequence, LxxW, which is conserved among the Respirovirus C proteins, is important for the Alix-binding. SeV possessing a mutated C protein with a reduced Alix-binding affinity showed impaired virus production, which correlated with the binding affinity. Infectivity analysis showed a 160-fold reduction at 12 h post-infection compared with non-mutated virus, while C protein competes with CHMP4, one subunit of the ESCRT-III complex, on the binding to Alix. Altogether, these results highlight the critical role of C protein in the SeV budding. IMPORTANCE Human parainfluenza virus type I (hPIV1) is a respiratory pathogen affecting in young children, immunocompromised patients, and the elderly, with no available vaccines or antiviral drugs. Sendai virus (SeV), a murine counterpart of hPIV1, has been extensively studied to determine the molecular and biological properties of hPIV1. These viruses possess a multifunctional accessory protein, C protein, which is essential for stimulating the viral reproduction, however, its role in budding remains controversial. In the present study, the crystal structure of the C-terminal half of the SeV C protein associated with the Bro1 domain of Alix, a component of a cell membrane modulating machinery ESCRT, was elucidated. Based on the structure, we designed mutated C proteins with different binding affinity to Alix, and showed that the interaction between C and Alix is vital for the viral budding. These findings provide new insights into the development of a new antiviral drugs against hPIV1.
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8
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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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9
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Multiple Pathways To Avoid Beta Interferon Sensitivity of HIV-1 by Mutations in Capsid. J Virol 2019; 93:JVI.00986-19. [PMID: 31511380 PMCID: PMC6854511 DOI: 10.1128/jvi.00986-19] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 08/28/2019] [Indexed: 12/11/2022] Open
Abstract
HIV-1 infection causes robust innate immune activation in virus-infected patients. This immune activation is characterized by elevated levels of type I interferons (IFNs), which can block HIV-1 replication. Recent studies suggest that the viral capsid protein (CA) is a determinant for the sensitivity of HIV-1 to IFN-mediated restriction. Specifically, it was reported that the loss of CA interactions with CPSF6 or CypA leads to higher IFN sensitivity. However, the molecular mechanism of CA adaptation to IFN sensitivity is largely unknown. Here, we experimentally evolved an IFN-β-hypersensitive CA mutant which showed decreased binding to CPSF6 and CypA in IFN-β-treated cells. The CA mutations that emerged from this adaptation indeed conferred IFN-β resistance. Our genetic assays suggest a limited contribution of known host factors to IFN-β resistance. Strikingly, one of these mutations accelerated the kinetics of reverse transcription and uncoating. Our findings suggest that HIV-1 selected multiple, known host factor-independent pathways to avoid IFN-β-mediated restriction. Type I interferons (IFNs), including alpha IFN (IFN-α) and IFN-β, potently suppress HIV-1 replication by upregulating IFN-stimulated genes (ISGs). The viral capsid protein (CA) partly determines the sensitivity of HIV-1 to IFNs. However, it remains to be determined whether CA-related functions, including utilization of known host factors, reverse transcription, and uncoating, affect the sensitivity of HIV-1 to IFN-mediated restriction. Recently, we identified an HIV-1 CA variant that is unusually sensitive to IFNs. This variant, called the RGDA/Q112D virus, contains multiple mutations in CA: H87R, A88G, P90D, P93A, and Q112D. To investigate how an IFN-hypersensitive virus can evolve to overcome IFN-β-mediated blocks targeting the viral capsid, we adapted the RGDA/Q112D virus in IFN-β-treated cells. We successfully isolated IFN-β-resistant viruses which contained either a single Q4R substitution or the double amino acid change G94D/G116R. These two IFN-β resistance mutations variably changed the sensitivity of CA binding to human myxovirus resistance B (MxB), cleavage and polyadenylation specificity factor 6 (CPSF6), and cyclophilin A (CypA), indicating that the observed loss of sensitivity was not due to interactions with these known host CA-interacting factors. In contrast, the two mutations apparently functioned through distinct mechanisms. The Q4R mutation dramatically accelerated the kinetics of reverse transcription and initiation of uncoating of the RGDA/Q112D virus in the presence or absence of IFN-β, whereas the G94D/G116R mutations affected reverse transcription only in the presence of IFN-β, most consistent with a mechanism of the disruption of binding to an unknown IFN-β-regulated host factor. These results suggest that HIV-1 can exploit multiple, known host factor-independent pathways to avoid IFN-β-mediated restriction by altering capsid sequences and subsequent biological properties. IMPORTANCE HIV-1 infection causes robust innate immune activation in virus-infected patients. This immune activation is characterized by elevated levels of type I interferons (IFNs), which can block HIV-1 replication. Recent studies suggest that the viral capsid protein (CA) is a determinant for the sensitivity of HIV-1 to IFN-mediated restriction. Specifically, it was reported that the loss of CA interactions with CPSF6 or CypA leads to higher IFN sensitivity. However, the molecular mechanism of CA adaptation to IFN sensitivity is largely unknown. Here, we experimentally evolved an IFN-β-hypersensitive CA mutant which showed decreased binding to CPSF6 and CypA in IFN-β-treated cells. The CA mutations that emerged from this adaptation indeed conferred IFN-β resistance. Our genetic assays suggest a limited contribution of known host factors to IFN-β resistance. Strikingly, one of these mutations accelerated the kinetics of reverse transcription and uncoating. Our findings suggest that HIV-1 selected multiple, known host factor-independent pathways to avoid IFN-β-mediated restriction.
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10
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The R2TP complex regulates paramyxovirus RNA synthesis. PLoS Pathog 2019; 15:e1007749. [PMID: 31121004 PMCID: PMC6532945 DOI: 10.1371/journal.ppat.1007749] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 04/05/2019] [Indexed: 12/12/2022] Open
Abstract
The regulation of paramyxovirus RNA synthesis by host proteins is poorly understood. Here, we identified a novel regulation mechanism of paramyxovirus RNA synthesis by the Hsp90 co-chaperone R2TP complex. We showed that the R2TP complex interacted with the paramyxovirus polymerase L protein and that silencing of the R2TP complex led to uncontrolled upregulation of mumps virus (MuV) gene transcription but not genome replication. Regulation by the R2TP complex was critical for MuV replication and evasion of host innate immune responses. The R2TP complex also regulated measles virus (MeV) RNA synthesis, but its function was inhibitory and not beneficial to MeV, as MeV evaded host innate immune responses in the absence of the R2TP complex. The identification of the R2TP complex as a critical host factor sheds new light on the regulation of paramyxovirus RNA synthesis. The family Paramyxoviridae includes several important human and animal pathogens such as mumps virus (MuV) and measles virus (MeV). Paramyxovirus RNA synthesis is strictly regulated by both viral and host proteins. In this study, we identified the R2TP complex as a novel host factor regulating paramyxovirus RNA synthesis. The R2TP complex is a Hsp90 co-chaperone and is involved in Hsp90-mediated assembly of large protein complexes. We showed that the R2TP complex precisely regulated MuV transcription by interacting with the polymerase L protein. This regulation was critical for MuV evasion of host innate immune responses and for viral replication. We also showed that the R2TP complex regulated MeV RNA synthesis, but that its function was inhibitory and not beneficial to MeV. Our findings support a novel regulation mechanism of paramyxovirus RNA synthesis that is directly relevant to its biology and life cycle, and provide the first evidence linking the R2TP complex to defense against viral infection.
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11
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Odkhuu E, Komatsu T, Koide N, Naiki Y, Takeuchi K, Tanaka Y, Tsolmongyn B, Jambalganiin U, Morita N, Yoshida T, Gotoh B, Yokochi T. Sendai virus C protein limits NO production in infected RAW264.7 macrophages. Innate Immun 2018; 24:430-438. [PMID: 30189760 PMCID: PMC6830875 DOI: 10.1177/1753425918796619] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
To suppress virus multiplication, infected macrophages produce NO. However, it
remains unclear how infecting viruses then overcome NO challenge. In the present
study, we report the effects of accessory protein C from Sendai virus (SeV), a
prototypical paramyxovirus, on NO output. We found that in RAW264.7 murine
macrophages, a mutant SeV without C protein (4C(–)) significantly enhanced
inducible NO synthase (iNOS) expression and subsequent NO production compared to
wild type SeV (wtSeV). SeV 4C(-) infection caused marked production of IFN-β,
which is involved in induction of iNOS expression via the JAK-STAT pathway.
Addition of anti-IFN-β Ab, however, resulted in only marginal suppression of NO
production. In contrast, NF-κB, a primarily important factor for transcription
of the iNOS gene, was also activated by 4C(–) infection but not
wtSeV infection. Induction of NO production and iNOS expression by 4C(–) was
significantly suppressed in cells constitutively expressing influenza virus NS1
protein that can sequester double-stranded (ds)RNA, which triggers activation of
signaling pathways leading to activation of NF-κB and IRF3. Therefore, C protein
appears to suppress NF-κB activation to inhibit iNOS expression and subsequent
NO production, possibly by limiting dsRNA generation in the context of viral
infection.
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Affiliation(s)
- Erdenezaya Odkhuu
- 1 Department of Anatomy, Mongolian National University of Medical Sciences, Mongolia
| | - Takayuki Komatsu
- 2 Department of Microbiology and Immunology, School of Medicine, Aichi Medical University, Japan
| | - Naoki Koide
- 2 Department of Microbiology and Immunology, School of Medicine, Aichi Medical University, Japan
| | - Yoshikazu Naiki
- 2 Department of Microbiology and Immunology, School of Medicine, Aichi Medical University, Japan
| | - Kenji Takeuchi
- 3 Department of Genome Science and Microbiology, Faculty of Medical Sciences, University of Fukui, Japan
| | - Yukie Tanaka
- 4 Department of Molecular Biology and Chemistry, Faculty of Medical Sciences, University of Fukui, Japan
| | - Bilegtsaikhan Tsolmongyn
- 2 Department of Microbiology and Immunology, School of Medicine, Aichi Medical University, Japan
| | | | - Naoko Morita
- 2 Department of Microbiology and Immunology, School of Medicine, Aichi Medical University, Japan
| | - Tomoaki Yoshida
- 2 Department of Microbiology and Immunology, School of Medicine, Aichi Medical University, Japan
| | - Bin Gotoh
- 5 Division of Microbiology and Infectious Diseases, Department of Pathology, Shiga University of Medical Science, Japan
| | - Takashi Yokochi
- 2 Department of Microbiology and Immunology, School of Medicine, Aichi Medical University, Japan
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12
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Kitagawa Y, Sakai M, Shimojima M, Saijo M, Itoh M, Gotoh B. Nonstructural protein of severe fever with thrombocytopenia syndrome phlebovirus targets STAT2 and not STAT1 to inhibit type I interferon-stimulated JAK-STAT signaling. Microbes Infect 2018; 20:360-368. [PMID: 29886262 DOI: 10.1016/j.micinf.2018.05.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 05/30/2018] [Accepted: 05/31/2018] [Indexed: 01/17/2023]
Abstract
The nonstructural protein NSs of severe fever with thrombocytopenia syndrome phlebovirus blocks type I interferon (IFN)-stimulated JAK-STAT signaling. However, there is continuing controversy as to whether NSs targets STAT1 or STAT2 or both for this blockade. The present study was designed to gain a further understanding of the blockade mechanism. Immunoprecipitation experiments revealed a stronger interaction of NSs with STAT2 than with any other component constituting the JAK-STAT pathway. Expression of NSs resulted in the formation of cytoplasmic inclusion bodies (IBs), and affected cytoplasmic distribution of STAT2. STAT2 was relocated to NSs-induced IBs. Consequently, NSs inhibited IFN-α-stimulated tyrosine phosphorylation and nuclear translocation of STAT2. These inhibitory effects as well as the signaling blockade activity were not observed in NSs mutant proteins lacking the STAT2-binding ability. In contrast, NSs affected neither subcellular distribution nor phosphorylation of STAT1 in response to IFN-α and IFN-γ, demonstrating that NSs has little physical and functional interactions with STAT1. Taken together, these results suggest that NSs sequesters STAT2 into NSs-induced IBs, thereby blocking type I IFN JAK-STAT signaling.
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Affiliation(s)
- Yoshinori Kitagawa
- Division of Microbiology and Infectious Diseases, Department of Pathology, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga, 520-2192, Japan
| | - Madoka Sakai
- Division of Microbiology and Infectious Diseases, Department of Pathology, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga, 520-2192, Japan; Department of Microbiology, Faculty of Bio-Science, Nagahama Institute of Bio-Science and Technology, 1266 Tamura-cho, Nagahama, Shiga, 526-0829, Japan
| | - Masayuki Shimojima
- Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo, 162-8640, Japan
| | - Masayuki Saijo
- Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo, 162-8640, Japan
| | - Masae Itoh
- Department of Microbiology, Faculty of Bio-Science, Nagahama Institute of Bio-Science and Technology, 1266 Tamura-cho, Nagahama, Shiga, 526-0829, Japan
| | - Bin Gotoh
- Division of Microbiology and Infectious Diseases, Department of Pathology, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga, 520-2192, Japan.
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13
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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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14
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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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15
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Novel Strategy to Control Transgene Expression Mediated by a Sendai Virus-Based Vector Using a Nonstructural C Protein and Endogenous MicroRNAs. PLoS One 2016; 11:e0164720. [PMID: 27764162 PMCID: PMC5072705 DOI: 10.1371/journal.pone.0164720] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 09/29/2016] [Indexed: 12/30/2022] Open
Abstract
Tissue-specific control of gene expression is an invaluable tool for studying various biological processes and medical applications. Efficient regulatory systems have been utilized to control transgene expression in various types of DNA viral or integrating viral vectors. However, existing regulatory systems are difficult to transfer into negative-strand RNA virus vector platforms because of significant differences in their transcriptional machineries. In this study, we developed a novel strategy for regulating transgene expression mediated by a cytoplasmic RNA vector based on a replication-defective and persistent Sendai virus (SeVdp). Because of the capacity of Sendai virus (SeV) nonstructural C proteins to specifically inhibit viral RNA synthesis, overexpression of C protein significantly reduced transgene expression mediated by SeVdp vectors. We found that SeV C overexpression concomitantly reduced SeVdp mRNA levels and genomic RNA synthesis. To control C expression, target sequences for an endogenous microRNA were incorporated into the 3′ untranslated region of the C genes. Incorporation of target sequences for miR-21 into the SeVdp vector restored transgene expression in HeLa cells by decreasing C expression. Furthermore, the SeVdp vector containing target sequences for let-7a enabled cell-specific control of transgene expression in human fibroblasts and induced pluripotent stem cells. Our findings demonstrate that SeV C can be used as an effective regulator for controlling transgene expression. This strategy will contribute to efficient and less toxic SeVdp-mediated gene transfer in various biological applications.
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16
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Fleming SB. Viral Inhibition of the IFN-Induced JAK/STAT Signalling Pathway: Development of Live Attenuated Vaccines by Mutation of Viral-Encoded IFN-Antagonists. Vaccines (Basel) 2016; 4:vaccines4030023. [PMID: 27367734 PMCID: PMC5041017 DOI: 10.3390/vaccines4030023] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 06/20/2016] [Accepted: 06/21/2016] [Indexed: 12/27/2022] Open
Abstract
The interferon (IFN) induced anti-viral response is amongst the earliest and most potent of the innate responses to fight viral infection. The induction of the Janus kinase/signal transducer and activation of transcription (JAK/STAT) signalling pathway by IFNs leads to the upregulation of hundreds of interferon stimulated genes (ISGs) for which, many have the ability to rapidly kill viruses within infected cells. During the long course of evolution, viruses have evolved an extraordinary range of strategies to counteract the host immune responses in particular by targeting the JAK/STAT signalling pathway. Understanding how the IFN system is inhibited has provided critical insights into viral virulence and pathogenesis. Moreover, identification of factors encoded by viruses that modulate the JAK/STAT pathway has opened up opportunities to create new anti-viral drugs and rationally attenuated new generation vaccines, particularly for RNA viruses, by reverse genetics.
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Affiliation(s)
- Stephen B Fleming
- Department of Microbiology and Immunology, University of Otago, 720 Cumberland St, Dunedin 9016, New Zealand.
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17
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Bracken MK, Hayes BC, Kandel SR, Scott-Shemon D, Ackerson L, Hoffman MA. Viral protein requirements for assembly and release of human parainfluenza virus type 3 virus-like particles. J Gen Virol 2016; 97:1305-1310. [PMID: 26960133 DOI: 10.1099/jgv.0.000449] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
To understand the roles of human parainfluenza virus 3 (HPIV3) proteins in assembly and release, viral proteins were expressed individually and in combination in 293T cells. Expression of the matrix (M) protein triggered release of enveloped, matrix-containing virus-like particles (VLPs) from cells. When M was co-expressed with the nucleocapsid (N), fusion (F) or haemagglutinin-neuraminidase (HN) proteins, VLPs that contained M+N, M+F and M+HN, respectively, were generated, suggesting that M can independently interact with each protein to facilitate assembly and release. Additionally, expression of N protein enabled incorporation of the phosphoprotein (P) into VLPs, likely due to known N-P interactions. Finally, the HPIV3 C protein did not enhance VLP release, in contrast to observations with the related Sendai virus. These findings reinforce the central importance of the M protein in virus assembly and release, but also illustrate the variable roles of other paramyxovirus proteins during these processes.
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Affiliation(s)
- Megan K Bracken
- Department of Microbiology, University of Wisconsin - La Crosse, 1725 State St, La Crosse, WI 54601, USA
| | - Brandon C Hayes
- Department of Microbiology, University of Wisconsin - La Crosse, 1725 State St, La Crosse, WI 54601, USA
| | - Suresh R Kandel
- Department of Microbiology, University of Wisconsin - La Crosse, 1725 State St, La Crosse, WI 54601, USA
| | - Deja Scott-Shemon
- Department of Microbiology, University of Wisconsin - La Crosse, 1725 State St, La Crosse, WI 54601, USA
| | - Larissa Ackerson
- Department of Microbiology, University of Wisconsin - La Crosse, 1725 State St, La Crosse, WI 54601, USA
| | - Michael A Hoffman
- Department of Microbiology, University of Wisconsin - La Crosse, 1725 State St, La Crosse, WI 54601, USA
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18
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Audsley MD, Marsh GA, Lieu KG, Tachedjian M, Joubert DA, Wang LF, Jans DA, Moseley GW. The immune evasion function of J and Beilong virus V proteins is distinct from that of other paramyxoviruses, consistent with their inclusion in the proposed genus Jeilongvirus. J Gen Virol 2015; 97:581-592. [PMID: 26703878 DOI: 10.1099/jgv.0.000388] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
IFN-antagonist function is a major determinant of pathogenicity and cross-species infection by viruses, but remains poorly defined for many potentially zoonotic viruses resident in animal species. The paramyxovirus family contains several zoonotic viruses, including highly pathogenic viruses such as Nipah virus and Hendra virus, and an increasing number of largely uncharacterized animal viruses. Here, we report the characterization of IFN antagonism by the rodent viruses J virus (JPV) and Beilong virus (BeiPV) of the proposed genus Jeilongvirus of the paramyxoviruses. Infection of cells by JPV and BeiPV was found to inhibit IFN-activated nuclear translocation of signal transducer and activator of transcription 1 (STAT1). However, in contrast to most other paramyxoviruses, the JPV and BeiPV V proteins did not interact with or inhibit signalling by STAT1 or STAT2, suggesting that JPV/BeiPV use an atypical V protein-independent strategy to target STATs, consistent with their inclusion in a separate genus. Nevertheless, the V proteins of both viruses interacted with melanoma differentiation-associated protein 5 (MDA5) and robustly inhibited MDA5-dependent activation of the IFN-β promoter. This supports a growing body of evidence that MDA5 is a universal target of paramyxovirus V proteins, such that the V-MDA5 interaction represents a potential target for broad-spectrum antiviral approaches.
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Affiliation(s)
- Michelle D Audsley
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Glenn A Marsh
- CSIRO Health and Biosecurity, Australian Animal Health Laboratory (AAHL), Geelong, Victoria 3220, Australia
| | - Kim G Lieu
- Department of Biochemistry and Molecular Biology, BIO21 Molecular Science and Biotechnology Institute, University of Melbourne, Victoria 3010, Australia
| | - Mary Tachedjian
- CSIRO Health and Biosecurity, Australian Animal Health Laboratory (AAHL), Geelong, Victoria 3220, Australia
| | - D Albert Joubert
- CSIRO Health and Biosecurity, Australian Animal Health Laboratory (AAHL), Geelong, Victoria 3220, Australia
| | - Lin-Fa Wang
- CSIRO Health and Biosecurity, Australian Animal Health Laboratory (AAHL), Geelong, Victoria 3220, Australia.,Program in Emerging Infectious Diseases, Duke-NUS Graduate Medical School, 169857Singapore
| | - David A Jans
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Gregory W Moseley
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia.,Department of Biochemistry and Molecular Biology, BIO21 Molecular Science and Biotechnology Institute, University of Melbourne, Victoria 3010, Australia
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19
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Structural Basis of the Inhibition of STAT1 Activity by Sendai Virus C Protein. J Virol 2015; 89:11487-99. [PMID: 26339056 DOI: 10.1128/jvi.01887-15] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 08/28/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Sendai virus (SeV) C protein inhibits the signal transduction pathways of interferon alpha/beta (IFN-α/β) and IFN-γ by binding to the N-terminal domain of STAT1 (STAT1ND), thereby allowing SeV to escape from host innate immunity. Here we determined the crystal structure of STAT1ND associated with the C-terminal half of the C protein (Y3 [amino acids 99 to 204]) at a resolution of 2.0 Å. This showed that two molecules of Y3 symmetrically bind to each niche created between two molecules of the STAT1ND dimer. Molecular modeling suggested that an antiparallel form of the full-length STAT1 dimer can bind only one Y3 molecule and that a parallel form can bind two Y3 molecules. Affinity analysis demonstrated anticooperative binding of two Y3 molecules with the STAT1 dimer, which is consistent with the hypothetical model that the second Y3 molecule can only target the STAT1 dimer in a parallel form. STAT1 with excess amounts of Y3 was prone to inhibit the dephosphorylation at Tyr(701) by a phosphatase. In an electrophoretic mobility shift assay, tyrosine-phosphorylated STAT1 (pY-STAT1) with Y3 associated with the γ-activated sequence, probably as high-molecular-weight complexes (HMWCs), which may account for partial inhibition of a reporter assay from IFN-γ by Y3. Our study suggests that the full-length C protein interferes with the domain arrangement of the STAT1 dimer, leading to the accumulation of pY-STAT1 and the formation of HMWCs. In addition, we discuss the mechanism by which phosphorylation of STAT2 is inhibited in the presence of the C protein after stimulation by IFN-α/β. IMPORTANCE Sendai virus, a paramyxovirus that causes respiratory diseases in rodents, possesses the C protein, which inhibits the signal transduction pathways of interferon alpha/beta (IFN-α/β) and IFN-γ by binding to the transcription factor STAT1. In virus-infected cells, phosphorylation of STAT1 at the Tyr(701) residue is potently enhanced, although transcription by STAT1 is inert. Here, we determined the crystal structure of the N-terminal domain of STAT1 associated with the C-terminal half of the C protein. Molecular modeling and experiments suggested that the two C proteins bind to and stabilize the parallel form of the STAT1 dimer, which are likely to be phosphorylated at Tyr(701), further inducing high-molecular-weight complex formation and inhibition of transcription by IFN-γ. We also discuss the possible mechanism of inhibition of the IFN-α/β pathways by the C protein. This is the first structural report of the C protein, suggesting a mechanism of evasion of the paramyxovirus from innate immunity.
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20
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Odkhuu E, Komatsu T, Naiki Y, Koide N, Yokochi T. Sendai virus C protein inhibits lipopolysaccharide-induced nitric oxide production through impairing interferon-β signaling. Int Immunopharmacol 2014; 23:267-72. [PMID: 25242386 DOI: 10.1016/j.intimp.2014.09.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Revised: 09/08/2014] [Accepted: 09/08/2014] [Indexed: 12/29/2022]
Abstract
The effect of Sendai virus (SeV) C protein on lipopolysaccharide (LPS)-induced nitric oxide (NO) production was examined using RAW 264.7 macrophage cells. Infection of SeV inhibited LPS-induced NO production via downregulating the expression of an inducible NO synthase protein (iNOS). On the other hand, C gene-knockout 4C(-) SeV inhibited neither NO production nor iNOS expression. Wild type and 4C(-) SeV did not affect LPS-induced production of tumor necrosis factor-α and interleukin-6, and further LPS-induced activation of nuclear factor (NF)-κB and mitogen-activated protein kinases. Although wild type and 4C(-) SeV did not inhibit LPS-induced interferon (IFN)-β production, wild type SeV but not 4C(-) SeV inhibited the activation of STAT1/2 in the IFN-β signaling. SeV C protein inhibited LPS-induced iNOS expression and NO production. C protein inhibited the promotor activation of IFN-β and IFN-sensitive response element (ISRE) in response to LPS whereas the C mutant protein CF170S, which lacks the ability to block the STAT activation, did not inhibit it. Taken together, SeV C protein was suggested to inhibit LPS-induced NO production through impairing IFN-β signaling.
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Affiliation(s)
- Erdenezaya Odkhuu
- Department of Microbiology and Immunology, Aichi Medical University School of Medicine, Nagakute, Aichi 480-1195, Japan; Department of Anatomy, Mongolian National University of Medical Sciences, Ulaanbaatar 210648, Mongolia
| | - Takayuki Komatsu
- Department of Microbiology and Immunology, Aichi Medical University School of Medicine, Nagakute, Aichi 480-1195, Japan
| | - Yoshikazu Naiki
- Department of Microbiology and Immunology, Aichi Medical University School of Medicine, Nagakute, Aichi 480-1195, Japan
| | - Naoki Koide
- Department of Microbiology and Immunology, Aichi Medical University School of Medicine, Nagakute, Aichi 480-1195, Japan
| | - Takashi Yokochi
- Department of Microbiology and Immunology, Aichi Medical University School of Medicine, Nagakute, Aichi 480-1195, Japan.
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21
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Zimmermann M, Armeanu-Ebinger S, Bossow S, Lampe J, Smirnow I, Schenk A, Lange S, Weiss TS, Neubert W, Lauer UM, Bitzer M. Attenuated and protease-profile modified sendai virus vectors as a new tool for virotherapy of solid tumors. PLoS One 2014; 9:e90508. [PMID: 24598703 PMCID: PMC3944018 DOI: 10.1371/journal.pone.0090508] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 02/01/2014] [Indexed: 12/03/2022] Open
Abstract
Multiple types of oncolytic viruses are currently under investigation in clinical trials. To optimize therapeutic outcomes it is believed that the plethora of different tumor types will require a diversity of different virus types. Sendai virus (SeV), a murine parainfluenza virus, displays a broad host range, enters cells within minutes and already has been applied safely as a gene transfer vector in gene therapy patients. However, SeV spreading naturally is abrogated in human cells due to a lack of virus activating proteases. To enable oncolytic applications of SeV we here engineered a set of novel recombinant vectors by a two-step approach: (i) introduction of an ubiquitously recognized cleavage-motive into SeV fusion protein now enabling continuous spreading in human tissues, and (ii) profound attenuation of these rSeV by the knockout of viral immune modulating accessory proteins. When employing human hepatoma cell lines, newly generated SeV variants now reached high titers and induced a profound tumor cell lysis. In contrast, virus release from untransformed human fibroblasts or primary human hepatocytes was found to be reduced by about three log steps in a time course experiment which enables the cumulation of kinetic differences of the distinct phases of viral replication such as primary target cell infection, target cell replication, and progeny virus particle release. In a hepatoma xenograft animal model we found a tumor-specific spreading of our novel recombinant SeV vectors without evidence of biodistribution into non-malignant tissues. In conclusion, we successfully developed novel tumor-selective oncolytic rSeV vectors, constituting a new tool for virotherapy of solid tumors being ready for further preclinical and clinical development to address distinct tumor types.
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Affiliation(s)
- Martina Zimmermann
- Department of Internal Medicine I, Medical University Hospital, Tübingen, Germany
| | | | - Sascha Bossow
- Department of Translational Oncology, National Center for Tumor Diseases, Heidelberg, Germany
| | - Johanna Lampe
- Institute for Molecular Medicine Finland FIMM, Helsinki, Finland
| | - Irina Smirnow
- Department of Internal Medicine I, Medical University Hospital, Tübingen, Germany
| | - Andrea Schenk
- Department of Internal Medicine I, Medical University Hospital, Tübingen, Germany
| | - Sebastian Lange
- Medizinische Klinik, Klinikum rechts der Isar, Technische Universität, München, Germany
| | - Thomas S. Weiss
- Center for Liver Cell Research, Department of Pediatrics and Adolescent Medicine, University of Regensburg Hospital, Regensburg, Germany
| | - Wolfgang Neubert
- Max-Planck-Institute for Biochemistry, Department Molecular Virology, Martinsried Germany
| | - Ulrich M. Lauer
- Department of Internal Medicine I, Medical University Hospital, Tübingen, Germany
| | - Michael Bitzer
- Department of Internal Medicine I, Medical University Hospital, Tübingen, Germany
- * E-mail:
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22
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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: 25] [Impact Index Per Article: 2.5] [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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23
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Yamaguchi M, Kitagawa Y, Zhou M, Itoh M, Gotoh B. An anti-interferon activity shared by paramyxovirus C proteins: inhibition of Toll-like receptor 7/9-dependent alpha interferon induction. FEBS Lett 2013; 588:28-34. [PMID: 24269682 DOI: 10.1016/j.febslet.2013.11.015] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2013] [Revised: 10/31/2013] [Accepted: 11/06/2013] [Indexed: 10/26/2022]
Abstract
Paramyxovirus C protein targets the host interferon (IFN) system for virus immune evasion. To identify its unknown anti-IFN activity, we examined the effect of Sendai virus C protein on activation of the IFN-α promoter via various signaling pathways. This study uncovers a novel ability of C protein to block Toll-like receptor (TLR) 7- and TLR9-dependent IFN-α induction, which is specific to plasmacytoid dendritic cells. C protein interacts with a serine/threonine kinase IKKα and inhibits phosphorylation of IRF7. This anti-IFN activity of C protein is shared across genera of the Paramyxovirinae, and thus appears to play an important role in paramyxovirus immune evasion.
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Affiliation(s)
- Mayu Yamaguchi
- Division of Microbiology and Infectious Diseases, Department of Pathology, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga 520-2192, Japan
| | - Yoshinori Kitagawa
- Division of Microbiology and Infectious Diseases, Department of Pathology, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga 520-2192, Japan
| | - Min Zhou
- Division of Microbiology and Infectious Diseases, Department of Pathology, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga 520-2192, Japan
| | - Masae Itoh
- Department of Microbiology, Faculty of Bio-Science, Nagahama Institute of Bio-Science and Technology, 1266 Tamura-cho, Nagahama, Shiga 526-0829, Japan
| | - Bin Gotoh
- Division of Microbiology and Infectious Diseases, Department of Pathology, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga 520-2192, Japan.
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24
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Sendai virus C proteins regulate viral genome and antigenome synthesis to dictate the negative genome polarity. J Virol 2013; 88:690-8. [PMID: 24173229 DOI: 10.1128/jvi.02798-13] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The order Mononegavirales comprises a large number of nonsegmented negative-strand RNA viruses (NNSVs). How the genome polarity is determined is a central issue in RNA virus biology. Using a prototypic species, vesicular stomatitis virus (VSV), it has been established that the negative polarity of the viral genome is defined solely by different strengths of the cis-acting replication promoters located at the 3' ends of the genome and antigenome, resulting in the predominance of the genome over the antigenome. This VSV paradigm has long been applied for the Mononegavirales in general without concrete proof. We now found that another prototypic species, Sendai virus (SeV), undergoes a marked shift from the early antigenome-dominant to the late genome-dominant phase during the course of infection. This shift appeared to be governed primarily by the expression of the accessory C protein, because no such shift occurred in a recombinant SeV with the C gene deleted, and antigenomes were dominant throughout infection, generating antigenome-dominant and noninfectious progeny virions. Therefore, we proposed for the first time a trans-regulatory mechanism, the SeV paradigm, to dictate the genome polarity of an NNSV. A series of promoter-swapped SeV recombinants suggested the importance of the primary as well as secondary structures of the promoters in this trans-regulation.
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Paramyxovirus activation and inhibition of innate immune responses. J Mol Biol 2013; 425:4872-92. [PMID: 24056173 DOI: 10.1016/j.jmb.2013.09.015] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 09/12/2013] [Accepted: 09/12/2013] [Indexed: 12/18/2022]
Abstract
Paramyxoviruses represent a remarkably diverse family of enveloped nonsegmented negative-strand RNA viruses, some of which are the most ubiquitous disease-causing viruses of humans and animals. This review focuses on paramyxovirus activation of innate immune pathways, the mechanisms by which these RNA viruses counteract these pathways, and the innate response to paramyxovirus infection of dendritic cells (DC). Paramyxoviruses are potent activators of extracellular complement pathways, a first line of defense that viruses must face during natural infections. We discuss mechanisms by which these viruses activate and combat complement to delay neutralization. Once cells are infected, virus replication drives type I interferon (IFN) synthesis that has the potential to induce a large number of antiviral genes. Here we describe four approaches by which paramyxoviruses limit IFN induction: by limiting synthesis of IFN-inducing aberrant viral RNAs, through targeted inhibition of RNA sensors, by providing viral decoy substrates for cellular kinase complexes, and through direct blocking of the IFN promoter. In addition, paramyxoviruses have evolved diverse mechanisms to disrupt IFN signaling pathways. We describe three general mechanisms, including targeted proteolysis of signaling factors, sequestering cellular factors, and upregulation of cellular inhibitors. DC are exceptional cells with the capacity to generate adaptive immunity through the coupling of innate immune signals and T cell activation. We discuss the importance of innate responses in DC following paramyxovirus infection and their consequences for the ability to mount and maintain antiviral T cells.
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Clustered basic amino acids of the small sendai virus C protein Y1 are critical to its RAN GTPase-mediated nuclear localization. PLoS One 2013; 8:e73740. [PMID: 23951363 PMCID: PMC3739745 DOI: 10.1371/journal.pone.0073740] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 07/26/2013] [Indexed: 12/15/2022] Open
Abstract
The Sendai virus (SeV) C proteins are shown to exert multiple functions during the course of infection. Perhaps reflecting their many functions, they occur at multiple sites of the cell. In this study, we focused on the nuclear-localizing ability of the smaller C protein, Y1, and found that this translocation is mediated by Ran GTPase but not by passive diffusion, and that basic residues within the 149-157 amino acid region are critical for that. The mechanism of inhibition of interferon (IFN)-signaling seemed to differ between the C and Y1 proteins, since deletion of 12 C-terminal amino acids resulted in a loss of the function for the C but not for the Y1 protein. The ability of Y1 mutants to inhibit IFN-α-induced, ISRE-driven expression of a reporter gene almost paralleled with that to localize in the nucleus. These results suggest that nuclear localization of the Y1 protein might be important for the inhibitory effect on type-I IFN-stimulated gene expression.
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Audsley MD, Moseley GW. Paramyxovirus evasion of innate immunity: Diverse strategies for common targets. World J Virol 2013; 2:57-70. [PMID: 24175230 PMCID: PMC3785049 DOI: 10.5501/wjv.v2.i2.57] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 02/14/2013] [Accepted: 04/10/2013] [Indexed: 02/05/2023] Open
Abstract
The paramyxoviruses are a family of > 30 viruses that variously infect humans, other mammals and fish to cause diverse outcomes, ranging from asymptomatic to lethal disease, with the zoonotic paramyxoviruses Nipah and Hendra showing up to 70% case-fatality rate in humans. The capacity to evade host immunity is central to viral infection, and paramyxoviruses have evolved multiple strategies to overcome the host interferon (IFN)-mediated innate immune response through the activity of their IFN-antagonist proteins. Although paramyxovirus IFN antagonists generally target common factors of the IFN system, including melanoma differentiation associated factor 5, retinoic acid-inducible gene-I, signal transducers and activators of transcription (STAT)1 and STAT2, and IFN regulatory factor 3, the mechanisms of antagonism show remarkable diversity between different genera and even individual members of the same genus; the reasons for this diversity, however, are not currently understood. Here, we review the IFN antagonism strategies of paramyxoviruses, highlighting mechanistic differences observed between individual species and genera. We also discuss potential sources of this diversity, including biological differences in the host and/or tissue specificity of different paramyxoviruses, and potential effects of experimental approaches that have largely relied on in vitro systems. Importantly, recent studies using recombinant virus systems and animal infection models are beginning to clarify the importance of certain mechanisms of IFN antagonism to in vivo infections, providing important indications not only of their critical importance to virulence, but also of their potential targeting for new therapeutic/vaccine approaches.
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Yoshida A, Sakaguchi T, Irie T. Passage of a Sendai virus recombinant in embryonated chicken eggs leads to markedly rapid accumulation of U-to-C transitions in a limited region of the viral genome. PLoS One 2012. [PMID: 23185501 PMCID: PMC3503868 DOI: 10.1371/journal.pone.0049968] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
The P gene of paramyxoviruses is unique in producing not only P but also “accessory” C and/or V proteins. Successful generation of C- or V-deficient recombinant viruses using a reverse genetics technique has been revealing their importance in viral pathogenesis as well as replication. As for Sendai virus (SeV), the C proteins, a nested set of four polypeptides C’, C, Y1, and Y2, have been shown to exert multiple functions in escaping from the host innate immunity, inhibiting virus-induced apoptosis, promoting virus assembly and budding, and regulating viral RNA synthesis. In this study, we subjected the 4C(-) recombinant lacking expression of all four C proteins to serial passages through eggs, and found the rapid emergence of a C-recovered revertant virus. Unlike the SeV strains or the recombinants reported previously or tested in this study, this was caused by an exceptionally quick accumulation of U-to-C transitions in a limited region of the 4C(-) genome causing recovery of the C protein expression. These results suggest that a lack of C proteins could lead unexpectedly to strong selective pressures, and that the C proteins might play more critical roles in SeV replication than ever reported.
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Affiliation(s)
- Asuka Yoshida
- Department of Virology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, 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
- * E-mail:
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29
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Inhibition of interferon regulatory factor 3 activation by paramyxovirus V protein. J Virol 2012; 86:7136-45. [PMID: 22532687 DOI: 10.1128/jvi.06705-11] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The V protein of Sendai virus (SeV) suppresses innate immunity, resulting in enhancement of viral growth in mouse lungs and viral pathogenicity. The innate immunity restricted by the V protein is induced through activation of interferon regulatory factor 3 (IRF3). The V protein has been shown to interact with melanoma differentiation-associated gene 5 (MDA5) and to inhibit beta interferon production. In the present study, we infected MDA5-knockout mice with V-deficient SeV and found that MDA5 was largely unrelated to the innate immunity that the V protein suppresses in vivo. We therefore investigated the target of the SeV V protein. We previously reported interaction of the V protein with IRF3. Here we extended the observation and showed that the V protein appeared to inhibit translocation of IRF3 into the nucleus. We also found that the V protein inhibited IRF3 activation when induced by a constitutive active form of IRF3. The V proteins of measles virus and Newcastle disease virus inhibited IRF3 transcriptional activation, as did the V protein of SeV, while the V proteins of mumps virus and Nipah virus did not, and inhibition by these proteins correlated with interaction of each V protein with IRF3. These results indicate that IRF3 is important as an alternative target of paramyxovirus V proteins.
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30
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Basler CF. Nipah and hendra virus interactions with the innate immune system. Curr Top Microbiol Immunol 2012; 359:123-52. [PMID: 22491899 DOI: 10.1007/82_2012_209] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Nipah virus and Hendra virus are related, highly pathogenic paramyxoviruses with unusually broad host ranges. Henipaviruses encode several proteins that block innate immune responses, and these are likely to serve as virulence factors. Specfically, four virus-encoded proteins, the phosphoprotein (P), the V protein, the W protein, and the C protein have each been demonstrated to counteract aspects of the interferon (IFN)-α/β response, a key component of the innate immune response to virus infection. The available data indicate that V and W can inhibit the production of IFNα/β in response to various stimuli, while the P, V, and W proteins also block the ability of IFNs to signal and induce an antiviral state in cells. The C protein also inhibits the antiviral effects of IFNα/β by a poorly characterized mechanism. Reverse genetics systems, which allow the generation of recombinant viruses bearing specific mutations, have demonstrated the importance of the viral IFN-antagonists for replication. With these systems in hand, the field is now poised to define how specific viral IFN-antagonist functions influence viral pathogenesis.
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Affiliation(s)
- Christopher F Basler
- Department of Microbiology, Mount Sinai School of Medicine, New York, NY 10029, USA.
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31
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Gerlier D, Lyles DS. Interplay between innate immunity and negative-strand RNA viruses: towards a rational model. Microbiol Mol Biol Rev 2011; 75:468-90, second page of table of contents. [PMID: 21885681 PMCID: PMC3165544 DOI: 10.1128/mmbr.00007-11] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The discovery of a new class of cytosolic receptors recognizing viral RNA, called the RIG-like receptors (RLRs), has revolutionized our understanding of the interplay between viruses and host cells. A tremendous amount of work has been accumulating to decipher the RNA moieties required for an RLR agonist, the signal transduction pathway leading to activation of the innate immunity orchestrated by type I interferon (IFN), the cellular and viral regulators of this pathway, and the viral inhibitors of the innate immune response. Previous reviews have focused on the RLR signaling pathway and on the negative regulation of the interferon response by viral proteins. The focus of this review is to put this knowledge in the context of the virus replication cycle within a cell. Likewise, there has been an expansion of knowledge about the role of innate immunity in the pathophysiology of viral infection. As a consequence, some discrepancies have arisen between the current models of cell-intrinsic innate immunity and current knowledge of virus biology. This holds particularly true for the nonsegmented negative-strand viruses (Mononegavirales), which paradoxically have been largely used to build presently available models. The aim of this review is to bridge the gap between the virology and innate immunity to favor the rational building of a relevant model(s) describing the interplay between Mononegavirales and the innate immune system.
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Affiliation(s)
- Denis Gerlier
- INSERM U758, CERVI, 21 avenue Tony Garnier, 69007 Lyon, France.
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32
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The nonstructural proteins of Nipah virus play a key role in pathogenicity in experimentally infected animals. PLoS One 2010; 5:e12709. [PMID: 20856799 PMCID: PMC2939873 DOI: 10.1371/journal.pone.0012709] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Accepted: 04/25/2010] [Indexed: 12/31/2022] Open
Abstract
Nipah virus (NiV) P gene encodes P protein and three accessory proteins (V, C and W). It has been reported that all four P gene products have IFN antagonist activity when the proteins were transiently expressed. However, the role of those accessory proteins in natural infection with NiV remains unknown. We generated recombinant NiVs lacking V, C or W protein, rNiV(V−), rNiV(C−), and rNiV(W−), respectively, to analyze the functions of these proteins in infected cells and the implications in in vivo pathogenicity. All the recombinants grew well in cell culture, although the maximum titers of rNiV(V−) and rNiV(C−) were lower than the other recombinants. The rNiV(V−), rNiV(C−) and rNiV(W−) suppressed the IFN response as well as the parental rNiV, thereby indicating that the lack of each accessory protein does not significantly affect the inhibition of IFN signaling in infected cells. In experimentally infected golden hamsters, rNiV(V−) and rNiV(C−) but not the rNiV(W−) virus showed a significant reduction in virulence. These results suggest that V and C proteins play key roles in NiV pathogenicity, and the roles are independent of their IFN-antagonist activity. This is the first report that identifies the molecular determinants of NiV in pathogenicity in vivo.
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33
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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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34
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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: 127] [Impact Index Per Article: 9.1] [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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35
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Gitlin L, Benoit L, Song C, Cella M, Gilfillan S, Holtzman MJ, Colonna M. Melanoma differentiation-associated gene 5 (MDA5) is involved in the innate immune response to Paramyxoviridae infection in vivo. PLoS Pathog 2010; 6:e1000734. [PMID: 20107606 PMCID: PMC2809771 DOI: 10.1371/journal.ppat.1000734] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2009] [Accepted: 12/21/2009] [Indexed: 12/24/2022] Open
Abstract
The early host response to pathogens is mediated by several distinct pattern recognition receptors. Cytoplasmic RNA helicases including RIG-I and MDA5 have been shown to respond to viral RNA by inducing interferon (IFN) production. Previous in vitro studies have demonstrated a direct role for MDA5 in the response to members of the Picornaviridae, Flaviviridae and Caliciviridae virus families ((+) ssRNA viruses) but not to Paramyxoviridae or Orthomyxoviridae ((-) ssRNA viruses). Contrary to these findings, we now show that MDA5 responds critically to infections caused by Paramyxoviridae in vivo. Using an established model of natural Sendai virus (SeV) infection, we demonstrate that MDA5(-/-) mice exhibit increased morbidity and mortality as well as severe histopathological changes in the lower airways in response to SeV. Moreover, analysis of viral propagation in the lungs of MDA5(-/-) mice reveals enhanced replication and a distinct distribution involving the interstitium. Though the levels of antiviral cytokines were comparable early during SeV infection, type I, II, and III IFN mRNA expression profiles were significantly decreased in MDA5(-/-) mice by day 5 post infection. Taken together, these findings indicate that MDA5 is indispensable for sustained expression of IFN in response to paramyxovirus infection and provide the first evidence of MDA5-dependent containment of in vivo infections caused by (-) sense RNA viruses.
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Affiliation(s)
- Leonid Gitlin
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Loralyn Benoit
- Pulmonary and Critical Care Medicine, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Christina Song
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Marina Cella
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Susan Gilfillan
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Michael J. Holtzman
- Pulmonary and Critical Care Medicine, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Marco Colonna
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- * E-mail:
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36
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Mao H, Chattopadhyay S, Banerjee AK. Domain within the C protein of human parainfluenza virus type 3 that regulates interferon signaling. Gene Expr 2010; 15:43-50. [PMID: 21061916 PMCID: PMC6043821 DOI: 10.3727/105221610x12819686555132] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Human parainfluenza virus type 3 (HPIV3), one of the paramyxoviruses, uses its accessory C protein as an antagonist against interferon (IFN)-mediated host innate immunity. We have previously shown that the C protein significantly decreased the IFN-induced phosphorylation of signal transducer and activator of transcription (Stat) 1 and the formation of gamma IFN activation factor (GAF) complex, thus abrogating the antiviral activity of the IFNs against vesicular stomatitis virus (VSV) replication. Here, by mutational analyses we demonstrated that the N-terminal truncation of the C protein (CNdelta25 and CNdelta50) substantially (approximately 50%) recovers the IFN-induced responses, suggesting the critical role of the N-terminal region of the C protein in IFN signaling. Furthermore, our results indicate that the charged amino acid residues within the N-terminal region of the C protein regulate the antagonistic effect of the C protein on IFN signaling.
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Affiliation(s)
- Hongxia Mao
- Virology Section, Department of Molecular Genetics, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Santanu Chattopadhyay
- Virology Section, Department of Molecular Genetics, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Amiya K. Banerjee
- Virology Section, Department of Molecular Genetics, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
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37
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Chambers R, Takimoto T. Antagonism of innate immunity by paramyxovirus accessory proteins. Viruses 2009; 1:574-593. [PMID: 21994561 PMCID: PMC3185518 DOI: 10.3390/v1030574] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2009] [Revised: 10/22/2009] [Accepted: 10/26/2009] [Indexed: 12/15/2022] Open
Abstract
Paramyxovirinae, a subfamily of Paramyxoviridae, are negative strand RNA viruses comprised of many important human and animal pathogens, which share a high degree of genetic and structural homology. The accessory proteins expressed from the P/V/C gene are major factors in the pathogenicity of the viruses, because of their ability to abrogate various facets of type I interferon (IFN) induction and signaling. Most of the paramyxoviruses exhibit a commonality in their ability to antagonize innate immunity by blocking IFN induction and the Jak/STAT pathway. However, the manner in which the accessory proteins inhibit the pathway differs among viruses. Similarly, there are variations in the capability of the viruses to counteract intracellular detectors (RNA helicases, mda-5 and RIG-I). Furthermore, a functional specificity in the antagonism of the IFN response has been reported, suggesting that specificity in the circumvention of innate immunity restricts viral host range. Available evidence indicates that paramyxoviruses employ specific strategies to antagonize the IFN response of their specific hosts, which is one of the major factors that determine viral pathogenicity and host range.
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Affiliation(s)
| | - Toru Takimoto
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-585-273-2856; Fax: +1-585-473-9573
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38
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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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Ashour J, Laurent-Rolle M, Shi PY, García-Sastre A. NS5 of dengue virus mediates STAT2 binding and degradation. J Virol 2009; 83:5408-18. [PMID: 19279106 PMCID: PMC2681973 DOI: 10.1128/jvi.02188-08] [Citation(s) in RCA: 331] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2008] [Accepted: 02/26/2009] [Indexed: 12/23/2022] Open
Abstract
The mammalian interferon (IFN) signaling pathway is a primary component of the innate antiviral response. As such, viral pathogens have devised multiple mechanisms to antagonize this pathway and thus facilitate infection. Dengue virus (DENV) encodes several proteins (NS2a, NS4a, and NS4b) that have been shown individually to inhibit the IFN response. In addition, DENV infection results in reduced levels of expression of STAT2, which is required for IFN signaling (M. Jones, A. Davidson, L. Hibbert, P. Gruenwald, J. Schlaak, S. Ball, G. R. Foster, and M. Jacobs, J. Virol. 79:5414-5420, 2005). Translation of the DENV genome results in a single polypeptide, which is processed by viral and host proteases into at least 10 separate proteins. To date, no single DENV protein has been implicated in the targeting of STAT2 for decreased levels of expression. We demonstrate here that the polymerase of the virus, NS5, binds to STAT2 and is necessary and sufficient for its reduced level of expression. The decrease in protein level observed requires ubiquitination and proteasome activity, strongly suggesting an active degradation process. Furthermore, we show that the degradation of but not binding to STAT2 is dependent on the expression of the polymerase in the context of a polyprotein that undergoes proteolytic processing for NS5 maturation. Thus, the mature form of NS5, when not expressed as a precursor, was able to bind to STAT2 but was unable to target it for degradation, establishing a unique role for viral polyprotein processing in providing an additional function to a viral polypeptide. Therefore, we have identified both a novel mechanism by which DENV evades the innate immune response and a potential target for antiviral therapeutics.
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Affiliation(s)
- Joseph Ashour
- Department of Microbiology, Emerging Pathogens Institute, Mount Sinai School of Medicine, New York, NY 10029, USA
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40
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The C proteins of human parainfluenza virus type 1 (HPIV1) control the transcription of a broad array of cellular genes that would otherwise respond to HPIV1 infection. J Virol 2008; 83:1892-910. [PMID: 19052086 DOI: 10.1128/jvi.01373-08] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Human parainfluenza virus type 1 (HPIV1) is an important respiratory pathogen in children and the most common cause of viral croup. We performed a microarray-based analysis of gene expression kinetics to examine how wild-type (wt) HPIV1 infection altered gene expression in human respiratory epithelial cells and what role beta interferon played in this response. We similarly evaluated HPIV1-P(C-), a highly attenuated and apoptosis-inducing virus that does not express any of the four C proteins, and HPIV1-C(F170S), a less attenuated mutant that contains a single point mutation in C and, like wt HPIV1, does not efficiently induce apoptosis, to examine the role of the C proteins in controlling host gene expression. We also used these data to investigate whether the phenotypic differences between the two C mutants could be explained at the transcriptional level. Mutation or deletion of the C proteins of HPIV1 permitted the activation of over 2,000 cellular genes that otherwise would be repressed by HPIV1 infection. Thus, the C proteins profoundly suppress the response of human respiratory cells to HPIV1 infection. Cellular pathways targeted by the HPIV1 C proteins were identified and their transcriptional control was analyzed using bioinformatics. Transcription factor binding sites for IRF and NF-kappaB were overrepresented in some of the C protein-targeted pathways, but other pathways were dominated by less-known factors, such as forkhead transcription factor FOXD1. Surprisingly, the host responses to the P(C-) and C(F170S) mutants were very similar, and only subtle differences in the expression kinetics of caspase 3 and TRAIL receptor 2 were observed. Thus, changes in host cell transcription did not reflect the striking phenotypic differences observed between these two viruses.
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Sendai virus C protein plays a role in restricting PKR activation by limiting the generation of intracellular double-stranded RNA. J Virol 2008; 82:10102-10. [PMID: 18684815 DOI: 10.1128/jvi.00599-08] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Sendai virus (SeV) C protein is a multifunctional protein that plays important roles in regulating viral genome replication and transcription, antagonizing the host interferon system, suppressing virus-induced apoptosis, and facilitating virus assembly and budding. We here report a novel role of SeV C protein, the limitation of double-stranded RNA (dsRNA) generation for maintaining the rate of protein synthesis in infected cells. It was found that the intracellular protein synthesis rate was maintained even after wild-type (wt) SeV infection, but markedly suppressed following C-knockout SeV infection. This indicates the requirement of C protein for maintaining protein synthesis after infection. In contrast to wt SeV infection, C-knockout SeV infection caused phosphorylation of both the translation initiation factor eIF2alpha and dsRNA-dependent protein kinase (PKR). Phosphorylation of eIF2alpha occurred mainly due to the action of PKR, since knockdown of PKR by small interfering RNA limited eIF2alpha phosphorylation. C protein, however, could inhibit neither poly(I):poly(C)-activated nor Newcastle disease virus-induced phosphorylation of PKR and eIF2alpha, suggesting that C protein does not target common pathways leading to PKR activation. Immunofluorescent staining experiments with a monoclonal antibody specifically recognizing dsRNA revealed generation of a large amount of dsRNA in cells infected with C-knockout SeV but not wt SeV. The dsRNA generation as well as phosphorylation of PKR and eIF2alpha induced by C-knockout SeV was markedly suppressed in cells constitutively expressing C protein. Taken together, these results demonstrate that the SeV C protein limits generation of dsRNA, thereby keeping PKR inactive to maintain intracellular protein synthesis.
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Human parainfluenza virus type 2 V protein inhibits genome replication by binding to the L protein: possible role in promoting viral fitness. J Virol 2008; 82:6130-8. [PMID: 18417591 DOI: 10.1128/jvi.02635-07] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The human parainfluenza virus type 2 (hPIV2) V protein plays important roles in inhibiting the host interferon response and promoting virus growth, but its role in hPIV2 replication and transcription is not clear. A green fluorescent protein (GFP)-expressing a negative-sense minigenomic construct of hPIV2 has been established by standard technology, with helper plasmids expressing the nucleocapsid protein (NP), phosphoprotein (P), and large RNA polymerase (L) protein, to examine the role of V protein. We found that the simultaneous expression of wild-type V protein in the minigenome system inhibited GFP expression, at least in part, by inhibiting minigenome replication. In contrast, expression of C terminally truncated or mutant hPIV2 V proteins had no effect. Moreover, the V protein of simian virus 41, the rubulavirus most closely related virus to hPIV2, also inhibited GFP expression, whereas that of PIV5, a more distantly related rubulavirus, did not. Using these other rubulavirus V proteins, as well as various mutant hPIV2 V proteins, we found that the ability of V protein to inhibit GFP expression correlated with its ability to bind to L protein via its C-terminal V protein-specific region, but there was no correlation with NP binding. A possible role for this inhibition of genome replication in promoting viral fitness is discussed.
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Regulation of interferon signaling by the C and V proteins from attenuated and wild-type strains of measles virus. Virology 2008; 374:71-81. [DOI: 10.1016/j.virol.2007.12.031] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2007] [Revised: 09/26/2007] [Accepted: 12/21/2007] [Indexed: 11/20/2022]
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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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Dibben O, Thorpe LC, Easton AJ. Roles of the PVM M2-1, M2-2 and P gene ORF 2 (P-2) proteins in viral replication. Virus Res 2007; 131:47-53. [PMID: 17881076 DOI: 10.1016/j.virusres.2007.08.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2007] [Revised: 08/11/2007] [Accepted: 08/12/2007] [Indexed: 10/22/2022]
Abstract
A plasmid-based reverse genetics system for pneumonia virus of mice (PVM) using a synthetic minigenome is described. The system was used to investigate the functions of several viral proteins. The M2-1 protein of PVM was shown to enhance reporter gene expression when present at low levels, similar to the situation for the equivalent respiratory syncytial virus (RSV) M2-1 protein, but at high levels was shown to reduce gene expression from the minigenome activity, which differs significantly form the situation with RSV. Analysis of levels of nucleocapsid complex RNA showed that high levels of the PVM M2-1 protein inhibits RNA replication rather than transcription. In contrast, expression of the PVM M2-2 protein in conjunction with the polymerase proteins in a minigenome assay greatly reduced the levels of CAT reporter protein. This is similar to the situation with the RSV M2-2 protein although there is no significant sequence identity between the M2-2 proteins of the pneumoviruses. A significant difference between the genome organisations of RSV and PVM is that the P gene of PVM contains a second open reading frame, encoding the P-2 protein, which has no counterpart in the RSV P gene. Co-expression of the PVM P-2 protein with the minigenome inhibited virus gene expression. This resembles the situation seen with the accessory proteins expressed from alternate reading frames of the P gene of other paramyxoviruses. Analysis of levels of antigenome RNA and CAT mRNA produced by the minigenome in the presence of the P2 protein indicated that the protein inhibits viral transcription in a dose-dependent fashion.
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Affiliation(s)
- Oliver Dibben
- Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK
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Komatsu T, Takeuchi K, Gotoh B. Bovine parainfluenza virus type 3 accessory proteins that suppress beta interferon production. Microbes Infect 2007; 9:954-62. [PMID: 17548221 DOI: 10.1016/j.micinf.2007.03.014] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2006] [Revised: 03/29/2007] [Accepted: 03/30/2007] [Indexed: 11/23/2022]
Abstract
The paramyxovirus P gene encodes accessory proteins antagonistic to interferon (IFN). Viral proteins responsible for the IFN antagonism, however, are distinct among paramyxoviruses. Here we determine bovine parainfluenza virus type 3 (bPIV3) IFN antagonists that suppress IFN-beta production, and investigate the underlying molecular mechanism. Of bPIV3 P gene products, C and V proteins were found to suppress double-stranded RNA-stimulated IFN-beta production. The V protein of bPIV3 and Sendai virus in the same genus Respirovirus significantly inhibits double-stranded RNA-stimulated IFN-beta production and the IFN-beta promoter activation enhanced by overexpression of MDA5 but not RIG-I, and yet does not suppress IFN-beta production induced by TRIF, TBK1, and IKKi. The V protein of both viruses specifically binds to MDA5 but not RIG-I. These results suggest that the V protein targets MDA5 for blockage of the IFN-beta gene activation signal. On the other hand, both bPIV3 and Sendai virus C proteins modestly inhibited IFN-beta production irrespective of a species of the signaling molecules used as an inducer. Interestingly, reporter gene expression driven by various promoters was also suppressed by the C proteins irrespective of the promoter species. These results demonstrate that the target of the respirovirus C protein is undoubtedly different from that of the V protein.
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Affiliation(s)
- Takayuki Komatsu
- Microbiology Section, Department of Pathological Sciences, Faculty of Medical Sciences, University of Fukui, 23-3 Shimoaizuki, Matsuoka, Yoshida-gun, Fukui 910-1193, Japan
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Gosselin-Grenet AS, Marq JB, Abrami L, Garcin D, Roux L. Sendai virus budding in the course of an infection does not require Alix and VPS4A host factors. Virology 2007; 365:101-12. [PMID: 17467023 DOI: 10.1016/j.virol.2007.03.039] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2006] [Revised: 01/19/2007] [Accepted: 03/21/2007] [Indexed: 10/23/2022]
Abstract
Closing the Sendai virus C protein open reading frames (rSeV-DeltaC virus) results in the production of virus particles with highly reduced infectivity. Besides, the Sendai virus C proteins interact with Alix/AIP1 and Alix suppression negatively affects Sendai virus like particle (VLP) budding. Similarly, the Sendai virus M protein has been shown to interact with Alix. On this basis, it has been suggested that Sendai virus budding involves recruitment of the multivesicular body formation machinery. We follow, here, the production of SeV particles upon regular virus infection. We find that neither Alix suppression nor dominant negative-VPS4A expression, applied separately or in combination, affects physical or infectious virion production. This contrasts with the observed decrease of SV5 virion production upon dominant negative-VPS4A expression. Finally, we show that suppression of more than 70% of a GFP/C protein in the background of a rSeV-DeltaC virus infection has no effect either on SeV particle production or on virus particle infectivity. Our results contrast with what has been published before. Possible explanations for this discrepancy are discussed.
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Affiliation(s)
- Anne-Sophie Gosselin-Grenet
- Department of Microbiology and Molecular Medicine, University of Geneva Medical School, CMU, 1 rue Michel Servet, 1211 Geneva 4, Switzerland
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Nishio M, Tsurudome M, Ishihara H, Ito M, Ito Y. The conserved carboxyl terminus of human parainfluenza virus type 2 V protein plays an important role in virus growth. Virology 2007; 362:85-98. [PMID: 17250865 DOI: 10.1016/j.virol.2006.12.017] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2006] [Revised: 10/18/2006] [Accepted: 12/18/2006] [Indexed: 10/23/2022]
Abstract
Our previous results have shown that some residues of V protein-specific domain in human parainfluenza virus type 2 (hPIV2) are essential not only for STAT protein degradation but also for promoting virus growth. Here, we demonstrated that the virus growth of these recombinant hPIV2s (rPIV2) expressing mutated V proteins were improved in HeLa cell transiently expressing the wild-type V protein, but not in the cells constitutively expressing it. Consequently, we identified the region of the V protein that is essential for its oligomerization and for complex formation with NP protein. We also identified a host protein, AlP1/Alix, involved in apoptosis and efficient budding of several enveloped viruses as an interacting partner of the V and NP proteins. Depletion of AIP1/Alix by small interfering RNA suppressed virus growth. These data suggest that the conserved carboxyl terminus of the V protein plays an important role in virus growth.
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Affiliation(s)
- Machiko Nishio
- Department of Microbiology, Mie University Graduate School of Medicine, 2-174, Edobashi, Tsu, Mie, 514-8507, Japan.
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Kato A, Kiyotani K, Kubota T, Yoshida T, Tashiro M, Nagai Y. Importance of the anti-interferon capacity of Sendai virus C protein for pathogenicity in mice. J Virol 2007; 81:3264-71. [PMID: 17215288 PMCID: PMC1866026 DOI: 10.1128/jvi.02590-06] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The Sendai virus (SeV) C protein blocks signal transduction of interferon (IFN), thereby counteracting the antiviral actions of IFN. Using HeLa cell lines expressing truncated or mutated SeV C proteins, we found that the C-terminal half has anti-IFN capacity, and that K(151)A, E(153)A, and R(154)A substitutions in the C protein eliminated this capacity. Here, we further created the mutant virus SeV Cm*, in which K(151)A, E(153)K, and R(157)L substitutions in the C protein were introduced without changing the amino acid sequence of overlapped P, V, and W proteins. SeV Cm* was found to lack anti-IFN capacity, as expected. While the growth rate and final yield of SeV Cm* were inferior to those of the wild-type SeV in IFN-responsive, STAT1-positive 2fTGH cells, SeV Cm* grew equivalently to the wild-type SeV in IFN-nonresponsive, STAT1-deficient U3A cells. SeV Cm* was thus shown to maintain multiplication capacity, except that it lacked anti-IFN capacity. Intranasally inoculated SeV Cm* could propagate in the lungs of STAT1(-/-) mice but was cleared from those of STAT1(+/+) mice without propagation. It was found that the anti-IFN capacity of the SeV C protein was indispensable for pathogenicity in mice. Conversely, the results show that the innate immunity contributed to elimination of SeV in early stages of infection in the absence of anti-IFN capacity.
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Affiliation(s)
- Atsushi Kato
- Department of Virology 3, National Institute of Infectious Diseases, Gakuen 4-7-1, Musashi-Murayama, Tokyo 208-0011, Japan.
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Rivals JP, Plattet P, Currat-Zweifel C, Zurbriggen A, Wittek R. Adaptation of canine distemper virus to canine footpad keratinocytes modifies polymerase activity and fusogenicity through amino acid substitutions in the P/V/C and H proteins. Virology 2006; 359:6-18. [PMID: 17046044 DOI: 10.1016/j.virol.2006.07.054] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2006] [Revised: 04/27/2006] [Accepted: 07/17/2006] [Indexed: 11/16/2022]
Abstract
The wild-type canine distemper virus (CDV) strain A75/17 induces a non-cytocidal infection in cultures of canine footpad keratinocytes (CFKs) but produces very little progeny virus. After only three passages in CFKs, the virus produced 100-fold more progeny and induced a limited cytopathic effect. Sequence analysis of the CFK-adapted virus revealed only three amino acid differences, of which one was located in each the P/V/C, M and H proteins. In order to assess which amino acid changes were responsible for the increase of infectious virus production and altered phenotype of infection, we generated a series of recombinant viruses. Their analysis showed that the altered P/V/C proteins were responsible for the higher levels of virus progeny formation and that the amino acid change in the cytoplasmic tail of the H protein was the major determinant of cytopathogenicity.
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Affiliation(s)
- Jean-Paul Rivals
- Institut de Biotechnologie, Bâtiment de Biologie, University of Lausanne, CH-1015 Lausanne, Switzerland
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