1
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Yang CH, Song AL, Qiu Y, Ge XY. Cross-species transmission and host range genes in poxviruses. Virol Sin 2024; 39:177-193. [PMID: 38272237 PMCID: PMC11074647 DOI: 10.1016/j.virs.2024.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 01/18/2024] [Indexed: 01/27/2024] Open
Abstract
The persistent epidemic of human mpox, caused by mpox virus (MPXV), raises concerns about the future spread of MPXV and other poxviruses. MPXV is a typical zoonotic virus which can infect human and cause smallpox-like symptoms. MPXV belongs to the Poxviridae family, which has a relatively broad host range from arthropods to vertebrates. Cross-species transmission of poxviruses among different hosts has been frequently reported and resulted in numerous epidemics. Poxviruses have a complex linear double-strand DNA genome that encodes hundreds of proteins. Genes related to the host range of poxvirus are called host range genes (HRGs). This review briefly introduces the taxonomy, phylogeny and hosts of poxviruses, and then comprehensively summarizes the current knowledge about the cross-species transmission of poxviruses. In particular, the HRGs of poxvirus are described and their impacts on viral host range are discussed in depth. We hope that this review will provide a comprehensive perspective about the current progress of researches on cross-species transmission and HRG variation of poxviruses, serving as a valuable reference for academic studies and disease control in the future.
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Affiliation(s)
- Chen-Hui Yang
- College of Biology, Hunan Provincial Key Laboratory of Medical Virology, Hunan University, Changsha, 410012, China
| | - A-Ling Song
- College of Biology, Hunan Provincial Key Laboratory of Medical Virology, Hunan University, Changsha, 410012, China
| | - Ye Qiu
- College of Biology, Hunan Provincial Key Laboratory of Medical Virology, Hunan University, Changsha, 410012, China.
| | - Xing-Yi Ge
- College of Biology, Hunan Provincial Key Laboratory of Medical Virology, Hunan University, Changsha, 410012, China.
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2
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Alvarez-de Miranda FJ, Alonso-Sánchez I, Alcamí A, Hernaez B. TNF Decoy Receptors Encoded by Poxviruses. Pathogens 2021; 10:pathogens10081065. [PMID: 34451529 PMCID: PMC8401223 DOI: 10.3390/pathogens10081065] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 07/29/2021] [Accepted: 08/18/2021] [Indexed: 12/16/2022] Open
Abstract
Tumour necrosis factor (TNF) is an inflammatory cytokine produced in response to viral infections that promotes the recruitment and activation of leukocytes to sites of infection. This TNF-based host response is essential to limit virus spreading, thus poxviruses have evolutionarily adopted diverse molecular mechanisms to counteract TNF antiviral action. These include the expression of poxvirus-encoded soluble receptors or proteins able to bind and neutralize TNF and other members of the TNF ligand superfamily, acting as decoy receptors. This article reviews in detail the various TNF decoy receptors identified to date in the genomes from different poxvirus species, with a special focus on their impact on poxvirus pathogenesis and their potential use as therapeutic molecules.
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3
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Gough P, Myles IA. Tumor Necrosis Factor Receptors: Pleiotropic Signaling Complexes and Their Differential Effects. Front Immunol 2020; 11:585880. [PMID: 33324405 PMCID: PMC7723893 DOI: 10.3389/fimmu.2020.585880] [Citation(s) in RCA: 105] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 11/02/2020] [Indexed: 12/15/2022] Open
Abstract
Since its discovery in 1975, TNFα has been a subject of intense study as it plays significant roles in both immunity and cancer. Such attention is well deserved as TNFα is unique in its engagement of pleiotropic signaling via its two receptors: TNFR1 and TNFR2. Extensive research has yielded mechanistic insights into how a single cytokine can provoke a disparate range of cellular responses, from proliferation and survival to apoptosis and necrosis. Understanding the intracellular signaling pathways induced by this single cytokine via its two receptors is key to further revelation of its exact functions in the many disease states and immune responses in which it plays a role. In this review, we describe the signaling complexes formed by TNFR1 and TNFR2 that lead to each potential cellular response, namely, canonical and non-canonical NF-κB activation, apoptosis and necrosis. This is followed by a discussion of data from in vivo mouse and human studies to examine the differential impacts of TNFR1 versus TNFR2 signaling.
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Affiliation(s)
- Portia Gough
- Epithelial Therapeutics Unit, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD, United States
| | - Ian A Myles
- Epithelial Therapeutics Unit, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD, United States
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4
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Forsyth KS, Roy NH, Peauroi E, DeHaven BC, Wold ED, Hersperger AR, Burkhardt JK, Eisenlohr LC. Ectromelia-encoded virulence factor C15 specifically inhibits antigen presentation to CD4+ T cells post peptide loading. PLoS Pathog 2020; 16:e1008685. [PMID: 32745153 PMCID: PMC7425992 DOI: 10.1371/journal.ppat.1008685] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 08/13/2020] [Accepted: 06/06/2020] [Indexed: 01/02/2023] Open
Abstract
Smallpox and monkeypox pose severe threats to human health. Other orthopoxviruses are comparably virulent in their natural hosts, including ectromelia, the cause of mousepox. Disease severity is linked to an array of immunomodulatory proteins including the B22 family, which has homologs in all pathogenic orthopoxviruses but not attenuated vaccine strains. We demonstrate that the ectromelia B22 member, C15, is necessary and sufficient for selective inhibition of CD4+ but not CD8+ T cell activation by immunogenic peptide and superantigen. Inhibition is achieved not by down-regulation of surface MHC- II or co-stimulatory protein surface expression but rather by interference with antigen presentation. The appreciable outcome is interference with CD4+ T cell synapse formation as determined by imaging studies and lipid raft disruption. Consequently, CD4+ T cell activating stimulus shifts to uninfected antigen-presenting cells that have received antigen from infected cells. This work provides insight into the immunomodulatory strategies of orthopoxviruses by elucidating a mechanism for specific targeting of CD4+ T cell activation, reflecting the importance of this cell type in control of the virus.
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Affiliation(s)
- Katherine S. Forsyth
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Nathan H. Roy
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Elise Peauroi
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Brian C. DeHaven
- Department of Biology, La Salle University, Philadelphia, Pennsylvania, United States of America
| | - Erik D. Wold
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Adam R. Hersperger
- Department of Biology, Albright College, Reading, Pennsylvania, United States of America
| | - Janis K. Burkhardt
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania, United States of America
| | - Laurence C. Eisenlohr
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania, United States of America
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5
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Pontejo SM, Sanchez C, Ruiz-Argüello B, Alcami A. Insights into ligand binding by a viral tumor necrosis factor (TNF) decoy receptor yield a selective soluble human type 2 TNF receptor. J Biol Chem 2019; 294:5214-5227. [PMID: 30723161 DOI: 10.1074/jbc.ra118.005828] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 01/17/2019] [Indexed: 12/20/2022] Open
Abstract
Etanercept is a soluble form of the tumor necrosis factor receptor 2 (TNFR2) that inhibits pathological tumor necrosis factor (TNF) responses in rheumatoid arthritis and other inflammatory diseases. However, besides TNF, etanercept also blocks lymphotoxin-α (LTα), which has no clear therapeutic value and might aggravate some of the adverse effects associated with etanercept. Poxviruses encode soluble TNFR2 homologs, termed viral TNF decoy receptors (vTNFRs), that display unique specificity properties. For instance, cytokine response modifier D (CrmD) inhibits mouse and human TNF and mouse LTα, but it is inactive against human LTα. Here, we analyzed the molecular basis of these immunomodulatory activities in the ectromelia virus-encoded CrmD. We found that the overall molecular mechanism to bind TNF and LTα from mouse and human origin is fairly conserved in CrmD and dominated by a groove under its 50s loop. However, other ligand-specific binding determinants optimize CrmD for the inhibition of mouse ligands, especially mouse TNF. Moreover, we show that the inability of CrmD to inhibit human LTα is caused by a Glu-Phe-Glu motif in its 90s loop. Importantly, transfer of this motif to etanercept diminished its anti-LTα activity in >60-fold while weakening its TNF-inhibitory capacity in 3-fold. This new etanercept variant could potentially be used in the clinic as a safer alternative to conventional etanercept. This work is the most detailed study of the vTNFR-ligand interactions to date and illustrates that a better knowledge of vTNFRs can provide valuable information to improve current anti-TNF therapies.
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Affiliation(s)
- Sergio M Pontejo
- From the Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Carolina Sanchez
- From the Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Begoña Ruiz-Argüello
- From the Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Antonio Alcami
- From the Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, 28049 Madrid, Spain
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6
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Parker S, Camilo de Oliveira L, Lefkowitz EJ, Hendrickson RC, Bonjardim CA, Wold WSM, Hartzler H, Crump R, Buller RM. The Virology of Taterapox Virus In Vitro. Viruses 2018; 10:E463. [PMID: 30158437 DOI: 10.3390/v10090463] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Revised: 08/08/2018] [Accepted: 08/16/2018] [Indexed: 11/29/2022] Open
Abstract
Taterapox virus (TATV) is phylogenetically the closest related virus to variola—the etiological agent of smallpox. Despite the similarity, few studies have evaluated the virus. In vivo, TATV can infect several animals but produces an inapparent infection in wild-type mice; however, TATV does cause morbidity and mortality in some immunocompromised strains. We employed in vitro techniques to compare TATV to ectromelia (ECTV) and vaccinia (VACV) viruses. Both ECTV and TATV replicate efficiently in primate cell lines but TATV replicates poorly in murine cells lines. Furthermore, TATV induces cytopathic effects, but to a lesser extent than ECTV, and changes cytoskeletal networks differently than both ECTV and VACV. Bioinformatic studies revealed differences in several immunomodulator open reading frames that could contribute to the reduced virulence of TATV, which were supported by in vitro cytokine assays.
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7
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Alejo A, Ruiz-Argüello MB, Pontejo SM, Fernández de Marco MDM, Saraiva M, Hernáez B, Alcamí A. Chemokines cooperate with TNF to provide protective anti-viral immunity and to enhance inflammation. Nat Commun 2018; 9:1790. [PMID: 29724993 PMCID: PMC5934441 DOI: 10.1038/s41467-018-04098-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 04/03/2018] [Indexed: 12/16/2022] Open
Abstract
The role of cytokines and chemokines in anti-viral defense has been demonstrated, but their relative contribution to protective anti-viral responses in vivo is not fully understood. Cytokine response modifier D (CrmD) is a secreted receptor for TNF and lymphotoxin containing the smallpox virus-encoded chemokine receptor (SECRET) domain and is expressed by ectromelia virus, the causative agent of the smallpox-like disease mousepox. Here we show that CrmD is an essential virulence factor that controls natural killer cell activation and allows progression of fatal mousepox, and demonstrate that both SECRET and TNF binding domains are required for full CrmD activity. Vaccination with recombinant CrmD protects animals from lethal mousepox. These results indicate that a specific set of chemokines enhance the inflammatory and protective anti-viral responses mediated by TNF and lymphotoxin, and illustrate how viruses optimize anti-TNF strategies with the addition of a chemokine binding domain as soluble decoy receptors.
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Affiliation(s)
- Alí Alejo
- Centro de Investigación en Sanidad Animal; Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Valdeolmos, Madrid, 28130, Spain
| | - M Begoña Ruiz-Argüello
- Centro de Investigación en Sanidad Animal; Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Valdeolmos, Madrid, 28130, Spain.,Progenika Biopharma, 48160, Derio, Spain
| | - Sergio M Pontejo
- Centro de Biología Molecular Severo Ochoa (Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid), Cantoblanco, Madrid, 28049, Spain.,National Institutes of Health, Bethesda, Maryland, 20892, USA
| | - María Del Mar Fernández de Marco
- Centro de Biología Molecular Severo Ochoa (Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid), Cantoblanco, Madrid, 28049, Spain.,Animal & Plant Health Agency, Addlestone, Surrey, KT15 3NB, UK
| | - Margarida Saraiva
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 2QQ, United Kingdom.,Institute for Molecular and Cell Biology, 4200-135, Porto, Portugal
| | - Bruno Hernáez
- Centro de Biología Molecular Severo Ochoa (Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid), Cantoblanco, Madrid, 28049, Spain
| | - Antonio Alcamí
- Centro de Biología Molecular Severo Ochoa (Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid), Cantoblanco, Madrid, 28049, Spain. .,Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 2QQ, United Kingdom.
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8
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Nichols DB, De Martini W, Cottrell J. Poxviruses Utilize Multiple Strategies to Inhibit Apoptosis. Viruses 2017; 9:v9080215. [PMID: 28786952 PMCID: PMC5580472 DOI: 10.3390/v9080215] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 07/31/2017] [Accepted: 08/02/2017] [Indexed: 12/11/2022] Open
Abstract
Cells have multiple means to induce apoptosis in response to viral infection. Poxviruses must prevent activation of cellular apoptosis to ensure successful replication. These viruses devote a substantial portion of their genome to immune evasion. Many of these immune evasion products expressed during infection antagonize cellular apoptotic pathways. Poxvirus products target multiple points in both the extrinsic and intrinsic apoptotic pathways, thereby mitigating apoptosis during infection. Interestingly, recent evidence indicates that poxviruses also hijack cellular means of eliminating apoptotic bodies as a means to spread cell to cell through a process called apoptotic mimicry. Poxviruses are the causative agent of many human and veterinary diseases. Further, there is substantial interest in developing these viruses as vectors for a variety of uses including vaccine delivery and as oncolytic viruses to treat certain human cancers. Therefore, an understanding of the molecular mechanisms through which poxviruses regulate the cellular apoptotic pathways remains a top research priority. In this review, we consider anti-apoptotic strategies of poxviruses focusing on three relevant poxvirus genera: Orthopoxvirus, Molluscipoxvirus, and Leporipoxvirus. All three genera express multiple products to inhibit both extrinsic and intrinsic apoptotic pathways with many of these products required for virulence.
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Affiliation(s)
- Daniel Brian Nichols
- Department of Biological Sciences, Seton Hall University, South Orange, NJ 07039, USA.
| | - William De Martini
- Department of Biological Sciences, Seton Hall University, South Orange, NJ 07039, USA.
| | - Jessica Cottrell
- Department of Biological Sciences, Seton Hall University, South Orange, NJ 07039, USA.
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9
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Abstract
Immune responses are regulated by effector cytokines and chemokines that signal through cell surface receptors. Mammalian decoy receptors - which are typically soluble or inactive versions of cell surface receptors or soluble protein modules termed binding proteins - modulate and antagonize signalling by canonical effector-receptor complexes. Viruses have developed a diverse array of molecular decoys to evade host immune responses; these include viral homologues of host cytokines, chemokines and chemokine receptors; variants of host receptors with new functions; and novel decoy receptors that do not have host counterparts. Over the past decade, the number of known mammalian and viral decoy receptors has increased considerably, yet a comprehensive curation of the corresponding structure-mechanism relationships has not been carried out. In this Review, we provide a comprehensive resource on this topic with a view to better understanding the roles and evolutionary relationships of mammalian and viral decoy receptors, and the opportunities for leveraging their therapeutic potential.
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10
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Abstract
In mammalian cells, early defenses against infection by pathogens are mounted through a complex network of signaling pathways shepherded by immune-modulatory pattern-recognition receptors. As obligate parasites, the survival of viruses is dependent on the evolutionary acquisition of mechanisms that tactfully dismantle and subvert the cellular intrinsic and innate immune responses. Here, we review the diverse mechanisms by which viruses that accommodate DNA genomes are able to circumvent activation of cellular immunity. We start by discussing viral manipulation of host defense protein levels by either transcriptional regulation or protein degradation. We next review viral strategies used to repurpose or inhibit these cellular immune factors by molecular hijacking or by regulating their post-translational modification status. Additionally, we explore the infection-induced temporal modulation of apoptosis to facilitate viral replication and spread. Lastly, the co-evolution of viruses with their hosts is highlighted by the acquisition of elegant mechanisms for suppressing host defenses via viral mimicry of host factors. In closing, we present a perspective on how characterizing these viral evasion tactics both broadens the understanding of virus-host interactions and reveals essential functions of the immune system at the molecular level. This knowledge is critical in understanding the sources of viral pathogenesis, as well as for the design of antiviral therapeutics and autoimmunity treatments.
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Affiliation(s)
- Marni S. Crow
- Department of Molecular Biology, Princeton University, Lewis Thomas Laboratory, Washington Road, Princeton, NJ 08544
| | - Krystal K. Lum
- Department of Molecular Biology, Princeton University, Lewis Thomas Laboratory, Washington Road, Princeton, NJ 08544
| | - Xinlei Sheng
- Department of Molecular Biology, Princeton University, Lewis Thomas Laboratory, Washington Road, Princeton, NJ 08544
| | - Bokai Song
- Department of Molecular Biology, Princeton University, Lewis Thomas Laboratory, Washington Road, Princeton, NJ 08544
| | - Ileana M. Cristea
- Department of Molecular Biology, Princeton University, Lewis Thomas Laboratory, Washington Road, Princeton, NJ 08544
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11
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Abstract
Viruses have evolved numerous mechanisms to evade the immune response, including proteins that target the function of cytokines. This article provides an overview of the different strategies used by viruses to block the induction of cytokines and immune signals triggered by cytokines. Examples of virus evasion proteins are presented, such as intracellular proteins that block signal transduction and immune activation mechanisms, secreted proteins that mimic cytokines, or viral decoy receptors that inhibit the binding of cytokines to their cognate receptors. Virus-encoded proteins that target cytokines play a major role in immune modulation, and their contributions to viral pathogenesis, promoting virus replication or preventing immunopathology, are discussed.
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12
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Yu Y, Huang Y, Wei S, Li P, Zhou L, Ni S, Huang X, Qin Q. A tumour necrosis factor receptor-like protein encoded by Singapore grouper iridovirus modulates cell proliferation, apoptosis and viral replication. J Gen Virol 2015; 97:756-766. [PMID: 26691529 DOI: 10.1099/jgv.0.000379] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
It has been demonstrated that tumour necrosis factor receptor (TNFR) homologues encoded by viruses are usually involved in virus immune evasion by regulating the host immune response or mediating apoptotic cell death. Here, a novel TNFR-like protein encoded by Singapore grouper iridovirus (SGIV VP51) was cloned and characterized. Amino acid analysis showed that VP51 contained three cysteine-rich domains (CRDs) and a transmembrane domain at its C terminus. The expression of VP51 in vitro enhanced cell proliferation, and affected cell cycle progression via altering the G1/S transition. Furthermore, VP51 overexpression improved cell viability during SGIV infection via inhibiting virus-induced apoptosis, evidenced by the reduction of apoptotic bodies and the decrease of caspase-3 activation. In addition, overexpression of VP51 increased viral titre and the expression of viral structural protein gene MCP and cell proliferation promoting gene ICP-18. In contrast, the expression of the viral apoptosis inducing gene, LITAF, was significantly decreased. Although all three CRDs were essential for the action of VP51, CRD2 and CRD3 exerted more crucial roles on virus-induced apoptosis, viral gene transcription and virus production, while CRD1 was more crucial for cell proliferation. Together, SGIV TNFR-like products not only affected cell cycle progression and enhanced cell growth by increasing the expression of the virus encoded cell proliferation gene, but also inhibited virus-induced apoptotic cell death by decreasing the expression of the viral apoptosis inducing gene. Our results provided new insights into understanding the underlying mechanism by which iridovirus regulated the apoptotic pathway to complete its life cycle.
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Affiliation(s)
- Yepin Yu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, PR China.,University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049, PR China
| | - Youhua Huang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, PR China
| | - Shina Wei
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, PR China
| | - Pengfei Li
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, PR China.,University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049, PR China
| | - Lingli Zhou
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, PR China.,University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049, PR China
| | - Songwei Ni
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, PR China.,University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049, PR China
| | - Xiaohong Huang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, PR China
| | - Qiwei Qin
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, PR China
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13
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Abstract
Poxviruses encode up to four different soluble TNF receptors, named cytokine response modifier B (CrmB), CrmC, CrmD and CrmE. These proteins mimic the extracellular domain of the cellular TNF receptors to bind and inhibit the activity of TNF and, in some cases, other TNF superfamily ligands. Most of these ligands are released after the enzymic cleavage of a membrane precursor. However, transmembrane TNF (tmTNF) is not only a precursor of soluble TNF but also exerts specific pro-inflammatory and immunological activities. Here, we report that viral TNF receptors bound and inhibited tmTNF and describe some interesting differences in their activity against the soluble cytokine. Thus, CrmE, which does not inhibit mouse soluble TNF, could block murine tmTNF-induced cytotoxicity. We propose that this anti-tmTNF effect should be taken into consideration when assessing the role of viral TNF decoy receptors in the pathogenesis of poxvirus.
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Affiliation(s)
- Sergio M Pontejo
- Centro de Biologia Molecular Severo Ochoa (Consejo Superior de Investigaciones Científicas-Universidad Autonoma de Madrid), 28049 Madrid, Spain
| | - Ali Alejo
- Centro de Investigacion en Sanidad Animal (Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria), 28130 Valdeolmos, Madrid, Spain
| | - Antonio Alcami
- Centro de Biologia Molecular Severo Ochoa (Consejo Superior de Investigaciones Científicas-Universidad Autonoma de Madrid), 28049 Madrid, Spain
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14
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Yi Y, Qi H, Yuan J, Wang R, Weng S, He J, Dong C. Functional characterization of viral tumor necrosis factor receptors encoded by cyprinid herpesvirus 3 (CyHV3) genome. Fish Shellfish Immunol 2015; 45:757-770. [PMID: 26052019 DOI: 10.1016/j.fsi.2015.05.035] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 05/15/2015] [Accepted: 05/28/2015] [Indexed: 06/04/2023]
Abstract
Cyprinid herpesvirus 3 (CyHV3) is a large double-stranded DNA virus of Alloherpesviridae family in the order Herpesvirales. It causes significant morbidity and mortality in common carp and its ornamental koi variety, and threatens the aquaculture industries worldwide. Mimicry of cytokines and cytokine receptors is a particular strategy for large DNA viruses in modulating the host immune response. Here, we report the identification and characterization of two novel viral homologues of tumor necrosis factor receptor (TNFR) encoded by CyHV3-ORF4 and -ORF12, respectively. CyHV3-ORF4 was identified as a homologue of HVEM and CyHV3-ORF12 as a homologue of TNFRSF1. Overexpression of ORF4 and ORF12 in zebrafish embryos results in embryonic lethality, morphological defects and increased apoptosis. Although we failed to identify any interaction between the two vTNFRs and their potential ligands in zebrafish TNF superfamily by yeast two-hybrid system, the expression of some genes in TNF superfamily or TNFR superfamily were mis-regulated in ORF4 or ORF12-overexpressing embryos, especially the death receptor zHDR and its cognate ligand DL1b. Further studies showed that the apoptosis induced by the both CyHV3 vTNFRs is mainly activated through the intrinsic apoptotic pathway and requires the crosstalk between the intrinsic and extrinsic apoptotic pathway. Additionally, using RT-qPCR and Western blot assays, the expression patterns of the both vTNFRs were also analyzed during CyHV3 productive infection. Collectively, this is the first functional study of two unique vTNFRs encoded by a herpesvirus infecting non-mammalian vertebrates, which may provide novel insights into viral immune regulation mechanism and the pathogenesis of CyHV3 infection.
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MESH Headings
- Amino Acid Sequence
- Animals
- Carps
- Cell Line
- Female
- Fish Diseases/genetics
- Fish Diseases/metabolism
- Fish Diseases/virology
- Gene Expression Regulation
- Herpesviridae/genetics
- Herpesviridae/physiology
- Herpesviridae Infections/genetics
- Herpesviridae Infections/metabolism
- Herpesviridae Infections/veterinary
- Herpesviridae Infections/virology
- Male
- Open Reading Frames
- Receptors, Tumor Necrosis Factor, Member 14/chemistry
- Receptors, Tumor Necrosis Factor, Member 14/genetics
- Receptors, Tumor Necrosis Factor, Member 14/metabolism
- Receptors, Tumor Necrosis Factor, Type I/chemistry
- Receptors, Tumor Necrosis Factor, Type I/genetics
- Receptors, Tumor Necrosis Factor, Type I/metabolism
- Sequence Alignment/veterinary
- Viral Proteins/chemistry
- Viral Proteins/genetics
- Viral Proteins/metabolism
- Zebrafish
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Affiliation(s)
- Yang Yi
- MOE Key Laboratory of Aquatic Food Safety/State Key Laboratory for Bio-control, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Hemei Qi
- MOE Key Laboratory of Aquatic Food Safety/State Key Laboratory for Bio-control, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Jimin Yuan
- MOE Key Laboratory of Aquatic Food Safety/State Key Laboratory for Bio-control, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Rui Wang
- MOE Key Laboratory of Aquatic Food Safety/State Key Laboratory for Bio-control, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Shaoping Weng
- MOE Key Laboratory of Aquatic Food Safety/State Key Laboratory for Bio-control, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Jianguo He
- MOE Key Laboratory of Aquatic Food Safety/State Key Laboratory for Bio-control, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou 510275, People's Republic of China; Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, People's Republic of China
| | - Chuanfu Dong
- MOE Key Laboratory of Aquatic Food Safety/State Key Laboratory for Bio-control, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou 510275, People's Republic of China.
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15
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Pontejo SM, Alejo A, Alcami A. Comparative Biochemical and Functional Analysis of Viral and Human Secreted Tumor Necrosis Factor (TNF) Decoy Receptors. J Biol Chem 2015; 290:15973-84. [PMID: 25940088 PMCID: PMC4481203 DOI: 10.1074/jbc.m115.650119] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 04/15/2015] [Indexed: 12/31/2022] Open
Abstract
The blockade of tumor necrosis factor (TNF) by etanercept, a soluble version of the human TNF receptor 2 (hTNFR2), is a well established strategy to inhibit adverse TNF-mediated inflammatory responses in the clinic. A similar strategy is employed by poxviruses, encoding four viral TNF decoy receptor homologues (vTNFRs) named cytokine response modifier B (CrmB), CrmC, CrmD, and CrmE. These vTNFRs are differentially expressed by poxviral species, suggesting distinct immunomodulatory properties. Whereas the human variola virus and mouse ectromelia virus encode one vTNFR, the broad host range cowpox virus encodes all vTNFRs. We report the first comprehensive study of the functional and binding properties of these four vTNFRs, providing an explanation for their expression profile among different poxviruses. In addition, the vTNFRs activities were compared with the hTNFR2 used in the clinic. Interestingly, CrmB from variola virus, the causative agent of smallpox, is the most potent TNFR of those tested here including hTNFR2. Furthermore, we demonstrate a new immunomodulatory activity of vTNFRs, showing that CrmB and CrmD also inhibit the activity of lymphotoxin β. Similarly, we report for the first time that the hTNFR2 blocks the biological activity of lymphotoxin β. The characterization of vTNFRs optimized during virus-host evolution to modulate the host immune response provides relevant information about their potential role in pathogenesis and may be used to improve anti-inflammatory therapies based on soluble decoy TNFRs.
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Affiliation(s)
- Sergio M Pontejo
- From the Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, 28049 Madrid, Spain and
| | - Ali Alejo
- Centro de Investigacion en Sanidad Animal, Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria, Valdeolmos, 28130 Madrid, Spain
| | - Antonio Alcami
- From the Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, 28049 Madrid, Spain and
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16
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Abstract
Chemokines are chemoattractant cytokines that mediate the migration of immune cells to sites of infection which play an important role in innate and adaptive immunity. As an immune evasion strategy, large DNA viruses (herpesviruses and poxviruses) encode soluble chemokine binding proteins that bind chemokines with high affinity, even though they do not show sequence similarity to cellular chemokine receptors. This review summarizes the different secreted viral chemokine binding proteins described to date, with special emphasis on the diverse mechanisms of action they exhibit to interfere with chemokine function and their specific contribution to virus pathogenesis.
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Affiliation(s)
- Haleh Heidarieh
- Centro de Biología Molecular Severo Ochoa (Consejo Superior de Investigaciones Científicas - Universidad Autónoma de Madrid), Cantoblanco, Madrid, Spain
| | - Bruno Hernáez
- Centro de Biología Molecular Severo Ochoa (Consejo Superior de Investigaciones Científicas - Universidad Autónoma de Madrid), Cantoblanco, Madrid, Spain
| | - Antonio Alcamí
- Centro de Biología Molecular Severo Ochoa (Consejo Superior de Investigaciones Científicas - Universidad Autónoma de Madrid), Cantoblanco, Madrid, Spain.
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17
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Haller SL, Peng C, McFadden G, Rothenburg S. Poxviruses and the evolution of host range and virulence. Infect Genet Evol 2014; 21:15-40. [PMID: 24161410 PMCID: PMC3945082 DOI: 10.1016/j.meegid.2013.10.014] [Citation(s) in RCA: 169] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 10/15/2013] [Accepted: 10/15/2013] [Indexed: 11/22/2022]
Abstract
Poxviruses as a group can infect a large number of animals. However, at the level of individual viruses, even closely related poxviruses display highly diverse host ranges and virulence. For example, variola virus, the causative agent of smallpox, is human-specific and highly virulent only to humans, whereas related cowpox viruses naturally infect a broad spectrum of animals and only cause relatively mild disease in humans. The successful replication of poxviruses depends on their effective manipulation of the host antiviral responses, at the cellular-, tissue- and species-specific levels, which constitutes a molecular basis for differences in poxvirus host range and virulence. A number of poxvirus genes have been identified that possess host range function in experimental settings, and many of these host range genes target specific antiviral host pathways. Herein, we review the biology of poxviruses with a focus on host range, zoonotic infections, virulence, genomics and host range genes as well as the current knowledge about the function of poxvirus host range factors and how their interaction with the host innate immune system contributes to poxvirus host range and virulence. We further discuss the evolution of host range and virulence in poxviruses as well as host switches and potential poxvirus threats for human and animal health.
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Affiliation(s)
- Sherry L Haller
- Laboratory for Host-Specific Virology, Division of Biology, Kansas State University, KS 66506, USA
| | - Chen Peng
- Laboratory for Host-Specific Virology, Division of Biology, Kansas State University, KS 66506, USA
| | - Grant McFadden
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL 32610, USA
| | - Stefan Rothenburg
- Laboratory for Host-Specific Virology, Division of Biology, Kansas State University, KS 66506, USA.
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18
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Huang X, Huang Y, Cai J, Wei S, Gao R, Qin Q. Identification and characterization of a tumor necrosis factor receptor like protein encoded by Singapore grouper iridovirus. Virus Res 2013; 178:340-8. [DOI: 10.1016/j.virusres.2013.09.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2013] [Revised: 09/12/2013] [Accepted: 09/13/2013] [Indexed: 12/01/2022]
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19
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Luo S, Skerka C, Kurzai O, Zipfel PF. Complement and innate immune evasion strategies of the human pathogenic fungus Candida albicans. Mol Immunol 2013; 56:161-9. [DOI: 10.1016/j.molimm.2013.05.218] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2013] [Accepted: 05/10/2013] [Indexed: 01/09/2023]
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20
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Smith GL, Benfield CTO, Maluquer de Motes C, Mazzon M, Ember SWJ, Ferguson BJ, Sumner RP. Vaccinia virus immune evasion: mechanisms, virulence and immunogenicity. J Gen Virol 2013; 94:2367-2392. [PMID: 23999164 DOI: 10.1099/vir.0.055921-0] [Citation(s) in RCA: 248] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Virus infection of mammalian cells is sensed by pattern recognition receptors and leads to an innate immune response that restricts virus replication and induces adaptive immunity. In response, viruses have evolved many countermeasures that enable them to replicate and be transmitted to new hosts, despite the host innate immune response. Poxviruses, such as vaccinia virus (VACV), have large DNA genomes and encode many proteins that are dedicated to host immune evasion. Some of these proteins are secreted from the infected cell, where they bind and neutralize complement factors, interferons, cytokines and chemokines. Other VACV proteins function inside cells to inhibit apoptosis or signalling pathways that lead to the production of interferons and pro-inflammatory cytokines and chemokines. In this review, these VACV immunomodulatory proteins are described and the potential to create more immunogenic VACV strains by manipulation of the gene encoding these proteins is discussed.
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Affiliation(s)
- Geoffrey L Smith
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Camilla T O Benfield
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | | | - Michela Mazzon
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Stuart W J Ember
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Brian J Ferguson
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Rebecca P Sumner
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
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21
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Etemadi N, Holien JK, Chau D, Dewson G, Murphy JM, Alexander WS, Parker MW, Silke J, Nachbur U. Lymphotoxin α induces apoptosis, necroptosis and inflammatory signals with the same potency as tumour necrosis factor. FEBS J 2013; 280:5283-97. [PMID: 23815148 DOI: 10.1111/febs.12419] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Revised: 05/08/2013] [Accepted: 06/28/2013] [Indexed: 01/08/2023]
Abstract
Both of the TNF superfamily ligands, TNF and LTα, can bind and signal through TNFR1 and TNFR2, yet mice mutant for each have different phenotypes. Part of this difference is because LTα but not TNF can activate Herpes Virus Entry Mediator and also heterotrimerise with LTβ to activate LTβR, which is consistent with the similar phenotypes of the LTα and LTβR deficient mice. However, it has also been reported that the LTα3 homotrimer signals differently than TNF through TNFR1, and has unique roles in initiation and exacerbation of some inflammatory diseases. Our modeling of the TNF/TNFR1 interface compared to the LTα3/TNFR1 structure revealed some differences that could affect signalling by the two ligands. To determine whether there were any functional differences in the ability of TNF and LTα3 to induce TNFR1-dependent apoptosis or necroptosis, and if there were different requirements for cIAPs and Sharpin to transmit the TNFR1 signal, we compared the ability of cells to respond to TNF and LTα3. Contrary to our hypothesis, we were unable to discover differences in signalling by TNFR1 in response to TNF and LTα3. Our results imply that the reasons for the conservation of LTα are most likely due either to differential regulation, the ability to signal through Herpes Virus Entry Mediator or the ability of LTα to form heterotrimers with LTβ.
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Affiliation(s)
- Nima Etemadi
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Department of Medical Biology, University of Melbourne, Parkville, Australia
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22
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Bratke KA, McLysaght A, Rothenburg S. A survey of host range genes in poxvirus genomes. Infect Genet Evol 2012; 14:406-25. [PMID: 23268114 DOI: 10.1016/j.meegid.2012.12.002] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Revised: 12/01/2012] [Accepted: 12/06/2012] [Indexed: 12/17/2022]
Abstract
Poxviruses are widespread pathogens, which display extremely different host ranges. Whereas some poxviruses, including variola virus, display narrow host ranges, others such as cowpox viruses naturally infect a wide range of mammals. The molecular basis for differences in host range are poorly understood but apparently depend on the successful manipulation of the host antiviral response. Some poxvirus genes have been shown to confer host tropism in experimental settings and are thus called host range factors. Identified host range genes include vaccinia virus K1L, K3L, E3L, B5R, C7L and SPI-1, cowpox virus CP77/CHOhr, ectromelia virus p28 and 022, and myxoma virus T2, T4, T5, 11L, 13L, 062R and 063R. These genes encode for ankyrin repeat-containing proteins, tumor necrosis factor receptor II homologs, apoptosis inhibitor T4-related proteins, Bcl-2-related proteins, pyrin domain-containing proteins, cellular serine protease inhibitors (serpins), short complement-like repeats containing proteins, KilA-N/RING domain-containing proteins, as well as inhibitors of the double-stranded RNA-activated protein kinase PKR. We conducted a systematic survey for the presence of known host range genes and closely related family members in poxvirus genomes, classified them into subgroups based on their phylogenetic relationship and correlated their presence with the poxvirus phylogeny. Common themes in the evolution of poxvirus host range genes are lineage-specific duplications and multiple independent inactivation events. Our analyses yield new insights into the evolution of poxvirus host range genes. Implications of our findings for poxvirus host range and virulence are discussed.
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Affiliation(s)
- Kirsten A Bratke
- Smurfit Institute of Genetics, University of Dublin, Trinity College, Dublin 2, Ireland
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23
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Abstract
During the course of evolution, viruses have captured or created a diverse array of open reading frames, which encode for proteins that serve to evade and sabotage the host innate and adaptive immune responses that would otherwise lead to their elimination. These viral genomes are some of the best textbooks of immunology ever written. The established arsenal of immunomodulatory proteins encoded by viruses is large and growing, and includes specificities for virtually all known inflammatory pathways and targets. The focus of this review is on herpes and poxvirus-encoded cytokine and chemokine-binding proteins that serve to undermine the coordination of host immune surveillance. Structural and mechanistic studies of these decoy receptors have provided a wealth of information, not only about viral pathogenesis but also about the inner workings of cytokine signaling networks.
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Affiliation(s)
- Megan L Epperson
- Department of Pathology & Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
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24
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Abstract
In the course of evolution, viruses have developed various molecular mechanisms to evade the defense reactions of the host organism. When understanding the mechanisms used by viruses to overcome manifold defense systems of the animal organism, represented by molecular factors and cells of the immune system, we would not only comprehend better but also discover new patterns of organization and function of these most important reactions directed against infectious agents. Here, study of the orthopoxviruses pathogenic for humans, such as variola (smallpox), monkeypox, cowpox, and vaccinia viruses, may be most important. Analysis of the experimental data, presented in this paper, allows to infer that variola virus and other orthopoxviruses possess an unexampled set of genes whose protein products efficiently modulate the manifold defense mechanisms of the host organisms compared with the viruses from other families.
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25
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Abstract
Viruses are the most abundant and diverse pathogens challenging the host immune system, and as such are a severe threat to human health. To this end, viruses have evolved multiple strategies to evade and subvert the host immune response. Host-pathogen interactions are usually initiated via recognition of pathogen-associated molecular patterns (PAMPs) by host sensors known as pattern recognition receptors (PRRs), which include, Toll-like receptors (TLRs), RIG-I-like receptors (RLRs), NOD-like receptors (NLRs) and DNA receptors. Effective sensing of PAMPs rapidly triggers host immune responses, via activation of complex signalling pathways that culminates in the induction of inflammatory responses and the eradication of pathogens. Activation of the nuclear factor-κB (NF-κB) transcription pathway is crucial for the immediate early step of immune activation. This review discusses the recent evidence describing a variety of viral effectors that have been shown to prevent NF-κB signalling. Most of these viral effectors can be broadly classified into three categories based on the site of inhibition within the NF-κB pathway, that is, at the (i) TLRs, (ii) IKK complex or (iii) the transcriptional level.
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Affiliation(s)
- Gaëlle Le Negrate
- Institute of Medical Microbiology and Hospital Hygiene, Heinrich Heine University, Düsseldorf, Germany.
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26
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27
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Hansen SJ, Rushton J, Dekonenko A, Chand HS, Olson GK, Hutt JA, Pickup D, Lyons CR, Lipscomb MF. Cowpox virus inhibits human dendritic cell immune function by nonlethal, nonproductive infection. Virology 2011; 412:411-25. [PMID: 21334039 DOI: 10.1016/j.virol.2011.01.024] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Revised: 11/03/2010] [Accepted: 01/18/2011] [Indexed: 01/14/2023]
Abstract
Orthopoxviruses encode multiple proteins that modulate host immune responses. We determined whether cowpox virus (CPXV), a representative orthopoxvirus, modulated innate and acquired immune functions of human primary myeloid DCs and plasmacytoid DCs and monocyte-derived DCs (MDDCs). A CPXV infection of DCs at a multiplicity of infection of 10 was nonproductive, altered cellular morphology, and failed to reduce cell viability. A CPXV infection of DCs did not stimulate cytokine or chemokine secretion directly, but suppressed toll-like receptor (TLR) agonist-induced cytokine secretion and a DC-stimulated mixed leukocyte reaction (MLR). LPS-stimulated NF-κB nuclear translocation and host cytokine gene transcription were suppressed in CPXV-infected MDDCs. Early viral immunomodulatory genes were upregulated in MDDCs, consistent with early DC immunosuppression via synthesis of intracellular viral proteins. We conclude that a nonproductive CPXV infection suppressed DC immune function by synthesizing early intracellular viral proteins that suppressed DC signaling pathways.
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Affiliation(s)
- Spencer J Hansen
- Department of Pathology, University of New Mexico School of Medicine, Albuquerque, NM, USA.
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28
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Nepomnyashchikh TS, Antonets DV, Lebedev LR, Gileva IP, Shchelkunov SN. 3D structure modeling of complexes formed by CrmB TNF-binding proteins of Variola and cowpox viruses with murine and human TNFs. Mol Biol 2010. [DOI: 10.1134/s0026893310060117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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30
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Alzhanova D, Früh K. Modulation of the host immune response by cowpox virus. Microbes Infect 2010; 12:900-9. [PMID: 20673807 DOI: 10.1016/j.micinf.2010.07.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2010] [Revised: 07/09/2010] [Accepted: 07/12/2010] [Indexed: 11/20/2022]
Abstract
Cowpox virus, a zoonotic poxvirus endemic to Eurasia, infects a large number of host species which makes its eradication impossible. The elimination of world-wide smallpox vaccination programs renders the human population increasingly susceptible to infection by orthopoxviruses resulting in a growing number of zoonotic infections including CPXV transmitted from domestic animals to humans. The ability of CPXV to infect a wide range of mammalian host is likely due to the fact that, among the orthopoxviruses, CPXV encodes the most complete set of open reading frames expected to encode immunomodulatory proteins. This renders CPXV particularly interesting for studying poxviral strategies to evade and counteract the host immune responses.
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31
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Lynch HE, Ray CA, Oie KL, Pollara JJ, Petty IT, Sadler AJ, Williams BR, Pickup DJ. Modified vaccinia virus Ankara can activate NF-kappaB transcription factors through a double-stranded RNA-activated protein kinase (PKR)-dependent pathway during the early phase of virus replication. Virology 2009; 391:177-86. [PMID: 19596385 DOI: 10.1016/j.virol.2009.06.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2008] [Revised: 01/09/2009] [Accepted: 06/06/2009] [Indexed: 01/09/2023]
Abstract
Modified vaccinia virus Ankara (MVA), which is a promising replication-defective vaccine vector, is unusual among the orthopoxviruses in activating NF-kappaB transcription factors in cells of several types. In human embryonic kidney (HEK 293T) cells, the MVA-induced depletion of IkappaBalpha required to activate NF-kappaB is inhibited by UV-inactivation of the virus, and begins before viral DNA replication. In HEK 293T, CHO, or RK13 cells, expression of the cowpox virus CP77 early gene, or the vaccinia virus K1L early gene suppresses MVA-induced IkappaBalpha depletion. In mouse embryonic fibroblasts (MEFs), MVA induction of IkappaBalpha depletion is dependent on the expression of mouse or human double-stranded RNA-activated protein kinase (PKR). These results demonstrate that events during the early phase of MVA replication can induce PKR-mediated processes contributing both to the activation of NF-kappaB signaling, and to processes that may restrict viral replication. This property may contribute to the efficacy of this vaccine virus.
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Rahman MM, Jeng D, Singh R, Coughlin J, Essani K, McFadden G. Interaction of human TNF and beta2-microglobulin with Tanapox virus-encoded TNF inhibitor, TPV-2L. Virology 2009; 386:462-8. [PMID: 19232662 DOI: 10.1016/j.virol.2009.01.026] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2008] [Revised: 01/01/2009] [Accepted: 01/20/2009] [Indexed: 11/15/2022]
Abstract
Tanapox virus (TPV) encodes and expresses a secreted TNF-binding protein, TPV-2L or gp38, that displays inhibitory properties against TNF from diverse mammalian species, including human, monkey, canine and rabbit. TPV-2L also has sequence similarity with the MHC-class I heavy chain and interacts differently with human TNF as compared to the known cellular TNF receptors or any of the known virus-encoded TNF receptor homologs derived from many poxviruses. In order to determine the TNF binding region in TPV-2L, various TPV-2L C-terminal truncations and internal deletions were created and the muteins were expressed using recombinant baculovirus vectors. C-terminal deletions from TPV-2L resulted in reduced binding affinity for human TNF and specific mutants of TNF that discriminate between TNF-R1 and TNF-R2. However, deletion of C-terminal 42 amino acid residues totally abolished the binding of human TNF and its mutants. Removal of any of the predicted internal domains resulted in a mutant TPV-2L protein incapable of binding to human TNF. Deletion of C-terminal residues also affected the ability of TPV-2L to block TNF-induced cellular cytotoxicity. In addition to TNF, TPV-2L can also form complexes with human beta2-microglobulin to form a novel macromolecular complex. In summary, the TPV-2L protein is a bona fide MHC-1 heavy chain family member that binds and inhibits human TNF in a fashion very distinct from other known poxvirus-encoded TNF inhibitors, and also can form a novel complex with the human MHC-1 light chain, beta2-microglobulin.
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Affiliation(s)
- Masmudur M Rahman
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, 1600 SW Archer Road, Gainesville, FL 32610, USA
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Chang SJ, Hsiao JC, Sonnberg S, Chiang CT, Yang MH, Tzou DL, Mercer AA, Chang W. Poxvirus host range protein CP77 contains an F-box-like domain that is necessary to suppress NF-kappaB activation by tumor necrosis factor alpha but is independent of its host range function. J Virol 2009; 83:4140-52. [PMID: 19211746 DOI: 10.1128/JVI.01835-08] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Tumor necrosis factor alpha (TNF-alpha) activates the nuclear factor kappaB (NF-kappaB) signaling pathway that regulates expression of many cellular factors playing important roles in innate immune responses and inflammation in infected hosts. Poxviruses employ many strategies to inhibit NF-kappaB activation in cells. In this report, we describe a poxvirus host range protein, CP77, which blocked NF-kappaB activation by TNF-alpha. Immunofluorescence analyses revealed that nuclear translocation of NF-kappaB subunit p65 protein in TNF-alpha-treated HeLa cells was blocked by CP77. CP77 did so without blocking IkappaBalpha phosphorylation, suggesting that upstream kinase activation was not affected by CP77. Using GST pull-down, we showed that CP77 bound to the NF-kappaB subunit p65 through the N-terminal six-ankyrin-repeat region in vitro. CP77 also bound to Cullin-1 and Skp1 of the SCF complex through a C-terminal 13-amino-acid F-box-like sequence. Both regions of CP77 are required to block NF-kappaB activation. We thus propose a model in which poxvirus CP77 suppresses NF-kappaB activation by two interactions: the C-terminal F-box of CP77 binding to the SCF complex and the N-terminal six ankyrins binding to the NF-kappaB subunit p65. In this way, CP77 attenuates innate immune response signaling in cells. Finally, we expressed CP77 or a CP77 F-box deletion protein from a vaccinia virus host range mutant (VV-hr-GFP) and showed that either protein was able to rescue the host range defect, illustrating that the F-box region, which is important for NF-kappaB modulation and binding to SCF complex, is not required for CP77's host range function. Consistently, knocking down the protein level of NF-kappaB did not relieve the growth restriction of VV-hr-GFP in HeLa cells.
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Abstract
Chemokines are chemoattractant cytokines that play an important role in immunity. The role of chemokines against invading pathogens is emphasized by the expression of chemokine inhibitors by many pathogens. A mechanims employed by poxviruses and herpesviruses is the secretion of chemokine bindingproteins unrelated to host receptors that bind chemokines with high affinity and block their activity. Soluble chemokine binding proteins have also been identified in the human parasite Schistosoma mansoni and in ticks. The binding specificity of these inhibitors of cell migration point at chemokines that contribute to host defense mechanisms against various pathogens. Chemokine binding proteins modulate the immune response and may lead to new therapeutic approaches to treat inflamatory diseases.
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Affiliation(s)
- Antonio Alcami
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones científicas, Universidad Autónoma de Madrid, Madrid, Spain.
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35
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Abstract
The immune system functions by maintaining a delicate balance between the activities of pro-inflammatory and anti-inflammatory pathways. Unbalanced activation of these pathways often leads to the development of serious inflammatory diseases. TNF (Tumor Necrosis Factor) is a key pro-inflammatory cytokine, which can cause several inflammatory diseases when inappropriately up-regulated. Inhibition of TNF activities by using modulatory recombinant proteins has become a successful therapeutic approach to control TNF activity levels but these anti-TNF reagents also have risks and certain limitations. Biological molecules with a different mode of action in regulating TNF biology might provide a clinically useful alternative to the current therapeutics or in some cases might be efficacious in combination with existinganti-TNF therapies. TNF is also a powerful host defense cytokine commonly induced in the host response against various invading pathogens. Many viral pathogens can block TNF function by encoding modulators of TNF, its receptors or downstream signaling pathways. Here, we review the known virus-encoded TNF inhibitors and evaluate their potential as alternative future anti-TNF therapies.
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Affiliation(s)
- Masmudur M Rahman
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
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Dai K, Liu Y, Liu M, Xu J, Huang W, Huang X, Liu L, Wan Y, Hao Y, Shao Y. Pathogenicity and immunogenicity of recombinant Tiantan Vaccinia Virus with deleted C12L and A53R genes. Vaccine 2008; 26:5062-71. [DOI: 10.1016/j.vaccine.2008.06.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2008] [Revised: 05/07/2008] [Accepted: 06/05/2008] [Indexed: 12/21/2022]
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Waibler Z, Anzaghe M, Ludwig H, Akira S, Weiss S, Sutter G, Kalinke U. Modified vaccinia virus Ankara induces Toll-like receptor-independent type I interferon responses. J Virol 2007; 81:12102-10. [PMID: 17855554 PMCID: PMC2168990 DOI: 10.1128/jvi.01190-07] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Modified vaccinia virus Ankara (MVA) is a highly attenuated vaccinia virus strain undergoing clinical evaluation as a replication-deficient vaccine vector against various infections and tumor diseases. To analyze the basis of its high immunogenicity, we investigated the mechanism of how MVA induces type I interferon (IFN) responses. MVA stimulation of bone marrow-derived dendritic cells (DC) showed that plasmacytoid DC were main alpha IFN (IFN-alpha) producers that were triggered independently of productive infection, viral replication, or intermediate and late viral gene expression. Increased IFN-alpha levels were induced upon treatment with mildly UV-irradiated MVA, suggesting that a virus-encoded immune modulator(s) interfered with the host cytokine response. Mice devoid of Toll-like receptor 9 (TLR9), the receptor for double-stranded DNA, mounted normal IFN-alpha responses upon MVA treatment. Furthermore, mice devoid of the adaptors of TLR signaling MyD88 and TRIF and mice deficient in protein kinase R (PKR) showed IFN-alpha responses that were only slightly reduced compared to those of wild-type mice. MVA-induced IFN-alpha responses were critically dependent on autocrine/paracrine triggering of the IFN-alpha/beta receptor and were independent of IFN-beta, thus involving "one-half" of a positive-feedback loop. In conclusion, MVA-mediated type I IFN secretion was primarily triggered by non-TLR molecules, was independent of virus propagation, and critically involved IFN feedback stimulation. These data provide the basis to further improve MVA as a vaccine vector.
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Affiliation(s)
- Zoe Waibler
- Division of Immunology, Paul-Ehrlich-Institut, D-63225, Langen, Germany
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38
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Graham SC, Bahar MW, Abrescia NGA, Smith GL, Stuart DI, Grimes JM. Structure of CrmE, a Virus-encoded Tumour Necrosis Factor Receptor. J Mol Biol 2007; 372:660-71. [PMID: 17681535 DOI: 10.1016/j.jmb.2007.06.082] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2007] [Revised: 06/18/2007] [Accepted: 06/28/2007] [Indexed: 11/17/2022]
Abstract
Vaccinia virus (VACV), the smallpox vaccine, encodes many proteins that subvert the host immune response. One of these, cytokine response modifier E (CrmE), is secreted by infected cells and protects these cells from apoptotic challenge by tumour necrosis factor alpha (TNFalpha). We have expressed recombinant CrmE from VACV strain Lister in Escherichia coli, shown that the purified protein is monomeric in solution and competent to bind TNFalpha, and solved the structure to 2.0 A resolution. This is the first structure of a virus-encoded tumour necrosis factor receptor (TNFR). CrmE shares significant sequence similarity with mammalian type 2 TNF receptors (TNFSFR1B, p75; TNFR type 2). The structure confirms that CrmE adopts the canonical TNFR fold but only one of the two "ligand-binding" loops of TNFRSF1A is conserved in CrmE, suggesting a mechanism for the higher affinity of poxvirus TNFRs for TNFalpha over lymphotoxin-alpha. The roles of dimerisation and pre-ligand-assembly domains (PLADs) in poxvirus and mammalian TNFR activity are discussed.
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MESH Headings
- Amino Acid Sequence
- Crystallography, X-Ray
- Humans
- Hydrophobic and Hydrophilic Interactions
- Ligands
- Models, Molecular
- Molecular Sequence Data
- Protein Binding
- Protein Structure, Quaternary
- Protein Structure, Tertiary
- Receptors, Tumor Necrosis Factor/chemistry
- Receptors, Tumor Necrosis Factor/isolation & purification
- Receptors, Tumor Necrosis Factor/metabolism
- Receptors, Tumor Necrosis Factor, Type I/chemistry
- Receptors, Tumor Necrosis Factor, Type I/metabolism
- Recombinant Proteins/chemistry
- Recombinant Proteins/metabolism
- Tumor Necrosis Factor-alpha/isolation & purification
- Tumor Necrosis Factor-alpha/metabolism
- Vaccinia virus/chemistry
- Viral Proteins/chemistry
- Viral Proteins/isolation & purification
- Viral Proteins/metabolism
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Affiliation(s)
- Stephen C Graham
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics and Oxford Protein Production Facility Roosevelt Drive, Headington, Oxford OX3 7BN, UK
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Abstract
Jenner's original vaccine used cowpox virus. Cowpox virus and, subsequently, vaccinia virus, a closely related Orthopoxvirus, provided the means to eradicate smallpox. This history and the unique properties of the virus suggest that vaccinia virus will continue to provide a useful vaccine platform. Yet, surprisingly, it has become apparent that much of the virus genome encodes accessory proteins that interfere with host immune responses to infection. Manipulation of these genes offers the potential for new generations of orthopoxvirus vaccines in which we will have far greater control over key features of the vaccination, including the sites of virus infection, the degree of virus replication, the pathogenicity of the virus and, most importantly, the suppression or induction of immune responses of specific types.
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Affiliation(s)
- David J Pickup
- Department of Molecular Genetics and Microbiology, and Duke Human Vaccine Institute, Box 3020, Duke University Medical Center, Durham, NC 27710 USA.
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Gileva IP, Nepomnyashchikh TS, Antonets DV, Lebedev LR, Kochneva GV, Grazhdantseva AV, Shchelkunov SN. Properties of the recombinant TNF-binding proteins from variola, monkeypox, and cowpox viruses are different. Biochim Biophys Acta 2006; 1764:1710-8. [PMID: 17070121 PMCID: PMC9628946 DOI: 10.1016/j.bbapap.2006.09.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2006] [Revised: 08/10/2006] [Accepted: 09/08/2006] [Indexed: 11/30/2022]
Abstract
Tumor necrosis factor (TNF), a potent proinflammatory and antiviral cytokine, is a critical extracellular immune regulator targeted by poxviruses through the activity of virus-encoded family of TNF-binding proteins (CrmB, CrmC, CrmD, and CrmE). The only TNF-binding protein from variola virus (VARV), the causative agent of smallpox, infecting exclusively humans, is CrmB. Here we have aligned the amino acid sequences of CrmB proteins from 10 VARV, 14 cowpox virus (CPXV), and 22 monkeypox virus (MPXV) strains. Sequence analyses demonstrated a high homology of these proteins. The regions homologous to cd00185 domain of the TNF receptor family, determining the specificity of ligand–receptor binding, were found in the sequences of CrmB proteins. In addition, a comparative analysis of the C-terminal SECRET domain sequences of CrmB proteins was performed. The differences in the amino acid sequences of these domains characteristic of each particular orthopoxvirus species were detected. It was assumed that the species-specific distinctions between the CrmB proteins might underlie the differences in these physicochemical and biological properties. The individual recombinant proteins VARV-CrmB, MPXV-CrmB, and CPXV-CrmB were synthesized in a baculovirus expression system in insect cells and isolated. Purified VARV-CrmB was detectable as a dimer with a molecular weight of 90 kDa, while MPXV- and CPXV-CrmBs, as monomers when fractioned by non-reducing SDS-PAGE. The CrmB proteins of VARV, MPXV, and CPXV differed in the efficiencies of inhibition of the cytotoxic effects of human, mouse, or rabbit TNFs in L929 mouse fibroblast cell line. Testing of CrmBs in the experimental model of LPS-induced shock using SPF BALB/c mice detected a pronounced protective effect of VARV-CrmB. Thus, our data demonstrated the difference in anti-TNF activities of VARV-, MPXV-, and CPXV-CrmBs and efficiency of VARV-CrmB rather than CPXV- or MPXV-CrmBs against LPS-induced mortality in mice.
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Affiliation(s)
- Irina P Gileva
- State Research Center of Virology and Biotechnology Vector, Koltsovo, Novosibirsk oblast, 630559 Russia
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41
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Rahman MM, Barrett JW, Brouckaert P, McFadden G. Variation in Ligand Binding Specificities of a Novel Class of Poxvirus-encoded Tumor Necrosis Factor-binding Protein. J Biol Chem 2006; 281:22517-26. [PMID: 16782702 DOI: 10.1074/jbc.m604645200] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Yatapoxviruses encode a distinct class of secreted TNF-binding protein (TNF-BP) that resembles an MHC class I heavy chain but distinct from any other known TNF inhibitor. Characterization of these viral TNF inhibitors from Tanapox virus, Yaba monkey tumor virus (YMTV) and a closely related version from Swinepox virus revealed dramatically differential TNF binding specificities for different mammalian species. The Tanapox virus 2L protein (TPV-2L) formed inhibitory complexes with human TNF, and interacted with monkey and canine TNF with high affinity but rabbit TNF with low affinity. On the other hand, YMTV-2L bound human and monkey TNF with high affinity but rabbit TNF with only low affinity. The TNF-BP from swinepox virus (SPV003/148) only interacted with porcine TNF with high affinity. The observed TNF binding analysis mirrored the biological activity of these TNF-binding protein to block TNF-induced cellular cytolysis. TPV-2L and YMTV-2L also inhibited the human TNF-mediated signaling in cells but TPV-2L exhibited higher affinity for human TNF (KD, 43 pm) compared with monkey (KD, 120 pm) whereas for YMTV-2L, the affinities were reversed (human TNF KD, 440 pm; monkey TNF KD, 230 pm). The interaction domain of human TNF with TNF-binding proteins is significantly different from that of TNFRs, as determined using human TNF mutants. We conclude that these poxvirus TNF-binding proteins represent a new class of TNF inhibitors and are distinct from the viral TNF receptor homologues characterized to date.
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Affiliation(s)
- Masmudur M Rahman
- BioTherapeutics Research Group, Robarts Research Institute and Department of Microbiology and Immunology, University of Western Ontario, London, Ontario N6G2V4, Canada
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Alejo A, Ruiz-Argüello MB, Ho Y, Smith VP, Saraiva M, Alcami A. A chemokine-binding domain in the tumor necrosis factor receptor from variola (smallpox) virus. Proc Natl Acad Sci U S A 2006; 103:5995-6000. [PMID: 16581912 PMCID: PMC1458686 DOI: 10.1073/pnas.0510462103] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Variola virus (VaV) is the causative agent of smallpox, one of the most devastating diseases encountered by man, that was eradicated in 1980. The deliberate release of VaV would have catastrophic consequences on global public health. However, the mechanisms that contribute to smallpox pathogenesis are poorly understood at the molecular level. The ability of viruses to evade the host defense mechanisms is an important determinant of viral pathogenesis. Here we show that the tumor necrosis factor receptor (TNFR) homologue CrmB encoded by VaV functions not only as a soluble decoy TNFR but also as a highly specific binding protein for several chemokines that mediate recruitment of immune cells to mucosal surfaces and the skin, sites of virus entry and viral replication at late stages of smallpox. CrmB binds chemokines through its C-terminal domain, which is unrelated to TNFRs, was named smallpox virus-encoded chemokine receptor (SECRET) domain and uncovers a family of poxvirus chemokine inhibitors. An active SECRET domain was found in another viral TNFR (CrmD) and three secreted proteins encoded by orthopoxviruses. These findings identify a previously undescribed chemokine-binding and inhibitory domain unrelated to host chemokine receptors and a mechanism of immune modulation in VaV that may influence smallpox pathogenesis.
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Affiliation(s)
- Alí Alejo
- *Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, Cambridge CB2 2QQ, United Kingdom
- Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Campus de Cantoblanco, 28049 Madrid, Spain; and
| | - M. Begoña Ruiz-Argüello
- *Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, Cambridge CB2 2QQ, United Kingdom
- Centro de Investigación en Sanidad Animal, Instituto Nacional de Investigaciones Agrarias, Valdeolmos, 28130 Madrid, Spain
| | - Yin Ho
- *Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, Cambridge CB2 2QQ, United Kingdom
| | - Vincent P. Smith
- *Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, Cambridge CB2 2QQ, United Kingdom
| | - Margarida Saraiva
- *Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, Cambridge CB2 2QQ, United Kingdom
| | - Antonio Alcami
- *Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, Cambridge CB2 2QQ, United Kingdom
- Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Campus de Cantoblanco, 28049 Madrid, Spain; and
- **To whom correspondence should be addressed. E-mail:
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Abstract
In response to invasion by microbial pathogens, host defense mechanisms get activated by both the innate and adaptive arms of the immune responses. TNF (tumor necrosis factor) is a potent proinflammatory cytokine expressed by activated macrophages and lymphocytes that induces diverse cellular responses that can vary from apoptosis to the expression of genes involved in both early inflammatory and acquired immune responses. A wide spectrum of microbes has acquired elegant mechanisms to overcome or deflect the host responses mediated by TNF. For example, modulatory proteins encoded by multiple families of viruses can block TNF and TNF-mediated responses at multiple levels, such as the inhibition of the TNF ligand or its receptors, or by modulating key transduction molecules of the TNF signaling pathway. Bacteria, on the other hand, tend to modify TNF-mediated responses specifically by regulating components of the TNF signaling pathway. Investigation of these diverse strategies employed by viral and bacterial pathogens has significantly advanced our understanding of both host TNF responses and microbial pathogenesis. This review summarizes the diverse microbial strategies to regulate TNF and how such insights into TNF modulation could benefit the treatment of inflammatory or autoimmune diseases.
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Abstract
Through eons of co-evolution, poxviruses and their hosts have come to an elegant point of equilibrium whereby the host immune system is systematically modulated in favor of the virus. Owing to the large coding capacity of poxviruses, many gene products are dedicated as virulence factors. Key targets of these immunomodulators include mediators of inflammation, chemotaxis, apoptosis and the antiviral state. It is not surprising that these systems have become targets since they are crucial for mounting an effective immune response against poxviruses. The following discussion will focus on a select group of poxvirus proteins that are able to modulate particular components of the host response efficiently to ensure propagation of the virus.
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Affiliation(s)
- Grant McFadden
- The University of Western Ontario, Robarts Research Institute and Department of Microbiology and Immunology, Siebens-Drake Building Room 1331400 Western Road, London, Ontario, N6G 2V4, Canada
| | - Steven H Nazarian
- The University of Western Ontario, Robarts Research Institute and Department of Microbiology and Immunology, London, Ontario, N6G 2V4, Canada
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Abstract
Ectromelia virus (ECTV) is an orthopoxvirus whose natural host is the mouse; it is related closely to Variola virus, the causative agent of smallpox, and Monkeypox virus, the cause of an emerging zoonosis. The recent sequencing of its genome, along with an effective animal model, makes ECTV an attractive model for the study of poxvirus pathogenesis, antiviral and vaccine testing and viral immune and inflammatory responses. This review discusses the pathogenesis of mousepox, modulation of the immune response by the virus and the cytokine and cellular components of the skin and systemic immune system that are critical to recovery from infection.
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Affiliation(s)
- David J Esteban
- University of Victoria, Department of Biochemistry and Microbiology, PO Box 3055 STN CSC, Victoria BC, Canada V8W 3P6
| | - R Mark L Buller
- St Louis University Health Sciences Center, Department of Molecular Microbiology and Immunology, 1402 S. Grand Blvd, St Louis, MO 63104, USA
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46
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Gileva IP, Ryazankin IA, Nepomnyashchikh TS, Totmenin AV, Maxutov ZA, Lebedev LR, Afinogenova GN, Pustoshilova NM, Shchelkunov SN. Expression of genes for orthopoxviral TNF-binding proteins in insect cells and investigation of the recombinant TNF-binding proteins. Mol Biol 2005. [DOI: 10.1007/s11008-005-0032-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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47
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Gillet L, Vanderplasschen A. Viral Subversion of the Immune System. Applications of Gene-Based Technologies for Improving Animal Production and Health in Developing Countries 2005. [PMCID: PMC7121541 DOI: 10.1007/1-4020-3312-5_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The continuous interactions between host and viruses during their co-evolution have shaped not only the immune system but also the countermeasures used by viruses. Studies in the last decade have described the diverse arrays of pathways and molecular targets that are used by viruses to elude immune detection or destruction, or both. These include targeting of pathways for major histocompatibility complex class I and class II antigen presentation, natural killer cell recognition, apoptosis, cytokine signalling, and complement activation. This paper provides an overview of the viral immune-evasion mechanisms described to date. It highlights the contribution of this field to our understanding of the immune system, and the importance of understanding this aspect of the biology of viral infection to develop efficacious and safe vaccines.
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Abstract
Soluble cytokine receptors regulate inflammatory and immune events by functioning as agonists or antagonists of cytokine signaling. As such, they act within complex receptor systems that include signaling receptors, nonsignaling decoy receptors, receptor-associated proteins, and soluble receptor antagonists. Soluble cytokine receptors can be generated by several mechanisms, which include proteolytic cleavage of receptor ectodomains, alternative splicing of mRNA transcripts, transcription of distinct genes that encode soluble cytokine-binding proteins, release of full-length receptors within the context of exosome-like vesicles, and cleavage of GPI-anchored receptors. Furthermore, the important role of soluble cytokine receptors in regulating host defense mechanisms is evidenced by viruses that encode soluble homologues of mammalian receptors and thereby evade innate host immune responses via the sequestration of essential cytokines.
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Affiliation(s)
- Stewart J Levine
- Pulmonary-Critical Care Medicine Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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Abstract
Poxvirus interleukin (IL)-18 binding proteins (IL-18BPs) are soluble decoys that inhibit the activity of IL-18. The aim of this study was to demonstrate IL-18 binding activity of the Variola virus protein D7L. D7L effectively inhibited the biological activity of IL-18 in a bioassay. We compared the affinity and kinetics of D7L and the Ectromelia virus IL-18BP, p13, for human and murine IL-18 using surface plasmon resonance and no differences were detected, indicating that the differences in amino acid sequence did not affect binding or species specificity. Both proteins had higher affinity for murine than human IL-18. This was similar to human IL-18BP and the Molluscum contagiosum virus IL-18BP, which also demonstrated higher affinity for human IL-18. The host range of Variola virus is limited to humans and thus the affinity of D7L for IL-18 does not correlate with its host range. Furthermore, we demonstrated that D7L is capable of interacting with glycosaminoglycans (GAGs) via the C terminus, while p13 is not. Importantly, D7L interacted with both GAG and IL-18 simultaneously, indicating that the binding sites were distinct.
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Affiliation(s)
- David J Esteban
- St Louis University Health Sciences Center, Department of Molecular Microbiology and Immunology, 1402 South Grand Blvd, St Louis, MO 63104, USA
| | - Anthony A Nuara
- St Louis University Health Sciences Center, Department of Molecular Microbiology and Immunology, 1402 South Grand Blvd, St Louis, MO 63104, USA
| | - R Mark L Buller
- St Louis University Health Sciences Center, Department of Molecular Microbiology and Immunology, 1402 South Grand Blvd, St Louis, MO 63104, USA
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Abstract
Ectromelia virus is the causative agent of mousepox, an acute exanthematous disease of mouse colonies in Europe, Japan, China, and the U.S. The Moscow, Hampstead, and NIH79 strains are the most thoroughly studied with the Moscow strain being the most infectious and virulent for the mouse. In the late 1940s mousepox was proposed as a model for the study of the pathogenesis of smallpox and generalized vaccinia in humans. Studies in the last five decades from a succession of investigators have resulted in a detailed description of the virologic and pathologic disease course in genetically susceptible and resistant inbred and out-bred mice. We report the DNA sequence of the left-hand end, the predicted right-hand terminal repeat, and central regions of the genome of the Moscow strain of ectromelia virus (approximately 177,500 bp), which together with the previously sequenced right-hand end, yields a genome of 209,771 bp. We identified 175 potential genes specifying proteins of between 53 and 1924 amino acids, and 29 regions containing sequences related to genes predicted in other poxviruses, but unlikely to encode for functional proteins in ectromelia virus. The translated protein sequences were compared with the protein database for structure/function relationships, and these analyses were used to investigate poxvirus evolution and to attempt to explain at the cellular and molecular level the well-characterized features of the ectromelia virus natural life cycle.
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Affiliation(s)
- Nanhai Chen
- Department of Molecular Microbiology and Immunology, Saint Louis University Health Sciences Center, 1402 South Grand Boulevard, St. Louis, MO 63104, USA
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