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Piralla A, Mileto D, Rizzo A, Ferrari G, Giardina F, Gaiarsa S, Petazzoni G, Bianchi M, Salari F, Bracchitta F, Sammartino JC, Ferrari A, Gagliardi G, Mancon A, Fenizia C, Biasin M, Rovida F, Paolucci S, Percivalle E, Lombardi A, Micheli V, Nozza S, Castagna A, Moschese D, Antinori S, Gori A, Bonfanti P, Rossotti R, D'Arminio Monforte A, Attanasi F, Tirani M, Cereda D, Baldanti F, Gismondo MR. Dynamics of viral DNA shedding and culture viral DNA positivity in different clinical samples collected during the 2022 mpox outbreak in Lombardy, Italy. Travel Med Infect Dis 2024; 59:102698. [PMID: 38556220 DOI: 10.1016/j.tmaid.2024.102698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 02/15/2024] [Accepted: 02/17/2024] [Indexed: 04/02/2024]
Abstract
BACKGROUND Mpox virus (MPXV) has recently spread outside of sub-Saharan Africa. This large multicentre study was conducted in Lombardy, the most densely populated Italian region accounting for more than 40% of Italian cases. The present study aims to: i) evaluate the presence and the shedding duration of MPXV DNA in different body compartments correlating the MPXV viability with the time to onset of symptoms; ii) provide evidence of MPXV persistence in different body compartment as a source of infection and iii) characterize the MPXV evolution by whole genome sequencing (WGS) during the outbreak occurred in Italy. MATERIAL AND METHODS The study included 353 patients with a laboratory-confirmed diagnosis of MPXV infection screened in several clinical specimens in the period May 24th - September 1st, 2022. Viral isolation was attempted from different biological matrices and complete genome sequencing was performed for 61 MPXV strains. RESULTS MPXV DNA detection was more frequent in the skin (94.4%) with the longest median time of viral clearance (16 days). The actively-replicating virus in cell culture was obtained for 123/377 (32.6%) samples with a significant higher viral quantity on isolation positive samples (20 vs 31, p < 0.001). The phylogenetic analysis highlighted the high genetic identity of the MPXV strains collected, both globally and within the Lombardy region. CONCLUSION Skin lesion is gold standard material and the high viral load and the actively-replicating virus observed in genital sites confirms that sexual contact plays a key role in the viral transmission.
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Affiliation(s)
- Antonio Piralla
- Microbiology and Virology Department, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Davide Mileto
- Clinical Microbiology, Virology and Bioemergency Diagnostics, ASST Fatebenefratelli Sacco, Luigi Sacco Hospital, Milan, Italy
| | - Alberto Rizzo
- Clinical Microbiology, Virology and Bioemergency Diagnostics, ASST Fatebenefratelli Sacco, Luigi Sacco Hospital, Milan, Italy
| | - Guglielmo Ferrari
- Microbiology and Virology Department, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Federica Giardina
- Department of Clinical-Surgical, Diagnostic and Pediatric Sciences, Università degli Studi di Pavia, Pavia, Italy
| | - Stefano Gaiarsa
- Microbiology and Virology Department, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Greta Petazzoni
- Microbiology and Virology Department, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Micol Bianchi
- Clinical Microbiology, Virology and Bioemergency Diagnostics, ASST Fatebenefratelli Sacco, Luigi Sacco Hospital, Milan, Italy
| | - Federica Salari
- Clinical Microbiology, Virology and Bioemergency Diagnostics, ASST Fatebenefratelli Sacco, Luigi Sacco Hospital, Milan, Italy
| | - Fiorenza Bracchitta
- Clinical Microbiology, Virology and Bioemergency Diagnostics, ASST Fatebenefratelli Sacco, Luigi Sacco Hospital, Milan, Italy
| | - Josè Camilla Sammartino
- Department of Clinical-Surgical, Diagnostic and Pediatric Sciences, Università degli Studi di Pavia, Pavia, Italy
| | - Alessandro Ferrari
- Microbiology and Virology Department, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Gloria Gagliardi
- Clinical Microbiology, Virology and Bioemergency Diagnostics, ASST Fatebenefratelli Sacco, Luigi Sacco Hospital, Milan, Italy
| | - Alessandro Mancon
- Clinical Microbiology, Virology and Bioemergency Diagnostics, ASST Fatebenefratelli Sacco, Luigi Sacco Hospital, Milan, Italy
| | - Claudio Fenizia
- Department of Biomedical and Clinical Sciences "L.Sacco", University of Milan, Italy
| | - Mara Biasin
- Department of Biomedical and Clinical Sciences "L.Sacco", University of Milan, Italy
| | - Francesca Rovida
- Microbiology and Virology Department, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy; Department of Clinical-Surgical, Diagnostic and Pediatric Sciences, Università degli Studi di Pavia, Pavia, Italy
| | - Stefania Paolucci
- Microbiology and Virology Department, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Elena Percivalle
- Microbiology and Virology Department, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Alessandra Lombardi
- Clinical Microbiology, Virology and Bioemergency Diagnostics, ASST Fatebenefratelli Sacco, Luigi Sacco Hospital, Milan, Italy
| | - Valeria Micheli
- Clinical Microbiology, Virology and Bioemergency Diagnostics, ASST Fatebenefratelli Sacco, Luigi Sacco Hospital, Milan, Italy
| | - Silvia Nozza
- Clinic of Infectious Diseases, Vita-Salute University, San Raffaele Scientific Institute, Milan, Italy
| | - Antonella Castagna
- Clinic of Infectious Diseases, Vita-Salute University, San Raffaele Scientific Institute, Milan, Italy
| | - Davide Moschese
- I Division of Infectious Diseases, Luigi Sacco Hospital, ASST Fatebenefratelli Sacco, Milan, Italy
| | - Spinello Antinori
- Department of Biomedical and Clinical Science, Università degli Studi di Milano, III Division of Infectious Diseases, ASST Fatebenefratelli Sacco, Milan, Italy
| | - Andrea Gori
- Department of Infectious Diseases Ospedale "Luigi Sacco", Centre for Multidisciplinary Research in Health Science (MACH), University of Milan, Italy
| | - Paolo Bonfanti
- Department of Infectious Diseases, San Gerardo Hospital - University of Milano Bicocca, Monza, Italy
| | - Roberto Rossotti
- Department of Infectious Diseases, ASST Grande Ospedale Metropolitano Niguarda, Milan, Italy
| | - Antonella D'Arminio Monforte
- Clinic of Infectious Diseases, Department of Health Sciences, ASST Santi Paolo E Carlo, University of Milan, Milan, Italy
| | | | - Marcello Tirani
- Directorate General for Health, Lombardy Region, Milan, Italy
| | - Danilo Cereda
- Directorate General for Health, Lombardy Region, Milan, Italy
| | - Fausto Baldanti
- Microbiology and Virology Department, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy; Department of Clinical-Surgical, Diagnostic and Pediatric Sciences, Università degli Studi di Pavia, Pavia, Italy.
| | - Maria Rita Gismondo
- Clinical Microbiology, Virology and Bioemergency Diagnostics, ASST Fatebenefratelli Sacco, Luigi Sacco Hospital, Milan, Italy; Department of Biomedical and Clinical Sciences "L.Sacco", University of Milan, Italy
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2
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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] [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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3
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Lawson CA, Titus DJ, Koehler HS. Approaches to Evaluating Necroptosis in Virus-Infected Cells. Subcell Biochem 2023; 106:37-75. [PMID: 38159223 DOI: 10.1007/978-3-031-40086-5_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
The immune system functions to protect the host from pathogens. To counter host defense mechanisms, pathogens have developed unique strategies to evade detection or restrict host immune responses. Programmed cell death is a major contributor to the multiple host responses that help to eliminate infected cells for obligate intracellular pathogens like viruses. Initiation of programmed cell death pathways during the early stages of viral infections is critical for organismal survival as it restricts the virus from replicating and serves to drive antiviral inflammation immune recruitment through the release of damage-associated molecular patterns (DAMPs) from the dying cell. Necroptosis has been implicated as a critical programmed cell death pathway in a diverse set of diseases and pathological conditions including acute viral infections. This cell death pathway occurs when certain host sensors are triggered leading to the downstream induction of mixed-lineage kinase domain-like protein (MLKL). MLKL induction leads to cytoplasmic membrane disruption and subsequent cellular destruction with the release of DAMPs. As the role of this cell death pathway in human disease becomes apparent, methods identifying necroptosis patterns and outcomes will need to be further developed. Here, we discuss advances in our understanding of how viruses counteract necroptosis, methods to quantify the pathway, its effects on viral pathogenesis, and its impact on cellular signaling.
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Affiliation(s)
- Crystal A Lawson
- School of Molecular Biosciences, Washington State University, Pullman, WA, USA
- Center for Reproductive Biology, Washington State University, Pullman, WA, USA
| | - Derek J Titus
- Providence Sacred Heart, Spokane Teaching Health Center, Spokane, WA, USA
| | - Heather S Koehler
- School of Molecular Biosciences, Washington State University, Pullman, WA, USA.
- Center for Reproductive Biology, Washington State University, Pullman, WA, USA.
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4
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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] [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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5
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Lu JF, Jin TC, Zhou T, Lu XJ, Chen JP, Chen J. Identification and characterization of a tumor necrosis factor receptor like protein encoded by Cyprinid Herpesvirus 2. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2021; 116:103930. [PMID: 33212093 DOI: 10.1016/j.dci.2020.103930] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 10/10/2020] [Accepted: 11/15/2020] [Indexed: 06/11/2023]
Abstract
Virus-encoded tumor necrosis factor receptors (vTNFRs) facilitate viral escape from the host immune response during viral propagation. Cyprinid Herpesvirus-2 (CyHV-2) is a double-stranded DNA virus of alloherpesviridae family that causes great economic losses in the aquaculture industry. The present study identified and characterized a novel TNFR homolog termed ORF4 in CyHV-2. ORF4 was identified as a secreted protein and a homolog of herpesvirus entry mediator (HVEM). ORF4 localized to the cytoplasm in infected GiCF cells. ORF4 overexpression enhanced viral propagation, while downregulation of ORF4 via siRNA decreased viral propagation. ORF4 overexpression promoted GiCF proliferation, and its downregulation suppressed CyHV-2-induced apoptosis. GST-pulldown and LC-MS/MS assays identified 44 conditional binding proteins that interact with ORF4 protein, while the GST pulldown test did not support the idea that ORF4 interact with histone H3.3. Taken together, our results contribute to our understanding of the vTNFR function in alloherpesviridae pathogenesis and host immune regulation.
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Affiliation(s)
- Jian-Fei Lu
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, 315211, China; Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Ningbo, 315211, China; Key Laboratory of Applied Marine Biotechnology of Ministry of Education, Ningbo University, Ningbo, 315211, China
| | - Tian-Cheng Jin
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, 315211, China; Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Ningbo, 315211, China; Key Laboratory of Applied Marine Biotechnology of Ministry of Education, Ningbo University, Ningbo, 315211, China
| | - Ting Zhou
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, 315211, China; Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Ningbo, 315211, China; Key Laboratory of Applied Marine Biotechnology of Ministry of Education, Ningbo University, Ningbo, 315211, China
| | - Xin-Jiang Lu
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, 315211, China; Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Ningbo, 315211, China; Key Laboratory of Applied Marine Biotechnology of Ministry of Education, Ningbo University, Ningbo, 315211, China
| | - Jian-Ping Chen
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, 315211, China
| | - Jiong Chen
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, 315211, China; Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Ningbo, 315211, China; Key Laboratory of Applied Marine Biotechnology of Ministry of Education, Ningbo University, Ningbo, 315211, China.
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6
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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] [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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7
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Kattlun J, Menanteau-Ledouble S, El-Matbouli M. Non-structural protein pORF 12 of cyprinid herpesvirus 3 is recognized by the immune system of the common carp Cyprinus carpio. DISEASES OF AQUATIC ORGANISMS 2014; 111:269-73. [PMID: 25320039 DOI: 10.3354/dao02793] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Cyprinid herpesvirus 3 is an important pathogen and the causative agent of koi herpesvirus disease, which has been associated with mass mortalities in koi and common carp Cyprinus carpio. Currently, the only available commercial vaccine is an attenuated version of the virus. This has led to concerns about its risk to reversion to virulence. Furthermore, the vaccine is currently only available in Israel and the United States. In order to investigate the antigenic profile of the virus, western blot was performed using infected cell culture supernatant and sera from carp that had survived exposure to the virus. Only one antigen could be detected, and mass spectrometry analysis identified the corresponding protein as ORF 12, a putative secreted tumour necrosis factor receptor homologue. In other herpesviruses, such proteins have been associated with the viral infectious process in a number of ways, including the entry into the host cell and the inhibition of apoptosis in infected cells. The reason why only one antigen could be detected during this study is unknown.
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Affiliation(s)
- Julia Kattlun
- Clinical Division of Fish Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210 Vienna, Austria
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8
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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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Bahar MW, Graham SC, Chen RAJ, Cooray S, Smith GL, Stuart DI, Grimes JM. How vaccinia virus has evolved to subvert the host immune response. J Struct Biol 2011; 175:127-34. [PMID: 21419849 PMCID: PMC3477310 DOI: 10.1016/j.jsb.2011.03.010] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Revised: 03/10/2011] [Accepted: 03/14/2011] [Indexed: 01/06/2023]
Abstract
Viruses are obligate intracellular parasites and are some of the most rapidly evolving and diverse pathogens encountered by the host immune system. Large complicated viruses, such as poxviruses, have evolved a plethora of proteins to disrupt host immune signalling in their battle against immune surveillance. Recent X-ray crystallographic analysis of these viral immunomodulators has helped form an emerging picture of the molecular details of virus-host interactions. In this review we consider some of these immune evasion strategies as they apply to poxviruses, from a structural perspective, with specific examples from the European SPINE2-Complexes initiative. Structures of poxvirus immunomodulators reveal the capacity of viruses to mimic and compete against the host immune system, using a diverse range of structural folds that are unique or acquired from their hosts with both enhanced and unexpectedly divergent functions.
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Affiliation(s)
- Mohammad W Bahar
- Division of Structural Biology and Oxford Protein Production Facility, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX37BN, United Kingdom
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Rubins KH, Hensley LE, Relman DA, Brown PO. Stunned silence: gene expression programs in human cells infected with monkeypox or vaccinia virus. PLoS One 2011; 6:e15615. [PMID: 21267444 PMCID: PMC3022624 DOI: 10.1371/journal.pone.0015615] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Accepted: 11/12/2010] [Indexed: 12/20/2022] Open
Abstract
Poxviruses use an arsenal of molecular weapons to evade detection and disarm host immune responses. We used DNA microarrays to investigate the gene expression responses to infection by monkeypox virus (MPV), an emerging human pathogen, and Vaccinia virus (VAC), a widely used model and vaccine organism, in primary human macrophages, primary human fibroblasts and HeLa cells. Even as the overwhelmingly infected cells approached their demise, with extensive cytopathic changes, their gene expression programs appeared almost oblivious to poxvirus infection. Although killed (gamma-irradiated) MPV potently induced a transcriptional program characteristic of the interferon response, no such response was observed during infection with either live MPV or VAC. Moreover, while the gene expression response of infected cells to stimulation with ionomycin plus phorbol 12-myristate 13-acetate (PMA), or poly (I-C) was largely unimpaired by infection with MPV, a cluster of pro-inflammatory genes were a notable exception. Poly(I-C) induction of genes involved in alerting the innate immune system to the infectious threat, including TNF-alpha, IL-1 alpha and beta, CCL5 and IL-6, were suppressed by infection with live MPV. Thus, MPV selectively inhibits expression of genes with critical roles in cell-signaling pathways that activate innate immune responses, as part of its strategy for stealthy infection.
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Affiliation(s)
- Kathleen H. Rubins
- Departments of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
- Department of Biochemistry, Stanford University School of Medicine, Stanford, California, United States of America
| | - Lisa E. Hensley
- United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, United States of America
| | - David A. Relman
- Departments of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
- Department of Medicine, Stanford University School of Medicine, Stanford, California, United States of America
- Veterans Affairs Palo Alto Health Care System, Palo Alto, California, United States of America
| | - Patrick O. Brown
- Department of Biochemistry, Stanford University School of Medicine, Stanford, California, United States of America
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California, United States of America
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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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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12
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The full-length isoform of human papillomavirus 16 E6 and its splice variant E6* bind to different sites on the procaspase 8 death effector domain. J Virol 2009; 84:1453-63. [PMID: 19906919 DOI: 10.1128/jvi.01331-09] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Human papillomavirus 16 is a causative agent of most cases of cervical cancer and has also been implicated in the development of some head and neck cancers. The early viral E6 gene codes for two alternatively spliced isoforms, E6(large) and E6*. We have previously demonstrated the differential effects of E6(large) and E6* binding on the expression and stability of procaspase 8, a key mediator of the apoptotic pathway. Additionally, we have reported that E6 binds to the FADD death effector domain (DED) at a novel E6 binding domain. Sequence similarities between the FADD and procaspase 8 DEDs suggested a specific region for E6(large)/procaspase 8 binding, which was subsequently confirmed by mutational analysis as well as by the ability of peptides capable of blocking E6/FADD binding to also block E6(large)/caspase 8 binding. However, the binding of the smaller isoform, E6*, to procaspase 8 occurs at a different region, as deletion and point mutations that disrupt E6(large)/caspase 8 DED binding do not disrupt E6*/caspase 8 DED binding. In addition, peptide inhibitors that can block E6(large)/procaspase 8 binding do not affect the binding of E6* to procaspase 8. These results demonstrate that the residues that mediate E6*/procaspase 8 DED binding localize to a different region on the protein and employ a separate binding motif. This provides a molecular explanation for our initial findings that the two E6 isoforms affect procaspase 8 stability in an opposing manner.
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Alejo A, Saraiva M, Ruiz-Argüello MB, Viejo-Borbolla A, de Marco MF, Salguero FJ, Alcami A. A method for the generation of ectromelia virus (ECTV) recombinants: in vivo analysis of ECTV vCD30 deletion mutants. PLoS One 2009; 4:e5175. [PMID: 19365546 PMCID: PMC2664468 DOI: 10.1371/journal.pone.0005175] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2008] [Accepted: 03/10/2009] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Ectromelia virus (ECTV) is the causative agent of mousepox, a lethal disease of mice with similarities to human smallpox. Mousepox progression involves replication at the initial site of infection, usually the skin, followed by a rapid spread to the secondary replicative organs, spleen and liver, and finally a dissemination to the skin, where the typical rash associated with this and other orthopoxviral induced diseases appears. Case fatality rate is genetically determined and reaches up to 100% in susceptible mice strains. Like other poxviruses, ECTV encodes a number of proteins with immunomodulatory potential, whose role in mousepox progression remains largely undescribed. Amongst these is a secreted homologue of the cellular tumour necrosis factor receptor superfamily member CD30 which has been proposed to modulate a Th1 immune response in vivo. METHODOLOGY/PRINCIPAL FINDINGS To evaluate the contribution of viral CD30 (vCD30) to virus pathogenesis in the infected host, we have adapted a novel transient dominant method for the selection of recombinant ECTVs. Using this method, we have generated an ECTV vCD30 deletion mutant, its corresponding revertant control virus as well as a virus encoding the extracellular domain of murine CD30. These viruses contain no exogenous marker DNA sequences in their genomes, as opposed to other ECTVs reported up to date. CONCLUSIONS/SIGNIFICANCE We show that the vCD30 is expressed as a secreted disulfide linked trimer and that the absence of vCD30 does not impair mousepox induced fatality in vivo. Replacement of vCD30 by a secreted version of mouse CD30 caused limited attenuation of ECTV. The recombinant viruses generated may be of use in the study of the role of the cellular CD30-CD30L interaction in the development of the immune response. The method developed might be useful for the construction of ECTV mutants for the study of additional genes.
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Affiliation(s)
- Ali Alejo
- Centro de Investigación en Sanidad Animal, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Valdeolmos, Madrid, Spain
| | - Margarida Saraiva
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Maria Begoña Ruiz-Argüello
- Centro de Investigación en Sanidad Animal, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Valdeolmos, Madrid, Spain
| | - Abel Viejo-Borbolla
- Centro de Biología Molecular Severo Ochoa (Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid), Cantoblanco, Madrid, Spain
| | - Mar Fernández de Marco
- Centro de Biología Molecular Severo Ochoa (Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid), Cantoblanco, Madrid, Spain
| | - Francisco Javier Salguero
- Centro de Investigación en Sanidad Animal, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Valdeolmos, Madrid, Spain
| | - Antonio Alcami
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom
- Centro de Biología Molecular Severo Ochoa (Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid), Cantoblanco, Madrid, Spain
- * E-mail:
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14
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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] [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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15
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Rahman MM, Lucas AR, McFadden G. Viral TNF inhibitors as potential therapeutics. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2009; 666:64-77. [PMID: 20054975 DOI: 10.1007/978-1-4419-1601-3_5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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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16
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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] [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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17
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The interaction between human papillomavirus type 16 and FADD is mediated by a novel E6 binding domain. J Virol 2008; 82:9600-14. [PMID: 18632871 DOI: 10.1128/jvi.00538-08] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
High-risk strains of human papillomavirus, such as types 16 and 18, have been etiologically linked to cervical cancer. Most cervical cancer tissues are positive for both the E6 and E7 oncoproteins, since it is their cooperation that results in successful transformation and immortalization of infected cells. We have reported that E6 binds to tumor necrosis factor receptor 1 and to Fas-associated death domain (FADD) and, in doing so, prevents E6-expressing cells from responding to apoptotic stimuli. The binding site of E6 to FADD localizes to the first 23 amino acids of FADD and has now been further characterized by the use of deletion and site-directed mutants of FADD in pull-down and functional assays. The results from these experiments revealed that mutations of serine 16, serine 18, and leucine 20 obstruct FADD binding to E6, suggesting that these residues are part of the E6 binding domain on FADD. Because FADD does not contain the two previously identified E6 binding motifs, the LxxphiLsh motif, and the PDZ motif, a novel binding domain for E6 has been identified on FADD. Furthermore, peptides that correspond to this region can block E6/FADD binding in vitro and can resensitize E6-expressing cells to apoptotic stimuli in vivo. These results demonstrate the existence of a novel E6 binding domain.
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18
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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] [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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19
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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] [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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20
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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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21
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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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22
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Buckley CA, Rouhani FN, Kaler M, Adamik B, Hawari FI, Levine SJ. Amino-terminal TACE prodomain attenuates TNFR2 cleavage independently of the cysteine switch. Am J Physiol Lung Cell Mol Physiol 2005; 288:L1132-8. [PMID: 15749738 DOI: 10.1152/ajplung.00429.2004] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
TNF-alpha-converting enzyme (TACE, ADAM17) cleaves membrane-associated cytokines and receptors and thereby regulates inflammatory and immune events, as well as lung development and mucin production. For example, the TACE-mediated cleavage of the type II 75-kDa TNF receptor (TNFR2) generates a soluble TNF-binding protein that modulates TNF bioactivity. TACE is synthesized as a latent proenzyme that is retained in an inactive state via an interaction between its prodomain and catalytic domain. Although the formation of an intramolecular bond between a cysteine in the prodomain and a zinc atom in the catalytic site had been thought to mediate this inhibitory activity, it was recently reported that the cysteine-switch motif is not required. Here, we hypothesized that the amino terminus of the TACE prodomain might contribute to the ability of the prodomain to maintain TACE in an inactive state independently of a cysteine-switch mechanism. We synthesized a 37-amino acid peptide corresponding to TACE amino acids 18-54 (N-TACE(18-54)) and assessed whether it possessed TACE inhibitory activity. In an in vitro model assay system, N-TACE(18-54) attenuated TACE-catalyzed cleavage of a TNFR2:Fc substrate. Furthermore, N-TACE(18-54) inhibited constitutive TNFR2 shedding from a human monocytic cell line by 42%. A 19-amino acid, leucine-rich domain, corresponding to TACE amino acids 30-48, demonstrated partial inhibitory activity. In summary, we have identified a subdomain within the amino terminus of the TACE prodomain that attenuates TACE catalytic activity independently of a cysteine-switch mechanism, which provides new insight into the regulation of TACE enzymatic activity.
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Affiliation(s)
- Caitriona A Buckley
- Pulmonary-Critical Care Medicine Branch, National Heart, Lung, and Blood Inst., National Institutes of Health, Bldg. 10, Rm. 6D03, MSC 1590, Bethesda, MD 20892-1590, USA
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23
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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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24
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Rubins KH, Hensley LE, Jahrling PB, Whitney AR, Geisbert TW, Huggins JW, Owen A, Leduc JW, Brown PO, Relman DA. The host response to smallpox: analysis of the gene expression program in peripheral blood cells in a nonhuman primate model. Proc Natl Acad Sci U S A 2004; 101:15190-5. [PMID: 15477590 PMCID: PMC523453 DOI: 10.1073/pnas.0405759101] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Smallpox has played an unparalleled role in human history and remains a significant potential threat to public health. Despite the historical significance of this disease, we know little about the underlying pathophysiology or the virulence mechanisms of the causative agent, variola virus. To improve our understanding of variola pathogenesis and variola-host interactions, we examined the molecular and cellular features of hemorrhagic smallpox in cynomolgus macaques. We used cDNA microarrays to analyze host gene expression patterns in sequential blood samples from each of 22 infected animals. Variola infection elicited striking and temporally coordinated patterns of gene expression in peripheral blood. Of particular interest were features that appear to represent an IFN response, cell proliferation, immunoglobulin gene expression, viral dose-dependent gene expression patterns, and viral modulation of the host immune response. The virtual absence of a tumor necrosis factor alpha/NF-kappaB-activated transcriptional program in the face of an overwhelming systemic infection suggests that variola gene products may ablate this response. These results provide a detailed picture of the host transcriptional response during smallpox infection, and may help guide the development of diagnostic, therapeutic, and prophylactic strategies.
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Affiliation(s)
- Kathleen H Rubins
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305, USA
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25
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Johnston JB, McFadden G. Technical knockout: understanding poxvirus pathogenesis by selectively deleting viral immunomodulatory genes. Cell Microbiol 2004; 6:695-705. [PMID: 15236637 DOI: 10.1111/j.1462-5822.2004.00423.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The study of viral pathogens with genomes as large and complex as poxviruses represents a constant experimental challenge. Advances in recombinant DNA technologies have provided sophisticated methods to produce mutants defective in one or more viral genes, termed knockout (KO) viruses, thereby facilitating research into the impact of specific gene products on viral pathogenesis. Such strategies have rapidly advanced the systematic mining of many poxvirus genomes and enabled researchers to identify and characterize poxvirus genes whose functions represent the culmination of host and pathogen coevolution. Of particular interest are the multiple classes of virus-encoded immunomodulatory proteins that have evolved specifically to allow poxviruses to evade, obstruct or subvert critical elements within the host innate and acquired immune responses. Functional characterization of these viral genes by generating KO viruses and investigating the phenotypic changes that result is an important tool for understanding the molecular mechanisms underlying poxvirus replication and pathogenesis. Moreover, the insights gained have led to new developments in basic and clinical virology, provided a basis for the design of new vaccines and antivirals, and increased the potential application of poxviruses as investigative tools and sources of biotherapeutics for the treatment of human diseases.
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Affiliation(s)
- J B Johnston
- Biotherapeutics Research Group, Robarts Research Institute and Department of Microbiology and Immunology, University of Western Ontario, London, Canada
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26
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Teoh MLT, Walasek PJ, Evans DH. Leporipoxvirus Cu,Zn-superoxide dismutase (SOD) homologs are catalytically inert decoy proteins that bind copper chaperone for SOD. J Biol Chem 2003; 278:33175-84. [PMID: 12773543 DOI: 10.1074/jbc.m300644200] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Many Chordopoxviruses encode catalytically inactive homologs of cellular Cu-Zn superoxide dismutase (SOD). The biological function of these proteins is unknown, although the proteins encoded by Leporipoxviruses have been shown to promote a slow decline in the level of superoxide dismutase activity in virus-infected cells. To gain more insights into their function, we have further characterized the enzymatic and biochemical properties of a SOD homolog encoded by Shope fibroma virus. Shope fibroma virus SOD has retained the zinc binding properties of its cellular homolog, but cannot bind copper. Site-directed mutagenesis showed that it requires at least four amino acid substitutions to partially restore copper binding activity, but even these changes still did not restore catalytic activity. Reciprocal co-immunoprecipitation experiments showed that recombinant Shope fibroma virus SOD forms very stable complexes with cellular copper chaperones for SOD and these observations were confirmed using glutathione-S-transferase tagged proteins. Similar viral SOD/chaperone complexes were formed in cells infected with a closely related myxoma virus, where we also noted that some of the SOD antigen co-localizes with mitochondrial markers using confocal fluorescence microscopy. About 2% of the viral SOD was subsequently detected in gradient-purified mitochondria extracted from virus-infected cells. These poxviral SOD homologs do not form stable complexes with cellular Cu,Zn-SOD or affect its concentration. We suggest that Leporipoxvirus SOD homologs are catalytically inert decoy proteins that are designed to interfere in the proper metallation and activation of cellular Cu,Zn-SOD. This reaction might be advantageous for tumorigenic poxviruses, since higher levels of superoxide have been proposed to have anti-apoptotic and tumorigenic activity.
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Affiliation(s)
- Melissa L T Teoh
- Department of Molecular Biology & Genetics, University of Guelph, Guelph, Ontario N1G 2W1, Canada
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27
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Seet BT, Johnston JB, Brunetti CR, Barrett JW, Everett H, Cameron C, Sypula J, Nazarian SH, Lucas A, McFadden G. Poxviruses and immune evasion. Annu Rev Immunol 2003; 21:377-423. [PMID: 12543935 DOI: 10.1146/annurev.immunol.21.120601.141049] [Citation(s) in RCA: 475] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Large DNA viruses defend against hostile assault executed by the host immune system by producing an array of gene products that systematically sabotage key components of the inflammatory response. Poxviruses target many of the primary mediators of innate immunity including interferons, tumor necrosis factors, interleukins, complement, and chemokines. Poxviruses also manipulate a variety of intracellular signal transduction pathways such as the apoptotic response. Many of the poxvirus genes that disrupt these pathways have been hijacked directly from the host immune system, while others have demonstrated no clear resemblance to any known host genes. Nonetheless, the immunological targets and the diversity of strategies used by poxviruses to disrupt these host pathways have provided important insights into diverse aspects of immunology, virology, and inflammation. Furthermore, because of their anti-inflammatory nature, many of these poxvirus proteins hold promise as potential therapeutic agents for acute or chronic inflammatory conditions.
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Affiliation(s)
- Bruce T Seet
- Department of Microbiology and Immunology, University of Western Ontario, London, Canada.
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28
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Affiliation(s)
- J B Johnston
- Robarts Research Institute and Department of Microbiology and Immunology, The University of Western Ontario, London, Canada N6G 2V4
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29
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Abstract
OBJECTIVES To characterize cell surface receptors, their ligands, and their proteins in the 2 major pathways of apoptosis; the components that promote/suppress these interactions; the noninflammatory removal of apoptotic bodies by dendritic cells; and methods of assay in studies of cell death. To describe: how deregulation of apoptosis may contribute to autoimmunity, cancer, and neurodegenerative disorders and strategies some viruses have evolved that interfere with the host's apoptotic pathways. METHODS The authors reviewed and compiled literature on the extrinsic (tumor necrosis factor [TNF] receptor superfamily and ligands) and intrinsic (mitochondria-associated) apoptotic pathways, the pro- and antiapoptotic proteins of the B-cell follicular lymphoma (Bcl)-2 family, the nuclear factor (NF)-kappaB family of proteins, commonly used laboratory methods to distinguish apoptosis from necrosis, the recognition and removal by phagocytosis of apoptotic cells by dendritic cells, and viral strategies to avoid a host's apoptotic response. RESULTS The 2 major pathways of apoptosis are (1). FasL and other TNF superfamily ligands induce trimerization of cell-surface death receptors and (2). perturbated mitochondria release cytochrome c, the flavoprotein apoptosis-inducing factor, and second mitochondria-derived activator of caspases/DIABLO (a protein that directly neutralizes inhibitors of apoptotic proteins and activates proteases). Catalytically inactive cysteine proteases, called caspases, and other proteases are activated, ultimately leading to cell death with characteristic cellular chromatin condensation and DNA cleavage to fragments of approximately 180 bp. The inhibitory/promoting action of Bcl-2 family members is involved in the release of cytochrome c, an essential factor for the mitochondrial-associated pathway. A balance between inhibition/promotion determines a cell's fate. The NF-kappaB family in the cytoplasm of cells activates various genes carrying the NF-kappaB response element, such as members of the inhibitor of apoptotic proteins family. A few of the more common methods to detect apoptotic cell death are described, which use immunochemical, morphologic and flow cytometric methods, and genetic markers. Exposed phosphatidylserine at the outer leaflet of the plasma membrane of the apoptotic cell serves as a possible receptor for phagocytosis by immature dendritic cells. These cells phagocytize both apoptotic and necrotic cells, but only the latter induce maturation to become fully functional antigen-presenting cells. Viral inhibitors of apoptosis allow increased virus replication in cells, possibly resulting in their oncogenicity. CONCLUSIONS Balanced apoptosis is crucial in development and homeostasis, and all multicellular organisms have a physiologically programmed continuum of pathways to apoptotic cell death. Further studies of the control at the molecular level of key components and promoters/suppressors of apoptosis may provide better approaches to treatment of autoimmune diseases, malignancies, and neurodegenerative disorders. Many important questions remain regarding the advantages of modifying apoptotic programs in clinical situations.
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Affiliation(s)
- Duane R Schultz
- Department of Medicine, University of Miami School of Medicine, Miami, FL 33101, USA
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30
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Brunetti CR, Paulose-Murphy M, Singh R, Qin J, Barrett JW, Tardivel A, Schneider P, Essani K, McFadden G. A secreted high-affinity inhibitor of human TNF from Tanapox virus. Proc Natl Acad Sci U S A 2003; 100:4831-6. [PMID: 12676996 PMCID: PMC153641 DOI: 10.1073/pnas.0737244100] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A class of secreted poxvirus tumor necrosis factor (TNF)-binding proteins has been isolated from Tanapox-infected cell supernatants. The inhibitor bound to a TNF-affinity column and was identified as the product of the 2L gene. Sequence analysis of 2L family members from other yatapoxviruses and swinepox virus yielded no sequence homology to any known cellular gene. The expressed Tanapox virus 2L protein bound to human TNF with high affinity (K(d) = 43 pM) and exhibits an unusually slow off-rate. However, 2L is unable to bind to a wide range of human TNF family members. The 2L protein can inhibit human TNF from binding to TNF receptors I and II as well as block TNF-induced cytolysis. Thus, Tanapox virus 2L represents an inhibitor of human TNF and offers a unique strategy with which to modulate TNF activity.
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Affiliation(s)
- Craig R Brunetti
- BioTherapeutics Group, Robarts Research Institute, 1400 Western Road, London, ON, Canada N6G 2V4
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31
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Abstract
All known apoptosis modulators in poxviruses have been shown to function as inhibitors. The mechanistic classes of these poxvirus-encoded inhibitors are quite diverse, and indicate that a wide variety of distinct host proteins in cellular apoptotic pathways have been targeted for inhibition by individual poxviruses.
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Affiliation(s)
- Helen Everett
- Department of Biochemistry, University of Alberta, 4-63 Medical Sciences Building, Edmonton, T6G 2H7, Alberta, Canada.
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32
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Abstract
Many viruses have as part of their arsenal the ability to modulate the apoptotic pathways of the host. It is counter-intuitive that such simple organisms would be efficient at regulating this the most crucial pathway within the host, given the relative complexity of the host cells. Yet, viruses have the potential to initiate or stay the onset of programmed cell death through the manipulation of a variety of key apoptotic proteins. It is the intention of this review to provide an overview of viral gene products that are able to promote or inhibit apoptotic death of the host cell and to discuss their mechanisms of action. It is not until recently that the depth at which viruses exploit the apoptotic pathways of their host has been seen. This understanding may provide a great opportunity for future therapeutic ventures.
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Affiliation(s)
- Stewart Hay
- The Fiona Elsey Cancer Research Laboratory, Cancer Research Centre, School of Science, University of Ballarat, St John of God Hospital, 1002 Mair Street, Ballarat, Victoria 3350, Australia1
| | - George Kannourakis
- The Fiona Elsey Cancer Research Laboratory, Cancer Research Centre, School of Science, University of Ballarat, St John of God Hospital, 1002 Mair Street, Ballarat, Victoria 3350, Australia1
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33
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Lapa S, Mikheev M, Shchelkunov S, Mikhailovich V, Sobolev A, Blinov V, Babkin I, Guskov A, Sokunova E, Zasedatelev A, Sandakhchiev L, Mirzabekov A. Species-level identification of orthopoxviruses with an oligonucleotide microchip. J Clin Microbiol 2002; 40:753-7. [PMID: 11880388 PMCID: PMC120230 DOI: 10.1128/jcm.40.3.753-757.2002] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
A method for species-specific detection of orthopoxviruses pathogenic for humans and animals is described. The method is based on hybridization of a fluorescently labeled amplified DNA specimen with the oligonucleotide DNA probes immobilized on a microchip (MAGIChip). The probes identify species-specific sites within the crmB gene encoding the viral analogue of tumor necrosis factor receptor, one of the most important determinants of pathogenicity in this genus of viruses. The diagnostic procedure takes 6 h and does not require any sophisticated equipment (a portable fluorescence reader can be used).
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Affiliation(s)
- Sergey Lapa
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
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34
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Abstract
In the past year, important advances have been made in the area of host-related immunomodulatory genes encoded by the larger DNA viruses, particularly for the poxviruses and herpesviruses. Not only has the repertoire of viral immunomodulator homologs expanded as a result of sequencing the complete genome of another six, large DNA viruses, but also new concepts of how they work have been proposed and in some cases supported by in vivo evidence. Recent developments have been made in understanding a spectrum of host-related viral modulators, including complement control proteins, TNF-receptor homologs, IL-18 binding proteins, viral interleukins (vIL-6 and vIL-10), chemokine mimics and chemokine receptor homologs.
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Affiliation(s)
- G McFadden
- The John P Robarts Research Institute, and Department of Microbiology and Immunology, The University of Western Ontario, London, Canada.
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