1
|
Georgana I, Scutts SR, Gao C, Lu Y, Torres AA, Ren H, Emmott E, Men J, Oei K, Smith GL. Filamin B restricts vaccinia virus spread and is targeted by vaccinia virus protein C4. J Virol 2024; 98:e0148523. [PMID: 38412044 PMCID: PMC10949515 DOI: 10.1128/jvi.01485-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Accepted: 02/06/2024] [Indexed: 02/29/2024] Open
Abstract
Vaccinia virus (VACV) is a large DNA virus that encodes scores of proteins that modulate the host immune response. VACV protein C4 is one such immunomodulator known to inhibit the activation of both the NF-κB signaling cascade and the DNA-PK-mediated DNA sensing pathway. Here, we show that the N-terminal region of C4, which neither inhibits NF-κB nor mediates interaction with DNA-PK, still contributes to virus virulence. Furthermore, this domain interacts directly and with high affinity to the C-terminal domain of filamin B (FLNB). FLNB is a large actin-binding protein that stabilizes the F-actin network and is implicated in other cellular processes. Deletion of FLNB from cells results in larger VACV plaques and increased infectious viral yield, indicating that FLNB restricts VACV spread. These data demonstrate that C4 has a new function that contributes to virulence and engages the cytoskeleton. Furthermore, we show that the cytoskeleton performs further previously uncharacterized functions during VACV infection. IMPORTANCE Vaccinia virus (VACV), the vaccine against smallpox and monkeypox, encodes many proteins to counteract the host immune response. Investigating these proteins provides insights into viral immune evasion mechanisms and thereby indicates how to engineer safer and more immunogenic VACV-based vaccines. Here, we report that the N-terminal domain of VACV protein C4 interacts directly with the cytoskeletal protein filamin B (FLNB), and this domain of C4 contributes to virus virulence. Furthermore, VACV replicates and spreads better in cells lacking FLNB, thus demonstrating that FLNB has antiviral activity. VACV utilizes the cytoskeleton for movement within and between cells; however, previous studies show no involvement of C4 in VACV replication or spread. Thus, C4 associates with FLNB for a different reason, suggesting that the cytoskeleton has further uncharacterized roles during virus infection.
Collapse
Affiliation(s)
- Iliana Georgana
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Simon R. Scutts
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Chen Gao
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Yongxu Lu
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Alice A. Torres
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Hongwei Ren
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Edward Emmott
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Jinghao Men
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Keefe Oei
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Geoffrey L. Smith
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| |
Collapse
|
2
|
Alakunle E, Kolawole D, Diaz-Cánova D, Alele F, Adegboye O, Moens U, Okeke MI. A comprehensive review of monkeypox virus and mpox characteristics. Front Cell Infect Microbiol 2024; 14:1360586. [PMID: 38510963 PMCID: PMC10952103 DOI: 10.3389/fcimb.2024.1360586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Accepted: 02/20/2024] [Indexed: 03/22/2024] Open
Abstract
Monkeypox virus (MPXV) is the etiological agent of monkeypox (mpox), a zoonotic disease. MPXV is endemic in the forested regions of West and Central Africa, but the virus has recently spread globally, causing outbreaks in multiple non-endemic countries. In this paper, we review the characteristics of the virus, including its ecology, genomics, infection biology, and evolution. We estimate by phylogenomic molecular clock that the B.1 lineage responsible for the 2022 mpox outbreaks has been in circulation since 2016. We interrogate the host-virus interactions that modulate the virus infection biology, signal transduction, pathogenesis, and host immune responses. We highlight the changing pathophysiology and epidemiology of MPXV and summarize recent advances in the prevention and treatment of mpox. In addition, this review identifies knowledge gaps with respect to the virus and the disease, suggests future research directions to address the knowledge gaps, and proposes a One Health approach as an effective strategy to prevent current and future epidemics of mpox.
Collapse
Affiliation(s)
- Emmanuel Alakunle
- Department of Natural and Environmental Sciences, American University of Nigeria, Yola, Nigeria
| | - Daniel Kolawole
- Department of Natural and Environmental Sciences, American University of Nigeria, Yola, Nigeria
| | - Diana Diaz-Cánova
- Department of Medical Biology, UIT – The Arctic University of Norway, Tromsø, Norway
| | - Faith Alele
- School of Health, University of the Sunshine Coast, Sippy Downs, QLD, Australia
| | - Oyelola Adegboye
- Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia
| | - Ugo Moens
- Department of Medical Biology, UIT – The Arctic University of Norway, Tromsø, Norway
| | - Malachy Ifeanyi Okeke
- Department of Natural and Environmental Sciences, American University of Nigeria, Yola, Nigeria
| |
Collapse
|
3
|
Semenov DV, Vasileva NS, Dymova MA, Mishinov SV, Savinovskaya YI, Ageenko AB, Dome AS, Zinchenko ND, Stepanov GA, Kochneva GV, Richter VA, Kuligina EV. Transcriptome Changes in Glioma Cells upon Infection with the Oncolytic Virus VV-GMCSF-Lact. Cells 2023; 12:2616. [PMID: 37998351 PMCID: PMC10670333 DOI: 10.3390/cells12222616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 10/25/2023] [Accepted: 11/09/2023] [Indexed: 11/25/2023] Open
Abstract
Oncolytic virotherapy is a rapidly evolving approach that aims to selectively kill cancer cells. We designed a promising recombinant vaccinia virus, VV-GMCSF-Lact, for the treatment of solid tumors, including glioma. We assessed how VV-GMCSF-Lact affects human cells using immortalized and patient-derived glioma cultures and a non-malignant brain cell culture. Studying transcriptome changes in cells 12 h or 24 h after VV-GMCSF-Lact infection, we detected the common activation of histone genes. Additionally, genes associated with the interferon-gamma response, NF-kappa B signaling pathway, and inflammation mediated by chemokine and cytokine signaling pathways showed increased expression. By contrast, genes involved in cell cycle progression, including spindle organization, sister chromatid segregation, and the G2/M checkpoint, were downregulated following virus infection. The upregulation of genes responsible for Golgi vesicles, protein transport, and secretion correlated with reduced sensitivity to the cytotoxic effect of VV-GMCSF-Lact. Higher expression of genes encoding proteins, which participate in the maturation of pol II nuclear transcripts and mRNA splicing, was associated with an increased sensitivity to viral cytotoxicity. Genes whose expression correlates with the sensitivity of cells to the virus are important for increasing the effectiveness of cancer virotherapy. Overall, the results highlight molecular markers, biological pathways, and gene networks influencing the response of glioma cells to VV-GMCSF-Lact.
Collapse
Affiliation(s)
- Dmitriy V. Semenov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch, Russian Academy of Sciences, Lavrentyev Avenue, 8, 630090 Novosibirsk, Russia; (N.S.V.); (M.A.D.); (Y.I.S.); (A.B.A.); (A.S.D.); (N.D.Z.); (G.A.S.); (V.A.R.); (E.V.K.)
| | - Natalia S. Vasileva
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch, Russian Academy of Sciences, Lavrentyev Avenue, 8, 630090 Novosibirsk, Russia; (N.S.V.); (M.A.D.); (Y.I.S.); (A.B.A.); (A.S.D.); (N.D.Z.); (G.A.S.); (V.A.R.); (E.V.K.)
| | - Maya A. Dymova
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch, Russian Academy of Sciences, Lavrentyev Avenue, 8, 630090 Novosibirsk, Russia; (N.S.V.); (M.A.D.); (Y.I.S.); (A.B.A.); (A.S.D.); (N.D.Z.); (G.A.S.); (V.A.R.); (E.V.K.)
| | - Sergey V. Mishinov
- Novosibirsk Research Institute of Traumatology and Orthopedics n.a. Ya.L. Tsivyan, Department of Neurosurgery, Frunze Street, 17, 630091 Novosibirsk, Russia;
| | - Yulya I. Savinovskaya
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch, Russian Academy of Sciences, Lavrentyev Avenue, 8, 630090 Novosibirsk, Russia; (N.S.V.); (M.A.D.); (Y.I.S.); (A.B.A.); (A.S.D.); (N.D.Z.); (G.A.S.); (V.A.R.); (E.V.K.)
| | - Alisa B. Ageenko
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch, Russian Academy of Sciences, Lavrentyev Avenue, 8, 630090 Novosibirsk, Russia; (N.S.V.); (M.A.D.); (Y.I.S.); (A.B.A.); (A.S.D.); (N.D.Z.); (G.A.S.); (V.A.R.); (E.V.K.)
| | - Anton S. Dome
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch, Russian Academy of Sciences, Lavrentyev Avenue, 8, 630090 Novosibirsk, Russia; (N.S.V.); (M.A.D.); (Y.I.S.); (A.B.A.); (A.S.D.); (N.D.Z.); (G.A.S.); (V.A.R.); (E.V.K.)
| | - Nikita D. Zinchenko
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch, Russian Academy of Sciences, Lavrentyev Avenue, 8, 630090 Novosibirsk, Russia; (N.S.V.); (M.A.D.); (Y.I.S.); (A.B.A.); (A.S.D.); (N.D.Z.); (G.A.S.); (V.A.R.); (E.V.K.)
| | - Grigory A. Stepanov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch, Russian Academy of Sciences, Lavrentyev Avenue, 8, 630090 Novosibirsk, Russia; (N.S.V.); (M.A.D.); (Y.I.S.); (A.B.A.); (A.S.D.); (N.D.Z.); (G.A.S.); (V.A.R.); (E.V.K.)
| | - Galina V. Kochneva
- State Research Center of Virology and Biotechnology “Vector”, Rospotrebnadzor, 630559 Koltsovo, Russia;
| | - Vladimir A. Richter
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch, Russian Academy of Sciences, Lavrentyev Avenue, 8, 630090 Novosibirsk, Russia; (N.S.V.); (M.A.D.); (Y.I.S.); (A.B.A.); (A.S.D.); (N.D.Z.); (G.A.S.); (V.A.R.); (E.V.K.)
| | - Elena V. Kuligina
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch, Russian Academy of Sciences, Lavrentyev Avenue, 8, 630090 Novosibirsk, Russia; (N.S.V.); (M.A.D.); (Y.I.S.); (A.B.A.); (A.S.D.); (N.D.Z.); (G.A.S.); (V.A.R.); (E.V.K.)
| |
Collapse
|
4
|
Otter AD, Jones S, Hicks B, Bailey D, Callaby H, Houlihan C, Rampling T, Gordon NC, Selman H, Satheshkumar PS, Townsend M, Mehta R, Pond M, Jones R, Wright D, Oeser C, Tonge S, Linley E, Hemingway G, Coleman T, Millward S, Lloyd A, Damon I, Brooks T, Vipond R, Rowe C, Hallis B. Monkeypox virus-infected individuals mount comparable humoral immune responses as Smallpox-vaccinated individuals. Nat Commun 2023; 14:5948. [PMID: 37741831 PMCID: PMC10517934 DOI: 10.1038/s41467-023-41587-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 09/11/2023] [Indexed: 09/25/2023] Open
Abstract
In early 2022, a cluster of monkeypox virus (MPXV) infection (mpox) cases were identified within the UK with no prior travel history to MPXV-endemic regions. Subsequently, case numbers exceeding 80,000 were reported worldwide, primarily affecting gay, bisexual, and other men who have sex with men (GBMSM). Public health agencies worldwide have offered the IMVANEX Smallpox vaccination to these individuals at high-risk to provide protection and limit the spread of MPXV. We have developed a comprehensive array of ELISAs to study poxvirus-induced antibodies, utilising 24 MPXV and 3 Vaccinia virus (VACV) recombinant antigens. Panels of serum samples from individuals with differing Smallpox-vaccine doses and those with prior MPXV infection were tested on these assays, where we observed that one dose of Smallpox vaccination induces a low number of antibodies to a limited number of MPXV antigens but increasing with further vaccination doses. MPXV infection induced similar antibody responses to diverse poxvirus antigens observed in Smallpox-vaccinated individuals. We identify MPXV A27 as a serological marker of MPXV-infection, whilst MPXV M1 (VACV L1) is likely IMVANEX-specific. Here, we demonstrate analogous humoral antigen recognition between both MPXV-infected or Smallpox-vaccinated individuals, with binding to diverse yet core set of poxvirus antigens, providing opportunities for future vaccine (e.g., mRNA) and therapeutic (e.g., mAbs) design.
Collapse
Affiliation(s)
- Ashley D Otter
- Emerging Pathogen Serology group, UK Health Security Agency, Porton Down, Wiltshire, UK.
| | - Scott Jones
- Emerging Pathogen Serology group, UK Health Security Agency, Porton Down, Wiltshire, UK
| | - Bethany Hicks
- Emerging Pathogen Serology group, UK Health Security Agency, Porton Down, Wiltshire, UK
| | - Daniel Bailey
- Rare and Imported Pathogens Laboratory, UK Health Security Agency, Porton Down, Wiltshire, UK
| | - Helen Callaby
- Rare and Imported Pathogens Laboratory, UK Health Security Agency, Porton Down, Wiltshire, UK
| | - Catherine Houlihan
- Rare and Imported Pathogens Laboratory, UK Health Security Agency, Porton Down, Wiltshire, UK
- Department of Infection and Immunity, University College London, London, UK
| | - Tommy Rampling
- Rare and Imported Pathogens Laboratory, UK Health Security Agency, Porton Down, Wiltshire, UK
- The Hospital for Tropical Diseases, University College London Hospital, London, UK
- NIHR University College London Hospitals BRC, London, UK
| | - Nicola Claire Gordon
- Rare and Imported Pathogens Laboratory, UK Health Security Agency, Porton Down, Wiltshire, UK
| | - Hannah Selman
- Emerging Pathogen Serology group, UK Health Security Agency, Porton Down, Wiltshire, UK
| | | | - Michael Townsend
- Poxvirus and Rabies Branch, Centre for Disease Control and Prevention, Atlanta, GA, USA
| | - Ravi Mehta
- Imperial College Healthcare NHS Trust, London, UK
| | - Marcus Pond
- Imperial College Healthcare NHS Trust, London, UK
| | - Rachael Jones
- Chelsea and Westminster Hospital NHS Foundation Trust, London, UK
| | - Deborah Wright
- Research and Development, UK Health Security Agency, Porton Down, Wiltshire, UK
| | - Clarissa Oeser
- Immunisation and Vaccine Preventable Diseases Division, UK Health Security Agency, Colindale, London, UK
| | - Simon Tonge
- Seroepidemiology Unit, UK Health Security Agency, Manchester, UK
| | - Ezra Linley
- Seroepidemiology Unit, UK Health Security Agency, Manchester, UK
| | - Georgia Hemingway
- Emerging Pathogen Serology group, UK Health Security Agency, Porton Down, Wiltshire, UK
| | - Tom Coleman
- Emerging Pathogen Serology group, UK Health Security Agency, Porton Down, Wiltshire, UK
| | - Sebastian Millward
- Emerging Pathogen Serology group, UK Health Security Agency, Porton Down, Wiltshire, UK
| | - Aaron Lloyd
- Emerging Pathogen Serology group, UK Health Security Agency, Porton Down, Wiltshire, UK
| | - Inger Damon
- Poxvirus and Rabies Branch, Centre for Disease Control and Prevention, Atlanta, GA, USA
| | - Tim Brooks
- Rare and Imported Pathogens Laboratory, UK Health Security Agency, Porton Down, Wiltshire, UK
| | - Richard Vipond
- Research and Development, UK Health Security Agency, Porton Down, Wiltshire, UK
| | - Cathy Rowe
- Emerging Pathogen Serology group, UK Health Security Agency, Porton Down, Wiltshire, UK
| | - Bassam Hallis
- Research and Development, UK Health Security Agency, Porton Down, Wiltshire, UK
| |
Collapse
|
5
|
Storozynsky QT, Han X, Komant S, Agopsowicz KC, Potts KG, Gamper AM, Godbout R, Evans DH, Hitt MM. Radiation-Induced Cellular Senescence Reduces Susceptibility of Glioblastoma Cells to Oncolytic Vaccinia Virus. Cancers (Basel) 2023; 15:3341. [PMID: 37444452 DOI: 10.3390/cancers15133341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 06/15/2023] [Accepted: 06/16/2023] [Indexed: 07/15/2023] Open
Abstract
Glioblastoma (GBM) is a malignant brain cancer refractory to the current standard of care, prompting an extensive search for novel strategies to improve outcomes. One approach under investigation is oncolytic virus (OV) therapy in combination with radiotherapy. In addition to the direct cytocidal effects of radiotherapy, radiation induces cellular senescence in GBM cells. Senescent cells cease proliferation but remain viable and are implicated in promoting tumor progression. The interaction of viruses with senescent cells is nuanced; some viruses exploit the senescent state to their benefit, while others are hampered, indicating senescence-associated antiviral activity. It is unknown how radiation-induced cellular senescence may impact the oncolytic properties of OVs based on the vaccinia virus (VACV) that are used in combination with radiotherapy. To better understand this, we induced cellular senescence by treating GBM cells with radiation, and then evaluated the growth kinetics, infectivity, and cytotoxicity of an oncolytic VACV, ∆F4LΔJ2R, as well as wild-type VACV in irradiated senescence-enriched and non-irradiated human GBM cell lines. Our results show that both viruses display attenuated oncolytic activities in irradiated senescence-enriched GBM cell populations compared to non-irradiated controls. These findings indicate that radiation-induced cellular senescence is associated with antiviral activity and highlight important considerations for the combination of VACV-based oncolytic therapies with senescence-inducing agents such as radiotherapy.
Collapse
Affiliation(s)
- Quinn T Storozynsky
- Department of Oncology, University of Alberta, Edmonton, AB T6G 1Z2, Canada
- Li Ka Shing Institute of Virology, University of Alberta, Edmonton, AB T6G 2E1, Canada
- Cancer Research Institute of Northern Alberta (CRINA), University of Alberta, Edmonton, AB T6G 2R3, Canada
| | - Xuefei Han
- Department of Oncology, University of Alberta, Edmonton, AB T6G 1Z2, Canada
| | - Shae Komant
- Li Ka Shing Institute of Virology, University of Alberta, Edmonton, AB T6G 2E1, Canada
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB T6G 2R3, Canada
| | - Kate C Agopsowicz
- Department of Oncology, University of Alberta, Edmonton, AB T6G 1Z2, Canada
| | - Kyle G Potts
- Alberta Children's Hospital Research Institute, Faculty of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
- Arnie Charbonneau Cancer Institute, Faculty of Medicine, University of Calgary, Calgary, AB T2N 4Z6, Canada
- Alberta Cellular Therapy and Immune Oncology (ACTION) Initiative, Faculty of Medicine, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Armin M Gamper
- Department of Oncology, University of Alberta, Edmonton, AB T6G 1Z2, Canada
- Cross Cancer Institute, Edmonton, AB T6G 1Z2, Canada
| | - Roseline Godbout
- Department of Oncology, University of Alberta, Edmonton, AB T6G 1Z2, Canada
- Cancer Research Institute of Northern Alberta (CRINA), University of Alberta, Edmonton, AB T6G 2R3, Canada
- Cross Cancer Institute, Edmonton, AB T6G 1Z2, Canada
| | - David H Evans
- Li Ka Shing Institute of Virology, University of Alberta, Edmonton, AB T6G 2E1, Canada
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB T6G 2R3, Canada
| | - Mary M Hitt
- Department of Oncology, University of Alberta, Edmonton, AB T6G 1Z2, Canada
- Li Ka Shing Institute of Virology, University of Alberta, Edmonton, AB T6G 2E1, Canada
- Cancer Research Institute of Northern Alberta (CRINA), University of Alberta, Edmonton, AB T6G 2R3, Canada
| |
Collapse
|
6
|
Phelan T, Lawler C, Pichlmair A, Little MA, Bowie AG, Brady G. Molluscum Contagiosum Virus Protein MC008 Targets NF-κB Activation by Inhibiting Ubiquitination of NEMO. J Virol 2023; 97:e0010823. [PMID: 36916940 PMCID: PMC10062130 DOI: 10.1128/jvi.00108-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 02/17/2023] [Indexed: 03/16/2023] Open
Abstract
Molluscum contagiosum virus (MCV) is a human-adapted poxvirus that causes a common and persistent yet mild infection characterized by distinct, contagious, papular skin lesions. These lesions are notable for having little or no inflammation associated with them and can persist for long periods without an effective clearance response from the host. Like all poxviruses, MCV encodes potent immunosuppressive proteins that perturb innate immune pathways involved in virus sensing, the interferon response, and inflammation, which collectively orchestrate antiviral immunity and clearance, with several of these pathways converging at common signaling nodes. One such node is the regulator of canonical nuclear factor kappa B (NF-κB) activation, NF-κB essential modulator (NEMO). Here, we report that the MCV protein MC008 specifically inhibits NF-κB through its interaction with NEMO, disrupting its early ubiquitin-mediated activation and subsequent downstream signaling. MC008 is the third NEMO-targeting inhibitor to be described in MCV to date, with each inhibiting NEMO activation in distinct ways, highlighting strong selective pressure to evolve multiple ways of disabling this key signaling protein. IMPORTANCE Inflammation lies at the heart of most human diseases. Understanding the pathways that drive this response is the key to new anti-inflammatory therapies. Viruses evolve to target inflammation; thus, understanding how they do this reveals how inflammation is controlled and, potentially, how to disable it when it drives disease. Molluscum contagiosum virus (MCV) has specifically evolved to infect humans and displays an unprecedented ability to suppress inflammation in our tissue. We have identified a novel inhibitor of human innate signaling from MCV, MC008, which targets NEMO, a core regulator of proinflammatory signaling. Furthermore, MC008 appears to inhibit early ubiquitination, thus interrupting later events in NEMO activation, thereby validating current models of IκB kinase (IKK) complex regulation.
Collapse
Affiliation(s)
- Thomas Phelan
- Trinity Health Kidney Centre, Trinity Translational Medicine Institute, Trinity College Dublin, St. James’ Hospital Campus, Dublin, Ireland
| | - Clara Lawler
- Trinity Health Kidney Centre, Trinity Translational Medicine Institute, Trinity College Dublin, St. James’ Hospital Campus, Dublin, Ireland
| | | | - Mark A. Little
- Trinity Health Kidney Centre, Trinity Translational Medicine Institute, Trinity College Dublin, St. James’ Hospital Campus, Dublin, Ireland
| | - Andrew G. Bowie
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - Gareth Brady
- Trinity Health Kidney Centre, Trinity Translational Medicine Institute, Trinity College Dublin, St. James’ Hospital Campus, Dublin, Ireland
| |
Collapse
|
7
|
Rivera-Calzada A, Arribas-Bosacoma R, Ruiz-Ramos A, Escudero-Bravo P, Boskovic J, Fernandez-Leiro R, Oliver AW, Pearl LH, Llorca O. Structural basis for the inactivation of cytosolic DNA sensing by the vaccinia virus. Nat Commun 2022; 13:7062. [PMID: 36400800 PMCID: PMC9674614 DOI: 10.1038/s41467-022-34843-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 11/08/2022] [Indexed: 11/19/2022] Open
Abstract
Detection of cytosolic DNA is a central element of the innate immunity system against viral infection. The Ku heterodimer, a component of the NHEJ pathway of DNA repair in the nucleus, functions as DNA sensor that detects dsDNA of viruses that replicate in the cytoplasm. Vaccinia virus expresses two proteins, C4 and C16, that inactivate DNA sensing and enhance virulence. The structural basis for this is unknown. Here we determine the structure of the C16 - Ku complex using cryoEM. Ku binds dsDNA by a preformed ring but C16 sterically blocks this access route, abrogating binding to a dsDNA end and its insertion into DNA-PK, thereby averting signalling into the downstream innate immunity system. C4 replicates these activities using a domain with 54% identity to C16. Our results reveal how vaccinia virus subverts the capacity of Ku to recognize viral DNA.
Collapse
Affiliation(s)
- Angel Rivera-Calzada
- Spanish National Cancer Research Centre (CNIO), Melchor Fernández Almagro 3, 28029, Madrid, Spain
| | - Raquel Arribas-Bosacoma
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9RQ, UK
- Division of Structural Biology, Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London, SW1E 6BT, UK
| | - Alba Ruiz-Ramos
- Spanish National Cancer Research Centre (CNIO), Melchor Fernández Almagro 3, 28029, Madrid, Spain
| | - Paloma Escudero-Bravo
- Spanish National Cancer Research Centre (CNIO), Melchor Fernández Almagro 3, 28029, Madrid, Spain
| | - Jasminka Boskovic
- Spanish National Cancer Research Centre (CNIO), Melchor Fernández Almagro 3, 28029, Madrid, Spain
| | - Rafael Fernandez-Leiro
- Spanish National Cancer Research Centre (CNIO), Melchor Fernández Almagro 3, 28029, Madrid, Spain
| | - Antony W Oliver
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9RQ, UK
| | - Laurence H Pearl
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9RQ, UK.
- Division of Structural Biology, Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London, SW1E 6BT, UK.
| | - Oscar Llorca
- Spanish National Cancer Research Centre (CNIO), Melchor Fernández Almagro 3, 28029, Madrid, Spain.
| |
Collapse
|
8
|
Forni D, Cagliani R, Molteni C, Clerici M, Sironi M. Monkeypox virus: The changing facets of a zoonotic pathogen. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2022; 105:105372. [PMID: 36202208 PMCID: PMC9534092 DOI: 10.1016/j.meegid.2022.105372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 09/28/2022] [Accepted: 10/02/2022] [Indexed: 11/07/2022]
Abstract
In the last five years, the prevalence of monkeypox has been increasing both in the regions considered endemic for the disease (West and Central Africa) and worldwide. Indeed, in July 2022, the World Health Organization declared the ongoing global outbreak of monkeypox a public health emergency of international concern. The disease is caused by monkeypox virus (MPXV), a member of the Orthopoxvirus genus, which also includes variola virus (the causative agent of smallpox) and vaccinia virus (used in the smallpox eradication campaign). Here, we review aspects of MPXV genetic diversity and epidemiology, with an emphasis on its genome structure, host range, and relationship with other orthopoxviruses. We also summarize the most recent findings deriving from the sequencing of outbreak MPXV genomes, and we discuss the apparent changing of MPXV evolutionary trajectory, which is characterized by the accumulation of point mutations rather than by gene gains/losses. Whereas the availability of a vaccine, the relatively mild presentation of the disease, and its relatively low transmissibility speak in favor of an efficient control of the global outbreak, the wide host range of MPXV raises concerns about the possible establishment of novel reservoirs. We also call for the deployment of field surveys and genomic surveillance programs to identify and control the MPXV reservoirs in West and Central Africa.
Collapse
Affiliation(s)
- Diego Forni
- IRCCS E. MEDEA, Bioinformatics, Bosisio Parini, Italy
| | | | | | - Mario Clerici
- University of Milan, Milan, Italy; Don C. Gnocchi Foundation ONLUS, IRCCS, Milan, Italy
| | | |
Collapse
|
9
|
Zhang RY, Pallett MA, French J, Ren H, Smith GL. Vaccinia virus BTB-Kelch proteins C2 and F3 inhibit NF-κB activation. J Gen Virol 2022; 103:10.1099/jgv.0.001786. [PMID: 36301238 PMCID: PMC7614845 DOI: 10.1099/jgv.0.001786] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/02/2023] Open
Abstract
Vaccinia virus (VACV) encodes scores of proteins that suppress host innate immunity and many of these target intracellular signalling pathways leading to activation of inflammation. The transcription factor NF-κB plays a critical role in the host response to infection and is targeted by many viruses, including VACV that encodes 12 NF-κB inhibitors that interfere at different stages in this signalling pathway. Here we report that VACV proteins C2 and F3 are additional inhibitors of this pathway. C2 and F3 are BTB-Kelch proteins that are expressed early during infection, are non-essential for virus replication, but affect the outcome of infection in vivo. Using reporter gene assays, RT-qPCR analyses of endogenous gene expression, and ELISA, these BTB-Kelch proteins are shown here to diminish NF-κB activation by reducing translocation of p65 into the nucleus. C2 and F3 are the 13th and 14th NF-κB inhibitors encoded by VACV. Remarkably, in every case tested, these individual proteins affect virulence in vivo and therefore have non-redundant functions. Lastly, immunisation with a VACV strain lacking C2 induced a stronger CD8+ T cell response and better protection against virus challenge.
Collapse
|
10
|
Reus JB, Rex EA, Gammon DB. How to Inhibit Nuclear Factor-Kappa B Signaling: Lessons from Poxviruses. Pathogens 2022; 11:pathogens11091061. [PMID: 36145493 PMCID: PMC9502310 DOI: 10.3390/pathogens11091061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 09/10/2022] [Accepted: 09/13/2022] [Indexed: 11/16/2022] Open
Abstract
The Nuclear Factor-kappa B (NF-κB) family of transcription factors regulates key host inflammatory and antiviral gene expression programs, and thus, is often activated during viral infection through the action of pattern-recognition receptors and cytokine–receptor interactions. In turn, many viral pathogens encode strategies to manipulate and/or inhibit NF-κB signaling. This is particularly exemplified by vaccinia virus (VV), the prototypic poxvirus, which encodes at least 18 different inhibitors of NF-κB signaling. While many of these poxviral NF-κB inhibitors are not required for VV replication in cell culture, they virtually all modulate VV virulence in animal models, underscoring the important influence of poxvirus–NF-κB pathway interactions on viral pathogenesis. Here, we review the diversity of mechanisms through which VV-encoded antagonists inhibit initial NF-κB pathway activation and NF-κB signaling intermediates, as well as the activation and function of NF-κB transcription factor complexes.
Collapse
|
11
|
Saud Z, Hitchings MD, Butt TM. Nanopore sequencing and de novo assembly of a misidentified Camelpox vaccine reveals putative epigenetic modifications and alternate protein signal peptides. Sci Rep 2021; 11:17758. [PMID: 34493784 PMCID: PMC8423768 DOI: 10.1038/s41598-021-97158-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Accepted: 08/19/2021] [Indexed: 11/25/2022] Open
Abstract
DNA viruses can exploit host cellular epigenetic processes to their advantage; however, the epigenome status of most DNA viruses remains undetermined. Third generation sequencing technologies allow for the identification of modified nucleotides from sequencing experiments without specialized sample preparation, permitting the detection of non-canonical epigenetic modifications that may distinguish viral nucleic acid from that of their host, thus identifying attractive targets for advanced therapeutics and diagnostics. We present a novel nanopore de novo assembly pipeline used to assemble a misidentified Camelpox vaccine. Two confirmed deletions of this vaccine strain in comparison to the closely related Vaccinia virus strain modified vaccinia Ankara make it one of the smallest non-vector derived orthopoxvirus genomes to be reported. Annotation of the assembly revealed a previously unreported signal peptide at the start of protein A38 and several predicted signal peptides that were found to differ from those previously described. Putative epigenetic modifications around various motifs have been identified and the assembly confirmed previous work showing the vaccine genome to most closely resemble that of Vaccinia virus strain Modified Vaccinia Ankara. The pipeline may be used for other DNA viruses, increasing the understanding of DNA virus evolution, virulence, host preference, and epigenomics.
Collapse
Affiliation(s)
- Zack Saud
- Department of Biosciences, College of Science, Swansea University, Singleton Park, Swansea, SA2 8PP, Wales, UK.
| | - Matthew D Hitchings
- Swansea University Medical School, Swansea University, Singleton Park, Swansea, Sa2 8PP, Wales, UK
| | - Tariq M Butt
- Department of Biosciences, College of Science, Swansea University, Singleton Park, Swansea, SA2 8PP, Wales, UK
| |
Collapse
|
12
|
El-Jesr M, Teir M, Maluquer de Motes C. Vaccinia Virus Activation and Antagonism of Cytosolic DNA Sensing. Front Immunol 2020; 11:568412. [PMID: 33117352 PMCID: PMC7559579 DOI: 10.3389/fimmu.2020.568412] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 08/24/2020] [Indexed: 12/16/2022] Open
Abstract
Cells express multiple molecules aimed at detecting incoming virus and infection. Recognition of virus infection leads to the production of cytokines, chemokines and restriction factors that limit virus replication and activate an adaptive immune response offering long-term protection. Recognition of cytosolic DNA has become a central immune sensing mechanism involved in infection, autoinflammation, and cancer immunotherapy. Vaccinia virus (VACV) is the prototypic member of the family Poxviridae and the vaccine used to eradicate smallpox. VACV harbors enormous potential as a vaccine vector and several attenuated strains are currently being developed against infectious diseases. In addition, VACV has emerged as a popular oncolytic agent due to its cytotoxic capacity even in hypoxic environments. As a poxvirus, VACV is an unusual virus that replicates its large DNA genome exclusively in the cytoplasm of infected cells. Despite producing large amounts of cytosolic DNA, VACV efficiently suppresses the subsequent innate immune response by deploying an arsenal of proteins with capacity to disable host antiviral signaling, some of which specifically target cytosolic DNA sensing pathways. Some of these strategies are conserved amongst orthopoxviruses, whereas others are seemingly unique to VACV. In this review we provide an overview of the VACV replicative cycle and discuss the recent advances on our understanding of how VACV induces and antagonizes innate immune activation via cytosolic DNA sensing pathways. The implications of these findings in the rational design of vaccines and oncolytics based on VACV are also discussed.
Collapse
Affiliation(s)
- Misbah El-Jesr
- Department of Microbial Sciences, University of Surrey, Guildford, United Kingdom
| | - Muad Teir
- Department of Microbial Sciences, University of Surrey, Guildford, United Kingdom
| | | |
Collapse
|
13
|
Lu Y, Zhang L. DNA-Sensing Antiviral Innate Immunity in Poxvirus Infection. Front Immunol 2020; 11:1637. [PMID: 32983084 PMCID: PMC7483915 DOI: 10.3389/fimmu.2020.01637] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 06/18/2020] [Indexed: 12/16/2022] Open
Abstract
As pattern recognition receptors, cytosolic DNA sensors quickly induce an effective innate immune response. Poxvirus, a large DNA virus, is capable of evading the host antiviral innate immune response. In this review, we summarize the latest studies on how poxvirus is sensed by the host innate immune system and how poxvirus-encoded proteins antagonize DNA sensors. A comprehensive understanding of the interplay between poxvirus and DNA-sensing antiviral immune responses of the host will contribute to the development of new antiviral therapies and vaccines in the future.
Collapse
Affiliation(s)
- Yue Lu
- Department of Laboratory Medicine, The First Affiliated Hospital of Shandong First Medical University, Jinan, China.,Institute of Basic Medicine, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, China.,Key Laboratory for Biotech-Drugs of National Health Commission, Jinan, China.,Key Laboratory for Rare and Uncommon Diseases of Shandong Province, Jinan, China
| | - Leiliang Zhang
- Department of Laboratory Medicine, The First Affiliated Hospital of Shandong First Medical University, Jinan, China.,Institute of Basic Medicine, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, China.,Key Laboratory for Biotech-Drugs of National Health Commission, Jinan, China.,Key Laboratory for Rare and Uncommon Diseases of Shandong Province, Jinan, China.,Science and Technology Innovation Center, Shandong First Medical University, Shandong Academy of Medical Sciences, Jinan, China
| |
Collapse
|
14
|
Neidel S, Torres AA, Ren H, Smith GL. Leaky scanning translation generates a second A49 protein that contributes to vaccinia virus virulence. J Gen Virol 2020; 101:533-541. [PMID: 32100702 PMCID: PMC7414448 DOI: 10.1099/jgv.0.001386] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 01/08/2020] [Indexed: 12/17/2022] Open
Abstract
Vaccinia virus (VACV) strain Western Reserve gene A49L encodes a small intracellular protein with a Bcl-2 fold that is expressed early during infection and has multiple functions. A49 co-precipitates with the E3 ubiquitin ligase β-TrCP and thereby prevents ubiquitylation and proteasomal degradation of IκBα, and consequently blocks activation of NF-κB. In a similar way, A49 stabilizes β-catenin, leading to activation of the wnt signalling pathway. However, a VACV strain expressing a mutant A49 that neither co-precipitates with β-TrCP nor inhibits NF-κB activation, is more virulent than a virus lacking A49, indicating that A49 has another function that also contributes to virulence. Here we demonstrate that gene A49L encodes a second, smaller polypeptide that is expressed via leaky scanning translation from methionine 20 and is unable to block NF-κB activation. Viruses engineered to express either only the large protein or only the small A49 protein both have lower virulence than wild-type virus and greater virulence than an A49L deletion mutant. This demonstrates that the small protein contributes to virulence by an unknown mechanism that is independent of NF-κB inhibition. Despite having a large genome with about 200 genes, this study illustrates how VACV makes efficient use of its coding potential and from gene A49L expresses a protein with multiple functions and multiple proteins with different functions.
Collapse
Affiliation(s)
- Sarah Neidel
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Alice A. Torres
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Hongwei Ren
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
- Present address: Department of Immunology and Inflammation, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK
| | - Geoffrey L. Smith
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| |
Collapse
|
15
|
Scutts SR, Ember SW, Ren H, Ye C, Lovejoy CA, Mazzon M, Veyer DL, Sumner RP, Smith GL. DNA-PK Is Targeted by Multiple Vaccinia Virus Proteins to Inhibit DNA Sensing. Cell Rep 2019; 25:1953-1965.e4. [PMID: 30428360 PMCID: PMC6250978 DOI: 10.1016/j.celrep.2018.10.034] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 07/26/2018] [Accepted: 10/05/2018] [Indexed: 12/16/2022] Open
Abstract
Virus infection is sensed by pattern recognition receptors (PRRs) detecting virus nucleic acids and initiating an innate immune response. DNA-dependent protein kinase (DNA-PK) is a PRR that binds cytosolic DNA and is antagonized by vaccinia virus (VACV) protein C16. Here, VACV protein C4 is also shown to antagonize DNA-PK by binding to Ku and blocking Ku binding to DNA, leading to a reduced production of cytokines and chemokines in vivo and a diminished recruitment of inflammatory cells. C4 and C16 share redundancy in that a double deletion virus has reduced virulence not seen with single deletion viruses following intradermal infection. However, non-redundant functions exist because both single deletion viruses display attenuated virulence compared to wild-type VACV after intranasal infection. It is notable that VACV expresses two proteins to antagonize DNA-PK, but it is not known to target other DNA sensors, emphasizing the importance of this PRR in the response to infection in vivo. DNA-PK is a pattern recognition receptor that binds cytosolic DNA Vaccinia virus proteins C4 and C16 antagonize DNA-PK by blocking DNA binding C4 and C16 inhibit IRF3 signaling, cytokine production, and immune cell recruitment C4 and C16 share redundant and non-redundant functions in vivo
Collapse
Affiliation(s)
- Simon R Scutts
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Stuart W Ember
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Hongwei Ren
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Chao Ye
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Christopher A Lovejoy
- 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
| | - David L Veyer
- 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
| | - Geoffrey L Smith
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK.
| |
Collapse
|
16
|
Parekh NJ, Krouse TE, Reider IE, Hobbs RP, Ward BM, Norbury CC. Type I interferon-dependent CCL4 is induced by a cGAS/STING pathway that bypasses viral inhibition and protects infected tissue, independent of viral burden. PLoS Pathog 2019; 15:e1007778. [PMID: 31603920 PMCID: PMC6808495 DOI: 10.1371/journal.ppat.1007778] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 10/23/2019] [Accepted: 09/16/2019] [Indexed: 11/18/2022] Open
Abstract
Type I interferons (T1-IFN) are critical in the innate immune response, acting upon infected and uninfected cells to initiate an antiviral state by expressing genes that inhibit multiple stages of the lifecycle of many viruses. T1-IFN triggers the production of Interferon-Stimulated Genes (ISGs), activating an antiviral program that reduces virus replication. The importance of the T1-IFN response is highlighted by the evolution of viral evasion strategies to inhibit the production or action of T1-IFN in virus-infected cells. T1-IFN is produced via activation of pathogen sensors within infected cells, a process that is targeted by virus-encoded immunomodulatory molecules. This is probably best exemplified by the prototypic poxvirus, Vaccinia virus (VACV), which uses at least 6 different mechanisms to completely block the production of T1-IFN within infected cells in vitro. Yet, mice lacking aspects of T1-IFN signaling are often more susceptible to infection with many viruses, including VACV, than wild-type mice. How can these opposing findings be rationalized? The cytosolic DNA sensor cGAS has been implicated in immunity to VACV, but has yet to be linked to the production of T1-IFN in response to VACV infection. Indeed, there are two VACV-encoded proteins that effectively prevent cGAS-mediated activation of T1-IFN. We find that the majority of VACV-infected cells in vivo do not produce T1-IFN, but that a small subset of VACV-infected cells in vivo utilize cGAS to sense VACV and produce T1-IFN to protect infected mice. The protective effect of T1-IFN is not mediated via ISG-mediated control of virus replication. Rather, T1-IFN drives increased expression of CCL4, which recruits inflammatory monocytes that constrain the VACV lesion in a virus replication-independent manner by limiting spread within the tissue. Our findings have broad implications in our understanding of pathogen detection and viral evasion in vivo, and highlight a novel immune strategy to protect infected tissue.
Collapse
Affiliation(s)
- Nikhil J. Parekh
- Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania, United States of America
| | - Tracy E. Krouse
- Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania, United States of America
| | - Irene E. Reider
- Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania, United States of America
| | - Ryan P. Hobbs
- Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania, United States of America
- Department of Dermatology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania, United States of America
| | - Brian M. Ward
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, New York, United States of America
| | - Christopher C. Norbury
- Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania, United States of America
- * E-mail:
| |
Collapse
|
17
|
De Martini W, Coutu J, Bugert J, Iversen T, Cottrell J, Nichols DB. The molluscum contagiosum virus protein MC163 inhibits TNF-α-induced NF-κB activation. Future Virol 2019. [DOI: 10.2217/fvl-2019-0018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Aim: The molluscum contagiosum virus (MCV) expresses several immune evasion molecules that inhibit activation of NF-κB. Presumably, inhibition of inflammatory responses mediated by NF-κB allows MCV to cause persistent infections. Materials & methods: MC163-IKK-α interactions were detected by immunoprecipitations. Results: Here, we identify a novel MCV inhibitor of NF-κB. Ectopic expression of the MC163 protein resulted in a significant decrease in TNF-α-induced NF-κB activation. However, MC163 had no detectable effect on mitochondrial antiviral-signaling protein-induced activation of the IFN-β-promoter. MC163 dampened NF-κB activation induced via the overexpression of either IKK-α or IKK-β suggesting MC163 targets the IKK complex. Conclusion: Our data highlight a previously unknown function for the MC163 protein and may represent an additional strategy used by MCV to subvert host immune responses.
Collapse
Affiliation(s)
- William De Martini
- Department of Biological Sciences, Seton Hall University, 400 S. Orange Ave, South Orange, NJ 07079, USA
| | - Jesse Coutu
- Department of Biological Sciences, Seton Hall University, 400 S. Orange Ave, South Orange, NJ 07079, USA
- Department of Microbiology, Oregon State University, Dryden Hall 106A, Corvallis, OR 97333, USA
| | - Joachim Bugert
- Bundeswehr Institute of Microbiology, Neuherbergstrasse 11, 80937 München, Germany
| | - Timothy Iversen
- Department of Biological Sciences, Seton Hall University, 400 S. Orange Ave, South Orange, NJ 07079, USA
| | - Jessica Cottrell
- Department of Biological Sciences, Seton Hall University, 400 S. Orange Ave, South Orange, NJ 07079, USA
| | - Daniel Brian Nichols
- Department of Biological Sciences, Seton Hall University, 400 S. Orange Ave, South Orange, NJ 07079, USA
| |
Collapse
|
18
|
Differential Response Following Infection of Mouse CNS with Virulent and Attenuated Vaccinia Virus Strains. Vaccines (Basel) 2019; 7:vaccines7010019. [PMID: 30759813 PMCID: PMC6466266 DOI: 10.3390/vaccines7010019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 02/04/2019] [Accepted: 02/07/2019] [Indexed: 12/18/2022] Open
Abstract
Viral infections of the central nervous system (CNS) lead to a broad range of pathologies. CNS infections with Orthopox viruses have been mainly documented as an adverse reaction to smallpox vaccination with vaccinia virus. To date, there is insufficient data regarding the mechanisms underlying pathological viral replication or viral clearance. Therefore, informed risk assessment of vaccine adverse reactions or outcome prediction is limited. This work applied a model of viral infection of the CNS, comparing neurovirulent with attenuated strains. We followed various parameters along the disease and correlated viral load, morbidity, and mortality with tissue integrity, innate and adaptive immune response and functionality of the blood–brain barrier. Combining these data with whole brain RNA-seq analysis performed at different time points indicated that neurovirulence is associated with host immune silencing followed by induction of tissue damage-specific pathways. In contrast, brain infection with attenuated strains resulted in rapid and robust induction of innate and adaptive protective immunity, followed by viral clearance and recovery. This study significantly improves our understanding of the mechanisms and processes determining the consequence of viral CNS infection and highlights potential biomarkers associated with such outcomes.
Collapse
|
19
|
Olson AT, Wang Z, Rico AB, Wiebe MS. A poxvirus pseudokinase represses viral DNA replication via a pathway antagonized by its paralog kinase. PLoS Pathog 2019; 15:e1007608. [PMID: 30768651 PMCID: PMC6395007 DOI: 10.1371/journal.ppat.1007608] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 02/28/2019] [Accepted: 01/31/2019] [Indexed: 12/26/2022] Open
Abstract
Poxviruses employ sophisticated, but incompletely understood, signaling pathways that engage cellular defense mechanisms and simultaneously ensure viral factors are modulated properly. For example, the vaccinia B1 protein kinase plays a vital role in inactivating the cellular antiviral factor BAF, and likely orchestrates other pathways as well. In this study, we utilized experimental evolution of a B1 deletion virus to perform an unbiased search for suppressor mutations and identify novel pathways involving B1. After several passages of the ΔB1 virus we observed a robust increase in viral titer of the adapted virus. Interestingly, our characterization of the adapted viruses reveals that mutations correlating with a loss of function of the vaccinia B12 pseudokinase provide a striking fitness enhancement to this virus. In support of predictions that reductive evolution is a driver of poxvirus adaptation, this is clear experimental evidence that gene loss can be of significant benefit. Next, we present multiple lines of evidence demonstrating that expression of full length B12 leads to a fitness reduction in viruses with a defect in B1, but has no apparent impact on wild-type virus or other mutant poxviruses. From these data we infer that B12 possesses a potent inhibitory activity that can be masked by the presence of the B1 kinase. Further investigation of B12 attributes revealed that it primarily localizes to the nucleus, a characteristic only rarely found among poxviral proteins. Surprisingly, BAF phosphorylation is reduced under conditions in which B12 is present in infected cells without B1, indicating that B12 may function in part by enhancing antiviral activity of BAF. Together, our studies of B1 and B12 present novel evidence that a paralogous kinase-pseudokinase pair can exhibit a unique epistatic relationship in a virus, perhaps serving to enhance B1 conservation during poxvirus evolution and to orchestrate yet-to-be-discovered nuclear events during infection.
Collapse
Affiliation(s)
- Annabel T. Olson
- Nebraska Center for Virology, University of Nebraska, Lincoln, NE, United States of America
- School of Biological Sciences, University of Nebraska, Lincoln, NE, United States of America
| | - Zhigang Wang
- Nebraska Center for Virology, University of Nebraska, Lincoln, NE, United States of America
| | - Amber B. Rico
- Nebraska Center for Virology, University of Nebraska, Lincoln, NE, United States of America
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska, Lincoln, NE, United States of America
| | - Matthew S. Wiebe
- Nebraska Center for Virology, University of Nebraska, Lincoln, NE, United States of America
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska, Lincoln, NE, United States of America
| |
Collapse
|
20
|
Suppression of NF-κB Activity: A Viral Immune Evasion Mechanism. Viruses 2018; 10:v10080409. [PMID: 30081579 PMCID: PMC6115930 DOI: 10.3390/v10080409] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 07/29/2018] [Accepted: 08/02/2018] [Indexed: 12/20/2022] Open
Abstract
Nuclear factor-κB (NF-κB) is an important transcription factor that induces the expression of antiviral genes and viral genes. NF-κB activation needs the activation of NF-κB upstream molecules, which include receptors, adaptor proteins, NF-κB (IκB) kinases (IKKs), IκBα, and NF-κB dimer p50/p65. To survive, viruses have evolved the capacity to utilize various strategies that inhibit NF-κB activity, including targeting receptors, adaptor proteins, IKKs, IκBα, and p50/p65. To inhibit NF-κB activation, viruses encode several specific NF-κB inhibitors, including NS3/4, 3C and 3C-like proteases, viral deubiquitinating enzymes (DUBs), phosphodegron-like (PDL) motifs, viral protein phosphatase (PPase)-binding proteins, and small hydrophobic (SH) proteins. Finally, we briefly describe the immune evasion mechanism of human immunodeficiency virus 1 (HIV-1) by inhibiting NF-κB activity in productive and latent infections. This paper reviews a viral mechanism of immune evasion that involves the suppression of NF-κB activation to provide new insights into and references for the control and prevention of viral diseases.
Collapse
|
21
|
Albarnaz JD, Torres AA, Smith GL. Modulating Vaccinia Virus Immunomodulators to Improve Immunological Memory. Viruses 2018; 10:E101. [PMID: 29495547 PMCID: PMC5869494 DOI: 10.3390/v10030101] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 02/21/2018] [Accepted: 02/22/2018] [Indexed: 12/14/2022] Open
Abstract
The increasing frequency of monkeypox virus infections, new outbreaks of other zoonotic orthopoxviruses and concern about the re-emergence of smallpox have prompted research into developing antiviral drugs and better vaccines against these viruses. This article considers the genetic engineering of vaccinia virus (VACV) to enhance vaccine immunogenicity and safety. The virulence, immunogenicity and protective efficacy of VACV strains engineered to lack specific immunomodulatory or host range proteins are described. The ultimate goal is to develop safer and more immunogenic VACV vaccines that induce long-lasting immunological memory.
Collapse
Affiliation(s)
- Jonas D Albarnaz
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK.
| | - Alice A Torres
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK.
| | - Geoffrey L Smith
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK.
| |
Collapse
|
22
|
Abstract
Interferons (IFNs) are secreted glycoproteins that are produced by cells in response to virus infection and other stimuli and induce an antiviral state in cells bearing IFN receptors. In this way, IFNs restrict virus replication and spread before an adaptive immune response is developed. Viruses are very sensitive to the effects of IFNs and consequently have evolved many strategies to interfere with interferon. This is particularly well illustrated by poxviruses, which have large dsDNA genomes and encode hundreds of proteins. Vaccinia virus is the prototypic poxvirus and expresses many proteins that interfere with IFN and are considered in this review. These proteins act either inside or outside the cell and within the cytoplasm or nucleus. They function by restricting the production of IFN by blocking the signaling pathways leading to transcription of IFN genes, stopping IFNs binding to their receptors, blocking IFN-induced signal transduction leading to expression of interferon-stimulated genes (ISGs), or inhibiting the antiviral activity of ISG products.
Collapse
Affiliation(s)
| | | | - Yongxu Lu
- University of Cambridge, Cambridge, United Kingdom
| |
Collapse
|
23
|
Nagendraprabhu P, Khatiwada S, Chaulagain S, Delhon G, Rock DL. A parapoxviral virion protein targets the retinoblastoma protein to inhibit NF-κB signaling. PLoS Pathog 2017; 13:e1006779. [PMID: 29244863 PMCID: PMC5747488 DOI: 10.1371/journal.ppat.1006779] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 12/29/2017] [Accepted: 11/28/2017] [Indexed: 12/14/2022] Open
Abstract
Poxviruses have evolved multiple strategies to subvert signaling by Nuclear Factor κB (NF-κB), a crucial regulator of host innate immune responses. Here, we describe an orf virus (ORFV) virion-associated protein, ORFV119, which inhibits NF-κB signaling very early in infection (≤ 30 min post infection). ORFV119 NF-κB inhibitory activity was found unimpaired upon translation inhibition, suggesting that virion ORFV119 alone is responsible for early interference in signaling. A C-terminal LxCxE motif in ORFV119 enabled the protein to interact with the retinoblastoma protein (pRb) a multifunctional protein best known for its tumor suppressor activity. Notably, experiments using a recombinant virus containing an ORFV119 mutation which abrogates its interaction with pRb together with experiments performed in cells lacking or with reduced pRb levels indicate that ORFV119 mediated inhibition of NF-κB signaling is largely pRb dependent. ORFV119 was shown to inhibit IKK complex activation early in infection. Consistent with IKK inhibition, ORFV119 also interacted with TNF receptor associated factor 2 (TRAF2), an adaptor protein recruited to signaling complexes upstream of IKK in infected cells. ORFV119-TRAF2 interaction was enhanced in the presence of pRb, suggesting that ORFV119-pRb complex is required for efficient interaction with TRAF2. Additionally, transient expression of ORFV119 in uninfected cells was sufficient to inhibit TNFα-induced IKK activation and NF-κB signaling, indicating that no other viral proteins are required for the effect. Infection of sheep with ORFV lacking the ORFV119 gene led to attenuated disease phenotype, indicating that ORFV119 contributes to virulence in the natural host. ORFV119 represents the first poxviral protein to interfere with NF-κB signaling through interaction with pRb.
Collapse
Affiliation(s)
- Ponnuraj Nagendraprabhu
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana- Champaign, Urbana, IL, United States of America
| | - Sushil Khatiwada
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana- Champaign, Urbana, IL, United States of America
| | - Sabal Chaulagain
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana- Champaign, Urbana, IL, United States of America
| | - Gustavo Delhon
- School of Veterinary and Biomedical Sciences, Center for Virology, University of Nebraska-Lincoln, Lincoln, NE, United States of America
- * E-mail: (GD); (DLR)
| | - Daniel L. Rock
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana- Champaign, Urbana, IL, United States of America
- * E-mail: (GD); (DLR)
| |
Collapse
|
24
|
Qin Y, Li M, Zhou SL, Yin W, Bian Z, Shu HB. SPI-2/CrmA inhibits IFN-β induction by targeting TBK1/IKKε. Sci Rep 2017; 7:10495. [PMID: 28874755 PMCID: PMC5585206 DOI: 10.1038/s41598-017-11016-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 08/17/2017] [Indexed: 12/18/2022] Open
Abstract
Viruses modulate the host immune system to evade host antiviral responses. The poxvirus proteins serine proteinase inhibitor 2 (SPI-2) and cytokine response modifier A (CrmA) are involved in multiple poxvirus evasion strategies. SPI-2 and CrmA target caspase-1 to prevent apoptosis and cytokine activation. Here, we identified SPI-2 and CrmA as negative regulators of virus-triggered induction of IFN-β. Ectopic expression of SPI-2 or CrmA inhibited virus-triggered induction of IFN-β and its downstream genes. Consistently, knockdown of SPI-2 by RNAi potentiated VACV-induced transcription of antiviral genes. Further studies revealed that SPI-2 and CrmA associated with TBK1 and IKKε to disrupt the MITA-TBK1/IKKε-IRF3 complex. These findings reveal a novel mechanism of SPI-2/CrmA-mediated poxvirus immune evasion.
Collapse
Affiliation(s)
- Yue Qin
- The State Key Laboratory Breeding Base of Basic Science of Stomatology, Hubei Province and Key Laboratory of Oral Biomedicine, Ministry of Education (Hubei-MOST KLOS & KLOBME), School and Hospital of Stomatology, Wuhan University, Wuhan, 430079, China.
| | - Mi Li
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Sheng-Long Zhou
- The State Key Laboratory Breeding Base of Basic Science of Stomatology, Hubei Province and Key Laboratory of Oral Biomedicine, Ministry of Education (Hubei-MOST KLOS & KLOBME), School and Hospital of Stomatology, Wuhan University, Wuhan, 430079, China
| | - Wei Yin
- The State Key Laboratory Breeding Base of Basic Science of Stomatology, Hubei Province and Key Laboratory of Oral Biomedicine, Ministry of Education (Hubei-MOST KLOS & KLOBME), School and Hospital of Stomatology, Wuhan University, Wuhan, 430079, China
| | - Zhuan Bian
- The State Key Laboratory Breeding Base of Basic Science of Stomatology, Hubei Province and Key Laboratory of Oral Biomedicine, Ministry of Education (Hubei-MOST KLOS & KLOBME), School and Hospital of Stomatology, Wuhan University, Wuhan, 430079, China
| | - Hong-Bing Shu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, 430072, China.,Medical Research Institute, Collaborative Innovation Center for Viral Immunology, School of Medicine, Wuhan University, Wuhan, 430071, China
| |
Collapse
|
25
|
Khatiwada S, Delhon G, Nagendraprabhu P, Chaulagain S, Luo S, Diel DG, Flores EF, Rock DL. A parapoxviral virion protein inhibits NF-κB signaling early in infection. PLoS Pathog 2017; 13:e1006561. [PMID: 28787456 PMCID: PMC5560748 DOI: 10.1371/journal.ppat.1006561] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 08/17/2017] [Accepted: 07/31/2017] [Indexed: 12/16/2022] Open
Abstract
Poxviruses have evolved unique proteins and mechanisms to counteract the nuclear factor κB (NF-κB) signaling pathway, which is an essential regulatory pathway of host innate immune responses. Here, we describe a NF-κB inhibitory virion protein of orf virus (ORFV), ORFV073, which functions very early in infected cells. Infection with ORFV073 gene deletion virus (OV-IA82Δ073) led to increased accumulation of NF-κB essential modulator (NEMO), marked phosphorylation of IκB kinase (IKK) subunits IKKα and IKKβ, IκBα and NF-κB subunit p65 (NF-κB-p65), and to early nuclear translocation of NF-κB-p65 in virus-infected cells (≤ 30 min post infection). Expression of ORFV073 alone was sufficient to inhibit TNFα induced activation of the NF-κB signaling in uninfected cells. Consistent with observed inhibition of IKK complex activation, ORFV073 interacted with the regulatory subunit of the IKK complex NEMO. Infection of sheep with OV-IA82Δ073 led to virus attenuation, indicating that ORFV073 is a virulence determinant in the natural host. Notably, ORFV073 represents the first poxviral virion-associated NF-κB inhibitor described, highlighting the significance of viral inhibition of NF-κB signaling very early in infection.
Collapse
Affiliation(s)
- Sushil Khatiwada
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Gustavo Delhon
- School of Veterinary Medicine and Biomedical Science, Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America
| | - Ponnuraj Nagendraprabhu
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Sabal Chaulagain
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Shuhong Luo
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Diego G. Diel
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Eduardo F. Flores
- Departamento de Medicina Veterinária Preventiva, Centro de Ciências Rurais, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul, Brazil
| | - Daniel L. Rock
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| |
Collapse
|
26
|
Deletion of the K1L Gene Results in a Vaccinia Virus That Is Less Pathogenic Due to Muted Innate Immune Responses, yet Still Elicits Protective Immunity. J Virol 2017; 91:JVI.00542-17. [PMID: 28490586 DOI: 10.1128/jvi.00542-17] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 05/03/2017] [Indexed: 12/14/2022] Open
Abstract
All viruses strategically alter the antiviral immune response to their benefit. The vaccinia virus (VACV) K1 protein has multiple immunomodulatory effects in tissue culture models of infection, including NF-κB antagonism. However, the effect of K1 during animal infection is poorly understood. We determined that a K1L-less vaccinia virus (vΔK1L) was less pathogenic than wild-type VACV in intranasal and intradermal models of infection. Decreased pathogenicity was correlated with diminished virus replication in intranasally infected mice. However, in intradermally inoculated ears, vΔK1L replicated to levels nearly identical to those of VACV, implying that the decreased immune response to vΔK1L infection, not virus replication, dictated lesion size. Several lines of evidence support this theory. First, vΔK1L induced slightly less edema than vK1L, as revealed by histopathology and noninvasive quantitative ultrasound technology (QUS). Second, infiltrating immune cell populations were decreased in vΔK1L-infected ears. Third, cytokine and chemokine gene expression was decreased in vΔK1L-infected ears. While these results identified the biological basis for smaller lesions, they remained puzzling; because K1 antagonizes NF-κB in vitro, antiviral gene expression was expected to be higher during vΔK1L infection. Despite these diminished innate immune responses, vΔK1L vaccination induced a protective VACV-specific CD8+ T cell response and protected against a lethal VACV challenge. Thus, vΔK1L is the first vaccinia virus construct reported that caused a muted innate immune gene expression profile and decreased immune cell infiltration in an intradermal model of infection yet still elicited protective immunity.IMPORTANCE The vaccinia virus (VACV) K1 protein inhibits NF-κB activation among its other antagonistic functions. A virus lacking K1 (vΔK1L) was predicted to be less pathogenic because it would trigger a more robust antiviral immune response than VACV. Indeed, vΔK1L was less pathogenic in intradermally infected mouse ear pinnae. However, vΔK1L infection unexpectedly elicited dramatically reduced infiltration of innate immune cells into ears. This was likely due to decreased expression of cytokine and chemokine genes in vΔK1L-infected ears. As such, our finding contradicted observations from cell culture systems. Interestingly, vΔK1L conferred protective immunity against lethal VACV challenge. This suggests that the muted immune response triggered during vΔK1L infection remained sufficient to mount an effective protective response. Our results highlight the complexity and unpredictable nature of virus-host interactions, a relationship that must be understood to better comprehend virus pathogenesis or to manipulate viruses for use as vaccines.
Collapse
|
27
|
Teferi WM, Desaulniers MA, Noyce RS, Shenouda M, Umer B, Evans DH. The vaccinia virus K7 protein promotes histone methylation associated with heterochromatin formation. PLoS One 2017; 12:e0173056. [PMID: 28257484 PMCID: PMC5336242 DOI: 10.1371/journal.pone.0173056] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 02/14/2017] [Indexed: 12/12/2022] Open
Abstract
It has been well established that many vaccinia virus proteins suppress host antiviral pathways by targeting the transcription of antiviral proteins, thus evading the host innate immune system. However, whether viral proteins have an effect on the host’s overall cellular transcription is less understood. In this study we investigated the regulation of heterochromatin during vaccinia virus infection. Heterochromatin is a highly condensed form of chromatin that is less transcriptionally active and characterized by methylation of histone proteins. We examined the change in methylation of two histone proteins, H3 and H4, which are major markers of heterochromatin, during the course of viral infection. Using immunofluorescence microscopy and flow cytometry we were able to track the overall change in the methylated levels of H3K9 and H4K20. Our results suggest that there is significant increase in methylation of H3K9 and H4K20 during Orthopoxviruses infection compared to mock-infected cells. However, this effect was not seen when we infected cells with Leporipoxviruses. We further screened several vaccinia virus single and multi-gene deletion mutant and identified the vaccinia virus gene K7R as a contributor to the increase in cellular histone methylation during infection.
Collapse
Affiliation(s)
- Wondimagegnehu M. Teferi
- Department of Medical Microbiology & Immunology, Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Alberta, Canada
| | - Megan A. Desaulniers
- Department of Medical Microbiology & Immunology, Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Alberta, Canada
| | - Ryan S. Noyce
- Department of Medical Microbiology & Immunology, Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Alberta, Canada
| | - Mira Shenouda
- Department of Medical Microbiology & Immunology, Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Alberta, Canada
| | - Brittany Umer
- Department of Medical Microbiology & Immunology, Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Alberta, Canada
| | - David H. Evans
- Department of Medical Microbiology & Immunology, Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Alberta, Canada
- * E-mail:
| |
Collapse
|
28
|
RNA-Seq Based Transcriptome Analysis of the Type I Interferon Host Response upon Vaccinia Virus Infection of Mouse Cells. J Immunol Res 2017; 2017:5157626. [PMID: 28280747 PMCID: PMC5322442 DOI: 10.1155/2017/5157626] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 01/09/2017] [Indexed: 11/26/2022] Open
Abstract
Vaccinia virus (VACV) encodes the soluble type I interferon (IFN) binding protein B18 that is secreted from infected cells and also attaches to the cell surface, as an immunomodulatory strategy to inhibit the host IFN response. By using next generation sequencing technologies, we performed a detailed RNA-seq study to dissect at the transcriptional level the modulation of the IFN based host response by VACV and B18. Transcriptome profiling of L929 cells after incubation with purified recombinant B18 protein showed that attachment of B18 to the cell surface does not trigger cell signalling leading to transcriptional activation. Consistent with its ability to bind type I IFN, B18 completely inhibited the IFN-mediated modulation of host gene expression. Addition of UV-inactivated virus particles to cell cultures altered the expression of a set of 53 cellular genes, including genes involved in innate immunity. Differential gene expression analyses of cells infected with replication competent VACV identified the activation of a broad range of host genes involved in multiple cellular pathways. Interestingly, we did not detect an IFN-mediated response among the transcriptional changes induced by VACV, even after the addition of IFN to cells infected with a mutant VACV lacking B18. This is consistent with additional viral mechanisms acting at different levels to block IFN responses during VACV infection.
Collapse
|
29
|
Liu Y, Olagnier D, Lin R. Host and Viral Modulation of RIG-I-Mediated Antiviral Immunity. Front Immunol 2017; 7:662. [PMID: 28096803 PMCID: PMC5206486 DOI: 10.3389/fimmu.2016.00662] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 12/16/2016] [Indexed: 12/21/2022] Open
Abstract
Innate immunity is the first line of defense against invading pathogens. Rapid and efficient detection of pathogen-associated molecular patterns via pattern-recognition receptors is essential for the host to mount defensive and protective responses. Retinoic acid-inducible gene-I (RIG-I) is critical in triggering antiviral and inflammatory responses for the control of viral replication in response to cytoplasmic virus-specific RNA structures. Upon viral RNA recognition, RIG-I recruits the mitochondrial adaptor protein mitochondrial antiviral signaling protein, which leads to a signaling cascade that coordinates the induction of type I interferons (IFNs), as well as a large variety of antiviral interferon-stimulated genes. The RIG-I activation is tightly regulated via various posttranslational modifications for the prevention of aberrant innate immune signaling. By contrast, viruses have evolved mechanisms of evasion, such as sequestrating viral structures from RIG-I detections and targeting receptor or signaling molecules for degradation. These virus–host interactions have broadened our understanding of viral pathogenesis and provided insights into the function of the RIG-I pathway. In this review, we summarize the recent advances regarding RIG-I pathogen recognition and signaling transduction, cell-intrinsic control of RIG-I activation, and the viral antagonism of RIG-I signaling.
Collapse
Affiliation(s)
- Yiliu Liu
- Jewish General Hospital, Lady Davis Institute, McGill University, Montreal, QC, Canada; Division of Experimental Medicine, McGill University, Montreal, QC, Canada
| | - David Olagnier
- Jewish General Hospital, Lady Davis Institute, McGill University, Montreal, QC, Canada; Division of Experimental Medicine, McGill University, Montreal, QC, Canada
| | - Rongtuan Lin
- Jewish General Hospital, Lady Davis Institute, McGill University, Montreal, QC, Canada; Division of Experimental Medicine, McGill University, Montreal, QC, Canada; Department of Microbiology and Immunology, McGill University, Montreal, QC, Canada
| |
Collapse
|
30
|
Stuart JH, Sumner RP, Lu Y, Snowden JS, Smith GL. Vaccinia Virus Protein C6 Inhibits Type I IFN Signalling in the Nucleus and Binds to the Transactivation Domain of STAT2. PLoS Pathog 2016; 12:e1005955. [PMID: 27907166 PMCID: PMC5131898 DOI: 10.1371/journal.ppat.1005955] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 09/26/2016] [Indexed: 12/17/2022] Open
Abstract
The type I interferon (IFN) response is a crucial innate immune signalling pathway required for defense against viral infection. Accordingly, the great majority of mammalian viruses possess means to inhibit this important host immune response. Here we show that vaccinia virus (VACV) strain Western Reserve protein C6, is a dual function protein that inhibits the cellular response to type I IFNs in addition to its published function as an inhibitor of IRF-3 activation, thereby restricting type I IFN production from infected cells. Ectopic expression of C6 inhibits the induction of interferon stimulated genes (ISGs) in response to IFNα treatment at both the mRNA and protein level. C6 inhibits the IFNα-induced Janus kinase/signal transducer and activator of transcription (JAK/STAT) signalling pathway at a late stage, downstream of STAT1 and STAT2 phosphorylation, nuclear translocation and binding of the interferon stimulated gene factor 3 (ISGF3) complex to the interferon stimulated response element (ISRE). Mechanistically, C6 associates with the transactivation domain of STAT2 and this might explain how C6 inhibits the type I IFN signalling very late in the pathway. During virus infection C6 reduces ISRE-dependent gene expression despite the presence of the viral protein phosphatase VH1 that dephosphorylates STAT1 and STAT2. The ability of a cytoplasmic replicating virus to dampen the immune response within the nucleus, and the ability of viral immunomodulators such as C6 to inhibit multiple stages of the innate immune response by distinct mechanisms, emphasizes the intricacies of host-pathogen interactions and viral immune evasion. In response to a viral infection, infected host cells mount an early, innate immune response to limit viral replication and spread. Type I interferons (IFNs) are produced by a cell when a viral infection is detected and are a crucial aspect of this early immune response. IFNs are released from the infected cell and can act on the infected cell itself or neighbouring cells to initiate a signalling pathway that results in the production of hundreds of anti-viral proteins. In this work we investigated a vaccinia virus protein called C6, a known inhibitor of type I IFN production. Here we show that C6 also inhibits signalling initiated in response to type I IFNs, therefore providing a dual defence against this essential immune response. The results show that, unlike the majority of viral inhibitors of IFN signalling, C6 inhibits the signalling pathway at a late stage once the proteins required for IFN-stimulated gene transcription have reached the nucleus and bound to the DNA. This work illustrates the complex relationship between infecting viruses and the host immune response and further investigation of the mechanism by which C6 inhibits this important immune pathway will likely increase our knowledge of the pathway itself.
Collapse
Affiliation(s)
- Jennifer H. Stuart
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Rebecca P. Sumner
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Yongxu Lu
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Joseph S. Snowden
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Geoffrey L. Smith
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
- * E-mail:
| |
Collapse
|
31
|
Bravo Cruz AG, Shisler JL. Vaccinia virus K1 ankyrin repeat protein inhibits NF-κB activation by preventing RelA acetylation. J Gen Virol 2016; 97:2691-2702. [DOI: 10.1099/jgv.0.000576] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Affiliation(s)
- Ariana G. Bravo Cruz
- Department of Microbiology, University of Illinois, 601 S. Goodwin Avenue, Urbana, IL 61801, USA
| | - Joanna L. Shisler
- Department of Microbiology, University of Illinois, 601 S. Goodwin Avenue, Urbana, IL 61801, USA
| |
Collapse
|
32
|
Li Y, Sheng Y, Chu Y, Ji H, Jiang S, Lan T, Li M, Chen S, Fan Y, Li W, Li X, Sun L, Jin N. Seven major genomic deletions of vaccinia virus Tiantan strain are sufficient to decrease pathogenicity. Antiviral Res 2016; 129:1-12. [PMID: 26821204 DOI: 10.1016/j.antiviral.2016.01.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 01/18/2016] [Accepted: 01/22/2016] [Indexed: 11/29/2022]
Abstract
Attenuated strain TTVAC7, as a multi-gene-deleted vaccinia virus Tiantan strain (VTT), was constructed by knocking out parts of non-essential genes related to virulence, host range and immunomodulation of VTT, and by combining double marker screening with exogenous selectable marker knockout techniques. In this study, shuttle vector plasmids pTC-EGFP, pTA35-EGFP, pTA66-EGFP, pTE-EGFP, pTB-EGFP, pTI-EGFP and pTJ-EGFP were constructed, which contained seven pairs of recombinant arms linked to the early and late strong promoter pE/L, as well as to enhanced green fluorescent protein (EGFP) as an exogenous selectable marker. BHK cells were co-transfected/infected successively with the above plasmids and VTT or gene-deleted VTT, and homologous recombination and fluorescence plaque screening methods were used to knock out the gene fragments (TC: TC7L ∼ TK2L; TA35: TA35L; TA66: TA66R; TE: TE3L ∼ TE4L; TB: TB13R; TI: TI4L; TJ: TJ2R). The Cre/LoxP system was then applied to knock out the exogenous selectable marker, and ultimately the gene-deleted attenuated strain TTVAC7 was obtained. A series of in vivo and in vitro experiments demonstrated that not only the host range of TTVAC7 could be narrowed and its toxicity weakened significantly, but its high immunogenicity was maintained at the same time. These results support the potential of TTVAC7 to be developed as a safe viral vector or vaccine.
Collapse
Affiliation(s)
- Yiquan Li
- Institute of Military Veterinary Medicine, Academy of Military Medical Science, Changchun 130122, PR China; Jiang su Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, PR China
| | - Yuan Sheng
- Institute of Military Veterinary Medicine, Academy of Military Medical Science, Changchun 130122, PR China; Jiang su Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, PR China
| | - Yunjie Chu
- Institute of Military Veterinary Medicine, Academy of Military Medical Science, Changchun 130122, PR China; The Affiliated Hospital of Changchun University of Traditional Chinese Medicine, Changchun 130021, PR China
| | - Huifan Ji
- Institute of Military Veterinary Medicine, Academy of Military Medical Science, Changchun 130122, PR China; Department of Gastroenterology, The First Hospital of Jilin University, Changchun 130021, PR China
| | - Shuang Jiang
- Institute of Military Veterinary Medicine, Academy of Military Medical Science, Changchun 130122, PR China; Jiang su Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, PR China
| | - Tian Lan
- Institute of Military Veterinary Medicine, Academy of Military Medical Science, Changchun 130122, PR China; Jiang su Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, PR China
| | - Min Li
- Institute of Military Veterinary Medicine, Academy of Military Medical Science, Changchun 130122, PR China; Jiang su Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, PR China
| | - Shuang Chen
- Institute of Military Veterinary Medicine, Academy of Military Medical Science, Changchun 130122, PR China; Jiang su Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, PR China
| | - Yuanyuan Fan
- Institute of Military Veterinary Medicine, Academy of Military Medical Science, Changchun 130122, PR China; Jiang su Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, PR China
| | - Wenjie Li
- Institute of Military Veterinary Medicine, Academy of Military Medical Science, Changchun 130122, PR China; The Affiliated Hospital of Changchun University of Traditional Chinese Medicine, Changchun 130021, PR China
| | - Xiao Li
- Institute of Military Veterinary Medicine, Academy of Military Medical Science, Changchun 130122, PR China; Jiang su Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, PR China.
| | - Lili Sun
- Institute of Military Veterinary Medicine, Academy of Military Medical Science, Changchun 130122, PR China; Department of Head and Neck Surgery, Tumor Hospital of Jilin Province, Changchun 130012, PR China.
| | - Ningyi Jin
- Institute of Military Veterinary Medicine, Academy of Military Medical Science, Changchun 130122, PR China; Jiang su Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, PR China; Department of Head and Neck Surgery, Tumor Hospital of Jilin Province, Changchun 130012, PR China.
| |
Collapse
|
33
|
Strnadova P, Ren H, Valentine R, Mazzon M, Sweeney TR, Brierley I, Smith GL. Inhibition of Translation Initiation by Protein 169: A Vaccinia Virus Strategy to Suppress Innate and Adaptive Immunity and Alter Virus Virulence. PLoS Pathog 2015; 11:e1005151. [PMID: 26334635 PMCID: PMC4559412 DOI: 10.1371/journal.ppat.1005151] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Accepted: 08/13/2015] [Indexed: 12/19/2022] Open
Abstract
Vaccinia virus (VACV) is the prototypic orthopoxvirus and the vaccine used to eradicate smallpox. Here we show that VACV strain Western Reserve protein 169 is a cytoplasmic polypeptide expressed early during infection that is excluded from virus factories and inhibits the initiation of cap-dependent and cap-independent translation. Ectopic expression of protein 169 causes the accumulation of 80S ribosomes, a reduction of polysomes, and inhibition of protein expression deriving from activation of multiple innate immune signaling pathways. A virus lacking 169 (vΔ169) replicates and spreads normally in cell culture but is more virulent than parental and revertant control viruses in intranasal and intradermal murine models of infection. Intranasal infection by vΔ169 caused increased pro-inflammatory cytokines and chemokines, infiltration of pulmonary leukocytes, and lung weight. These alterations in innate immunity resulted in a stronger CD8+ T-cell memory response and better protection against virus challenge. This work illustrates how inhibition of host protein synthesis can be a strategy for virus suppression of innate and adaptive immunity. Long after smallpox was eradicated by vaccination with vaccinia virus, the study of this virus continues to reveal novel aspects of the interactions between a virus and the host in which it replicates. In this work we investigated the function of a previously uncharacterized VACV protein, called 169. The results show that protein 169 inhibits the synthesis of host proteins in cells and thereby provides a broad inhibition of the host innate immune response to infection. Unlike several other virus inhibitors of host protein synthesis, protein 169 acts by inhibiting the initiation of protein synthesis by both cap-dependent and cap-independent pathways. Also unlike several other virus protein synthesis inhibitors, the loss of protein 169 does not affect virus replication or spread, but the virus virulence was increased. This more severe infection is, however, cleared more rapidly and results in a stronger immunological memory response that is mediated by T-cells and provides better protection against re-infection. This work illustrates how shutting down host protein synthesis can be a strategy to block the host immune response to infection rather than a means to manufacture more virus particles.
Collapse
Affiliation(s)
- Pavla Strnadova
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
- Department of Virology, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Hongwei Ren
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
- Department of Virology, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Robert Valentine
- Department of Virology, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Michela Mazzon
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
- Department of Virology, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Trevor R. Sweeney
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Ian Brierley
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Geoffrey L. Smith
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
- Department of Virology, Faculty of Medicine, Imperial College London, London, United Kingdom
- * E-mail:
| |
Collapse
|
34
|
Ren H, Ferguson BJ, Maluquer de Motes C, Sumner RP, Harman LER, Smith GL. Enhancement of CD8(+) T-cell memory by removal of a vaccinia virus nuclear factor-κB inhibitor. Immunology 2015; 145:34-49. [PMID: 25382035 PMCID: PMC4405322 DOI: 10.1111/imm.12422] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 10/30/2014] [Accepted: 11/03/2014] [Indexed: 12/20/2022] Open
Abstract
Factors influencing T-cell responses are important for vaccine development but are incompletely understood. Here, vaccinia virus (VACV) protein N1 is shown to impair the development of both effector and memory CD8+ T cells and this correlates with its inhibition of nuclear factor-κB (NF-κB) activation. Infection with VACVs that either have the N1L gene deleted (vΔN1) or contain a I6E mutation (vN1.I6E) that abrogates its inhibition of NF-κB resulted in increased central and memory CD8+ T-cell populations, increased CD8+ T-cell cytotoxicity and lower virus titres after challenge. Furthermore, CD8+ memory T-cell function was increased following infection with vN1.I6E, with more interferon-γ production and greater protection against VACV infection following passive transfer to naive mice, compared with CD8+ T cells from mice infected with wild-type virus (vN1.WT). This demonstrates the importance of NF-κB activation within infected cells for long-term CD8+ T-cell memory and vaccine efficacy. Further, it provides a rationale for deleting N1 from VACV vectors to enhance CD8+ T-cell immunogenicity, while simultaneously reducing virulence to improve vaccine safety.
Collapse
Affiliation(s)
- Hongwei Ren
- Department of Pathology, University of Cambridge, Cambridge, UK
| | | | | | | | | | | |
Collapse
|
35
|
Neidel S, Maluquer de Motes C, Mansur DS, Strnadova P, Smith GL, Graham SC. Vaccinia virus protein A49 is an unexpected member of the B-cell Lymphoma (Bcl)-2 protein family. J Biol Chem 2015; 290:5991-6002. [PMID: 25605733 PMCID: PMC4358236 DOI: 10.1074/jbc.m114.624650] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 01/11/2015] [Indexed: 12/18/2022] Open
Abstract
Vaccinia virus (VACV) encodes several proteins that inhibit activation of the proinflammatory transcription factor nuclear factor κB (NF-κB). VACV protein A49 prevents translocation of NF-κB to the nucleus by sequestering cellular β-TrCP, a protein required for the degradation of the inhibitor of κB. A49 does not share overall sequence similarity with any protein of known structure or function. We solved the crystal structure of A49 from VACV Western Reserve to 1.8 Å resolution and showed, surprisingly, that A49 has the same three-dimensional fold as Bcl-2 family proteins despite lacking identifiable sequence similarity. Whereas Bcl-2 family members characteristically modulate cellular apoptosis, A49 lacks a surface groove suitable for binding BH3 peptides and does not bind proapoptotic Bcl-2 family proteins Bax or Bak. The N-terminal 17 residues of A49 do not adopt a single well ordered conformation, consistent with their proposed role in binding β-TrCP. Whereas pairs of A49 molecules interact symmetrically via a large hydrophobic surface in crystallo, A49 does not dimerize in solution or in cells, and we propose that this hydrophobic interaction surface may mediate binding to a yet undefined cellular partner. A49 represents the eleventh VACV Bcl-2 family protein and, despite these proteins sharing very low sequence identity, structure-based phylogenetic analysis shows that all poxvirus Bcl-2 proteins are structurally more similar to each other than they are to any cellular or herpesvirus Bcl-2 proteins. This is consistent with duplication and diversification of a single BCL2 family gene acquired by an ancestral poxvirus.
Collapse
Affiliation(s)
- Sarah Neidel
- From the Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, United Kingdom and
| | - Carlos Maluquer de Motes
- From the Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, United Kingdom and
| | - Daniel S Mansur
- the Department of Microbiology, Immunology, and Parasitology, Universidade Federal de Santa Catarina, Florianopolis, 88040-900 Brazil
| | - Pavla Strnadova
- From the Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, United Kingdom and
| | - Geoffrey L Smith
- From the Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, United Kingdom and
| | - Stephen C Graham
- From the Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, United Kingdom and
| |
Collapse
|
36
|
NFκB activation by modified vaccinia virus as a novel strategy to enhance neutrophil migration and HIV-specific T-cell responses. Proc Natl Acad Sci U S A 2015; 112:E1333-42. [PMID: 25739961 DOI: 10.1073/pnas.1424341112] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Neutrophils are antigen-transporting cells that generate vaccinia virus (VACV)-specific T-cell responses, yet how VACV modulates neutrophil recruitment and its significance in the immune response are unknown. We generated an attenuated VACV strain that expresses HIV-1 clade C antigens but lacks three specific viral genes (A52R, K7R, and B15R). We found that these genes act together to inhibit the NFκB signaling pathway. Triple ablation in modified virus restored NFκB function in macrophages. After virus infection of mice, NFκB pathway activation led to expression of several cytokines/chemokines that increased the migration of neutrophil populations (Nα and Nβ) to the infection site. Nβ cells displayed features of antigen-presenting cells and activated virus-specific CD8 T cells. Enhanced neutrophil trafficking to the infection site correlated with an increased T-cell response to HIV vector-delivered antigens. These results identify a mechanism for poxvirus-induced immune response and alternatives for vaccine vector design.
Collapse
|
37
|
Evolution of and evolutionary relationships between extant vaccinia virus strains. J Virol 2014; 89:1809-24. [PMID: 25410873 DOI: 10.1128/jvi.02797-14] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
UNLABELLED Although vaccinia virus (VACV) was once used as a vaccine to eradicate smallpox on a worldwide scale, the biological origins of VACV are uncertain, as are the historical relationships between the different strains once used as smallpox vaccines. Here, we sequenced additional VACV strains that either represent relatively pristine examples of old vaccines (e.g., Dryvax, Lister, and Tashkent) or have been subjected to additional laboratory passage (e.g., IHD-W and WR). These genome sequences were compared with those previously reported for other VACVs as well as other orthopoxviruses. These extant VACVs do not always cluster in simple phylogenetic trees that are aligned with the known historical relationships between these strains. Rather, the pattern of deletions suggests that all existing strains likely come from a complex stock of viruses that has been passaged, distributed, and randomly sampled over time, thus obscuring simple historical or geographic links. We examined surviving nonclonal vaccine stocks, like Dryvax, which continue to harbor larger and now rare variants, including one that we have designated "clone DPP25." DPP25 encodes genes not found in most VACV strains, including an ankyrin-F-box protein, a homolog of the variola virus (Bangladesh) B18R gene which we show can be deleted without affecting virulence in mice. We propose a simple common mechanism by which recombination of a larger and hypothetical DPP25-like ancestral strain, combined with selection for retention of critically important genes near the terminal inverted repeat boundaries (vaccinia virus growth factor gene and an interferon alpha/beta receptor homolog), could produce all known VACV variants. IMPORTANCE Smallpox was eradicated by using a combination of intensive disease surveillance and vaccination using vaccinia virus (VACV). Interestingly, little is known about the historical relationships between different strains of VACV and how these viruses may have evolved from a common ancestral strain. To understand these relationships, additional strains were sequenced and compared to existing strains of VACV as well as other orthopoxviruses by using whole-genome sequence alignments. Extant strains of VACV did not always cluster in simple phylogenetic trees based on known historical relationships between these strains. Based on these findings, it is possible that all existing strains of VACV are derived from a single complex stock of viruses that has been passaged, distributed, and sampled over time.
Collapse
|
38
|
Amaya M, Keck F, Bailey C, Narayanan A. The role of the IKK complex in viral infections. Pathog Dis 2014; 72:32-44. [PMID: 25082354 PMCID: PMC7108545 DOI: 10.1111/2049-632x.12210] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 06/11/2014] [Accepted: 07/17/2014] [Indexed: 01/21/2023] Open
Abstract
The NF‐κB signal transduction pathway is a critical regulator of multiple cellular functions that ultimately shift the balance between cell survival and death. The cascade is activated by many intrinsic and extrinsic stimuli, which is transduced via adaptor proteins to phosphorylate the IκB kinase (IKK) complex, which in turn phosphorylates the inhibitory IκBα protein to undergo proteasomal degradation and sets in motion nuclear events in response to the initial stimulus. Viruses are important modulators of the NF‐κB cascade and have evolved multiple mechanisms to activate or inhibit this pathway in a manner conducive to viral multiplication and establishment of a productive infectious cycle. This is a subject of extensive research by multiple laboratories whereby unraveling the interactions between specific viral components and members of the NF‐κB signal transduction cascade can shed unique perspectives on infection associated pathogenesis and novel therapeutic targets. In this review, we highlight the interactions between components of the IKK complex and multiple RNA and DNA viruses with the emphasis on mechanisms by which the interaction feeds the infection. Understanding these interactions will shed light on the exploitative capabilities of viruses to maintain an environment favorable for a productive infection.
Collapse
Affiliation(s)
- Moushimi Amaya
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA, USA
| | | | | | | |
Collapse
|
39
|
Veyer DL, Maluquer de Motes C, Sumner RP, Ludwig L, Johnson BF, Smith GL. Analysis of the anti-apoptotic activity of four vaccinia virus proteins demonstrates that B13 is the most potent inhibitor in isolation and during viral infection. J Gen Virol 2014; 95:2757-2768. [PMID: 25090990 PMCID: PMC4233632 DOI: 10.1099/vir.0.068833-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Vaccinia virus (VACV) is a large dsDNA virus encoding ~200 proteins, several of which inhibit apoptosis. Here, a comparative study of anti-apoptotic proteins N1, F1, B13 and Golgi anti-apoptotic protein (GAAP) in isolation and during viral infection is presented. VACVs strains engineered to lack each gene separately still blocked apoptosis to some degree because of functional redundancy provided by the other anti-apoptotic proteins. To overcome this redundancy, we inserted each gene separately into a VACV strain (vv811) that lacked all these anti-apoptotic proteins and that induced apoptosis efficiently during infection. Each protein was also expressed in cells using lentivirus vectors. In isolation, each VACV protein showed anti-apoptotic activity in response to specific stimuli, as measured by immunoblotting for cleaved poly(ADP ribose) polymerase-1 and caspase-3 activation. Of the proteins tested, B13 was the most potent inhibitor, blocking both intrinsic and extrinsic stimuli, whilst the activity of the other proteins was largely restricted to inhibition of intrinsic stimuli. In addition, B13 and F1 were effective blockers of apoptosis induced by vv811 infection. Finally, whilst differences in induction of apoptosis were barely detectable during infection with VACV strain Western Reserve compared with derivative viruses lacking individual anti-apoptotic genes, several of these proteins reduced activation of caspase-3 during infection by vv811 strains expressing these proteins. These results illustrated that vv811 was a useful tool to determine the role of VACV proteins during infection and that whilst all of these proteins have some anti-apoptotic activity, B13 was the most potent.
Collapse
Affiliation(s)
- David L Veyer
- Virology Laboratory, Pontchaillou University Hospital, Rennes 35033, France.,Equipe Microbiologie, EA 1254, SFR BIOSIT, Université Européenne de Bretagne, Rennes, France.,Department of Pathology, University of Cambridge, Cambridge CB2 1QP, UK
| | - Carlos Maluquer de Motes
- Department of Virology, Imperial College London, London W2 1PG, UK.,Department of Pathology, University of Cambridge, Cambridge CB2 1QP, UK
| | - Rebecca P Sumner
- Department of Virology, Imperial College London, London W2 1PG, UK.,Department of Pathology, University of Cambridge, Cambridge CB2 1QP, UK
| | - Louisa Ludwig
- Department of Pathology, University of Cambridge, Cambridge CB2 1QP, UK
| | | | - Geoffrey L Smith
- Department of Virology, Imperial College London, London W2 1PG, UK.,Department of Pathology, University of Cambridge, Cambridge CB2 1QP, UK
| |
Collapse
|
40
|
Brady G, Bowie AG. Innate immune activation of NFκB and its antagonism by poxviruses. Cytokine Growth Factor Rev 2014; 25:611-20. [PMID: 25081317 DOI: 10.1016/j.cytogfr.2014.07.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Accepted: 07/03/2014] [Indexed: 12/18/2022]
Abstract
In recent years there has been an acceleration of discovery in the field of innate anti-viral immunity to the point that many of the key events in early virus sensing and the discrete anti-viral responses they trigger have been elucidated in detail. In particular, pattern recognition receptors (PRRs) that detect viruses at the plasma membrane, in endosomes, and within the cytosol have been characterized. Upon stimulation by viruses, most of these PRRs trigger signal transduction pathways culminating in NFκB activation. NFκB contributes both to type I interferon induction, and to production of pro-inflammatory cytokines from infected cells. Our understanding of host anti-viral innate immunity has been greatly aided by an appreciation of the ways in which poxviruses have evolved strategies to inhibit both innate sensing and effector responses. A recurring feature of poxviral immunomodulation is the apparent necessity for poxviruses to evolve multiple, non-redundant inhibitors of NFκB activation which often appear to act on the same innate signalling pathway. The reason for such apparent over-targeting of one transcription factor is not clear. Here we describe the current understanding of how host cells sense poxvirus infection to trigger signalling pathways leading to NFκB activation and pro-inflammatory cytokine induction, and the ways in which poxviruses have evolved to concisely antagonize these systems.
Collapse
Affiliation(s)
- Gareth Brady
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland.
| | - Andrew G Bowie
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland.
| |
Collapse
|
41
|
Maluquer de Motes C, Schiffner T, Sumner RP, Smith GL. Vaccinia virus virulence factor N1 can be ubiquitylated on multiple lysine residues. J Gen Virol 2014; 95:2038-2049. [PMID: 24914067 PMCID: PMC4135091 DOI: 10.1099/vir.0.065664-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Ubiquitylation is a covalent post-translational modification that regulates protein stability and is involved in many biological functions. Proteins may be modified with mono-ubiquitin or ubiquitin chains. Viruses have evolved multiple mechanisms to perturb the cell ubiquitin system and manipulate it to their own benefit. Here, we report ubiquitylation of vaccinia virus (VACV) protein N1. N1 is an inhibitor of the nuclear factor NF-κB and apoptosis that contributes to virulence, has a Bcl-2-like fold, and is highly conserved amongst orthopoxviruses. The interaction between N1 and ubiquitin occurs at endogenous protein levels during VACV infection and following ectopic expression of N1. Biochemical analysis demonstrated that N1 is covalently ubiquitylated, and heterodimers of ubiquitylated and non-ubiquitylated N1 monomers were identified, suggesting that ubiquitylation does not inhibit N1 dimerization. Studies with other VACV Bcl-2 proteins, such as C6 or B14, revealed that although these proteins also interact with ubiquitin, these interactions are non-covalent. Finally, mutagenesis of N1 showed that ubiquitylation occurs in a conventional lysine-dependent manner at multiple acceptor sites because only an N1 allele devoid of lysine residues remained unmodified. Taken together, we described a previously uncharacterized modification of the VACV protein N1 that provided a new layer of complexity to the biology of this virulence factor, and provided another example of the intricate interplay between poxviruses and the host ubiquitin system.
Collapse
Affiliation(s)
- Carlos Maluquer de Motes
- Department of Virology, Imperial College London, St Mary's Campus, Norfolk Place, London W2 1PG, UK.,Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Torben Schiffner
- Department of Virology, Imperial College London, St Mary's Campus, Norfolk Place, London W2 1PG, UK
| | - Rebecca P Sumner
- Department of Virology, Imperial College London, St Mary's Campus, Norfolk Place, London W2 1PG, UK.,Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Geoffrey L Smith
- Department of Virology, Imperial College London, St Mary's Campus, Norfolk Place, London W2 1PG, UK.,Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| |
Collapse
|
42
|
Abstract
The transcription factor nuclear factor kappa light-chain enhancer of activated B cells (NF-κB) plays a critical role in host defense against viral infection by inducing the production of proinflammatory mediators and type I interferon. Consequently, viruses have evolved many mechanisms to block its activation. The poxvirus vaccinia virus (VACV) encodes numerous inhibitors of NF-κB activation that target multiple points in the signaling pathway. A derivative of VACV strain Copenhagen, called vv811, lacking 55 open reading frames in the left and right terminal regions of the genome was reported to still inhibit NF-κB activation downstream of tumor necrosis factor alpha (TNF-α) and interleukin-1β (IL-1β), suggesting the presence of one or more additional inhibitors. In this study, we constructed a recombinant vv811 lacking the recently described NF-κB inhibitor A49 (vv811ΔA49), yielding a virus that lacked all currently described inhibitors downstream of TNF-α and IL-1β. Unlike vv811, vv811ΔA49 no longer inhibited degradation of the phosphorylated inhibitor of κBα and p65 translocated into the nucleus. However, despite this translocation, vv811ΔA49 still inhibited TNF-α- and IL-1β-induced NF-κB-dependent reporter gene expression and the transcription and production of cytokines induced by these agonists. This inhibition did not require late viral gene expression. These findings indicate the presence of another inhibitor of NF-κB that is expressed early during infection and acts by a novel mechanism downstream of p65 translocation into the nucleus.
Collapse
|
43
|
Stack J, Hurst TP, Flannery SM, Brennan K, Rupp S, Oda SI, Khan AR, Bowie AG. Poxviral protein A52 stimulates p38 mitogen-activated protein kinase (MAPK) activation by causing tumor necrosis factor receptor-associated factor 6 (TRAF6) self-association leading to transforming growth factor β-activated kinase 1 (TAK1) recruitment. J Biol Chem 2013; 288:33642-33653. [PMID: 24114841 DOI: 10.1074/jbc.m113.485490] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Vaccinia virus encodes a number of proteins that inhibit and manipulate innate immune signaling pathways that also have a role in virulence. These include A52, a protein shown to inhibit IL-1- and Toll-like receptor-stimulated NFκB activation, via interaction with interleukin-1 receptor-associated kinase 2 (IRAK2). Interestingly, A52 was also found to activate p38 MAPK and thus enhance Toll-like receptor-dependent IL-10 induction, which was TRAF6-dependent, but the manner in which A52 manipulates TRAF6 to stimulate p38 activation was unclear. Here, we show that A52 has a non-canonical TRAF6-binding motif that is essential for TRAF6 binding and p38 activation but dispensable for NFκB inhibition and IRAK2 interaction. Wild-type A52, but not a mutant defective in p38 activation and TRAF6 binding (F154A), caused TRAF6 oligomerization and subsequent TRAF6-TAK1 association. The crystal structure of A52 shows that it adopts a Bcl2-like fold and exists as a dimer in solution. Residue Met-65 was identified as being located in the A52 dimer interface, and consistent with that, A52-M65E was impaired in its ability to dimerize. A52-M65E although capable of interacting with TRAF6, was unable to cause either TRAF6 self-association, induce the TRAF6-TAK1 association, or activate p38 MAPK. The results suggest that an A52 dimer causes TRAF6 self-association, leading to TAK1 recruitment and p38 activation. This reveals a molecular mechanism whereby poxviruses manipulate TRAF6 to activate MAPKs (which can be proviral) without stimulating antiviral NFκB activation.
Collapse
Affiliation(s)
- Julianne Stack
- Immunology Research Centre, School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland
| | - Tara P Hurst
- Immunology Research Centre, School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland
| | - Sinead M Flannery
- Immunology Research Centre, School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland
| | - Kiva Brennan
- Immunology Research Centre, School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland
| | - Sebastian Rupp
- Immunology Research Centre, School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland
| | - Shun-Ichiro Oda
- Immunology Research Centre, School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland
| | - Amir R Khan
- Immunology Research Centre, School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland
| | - Andrew G Bowie
- Immunology Research Centre, School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland.
| |
Collapse
|
44
|
Peters NE, Ferguson BJ, Mazzon M, Fahy AS, Krysztofinska E, Arribas-Bosacoma R, Pearl LH, Ren H, Smith GL. A mechanism for the inhibition of DNA-PK-mediated DNA sensing by a virus. PLoS Pathog 2013; 9:e1003649. [PMID: 24098118 PMCID: PMC3789764 DOI: 10.1371/journal.ppat.1003649] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Accepted: 08/06/2013] [Indexed: 12/17/2022] Open
Abstract
The innate immune system is critical in the response to infection by pathogens and it is activated by pattern recognition receptors (PRRs) binding to pathogen associated molecular patterns (PAMPs). During viral infection, the direct recognition of the viral nucleic acids, such as the genomes of DNA viruses, is very important for activation of innate immunity. Recently, DNA-dependent protein kinase (DNA-PK), a heterotrimeric complex consisting of the Ku70/Ku80 heterodimer and the catalytic subunit DNA-PKcs was identified as a cytoplasmic PRR for DNA that is important for the innate immune response to intracellular DNA and DNA virus infection. Here we show that vaccinia virus (VACV) has evolved to inhibit this function of DNA-PK by expression of a highly conserved protein called C16, which was known to contribute to virulence but by an unknown mechanism. Data presented show that C16 binds directly to the Ku heterodimer and thereby inhibits the innate immune response to DNA in fibroblasts, characterised by the decreased production of cytokines and chemokines. Mechanistically, C16 acts by blocking DNA-PK binding to DNA, which correlates with reduced DNA-PK-dependent DNA sensing. The C-terminal region of C16 is sufficient for binding Ku and this activity is conserved in the variola virus (VARV) orthologue of C16. In contrast, deletion of 5 amino acids in this domain is enough to knockout this function from the attenuated vaccine strain modified vaccinia virus Ankara (MVA). In vivo a VACV mutant lacking C16 induced higher levels of cytokines and chemokines early after infection compared to control viruses, confirming the role of this virulence factor in attenuating the innate immune response. Overall this study describes the inhibition of DNA-PK-dependent DNA sensing by a poxvirus protein, adding to the evidence that DNA-PK is a critical component of innate immunity to DNA viruses.
Collapse
Affiliation(s)
- Nicholas E. Peters
- Section of Virology, Department of Medicine, Imperial College London, Norfolk Place, London, United Kingdom
| | - Brian J. Ferguson
- Section of Virology, Department of Medicine, Imperial College London, Norfolk Place, London, United Kingdom
- Department of Pathology, Cambridge University, Cambridge, United Kingdom
| | - Michela Mazzon
- Section of Virology, Department of Medicine, Imperial College London, Norfolk Place, London, United Kingdom
- Department of Pathology, Cambridge University, Cambridge, United Kingdom
| | - Aodhnait S. Fahy
- Section of Virology, Department of Medicine, Imperial College London, Norfolk Place, London, United Kingdom
| | - Ewelina Krysztofinska
- Section of Virology, Department of Medicine, Imperial College London, Norfolk Place, London, United Kingdom
| | - Raquel Arribas-Bosacoma
- Cancer Research UK DNA Repair Enzymes Group, Genome Damage and Stability Centre, University of Sussex, Falmer, Brighton, United Kingdom
| | - Laurence H. Pearl
- Cancer Research UK DNA Repair Enzymes Group, Genome Damage and Stability Centre, University of Sussex, Falmer, Brighton, United Kingdom
| | - Hongwei Ren
- Section of Virology, Department of Medicine, Imperial College London, Norfolk Place, London, United Kingdom
- Department of Pathology, Cambridge University, Cambridge, United Kingdom
| | - Geoffrey L. Smith
- Section of Virology, Department of Medicine, Imperial College London, Norfolk Place, London, United Kingdom
- Department of Pathology, Cambridge University, Cambridge, United Kingdom
| |
Collapse
|
45
|
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: 255] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [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.
Collapse
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
| |
Collapse
|
46
|
Mazzon M, Peters NE, Loenarz C, Krysztofinska EM, Ember SWJ, Ferguson BJ, Smith GL. A mechanism for induction of a hypoxic response by vaccinia virus. Proc Natl Acad Sci U S A 2013; 110:12444-9. [PMID: 23836663 PMCID: PMC3725076 DOI: 10.1073/pnas.1302140110] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Viruses have evolved sophisticated strategies to exploit host cell function for their benefit. Here we show that under physiologically normal oxygen levels (normoxia) vaccinia virus (VACV) infection leads to a rapid stabilization of hypoxia-inducible factor (HIF)-1α, its translocation into the nucleus and the activation of HIF-responsive genes, such as vascular endothelial growth factor (VEGF), glucose transporter-1, and pyruvate dehydrogenase kinase-1. HIF-1α stabilization is mediated by VACV protein C16 that binds the human oxygen sensing enzyme prolyl-hydroxylase domain containing protein (PHD)2 and thereby inhibits PHD2-dependent hydroxylation of HIF-1α. The binding between C16 and PHD2 is direct and specific, and ectopic expression of C16 alone induces transcription of HIF-1α responsive genes. Conversely, a VACV strain lacking the gene for C16, C16L, is unable to induce HIF-1α stabilization. Interestingly, the N-terminal region of C16 is predicted to have a PHD2-like structural fold but lacks the catalytic active site residues of PHDs. The induction of a hypoxic response by VACV is reminiscent of the biochemical consequences of solid tumor formation, and illustrates a poxvirus strategy for manipulation of cellular gene expression and biochemistry.
Collapse
Affiliation(s)
- Michela Mazzon
- Department of Pathology, University of Cambridge, Cambridge CB2 1QP, United Kingdom
- Department of Virology, Faculty of Medicine, Imperial College London, St. Mary’s Campus, London W2 1PG, United Kingdom; and
| | - Nicholas E. Peters
- Department of Virology, Faculty of Medicine, Imperial College London, St. Mary’s Campus, London W2 1PG, United Kingdom; and
| | - Christoph Loenarz
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Ewelina M. Krysztofinska
- Department of Virology, Faculty of Medicine, Imperial College London, St. Mary’s Campus, London W2 1PG, United Kingdom; and
| | - Stuart W. J. Ember
- Department of Pathology, University of Cambridge, Cambridge CB2 1QP, United Kingdom
- Department of Virology, Faculty of Medicine, Imperial College London, St. Mary’s Campus, London W2 1PG, United Kingdom; and
| | - Brian J. Ferguson
- Department of Pathology, University of Cambridge, Cambridge CB2 1QP, United Kingdom
- Department of Virology, Faculty of Medicine, Imperial College London, St. Mary’s Campus, London W2 1PG, United Kingdom; and
| | - Geoffrey L. Smith
- Department of Pathology, University of Cambridge, Cambridge CB2 1QP, United Kingdom
- Department of Virology, Faculty of Medicine, Imperial College London, St. Mary’s Campus, London W2 1PG, United Kingdom; and
| |
Collapse
|
47
|
Ferguson BJ, Benfield CTO, Ren H, Lee VH, Frazer GL, Strnadova P, Sumner RP, Smith GL. Vaccinia virus protein N2 is a nuclear IRF3 inhibitor that promotes virulence. J Gen Virol 2013; 94:2070-2081. [PMID: 23761407 PMCID: PMC3749055 DOI: 10.1099/vir.0.054114-0] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Vaccinia virus (VACV) expresses many proteins that are non-essential for virus replication but promote virulence by inhibiting components of the host immune response to infection. These immunomodulators include a family of proteins that have, or are predicted to have, a structure related to the B-cell lymphoma (Bcl)-2 protein. Five members of the VACV Bcl-2 family (N1, B14, A52, F1 and K7) have had their crystal structure solved, others have been characterized and a function assigned (C6, A46), and others are predicted to be Bcl-2 proteins but are uncharacterized hitherto (N2, B22, C1). Data presented here show that N2 is a nuclear protein that is expressed early during infection and inhibits the activation of interferon regulatory factor (IRF)3. Consistent with its nuclear localization, N2 inhibits IRF3 downstream of the TANK-binding kinase (TBK)-1 and after IRF3 translocation into the nucleus. A mutant VACV strain Western Reserve lacking the N2L gene (vΔN2) showed normal replication and spread in cultured cells compared to wild-type parental (vN2) and revertant (vN2-rev) viruses, but was attenuated in two murine models of infection. After intranasal infection, the vΔN2 mutant induced lower weight loss and signs of illness, and virus was cleared more rapidly from the infected tissue. In the intradermal model of infection, vΔN2 induced smaller lesions that were resolved more rapidly. In summary, the N2 protein is an intracellular virulence factor that inhibits IRF3 activity in the nucleus.
Collapse
Affiliation(s)
- Brian J Ferguson
- Department of Virology, Faculty of Medicine, Imperial College London, Norfolk Place, London W2 1PG, UK.,Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK
| | - Camilla T O Benfield
- Department of Virology, Faculty of Medicine, Imperial College London, Norfolk Place, London W2 1PG, UK.,Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK
| | - Hongwei Ren
- Department of Virology, Faculty of Medicine, Imperial College London, Norfolk Place, London W2 1PG, UK.,Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK
| | - Vivian H Lee
- Department of Virology, Faculty of Medicine, Imperial College London, Norfolk Place, London W2 1PG, UK
| | - Gordon L Frazer
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK
| | - Pavla Strnadova
- Department of Virology, Faculty of Medicine, Imperial College London, Norfolk Place, London W2 1PG, UK.,Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK
| | - Rebecca P Sumner
- Department of Virology, Faculty of Medicine, Imperial College London, Norfolk Place, London W2 1PG, UK.,Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK
| | - Geoffrey L Smith
- Department of Virology, Faculty of Medicine, Imperial College London, Norfolk Place, London W2 1PG, UK.,Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK
| |
Collapse
|
48
|
Mansur DS, Maluquer de Motes C, Unterholzner L, Sumner RP, Ferguson BJ, Ren H, Strnadova P, Bowie AG, Smith GL. Poxvirus targeting of E3 ligase β-TrCP by molecular mimicry: a mechanism to inhibit NF-κB activation and promote immune evasion and virulence. PLoS Pathog 2013; 9:e1003183. [PMID: 23468625 PMCID: PMC3585151 DOI: 10.1371/journal.ppat.1003183] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 12/20/2012] [Indexed: 12/31/2022] Open
Abstract
The transcription factor NF-κB is essential for immune responses against pathogens and its activation requires the phosphorylation, ubiquitination and proteasomal degradation of IκBα. Here we describe an inhibitor of NF-κB from vaccinia virus that has a closely related counterpart in variola virus, the cause of smallpox, and mechanistic similarity with the HIV protein Vpu. Protein A49 blocks NF-κB activation by molecular mimicry and contains a motif conserved in IκBα which, in IκBα, is phosphorylated by IKKβ causing ubiquitination and degradation. Like IκBα, A49 binds the E3 ligase β-TrCP, thereby preventing ubiquitination and degradation of IκBα. Consequently, A49 stabilised phosphorylated IκBα (p-IκBα) and its interaction with p65, so preventing p65 nuclear translocation. Serine-to-alanine mutagenesis within the IκBα-like motif of A49 abolished β-TrCP binding, stabilisation of p-IκBα and inhibition of NF-κB activation. Remarkably, despite encoding nine other inhibitors of NF-κB, a VACV lacking A49 showed reduced virulence in vivo.
Collapse
Affiliation(s)
- Daniel S. Mansur
- Department of Virology, Faculty of Medicine, Imperial College London, St Mary's Campus, London, United Kingdom
| | - Carlos Maluquer de Motes
- Department of Virology, Faculty of Medicine, Imperial College London, St Mary's Campus, London, United Kingdom
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Leonie Unterholzner
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - Rebecca P. Sumner
- Department of Virology, Faculty of Medicine, Imperial College London, St Mary's Campus, London, United Kingdom
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Brian J. Ferguson
- Department of Virology, Faculty of Medicine, Imperial College London, St Mary's Campus, London, United Kingdom
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Hongwei Ren
- Department of Virology, Faculty of Medicine, Imperial College London, St Mary's Campus, London, United Kingdom
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Pavla Strnadova
- Department of Virology, Faculty of Medicine, Imperial College London, St Mary's Campus, London, United Kingdom
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Andrew G. Bowie
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - Geoffrey L. Smith
- Department of Virology, Faculty of Medicine, Imperial College London, St Mary's Campus, London, United Kingdom
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| |
Collapse
|