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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] [What about the content of this article? (0)] [Affiliation(s)] [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.
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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
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2
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Torres AA, Macilwee SL, Rashid A, Cox SE, Albarnaz JD, Bonjardim CA, Smith GL. The actin nucleator Spir-1 is a virus restriction factor that promotes innate immune signalling. PLoS Pathog 2022; 18:e1010277. [PMID: 35148361 PMCID: PMC8870497 DOI: 10.1371/journal.ppat.1010277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 02/24/2022] [Accepted: 01/12/2022] [Indexed: 12/12/2022] Open
Abstract
Cellular proteins often have multiple and diverse functions. This is illustrated with protein Spir-1 that is an actin nucleator, but, as shown here, also functions to enhance innate immune signalling downstream of RNA sensing by RIG-I/MDA-5. In human and mouse cells lacking Spir-1, IRF3 and NF-κB-dependent gene activation is impaired, whereas Spir-1 overexpression enhanced IRF3 activation. Furthermore, the infectious virus titres and sizes of plaques formed by two viruses that are sensed by RIG-I, vaccinia virus (VACV) and Zika virus, are increased in Spir-1 KO cells. These observations demonstrate the biological importance of Spir-1 in the response to virus infection. Like cellular proteins, viral proteins also have multiple and diverse functions. Here, we also show that VACV virulence factor K7 binds directly to Spir-1 and that a diphenylalanine motif of Spir-1 is needed for this interaction and for Spir-1-mediated enhancement of IRF3 activation. Thus, Spir-1 is a new virus restriction factor and is targeted directly by an immunomodulatory viral protein that enhances virus virulence and diminishes the host antiviral responses.
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Affiliation(s)
- Alice A. Torres
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | | | - Amir Rashid
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Sarah E. Cox
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Jonas D. Albarnaz
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Claudio A. Bonjardim
- Laboratório de Vírus, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Geoffrey L. Smith
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
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3
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Albarnaz JD, Ren H, Torres AA, Shmeleva EV, Melo CA, Bannister AJ, Brember MP, Chung BYW, Smith GL. Molecular mimicry of NF-κB by vaccinia virus protein enables selective inhibition of antiviral responses. Nat Microbiol 2022; 7:154-168. [PMID: 34949827 PMCID: PMC7614822 DOI: 10.1038/s41564-021-01004-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Accepted: 10/21/2021] [Indexed: 12/16/2022]
Abstract
Infection of mammalian cells with viruses activates NF-κB to induce the expression of cytokines and chemokines and initiate an antiviral response. Here, we show that a vaccinia virus protein mimics the transactivation domain of the p65 subunit of NF-κB to inhibit selectively the expression of NF-κB-regulated genes. Using co-immunoprecipitation assays, we found that the vaccinia virus protein F14 associates with NF-κB co-activator CREB-binding protein (CBP) and disrupts the interaction between p65 and CBP. This abrogates CBP-mediated acetylation of p65, after which it reduces promoter recruitment of the transcriptional regulator BRD4 and diminishes stimulation of NF-κB-regulated genes CXCL10 and CCL2. Recruitment of BRD4 to the promoters of NFKBIA and CXCL8 remains unaffected by either F14 or JQ1 (a competitive inhibitor of BRD4 bromodomains), indicating that BRD4 recruitment is acetylation-independent. Unlike other viral proteins that are general antagonists of NF-κB, F14 is a selective inhibitor of NF-κB-dependent gene expression. An in vivo model of infection demonstrated that F14 promotes virulence. Molecular mimicry of NF-κB may be conserved because other orthopoxviruses, including variola, monkeypox and cowpox viruses, encode orthologues of F14.
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Affiliation(s)
- Jonas D Albarnaz
- Department of Pathology, University of Cambridge, Cambridge, UK.
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK.
| | - Hongwei Ren
- Department of Pathology, University of Cambridge, Cambridge, UK
- Department of Immunology and Inflammation, Imperial College London, Hammersmith Campus, London, UK
| | - Alice A Torres
- Department of Pathology, University of Cambridge, Cambridge, UK
| | - Evgeniya V Shmeleva
- Department of Pathology, University of Cambridge, Cambridge, UK
- Department of Obstetrics and Gynaecology, University of Cambridge, Cambridge, UK
| | - Carlos A Melo
- The Gurdon Institute, University of Cambridge, Cambridge, UK
| | | | | | - Betty Y-W Chung
- Department of Pathology, University of Cambridge, Cambridge, UK
| | - Geoffrey L Smith
- Department of Pathology, University of Cambridge, Cambridge, UK.
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4
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González-Flores MI, Torres AA, Lebrecht W, Ramirez-Pastor AJ. Site-bond percolation in two-dimensional kagome lattices: Analytical approach and numerical simulations. Phys Rev E 2021; 104:014130. [PMID: 34412224 DOI: 10.1103/physreve.104.014130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Accepted: 06/21/2021] [Indexed: 06/13/2023]
Abstract
The site-bond percolation problem in two-dimensional kagome lattices has been studied by means of theoretical modeling and numerical simulations. Motivated by considerations of cluster connectivity, two distinct schemes (denoted as S∩B and S∪B) have been considered. In S∩B (S∪B), two points are connected if a sequence of occupied sites and (or) bonds joins them. Analytical and simulation approaches, supplemented by analysis using finite-size scaling theory, were used to calculate the phase boundaries between the percolating and nonpercolating regions, thus determining the complete phase diagram of the system in the (p_{s},p_{b}) space. In the case of the S∩B model, the obtained results are in excellent agreement with previous theoretical and numerical predictions. In the case of the S∪B model, the limiting curve separating percolating and nonpercolating regions is reported here.
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Affiliation(s)
- M I González-Flores
- Departamento de Física, Universidad de La Frontera, Casilla 54-D, Temuco, Chile
| | - A A Torres
- Departamento de Física, Instituto de Física Aplicada (INFAP), Universidad Nacional de San Luis-CONICET, Ejército de Los Andes 950, D5700HHW San Luis, Argentina
| | - W Lebrecht
- Departamento de Física, Universidad de La Frontera, Casilla 54-D, Temuco, Chile
| | - A J Ramirez-Pastor
- Departamento de Física, Instituto de Física Aplicada (INFAP), Universidad Nacional de San Luis-CONICET, Ejército de Los Andes 950, D5700HHW San Luis, Argentina
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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] [What about the content of this article? (0)] [Affiliation(s)] [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.
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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
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6
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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: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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.
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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.
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7
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Leite FGG, Torres AA, De Oliveira LC, Da Cruz AFP, Soares-Martins JAP, Pereira ACTC, Trindade GS, Abrahão JS, Kroon EG, Ferreira PCP, Bonjardim CA. c-Jun integrates signals from both MEK/ERK and MKK/JNK pathways upon vaccinia virus infection. Arch Virol 2017. [PMID: 28620810 DOI: 10.1007/s00705-017-3446-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Usurpation of the host's signalling pathways is a common strategy employed by viruses to promote their successful replication. Here we show that infection with the orthopoxvirus vaccinia virus (VACV) leads to sustained stimulation of c-Jun activity during the entire infective cycle. This stimulation is temporally regulated through MEK/ERK or MKK/JNK pathways, i.e. during the early/mid phase (1 to 6 hpi) and in the late phase (9 to 24 hpi) of the infective cycle, respectively. As a transcriptional regulator, upon infection with VACV, c-Jun is translocated from the cytoplasm to the nucleus, where it binds to the AP-1 DNA sequence found at the promoter region of its target genes. To investigate the role played by c-Jun during VACV replication cycle, we generated cell lines that stably express a c-Jun-dominant negative (DNc-Jun) mutation. Our data revealed that c-Jun is required during early infection to assist with viral DNA replication, as demonstrated by the decreased amount of viral DNA found in the DNc-Jun cells. We also demonstrated that c-Jun regulates the expression of the early growth response gene (egr-1), a gene previously shown to affect VACV replication mediated by MEK/ERK signalling. VACV-induced stimulation of the MKK/JNK/JUN pathway impacts viral dissemination, as we observed a significant reduction in both viral yield, during late stages of infection, and virus plaque size. Collectively, our data suggest that, by modulating the host's signalling pathways through a common target such as c-Jun, VACV temporally regulates its infective cycle in order to successfully replicate and subsequently spread.
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Affiliation(s)
- Flávia G G Leite
- Signal Transduction Group/Orthopoxviruses, Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, MG, 31270-901, Brazil.,Laboratório de Vírus, Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, MG, 31270-901, Brazil.,Cellular Signalling and Cytoskeletal function Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Alice A Torres
- Signal Transduction Group/Orthopoxviruses, Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, MG, 31270-901, Brazil.,Laboratório de Vírus, Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, MG, 31270-901, Brazil.,University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK
| | - Leonardo C De Oliveira
- Signal Transduction Group/Orthopoxviruses, Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, MG, 31270-901, Brazil.,Laboratório de Vírus, Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, MG, 31270-901, Brazil
| | - André F P Da Cruz
- Signal Transduction Group/Orthopoxviruses, Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, MG, 31270-901, Brazil.,Laboratório de Vírus, Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, MG, 31270-901, Brazil
| | - Jamária A P Soares-Martins
- Signal Transduction Group/Orthopoxviruses, Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, MG, 31270-901, Brazil.,Laboratório de Vírus, Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, MG, 31270-901, Brazil.,Department of Math and Science, Waukesha County Technical College, 800 Main Street, Pewaukee, WI, 53072, USA
| | - Anna C T C Pereira
- Signal Transduction Group/Orthopoxviruses, Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, MG, 31270-901, Brazil.,Laboratório de Vírus, Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, MG, 31270-901, Brazil.,Laboratory of Biochemistry and Biology of Microorganisms and Plants, Universidade Federal do Piauí, Campus de Parnaíba, Av. São Sebastião, 2819, Bairro Reis Velloso, Parnaíba, PI, CEP 64202-020, Brazil
| | - Giliane S Trindade
- Laboratório de Vírus, Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, MG, 31270-901, Brazil
| | - Jonatas S Abrahão
- Laboratório de Vírus, Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, MG, 31270-901, Brazil
| | - Erna G Kroon
- Laboratório de Vírus, Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, MG, 31270-901, Brazil
| | - Paulo C P Ferreira
- Laboratório de Vírus, Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, MG, 31270-901, Brazil
| | - Cláudio A Bonjardim
- Signal Transduction Group/Orthopoxviruses, Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, MG, 31270-901, Brazil. .,Laboratório de Vírus, Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, MG, 31270-901, Brazil.
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Abstract
Vaccinia virus (VACV) is a poxvirus and encodes many proteins that modify the host cell metabolism or inhibit the host response to infection. For instance, it is known that VACV infection can activate the mitogen-activated protein kinase (MAPK)/activator protein 1 (AP-1) pathway and inhibit activation of the pro-inflammatory transcription factor NF-κB. Since NF-κB and MAPK/AP-1 share common upstream activators we investigated whether six different VACV Bcl-2-like NF-κB inhibitors can also influence MAPK/AP-1 activation. Data presented show that proteins A52, B14 and K7 each contribute to AP-1 activation during VACV infection, and when expressed individually outwith infection. B14 induced the greatest stimulation of AP-1 and further investigation showed B14 activated mainly the MAPKs ERK (extracellular signal-regulated kinase) and JNK (Jun N-terminal kinase), and their substrate c-Jun (a component of AP-1). These data indicate that the same viral protein can have different effects on distinct signalling pathways, in blocking NF-κB activation whilst leading to MAPK/AP-1 activation.
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Affiliation(s)
- Alice A Torres
- Laboratório de Vírus, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, Pampulha, CEP 31270-901, Belo Horizonte, MG, Brazil.,Department of Pathology, University of Cambridge, Cambridge, UK
| | | | - Cláudio A Bonjardim
- Laboratório de Vírus, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, Pampulha, CEP 31270-901, Belo Horizonte, MG, Brazil
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9
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Huth HW, Albarnaz JD, Torres AA, Bonjardim CA, Ropert C. MEK2 controls the activation of MKK3/MKK6-p38 axis involved in the MDA-MB-231 breast cancer cell survival: Correlation with cyclin D1 expression. Cell Signal 2016; 28:1283-1291. [PMID: 27181679 DOI: 10.1016/j.cellsig.2016.05.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 05/10/2016] [Accepted: 05/11/2016] [Indexed: 10/21/2022]
Abstract
The Ras-Raf-MEK-ERK1/2 signaling pathway regulates fundamental processes in malignant cells. However, the exact contributions of MEK1 and MEK2 to the development of cancer remain to be established. We studied the effects of MEK small-molecule inhibitors (PD98059 and U0126) and MEK1 and MEK2 knock-down on cell proliferation, apoptosis and MAPK activation. We showed a diminution of cell viability that was associated with a downregulation of cyclin D1 expression and an increase of apoptosis marker in MEK2 silenced cells; by contrast, a slight increase of cell survival was observed in the absence of MEK1 that correlated with an augment of cyclin D1 expression. These data indicate that MEK2 but not MEK1 is essential for MDA-MB-231 cell survival. Importantly, the role of MEK2 in cell survival appeared independent on ERK1/2 phosphorylation since its absence did not alter the level of activated ERK1/2. Indeed, we have reported an unrevealed link between MEK2 and MKK3/MKK6-p38 MAPK axis where MEK2 was essential for the phosphorylation of MKK3/MKK6 and p38 MAPK that directly impacted on cyclin D1 expression. Importantly, the MEK1 inhibitor PD98059, like MEK1 silencing, induced an augment of cyclin D1 expression that correlated with an increase of MDA-MB-231 cell proliferation suggesting that MEK1 may play a regulatory role in these cells. In sum, the crucial role of MEK2 in MDA-MB-231 cell viability and the unknown relationship between MEK2 and MKK3/MKK6-p38 axis here revealed may open new therapeutic strategies for aggressive breast cancer.
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Affiliation(s)
- Hugo W Huth
- Departamento de Morfologia, Universidade Federal de Minas Gerais, 31270-910 Belo Horizonte, Minas Gerais, Brazil
| | - Jonas D Albarnaz
- Departamento de Microbiologia, Universidade Federal de Minas Gerais, 31270-910 Belo Horizonte, Minas Gerais, Brazil; Department of Pathology, University of Cambridge, Cambridge, UK
| | - Alice A Torres
- Departamento de Microbiologia, Universidade Federal de Minas Gerais, 31270-910 Belo Horizonte, Minas Gerais, Brazil
| | - Claudio A Bonjardim
- Departamento de Microbiologia, Universidade Federal de Minas Gerais, 31270-910 Belo Horizonte, Minas Gerais, Brazil
| | - Catherine Ropert
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, 31270-910 Belo Horizonte, Minas Gerais, Brazil.
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10
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Albarnaz JD, De Oliveira LC, Torres AA, Palhares RM, Casteluber MC, Rodrigues CM, Cardozo PL, De Souza AM, Pacca CC, Ferreira PC, Kroon EG, Nogueira ML, Bonjardim CA. MEK/ERK activation plays a decisive role in yellow fever virus replication: Implication as an antiviral therapeutic target. Antiviral Res 2014; 111:82-92. [DOI: 10.1016/j.antiviral.2014.09.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 09/04/2014] [Accepted: 09/09/2014] [Indexed: 12/31/2022]
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Pereira ACTC, Soares-Martins JAP, Leite FGG, Da Cruz AFP, Torres AA, Souto-Padrón T, Kroon EG, Ferreira PCP, Bonjardim CA. SP600125 inhibits Orthopoxviruses replication in a JNK1/2 -independent manner: Implication as a potential antipoxviral. Antiviral Res 2011; 93:69-77. [PMID: 22068148 PMCID: PMC7114308 DOI: 10.1016/j.antiviral.2011.10.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Revised: 08/15/2011] [Accepted: 10/24/2011] [Indexed: 11/24/2022]
Abstract
The pharmacological inhibitor SP600125 [anthra(1,9-cd)pyrazol-6(2H)-one 1,9-pyrazoloanthrone] has been largely employed as a c-JUN N-terminal kinase (JNK1/2) inhibitor. In this study, we evaluated whether pretreatment with SP600125 was able to prevent Orthopoxviruses Vaccinia virus (VACV), Cowpox virus (CPXV) and modified Vaccinia virus Ankara (MVA) replication. We found that incubation with SP600125 not only blocked virus-stimulated JNK phosphorylation, but also, significantly reduced virus production. We observed 1-3 log decline in viral yield depending on the cell line infected (A31, BSC-40 or BHK-21). The reduction in viral yield correlated with a dramatic impact on virus morphogenesis progress, intracellular mature viruses (IMV) were barely detected. Despite the fact that SP600125 can act as an efficient anti-orthopoxviral compound, we also provide evidence that this antiviral effect is not specifically exerted through JNK1/2 inhibition. This conclusion is supported by the fact that viral titers measured after infections of JNK1/2 knockout cells were not altered as compared to those of wild-type cells. In contrast, a decline in viral titers was verified when the infection of KO cells was carried out in the presence of the pharmacological inhibitor. SP600125 has been the focus of recent studies that have evaluated its action on diverse viral infections including DNA viruses. Our data support the notion that SP600125 can be regarded as a potential antipoxviral compound.
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Affiliation(s)
- Anna C T C Pereira
- Grupo de Transdução de Sinal/Orthopoxvirus, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, MG, Brazil
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Abstract
To assess the role of hormonal factors in the pathogenesis of the dawn phenomenon, nocturnal (9:00 PM to 9 AM) concentrations of blood glucose, free insulin, and counterregulatory hormones were determined in eight insulin-dependent diabetic patients under feedback-controlled and continuous insulin infusions after previous blood glucose normalization. Under feedback control, mean insulin requirements, necessary for maintenance of euglycemia rose significantly in the early morning (11:00 PM to 3 AM: 8.4 +/- 1.4; 5 AM to 9 AM: 12.6 +/- 1.5 mU/kg/h; P less than 0.01). Mean free-insulin concentrations did not increase simultaneously. Correspondingly, mean insulin-clearance rates under continuous insulin infusion were higher in the morning (11:00 AM to 3 AM: 359 +/- 58; 5 AM to 9 AM: 459 +/- 72 mL/min/m2; P less than 0.05). Increases of insulin clearance rates were most marked (greater than 15%) in patients whose blood glucose rose during continuous insulin administration. Glucagon and norepinephrine concentrations were stable throughout both parts of the study. Cortisol and growth hormone exhibited the known nocturnal rhythms. Epinephrine levels were at the lower limit of detection at night and rose to normal basal concentrations at 9:00 AM. We conclude that increases of insulin clearance rates may be an important factor for the development of the dawn phenomenon while the role of most counter-regulatory hormones is still uncertain.
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Klier M, Kerner W, Torres AA, Pfeiffer EF. Comparison of the biologic activity of biosynthetic human insulin and natural pork insulin in juvenile-onset diabetic subjects assessed by the glucose controlled insulin infusion system. Diabetes Care 1981; 4:193-5. [PMID: 7011725 DOI: 10.2337/diacare.4.2.193] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
To assess the biologic activity of biosynthetic human insulin (BHI) synthesized by Escherichia coli, six insulin-dependent juvenile-onset diabetic subjects were studied with BHI and natural pork insulin, by means of the glucose controlled insulin infusion system (GCIIS). First, after an overnight normalization of blood glucose levels, the 24-h insulin requirement was determined while the patients were consuming a diet of 30 kcal/kg. Then, the amount of glucose necessary to maintain normal blood glucose levels during a 5-h intravenous infusion of BHI and pork insulin, respectively, was assessed. Both studies demonstrate that in the insulin-dependent diabetic subject, BHI is at least as effective as natural pork insulin and may, therefore, be useful for the treatment of insulin-dependent diabetes mellitus.
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Prat JM, Torres AA, Sanchón BR, Ramírez JI. [Sarcoidosis: our cases of erythema nodosum mediastinal adenopathies (20 cases)]. Rev Clin Esp 1975; 137:537-41. [PMID: 1162138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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15
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Torres AA. Alpha blocking "conditioning", sensitization and interstimulus interval. Psychol Rep 1968; 22:469-75. [PMID: 5650239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Abstract
Ss scoring high and low on four tests of the Objective Analytic Anxiety Battery and having at least 25% time alpha rhythm in their resting EEGs received 100 trials of a single photic flash in the presence of alpha rhythm. Analysis of variance of the alpha blocking responses in right and left parieto-occipital derivations yielded a significant anxiety effect, with the low-anxiety group giving consistently more responses than the high-anxiety group. This effect was discussed in relation to the alpha blocking “conditioned” response and habituation.
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