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Chacón RD, Sánchez-Llatas CJ, L Pajuelo S, Diaz Forero AJ, Jimenez-Vasquez V, Médico JA, Soto-Ugaldi LF, Astolfi-Ferreira CS, Piantino Ferreira AJ. Molecular characterization of the meq oncogene of Marek's disease virus in vaccinated Brazilian poultry farms reveals selective pressure on prevalent strains. Vet Q 2024; 44:1-13. [PMID: 38465827 DOI: 10.1080/01652176.2024.2318198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 02/05/2024] [Indexed: 03/12/2024] Open
Abstract
Marek's disease virus (MDV) has become an increasingly virulent pathogen in the poultry industry despite vaccination efforts to control it. Brazil has experienced a significant rise of Marek's disease (MD) outbreaks in recent years. Our study aimed to analyze the complete meq gene sequences to understand the molecular epidemiological basis of MD outbreaks in Brazilian vaccinated layer farms. We detected a high incidence rate of visceral MD (67.74%) and multiple circulating MDV strains. The most prevalent and geographically widespread genotype presented several clinical and molecular characteristics of a highly virulent strain and evolving under positive selective pressure. Phylogenetic and phylogeographic analysis revealed a closer relationship with strains from the USA and Japan. This study sheds light on the circulation of MDV strains capable of infecting vaccinated birds. We emphasize the urgency of adopting preventive measures to manage MDV outbreaks threatening the poultry farming industry.
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Affiliation(s)
- Ruy D Chacón
- Department of Pathology, School of Veterinary Medicine, University of São Paulo, São Paulo, Brazil
| | - Christian J Sánchez-Llatas
- Department of Genetics, Physiology, and Microbiology, Faculty of Biology, Complutense University of Madrid, Madrid, Spain
| | | | - Andrea J Diaz Forero
- Department of Pathology, School of Veterinary Medicine, University of São Paulo, São Paulo, Brazil
| | | | - Jack A Médico
- Vertebrate Genome Laboratory, The Rockefeller University, New York, NY, USA
| | - Luis F Soto-Ugaldi
- Tri-Institutional Program in Computational Biology and Medicine, New York, NY, USA
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2
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Davidson I, Lupini C, Catelli E, Quaglia G, Maddaloni L, Mescolini G. Virulence evaluation of Israeli Marek's disease virus isolates from commercial poultry using their meq gene sequence. Virus Genes 2024; 60:32-43. [PMID: 38184501 DOI: 10.1007/s11262-023-02042-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 11/17/2023] [Indexed: 01/08/2024]
Abstract
Fifty-seven Gallid alphaherpesvirus 2 (GaHV-2) isolates, collected during a 30-year period (1990-2019) from commercial poultry flocks affected by Marek's disease (MD), were molecularly characterised. The GaHV-2 meq gene was amplified and sequenced to evaluate the virus virulence, based on the number of PPPPs within the proline-rich repeats (PRRs) of its transactivation domain. The present illustration of virus virulence evaluation on a large scale of field virus isolates by molecular analysis exemplifies the practical benefit and usefulness of the molecular marker in commercial GaVH-2 isolates. The alternative assay of GaVH-2 virulence pathotyping is the classical Gold Standard ADOL method, which is difficult and impossible to employ on a large scale using the Specific Pathogen Free (SPF) chicks of the ADOL strains kept in isolators for two months. The phylogenetic analysis performed in the present study showed that the meq gene amino acid sequences of the 57 Israeli strains divide into 16 phylogenetic branches. The virulence evaluation was performed in comparison with 36 GaHV-2 prototype strains, previously characterised by the in vivo Gold Standard ADOL assay. The results obtained revealed that the GaHV-2 strains circulating in Israel have evolved into a higher virulence potential during the years, as the four-proline stretches number in the meq gene decreased over the investigated period, typically of very virulent virus prototypes. The present study supports the meq gene molecular markers for the assessment of field GaVH-2 strains virulence.
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Affiliation(s)
| | - Caterina Lupini
- Department of Veterinary Medical Sciences, University of Bologna, Ozzano dell'Emilia, Bologna, Italy
| | - Elena Catelli
- Department of Veterinary Medical Sciences, University of Bologna, Ozzano dell'Emilia, Bologna, Italy
| | - Giulia Quaglia
- Department of Veterinary Medical Sciences, University of Bologna, Ozzano dell'Emilia, Bologna, Italy
| | - Luca Maddaloni
- Department of Public Health and Infectious Diseases, Sapienza, University of Rome, Rome, Italy
| | - Giulia Mescolini
- Department of Veterinary Medical Sciences, University of Bologna, Ozzano dell'Emilia, Bologna, Italy
- Operating Unit of Animal Health and Hygiene of Livestock Production, Department of Public Health, AUSL della Romagna, Forlì, FC, Italy
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Fiddaman SR, Dimopoulos EA, Lebrasseur O, du Plessis L, Vrancken B, Charlton S, Haruda AF, Tabbada K, Flammer PG, Dascalu S, Marković N, Li H, Franklin G, Symmons R, Baron H, Daróczi-Szabó L, Shaymuratova DN, Askeyev IV, Putelat O, Sana M, Davoudi H, Fathi H, Mucheshi AS, Vahdati AA, Zhang L, Foster A, Sykes N, Baumberg GC, Bulatović J, Askeyev AO, Askeyev OV, Mashkour M, Pybus OG, Nair V, Larson G, Smith AL, Frantz LAF. Ancient chicken remains reveal the origins of virulence in Marek's disease virus. Science 2023; 382:1276-1281. [PMID: 38096384 DOI: 10.1126/science.adg2238] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 10/25/2023] [Indexed: 12/18/2023]
Abstract
The pronounced growth in livestock populations since the 1950s has altered the epidemiological and evolutionary trajectory of their associated pathogens. For example, Marek's disease virus (MDV), which causes lymphoid tumors in chickens, has experienced a marked increase in virulence over the past century. Today, MDV infections kill >90% of unvaccinated birds, and controlling it costs more than US$1 billion annually. By sequencing MDV genomes derived from archeological chickens, we demonstrate that it has been circulating for at least 1000 years. We functionally tested the Meq oncogene, one of 49 viral genes positively selected in modern strains, demonstrating that ancient MDV was likely incapable of driving tumor formation. Our results demonstrate the power of ancient DNA approaches to trace the molecular basis of virulence in economically relevant pathogens.
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Affiliation(s)
| | - Evangelos A Dimopoulos
- The Palaeogenomics and Bio-Archaeology Research Network, Research Laboratory for Archaeology and History of Art, University of Oxford, Oxford, UK
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Ophélie Lebrasseur
- Centre d'Anthropobiologie et de Génomique de Toulouse, CNRS/Université Toulouse III Paul Sabatier, Toulouse, France
- Instituto Nacional de Antropología y Pensamiento Latinoamericano, Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina
| | - Louis du Plessis
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Bram Vrancken
- Department of Microbiology, Immunology and Transplantation, Rega Institute, KU Leuven, Leuven, Belgium
- Spatial Epidemiology Lab (SpELL), Université Libre de Bruxelles, Brussels, Belgium
| | - Sophy Charlton
- The Palaeogenomics and Bio-Archaeology Research Network, Research Laboratory for Archaeology and History of Art, University of Oxford, Oxford, UK
- BioArCh, Department of Archaeology, University of York, York, UK
| | - Ashleigh F Haruda
- The Palaeogenomics and Bio-Archaeology Research Network, Research Laboratory for Archaeology and History of Art, University of Oxford, Oxford, UK
| | - Kristina Tabbada
- The Palaeogenomics and Bio-Archaeology Research Network, Research Laboratory for Archaeology and History of Art, University of Oxford, Oxford, UK
| | | | | | | | - Hannah Li
- Institute of Immunity and Transplantation, University College London, London, UK
| | | | | | | | | | - Dilyara N Shaymuratova
- Laboratory of Biomonitoring, The Institute of Problems in Ecology and Mineral Wealth, Tatarstan Academy of Sciences, Kazan, Russia
| | - Igor V Askeyev
- Laboratory of Biomonitoring, The Institute of Problems in Ecology and Mineral Wealth, Tatarstan Academy of Sciences, Kazan, Russia
| | | | - Maria Sana
- Departament de Prehistòria, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Hossein Davoudi
- Bioarchaeology Laboratory, Central Laboratory, University of Tehran, Tehran, Iran
| | - Homa Fathi
- Bioarchaeology Laboratory, Central Laboratory, University of Tehran, Tehran, Iran
| | - Amir Saed Mucheshi
- Department of Art and Architecture, Payame Noor University (PNU), Tehran, Iran
| | - Ali Akbar Vahdati
- Iranian Ministry of Cultural Heritage, Tourism, and Handicrafts, North Khorasan Office, Iran
| | - Liangren Zhang
- Department of Archaeology, School of History, Nanjing University, China
| | | | - Naomi Sykes
- Department of Archaeology, University of Exeter, Exeter, UK
| | - Gabrielle Cass Baumberg
- The Palaeogenomics and Bio-Archaeology Research Network, Research Laboratory for Archaeology and History of Art, University of Oxford, Oxford, UK
| | - Jelena Bulatović
- Department of Historical Studies, University of Gothenburg, Gothenburg, Sweden
| | - Arthur O Askeyev
- Laboratory of Biomonitoring, The Institute of Problems in Ecology and Mineral Wealth, Tatarstan Academy of Sciences, Kazan, Russia
| | - Oleg V Askeyev
- Laboratory of Biomonitoring, The Institute of Problems in Ecology and Mineral Wealth, Tatarstan Academy of Sciences, Kazan, Russia
| | - Marjan Mashkour
- Bioarchaeology Laboratory, Central Laboratory, University of Tehran, Tehran, Iran
- CNRS, National Museum Natural History Paris, Paris, France
| | - Oliver G Pybus
- Department of Biology, University of Oxford, Oxford, UK
- Department of Pathobiology and Population Sciences, Royal Veterinary College, London, UK
| | - Venugopal Nair
- Department of Biology, University of Oxford, Oxford, UK
- Viral Oncogenesis Group, Pirbright Institute, Woking, UK
| | - Greger Larson
- The Palaeogenomics and Bio-Archaeology Research Network, Research Laboratory for Archaeology and History of Art, University of Oxford, Oxford, UK
| | | | - Laurent A F Frantz
- Palaeogenomics Group, Institute of Palaeoanatomy, Domestication Research and the History of Veterinary Medicine, Ludwig-Maximilians-Universitat, Munich, Germany
- School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
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4
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Davidson I. Avian Oncogenic and Immunosuppressive Viruses. Infect Dis (Lond) 2023. [DOI: 10.1007/978-1-0716-2463-0_1091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
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Abstract
Circular RNAs (circRNAs) are a recently rediscovered class of functional noncoding RNAs that are involved in gene regulation and cancer development. Next-generation sequencing approaches identified circRNA fragments and sequences underlying circularization events in virus-induced cancers. In the present study, we performed viral circRNA expression analysis and full-length sequencing in infections with Marek’s disease virus (MDV), which serves as a model for herpesvirus-induced tumorigenesis. We established inverse PCRs to identify and characterize circRNA expression from the repeat regions of the MDV genome during viral replication, latency, and reactivation. We identified a large variety of viral circRNAs through precise mapping of full-length circular transcripts and detected matching sequences with several viral genes. Hot spots of circRNA expression included the transcriptional unit of the major viral oncogene encoding the Meq protein and the latency-associated transcripts (LATs). Moreover, we performed genome-wide bioinformatic analyses to extract back-splice junctions from lymphoma-derived samples. Using this strategy, we found that circRNAs were abundantly expressed in vivo from the same key virulence genes. Strikingly, the observed back-splice junctions do not follow a unique canonical pattern, compatible with the U2-dependent splicing machinery. Numerous noncanonical junctions were observed in viral circRNA sequences characterized from in vitro and in vivo infections. Given the importance of the genes involved in the transcription of these circRNAs, our study contributes to our understanding and complexity of this deadly pathogen. IMPORTANCE Circular RNAs (circRNAs) were rediscovered in recent years both in physiological and pathological contexts, such as in cancer. Viral circRNAs are encoded by at least two human herpesviruses, the Epstein Barr virus and the Kaposi’s Sarcoma-associated herpesvirus, both associated with the development of lymphoma. Marek’s disease virus (MDV) is a well-established animal model to study virus-induced lymphoma but circRNA expression has not been reported for MDV yet. Our study provided the first evidence of viral circRNAs that were expressed at key steps of the MDV lifecycle using genome-wide analyses of circRNAs. These circRNAs were primarily found in transcriptional units that corresponded to the major MDV virulence factors. In addition, we established a bioinformatics pipeline that offers a new tool to identify circular RNAs in other herpesviruses. This study on the circRNAs provided important insights into major MDV virulence genes and herpesviruses-mediated gene dysregulation.
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Sato J, Murata S, Yang Z, Kaufer BB, Fujisawa S, Seo H, Maekawa N, Okagawa T, Konnai S, Osterrieder N, Parcells MS, Ohashi K. Effect of Insertion and Deletion in the Meq Protein Encoded by Highly Oncogenic Marek’s Disease Virus on Transactivation Activity and Virulence. Viruses 2022; 14:v14020382. [PMID: 35215975 PMCID: PMC8876991 DOI: 10.3390/v14020382] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 02/11/2022] [Accepted: 02/11/2022] [Indexed: 02/04/2023] Open
Abstract
Marek’s disease virus (MDV) causes malignant lymphoma in chickens (Marek’s disease, MD). Although MD is currently controlled by vaccination, MDV strains have continuously increased in virulence over the recent decades. Polymorphisms in Meq, an MDV-encoded oncoprotein that serves as a transcription factor, have been associated with the enhanced virulence of the virus. In addition, insertions and deletions in Meq have been observed in MDV strains of higher virulence, but their contribution to said virulence remains elusive. In this study, we investigated the contribution of an insertion (L-Meq) and a deletion in the Meq gene (S-Meq) to its functions and MDV pathogenicity. Reporter assays revealed that both insertion and deletion enhanced the transactivation potential of Meq. Additionally, we generated RB-1B-based recombinant MDVs (rMDVs) encoding each Meq isoform and analyzed their pathogenic potential. rMDV encoding L-Meq indueced the highest mortality and tumor incidence in infected animals, whereas the rMDV encoding S-Meq exhibited the lowest pathogenicity. Thus, insertion enhanced the transactivation activity of Meq and MDV pathogenicity, whereas deletion reduced pathogenicity despite having increased transactivation activity. These data suggest that other functions of Meq affect MDV virulence. These data improve our understanding of the mechanisms underlying the evolution of MDV virulence.
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Affiliation(s)
- Jumpei Sato
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan; (J.S.); (Z.Y.); (S.F.); (H.S.); (S.K.); (K.O.)
| | - Shiro Murata
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan; (J.S.); (Z.Y.); (S.F.); (H.S.); (S.K.); (K.O.)
- Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan; (N.M.); (T.O.)
- Correspondence: ; Tel.: +81-11-706-5274; Fax: +81-11-706-5217
| | - Zhiyuan Yang
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan; (J.S.); (Z.Y.); (S.F.); (H.S.); (S.K.); (K.O.)
- Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China
| | - Benedikt B. Kaufer
- Institut für Virologie, Freie Universität Berlin, 14163 Berlin, Germany; (B.B.K.); (N.O.)
| | - Sotaro Fujisawa
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan; (J.S.); (Z.Y.); (S.F.); (H.S.); (S.K.); (K.O.)
| | - Hikari Seo
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan; (J.S.); (Z.Y.); (S.F.); (H.S.); (S.K.); (K.O.)
| | - Naoya Maekawa
- Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan; (N.M.); (T.O.)
| | - Tomohiro Okagawa
- Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan; (N.M.); (T.O.)
| | - Satoru Konnai
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan; (J.S.); (Z.Y.); (S.F.); (H.S.); (S.K.); (K.O.)
- Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan; (N.M.); (T.O.)
| | - Nikolaus Osterrieder
- Institut für Virologie, Freie Universität Berlin, 14163 Berlin, Germany; (B.B.K.); (N.O.)
- Department of Infectious Diseases and Public Health, City University of Hong Kong, Kowloon Tong, Hong Kong
| | - Mark S. Parcells
- Department of Animal and Food Sciences, University of Delaware, Newark, DE 19716, USA;
| | - Kazuhiko Ohashi
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan; (J.S.); (Z.Y.); (S.F.); (H.S.); (S.K.); (K.O.)
- Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan; (N.M.); (T.O.)
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7
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Liao Y, Lupiani B, Izumiya Y, Reddy SM. Marek's disease virus Meq oncoprotein interacts with chicken HDAC 1 and 2 and mediates their degradation via proteasome dependent pathway. Sci Rep 2021; 11:637. [PMID: 33437016 PMCID: PMC7803728 DOI: 10.1038/s41598-020-80792-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 12/28/2020] [Indexed: 12/02/2022] Open
Abstract
Marek's disease virus (MDV) encodes a basic-leucine zipper (BZIP) protein, Meq, which is considered the major MDV oncoprotein. It has been reported that the oncogenicity of Meq is associated with its interaction with C-terminal binding protein 1 (CtBP), which is also an interaction partner of Epstein-Barr virus encoded EBNA3A and EBNA3C oncoproteins. Since both EBNA3C and CtBP interact with histone deacetylase 1 (HDAC1) and HDAC2, we examined whether Meq shares this interaction with chicken HDAC1 (chHDAC1) and chHDAC2. Using confocal microscopy analysis, we show that Meq co-localizes with chHDAC1 and chHDAC2 in the nuclei of MDV lymphoblastoid tumor cells. In addition, immunoprecipitation assays demonstrate that Meq interacts with chHDAC1 and chHDAC2 in transfected cells and MDV lymphoblastoid tumor cells. Using deletion mutants, interaction domains were mapped to the N-terminal dimerization domain of chHDAC1 and chHDAC2, and the BZIP domain of Meq. Our results further demonstrate that this interaction mediates the degradation of chHDAC1 and chHDAC2 via the proteasome dependent pathway. In addition, our results show that Meq also induces the reduction of global ubiquitinated proteins through a proteasome dependent pathway. In conclusion, our results provide evidence that Meq interacts with chHDAC1 and chHDAC2, and induces their proteasome dependent degradation.
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Affiliation(s)
- Yifei Liao
- Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, MS4467, TAMU, College Station, TX, 77843, USA
| | - Blanca Lupiani
- Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, MS4467, TAMU, College Station, TX, 77843, USA
| | - Yoshihiro Izumiya
- Department of Dermatology, School of Medicine, University of California, Davis, Sacramento, CA, USA
| | - Sanjay M Reddy
- Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, MS4467, TAMU, College Station, TX, 77843, USA.
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8
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Deng Q, Shi M, Li Q, Wang P, Li M, Wang W, Gao Y, Li H, Lin L, Huang T, Wei P. Analysis of the evolution and transmission dynamics of the field MDV in China during the years 1995-2020, indicating the emergence of a unique cluster with the molecular characteristics of vv+ MDV that has become endemic in southern China. Transbound Emerg Dis 2020; 68:3574-3587. [PMID: 33354907 DOI: 10.1111/tbed.13965] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 12/19/2020] [Accepted: 12/20/2020] [Indexed: 01/23/2023]
Abstract
Marek's disease (MD) continues to threaten the sustainability of the world poultry industry. In this study, the sequences of the meq gene of 220 MDV strains isolated during the years 1964-2020 were analysed, including 50 from our group plus 170 isolates from the GenBank. Analyses, using phylogenetic trees, amino acid (aa)-mutation screening, evolutionary studies and transmission dynamics were all performed. All strains were divided into two clusters (Clusters 1 and 2), and Cluster 1 includes the mild strains, the vaccine strains and the foreign virulent strains, while Cluster 2 was dominated by the Chinese field strains. Our study identified that the Chinese field strains in Cluster 2 during the years 1995-2020 likely originated in the 1980s from abroad, and the estimated genetic diversity of these strains experienced two growth phases in the years 2005-2007.5 and 2015-2017. Viral phylogeography identified 3 major geographic provincial regions for the Chinese field strains of Cluster 2: the Northeastern Region (Jilin, Liaoning and Heilongjiang), the East-central Region (Henan, Shandong and Jiangsu) and the Southern Region (Guangxi, Guangdong and Yunnan). The spread of Northeastern strains to East-central chicken flocks and the further spread from Guangxi to Guangdong are strongly indicated. The emergence of the mutations A88T and Q93R together in the Southern strains during the years 2017-2020 with molecular characteristics of vv+ MDV were also found later than those in the Northern strains. Overall, the Chinese field strains in Cluster 2 in southern China in recent years have been rapidly evolving. Guangxi Province has become an epicentre for these viruses and the chicken flocks in the Southern region have been facing the adverse effects of the emerging vv+ MDV.
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Affiliation(s)
- Qiaomu Deng
- Institute for Poultry Science and Health, Guangxi University, Nanning, China
| | - Mengya Shi
- Institute for Poultry Science and Health, Guangxi University, Nanning, China
| | - Qiuhong Li
- Institute for Poultry Science and Health, Guangxi University, Nanning, China
| | - Peikun Wang
- Institute of Microbe and Host Health, Linyi University, Linyi, China
| | - Min Li
- Institute for Poultry Science and Health, Guangxi University, Nanning, China
| | - Weiwei Wang
- Institute for Poultry Science and Health, Guangxi University, Nanning, China
| | - Yanli Gao
- Institute for Poultry Science and Health, Guangxi University, Nanning, China
| | - Haijuan Li
- Institute for Poultry Science and Health, Guangxi University, Nanning, China
| | - Lulu Lin
- Institute for Poultry Science and Health, Guangxi University, Nanning, China
| | - Teng Huang
- Institute for Poultry Science and Health, Guangxi University, Nanning, China
| | - Ping Wei
- Institute for Poultry Science and Health, Guangxi University, Nanning, China
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Conradie AM, Bertzbach LD, Trimpert J, Patria JN, Murata S, Parcells MS, Kaufer BB. Distinct polymorphisms in a single herpesvirus gene are capable of enhancing virulence and mediating vaccinal resistance. PLoS Pathog 2020; 16:e1009104. [PMID: 33306739 PMCID: PMC7758048 DOI: 10.1371/journal.ppat.1009104] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 12/23/2020] [Accepted: 10/27/2020] [Indexed: 12/14/2022] Open
Abstract
Modified-live herpesvirus vaccines are widely used in humans and animals, but field strains can emerge that have a higher virulence and break vaccinal protection. Since the introduction of the first vaccine in the 1970s, Marek’s disease virus overcame the vaccine barrier by the acquisition of numerous genomic mutations. However, the evolutionary adaptations in the herpesvirus genome responsible for the vaccine breaks have remained elusive. Here, we demonstrate that point mutations in the multifunctional meq gene acquired during evolution can significantly alter virulence. Defined mutations found in highly virulent strains also allowed the virus to overcome innate cellular responses and vaccinal protection. Concomitantly, the adaptations in meq enhanced virus shedding into the environment, likely providing a selective advantage for the virus. Our study provides the first experimental evidence that few point mutations in a single herpesviral gene result in drastically increased virulence, enhanced shedding, and escape from vaccinal protection. Viruses can acquire mutations during evolution that alter their virulence. An example of a virus that has shown repeated shifts to higher virulence in response to more efficacious vaccines is the oncogenic Marek’s disease virus (MDV) that infects chickens. Until now, it remained unknown which mutations in the large virus genome are responsible for this increase in virulence. We could demonstrate that very few amino acid changes in the meq oncogene of MDV can significantly alter the virulence of the virus. In addition, these changes also allow the virus to overcome vaccinal protection and enhance the shedding into the environment. Taken together, our data provide fundamental insights into evolutionary changes that allow this deadly veterinary pathogen to evolve towards greater virulence.
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Affiliation(s)
| | | | - Jakob Trimpert
- Institut für Virologie, Freie Universität Berlin, Berlin, Germany
| | - Joseph N. Patria
- Department of Biological Sciences, University of Delaware, Newark, United States of America
| | - Shiro Murata
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Mark S. Parcells
- Department of Animal and Food Sciences, University of Delaware, Newark, United States of America
| | - Benedikt B. Kaufer
- Institut für Virologie, Freie Universität Berlin, Berlin, Germany
- * E-mail:
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10
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Murata S, Machida Y, Isezaki M, Maekawa N, Okagawa T, Konnai S, Ohashi K. Genetic characterization of a Marek's disease virus strain isolated in Japan. Virol J 2020; 17:186. [PMID: 33228722 PMCID: PMC7684920 DOI: 10.1186/s12985-020-01456-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 11/15/2020] [Indexed: 01/29/2023] Open
Abstract
Background Marek’s disease virus (MDV) causes malignant lymphomas in chickens (Marek’s disease, MD). MD is currently controlled by vaccination; however, MDV strains have a tendency to develop increased virulence. Distinct diversity and point mutations are present in the Meq proteins, the oncoproteins of MDV, suggesting that changes in protein function induced by amino acid substitutions might affect MDV virulence. We previously reported that recent MDV isolates in Japan display distinct mutations in Meq proteins from those observed in traditional MDV isolates in Japan, but similar to those in MDV strains isolated from other countries. Methods To further investigate the genetic characteristics in Japanese field strains, we sequenced the whole genome of an MDV strain that was successfully isolated from a chicken with MD in Japan. A phylogenetic analysis of the meq gene was also performed. Results Phylogenetic analysis revealed that the Meq proteins in most of the Japanese isolates were similar to those of Chinese and European strains, and the genomic sequence of the Japanese strain was classified into the Eurasian cluster. Comparison of coding region sequences among the Japanese strain and MDV strains from other countries revealed that the genetic characteristics of the Japanese strain were similar to those of Chinese and European strains. Conclusions The MDV strains distributed in Asian and European countries including Japan seem to be genetically closer to each other than to MDV strains from North America. These findings indicate that the genetic diversities of MDV strains that emerged may have been dependent on the different vaccination-based control approaches.
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Affiliation(s)
- Shiro Murata
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Kita-18, Nishi-9, Kita-ku, Sapporo, 060-0818, Japan. .,Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Kita-18, Nishi-9, Kita-ku, Sapporo, 060-0818, Japan.
| | - Yuka Machida
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Kita-18, Nishi-9, Kita-ku, Sapporo, 060-0818, Japan
| | - Masayoshi Isezaki
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Kita-18, Nishi-9, Kita-ku, Sapporo, 060-0818, Japan
| | - Naoya Maekawa
- Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Kita-18, Nishi-9, Kita-ku, Sapporo, 060-0818, Japan
| | - Tomohiro Okagawa
- Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Kita-18, Nishi-9, Kita-ku, Sapporo, 060-0818, Japan
| | - Satoru Konnai
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Kita-18, Nishi-9, Kita-ku, Sapporo, 060-0818, Japan.,Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Kita-18, Nishi-9, Kita-ku, Sapporo, 060-0818, Japan
| | - Kazuhiko Ohashi
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Kita-18, Nishi-9, Kita-ku, Sapporo, 060-0818, Japan.,Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Kita-18, Nishi-9, Kita-ku, Sapporo, 060-0818, Japan
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11
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Davidson I. Out of Sight, but Not Out of Mind: Aspects of the Avian Oncogenic Herpesvirus, Marek's Disease Virus. Animals (Basel) 2020; 10:E1319. [PMID: 32751762 PMCID: PMC7459476 DOI: 10.3390/ani10081319] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 07/27/2020] [Accepted: 07/28/2020] [Indexed: 02/08/2023] Open
Abstract
Marek's disease virus is an economically important avian herpesvirus that causes tumors and immunosuppression in chickens and turkeys. The virus, disease, and vaccines have been known for more than 50 years, but as knowledge gaps still exists, intensive research is still ongoing. The understanding of MDV complexity can provide scientific insight in topics that cannot be experimented in humans, providing a unique model that is dually useful for the benefit of the poultry industry and for studying general herpesvirology. The present review presents the following topics: the MDV biology, the vaccine's and virulent virus' peculiar presence in feathers, protection by vaccination. In addition, two relatively behind the scenes topics are reviewed; first, the meq MDV oncogene and its recent implication in molecular epidemiology and in the MDV virulence determination, and second, the functionality of conformational epitopes of the MDV immunodominant protein, glycoprotein B. Our studies were particular, as they were the only ones describing three-dimensional MDV gB oligomers. MDV gB (glycoprotein B) continuous and discontinuous epitopes were shown to possess distinctive neutralization activities. In contrast, the significance of oligomerization of the viral membrane proteins for the creation of discontinuous epitopes in other herpesviruses was explored extensively.
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Affiliation(s)
- Irit Davidson
- Division of Avian Diseases, Kimron Veterinary Institute, Bet Dagan 50250, Israel
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12
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Stolz ML, McCormick C. The bZIP Proteins of Oncogenic Viruses. Viruses 2020; 12:v12070757. [PMID: 32674309 PMCID: PMC7412551 DOI: 10.3390/v12070757] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 07/08/2020] [Accepted: 07/13/2020] [Indexed: 12/20/2022] Open
Abstract
Basic leucine zipper (bZIP) transcription factors (TFs) govern diverse cellular processes and cell fate decisions. The hallmark of the leucine zipper domain is the heptad repeat, with leucine residues at every seventh position in the domain. These leucine residues enable homo- and heterodimerization between ZIP domain α-helices, generating coiled-coil structures that stabilize interactions between adjacent DNA-binding domains and target DNA substrates. Several cancer-causing viruses encode viral bZIP TFs, including human T-cell leukemia virus (HTLV), hepatitis C virus (HCV) and the herpesviruses Marek’s disease virus (MDV), Epstein–Barr virus (EBV) and Kaposi’s sarcoma-associated herpesvirus (KSHV). Here, we provide a comprehensive review of these viral bZIP TFs and their impact on viral replication, host cell responses and cell fate.
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13
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Yilmaz A, Turan N, Bayraktar E, Tali HE, Aydin O, Umar S, Cakan B, Sadeyen JR, Baigent S, Iqbal M, Nair V, Yilmaz H. Molecular characterisation and phylogenetic analysis of Marek's disease virus in Turkish layer chickens. Br Poult Sci 2020; 61:523-530. [PMID: 32316760 DOI: 10.1080/00071668.2020.1758301] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
1. There is no current data about the genotypes of Marek's disease virus (MDV) in Turkish poultry flocks; hence, this study was performed to analyse CVI988/Rispens, turkey herpesvirus (HVT) vaccine viruses and MDV field viruses as well as to perform phylogenetic analysis of MDV in Turkish layer chickens. 2. In 2017 and 2018, a total of 602 spleen samples from 49 layer flocks were collected from the Marmara, West Black Sea and Aegean regions. DNA was extracted from the spleen samples and the samples were analysed by real-time PCR probe assay to detect CVI988/Rispens and HVT vaccine viruses and MDV field strains. Samples found positive for MDV by real-time PCR were subjected to PCR using the Meq gene primers for phylogenetic analysis. 3. Amongst 49 flocks, virulent MDV was detected in nine flocks. CVI988/Rispens and HVT vaccine strains were detected in 47 flocks and HVT in all 49 flocks. Splenomegaly, hepatomegaly and tumours in the oviduct were observed in chickens of affected flocks. Virulent MDV was detected in 120 out of 602 spleen samples. Sequencing and phylogenetic analyses showed that MDVs detected in this study were closely related to MDV strains from Italy, Poland, Saudi Arabia, Iraq, India and China but showed diversity with MDV strains from Egypt and Hungary. Multiple sequence analysis of the Meq protein revealed several point mutations in deduced amino acid sequences. Interestingly, CVI988/Rispens vaccine virus from China (AF493555) showed mutations at position 66 (G66R) and 71 (S66A) along with two other vaccine strains from China (GU354326.1) and Russia (EU032468.1), in comparison with the other vaccine strain CVI988/Rispens (DQ534538). The molecular analyses of the Meq gene suggested that Turkish field strains of MDV are in the class of virulent or very virulent pathotypes. 4. The results have shown that MDV still affects poultry health, and the phylogenetic and amino acid variation data obtained will help in vaccination and control strategies.
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Affiliation(s)
- A Yilmaz
- Department of Virology, Istanbul University-Cerrahpasa, Veterinary Faculty , Istanbul, Turkey
| | - N Turan
- Department of Virology, Istanbul University-Cerrahpasa, Veterinary Faculty , Istanbul, Turkey
| | - E Bayraktar
- Poultry Division, CEVA Animal Health , Maslak, Turkey
| | - H E Tali
- Department of Virology, Istanbul University-Cerrahpasa, Veterinary Faculty , Istanbul, Turkey
| | - O Aydin
- Department of Virology, Istanbul University-Cerrahpasa, Veterinary Faculty , Istanbul, Turkey
| | - S Umar
- Department of Virology, Istanbul University-Cerrahpasa, Veterinary Faculty , Istanbul, Turkey
| | - B Cakan
- Poultry Division, CEVA Animal Health , Maslak, Turkey
| | - J-R Sadeyen
- Avian Influenza Group, The Pirbright Institute , Woking, UK
| | - S Baigent
- Avian Influenza Group, The Pirbright Institute , Woking, UK
| | - M Iqbal
- Avian Influenza Group, The Pirbright Institute , Woking, UK
| | - V Nair
- Avian Influenza Group, The Pirbright Institute , Woking, UK
| | - H Yilmaz
- Department of Virology, Istanbul University-Cerrahpasa, Veterinary Faculty , Istanbul, Turkey
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14
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Sun P, Cui N, Liu L, Su S, Cheng Z, Chen R, Li Y, Cui Z. Attenuation of a recombinant Marek's disease virus lacking the meq oncogene and evaluation on its immune efficacy against Marek's disease virus. Poult Sci 2020; 99:1939-1945. [PMID: 32241474 PMCID: PMC7587640 DOI: 10.1016/j.psj.2019.11.059] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 11/15/2019] [Accepted: 11/15/2019] [Indexed: 11/30/2022] Open
Abstract
SC9-2 is a recombinant Marek's disease virus (MDV) strain lacking the meq oncogene. Previous study demonstrated that SC9-2 virus provides good protection against challenge with a very virulent MDV rMd5, but it induces immunosuppressive effects in specific pathogen-free (SPF) chickens. In the present study, SC9-2 was serially passaged on chicken embryo fibroblast (CEF) cell cultures. The pathogenicity and immune efficacy of SC9-2/10th and SC9-2/40th against rMd5 were evaluated. Animal experimental results showed that SC9-2/10th and SC9-2/40th showed no lethality or tumorigenicity in SPF chickens. Body weight of chickens inoculated with SC9-2/40th were significantly higher than that of the chickens inoculated with SC9-2/10th but lower than that of the uninoculated controls. The severity of bursa and thymus atrophy (BTA) and spleen enlargement in SC9-2/40th-inoculated chickens were also weaker than the SC9-2/10th-inoculated ones but stronger than the uninoculated controls. Chickens inoculated with SC9-2/40th and SC9-2/10th showed similar antibody levels induced by H9N2 subtype avian influenza virus/Newcastle disease virus inactivated vaccines, both of which were lower than the uninoculated controls. Replication of SC9-2/40th was significantly lower than SC9-2/10th in feather follicle epithelium (FFE) of infected chickens. The immune protection index of SC9-2/40th was also lower than that of SC9-2/10th, but the difference was not significantly, and both of which were significant higher than that of the commercial MDV vaccine CVI988/Rispens. The results of our studies demonstrated that SC9-2/40th showed weaker severity of BTA, spleen enlargement, and body weight loss and lower replication level in FFE than SC9-2/10th in SPF chickens. However, SC9-2/40th was able to confer better immune protection as compared with CVI988/Rispens vaccination in SPF chickens. In conclusion, serially attenuation of SC9-2 in CEFs reduced the lymphoid organ atrophy and replication in SPF chickens, and the immune protective efficacy of attenuated viruses was still superior than CVI988/Rispens.
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Affiliation(s)
- Peng Sun
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention; College of Veterinary Medicine, Shandong Agricultural University, Tai'an, Shandong 271018, China
| | - Ning Cui
- Shandong Key Laboratory of Animal Disease Control & Breeding; Institute of Animal Husbandry and Veterinary, Shandong Academy of Agricultural Sciences, Jinan 250100, China
| | - Linqing Liu
- China Animal Disease Control Center, Beijing, 100125 China
| | - Shuai Su
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention; College of Veterinary Medicine, Shandong Agricultural University, Tai'an, Shandong 271018, China.
| | - Ziqiang Cheng
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention; College of Veterinary Medicine, Shandong Agricultural University, Tai'an, Shandong 271018, China
| | - Ruiai Chen
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong 510642, China.
| | - Yanpeng Li
- Zhaoqing Institute of Biotechnology Co., Ltd., Zhaoqing, Guangdong 526238, China
| | - Zhizhong Cui
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention; College of Veterinary Medicine, Shandong Agricultural University, Tai'an, Shandong 271018, China
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15
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Mescolini G, Lupini C, Davidson I, Massi P, Tosi G, Catelli E. Marek's disease viruses circulating in commercial poultry in Italy in the years 2015-2018 are closely related by their meq gene phylogeny. Transbound Emerg Dis 2019; 67:98-107. [PMID: 31411371 DOI: 10.1111/tbed.13327] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 07/23/2019] [Accepted: 08/07/2019] [Indexed: 02/06/2023]
Abstract
Marek's disease (MD) is a lymphoproliferative disease important to the poultry industry worldwide; it is caused by Gallid alphaherpesvirus 2 (GaHV-2). The virulence of GaHV-2 isolates has shifted over the years from mild to virulent, very virulent and very virulent +. Nowadays the disease is controlled by vaccination, but field strains of increased virulence are emerging worldwide. Economic losses due to MD are mostly associated with its acute form, characterized by visceral lymphomas. The present study aimed to molecularly classify a group of 13 GaHV-2 strains detected in vaccinated Italian commercial chicken flocks during acute MD outbreaks, and to scrutinize the ability of predicting GaHV-2 virulence, according to the meq gene sequence. The full-length meq genes were amplified, and the obtained amino acid (aa) sequences were analysed, focusing mainly on the number of stretches of four proline molecules (PPPP) within the transactivation domain. Phylogenetic analysis was carried out with the Maximum Likelihood method using the obtained aa sequences, and the sequences of Italian strains detected in backyard flocks and of selected strains retrieved from GenBank. All the analysed strains showed 100% sequence identity in the meq gene, which encodes a Meq protein of 339 aa. The Meq protein includes four PPPP motifs in the transactivation domain and an interruption of a PPPP motif due to a proline-to-serine substitution at position 218. These features are typically encountered in highly virulent isolates. Phylogenetic analysis revealed that the analysed strains belonged to a cluster that includes high-virulence GaHV-2 strains detected in Italian backyard flocks and a hypervirulent Polish strain. Our results support the hypothesis that the virulence of field isolates can be suggested by meq aa sequence analysis.
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Affiliation(s)
- Giulia Mescolini
- Department of Veterinary Medical Sciences, University of Bologna, Ozzano dell'Emilia, Italy
| | - Caterina Lupini
- Department of Veterinary Medical Sciences, University of Bologna, Ozzano dell'Emilia, Italy
| | - Irit Davidson
- Division of Avian Diseases, Kimron Veterinary Institute, Bet Dagan, Israel
| | - Paola Massi
- Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna, Sezione Diagnostica di Forlì, Forlì, Italy
| | - Giovanni Tosi
- Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna, Sezione Diagnostica di Forlì, Forlì, Italy
| | - Elena Catelli
- Department of Veterinary Medical Sciences, University of Bologna, Ozzano dell'Emilia, Italy
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16
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Mescolini G, Lupini C, Felice V, Guerrini A, Silveira F, Cecchinato M, Catelli E. Molecular characterization of the meq gene of Marek's disease viruses detected in unvaccinated backyard chickens reveals the circulation of low- and high-virulence strains. Poult Sci 2019; 98:3130-3137. [PMID: 30850833 DOI: 10.3382/ps/pez095] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 02/13/2019] [Indexed: 11/20/2022] Open
Abstract
Marek's disease (MD) is an important lymphoproliferative disease of chickens, caused by Gallid alphaherpesvirus 2 (GaHV-2). Outbreaks are commonly reported in commercial flocks, but also in backyard chickens. Whereas the molecular characteristics of GaHV-2 strains from the commercial poultry sector have been reported, no recent data are available for the rural sector. To fill this gap, 19 GaHV-2 strains detected in 19 Italian backyard chicken flocks during suspected MD outbreaks were molecularly characterized through an analysis of the meq gene, the major GaHV-2 oncogene. The number of four consecutive prolines (PPPP) within the proline-rich repeats of the Meq transactivation domain, the proline content, and the presence of amino acid (aa) substitutions were determined. Phylogenetic analysis was performed using the Maximum Likelihood method. Sequence analysis revealed a heterogeneous population of GaHV-2 strains circulating in Italian backyard flocks. Seven strains, detected from birds affected by classical MD, showed a unique meq isoform of 418 aa with a very high number of PPPP motifs. Molecular and clinical features are suggestive of a low oncogenic potential of these strains. The remaining 12 strains, detected from flocks experiencing acute MD, transient paralysis, or sudden death, had shorter Meq protein isoforms (298 or 339 aa) with a lower number of PPPP motifs and point mutations interrupting PPPP. These features allow us to assert the high virulence of these strains. These findings reveal the circulation of low- and high-virulence GaHV-2 strains in the Italian rural sector.
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Affiliation(s)
- Giulia Mescolini
- Department of Veterinary Medical Sciences, University of Bologna, 40064 Ozzano dell'Emilia (BO), Italy
| | - Caterina Lupini
- Department of Veterinary Medical Sciences, University of Bologna, 40064 Ozzano dell'Emilia (BO), Italy
| | - Viviana Felice
- Department of Veterinary Medical Sciences, University of Bologna, 40064 Ozzano dell'Emilia (BO), Italy
| | - Alessandro Guerrini
- Department of Veterinary Medical Sciences, University of Bologna, 40064 Ozzano dell'Emilia (BO), Italy
| | - Flavio Silveira
- Department of Veterinary Medical Sciences, University of Bologna, 40064 Ozzano dell'Emilia (BO), Italy
| | - Mattia Cecchinato
- Department of Animal Medicine, Production and Health, University of Padua, 35020 Legnaro (PD), Italy
| | - Elena Catelli
- Department of Veterinary Medical Sciences, University of Bologna, 40064 Ozzano dell'Emilia (BO), Italy
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17
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Dunn JR, Black Pyrkosz A, Steep A, Cheng HH. Identification of Marek's disease virus genes associated with virulence of US strains. J Gen Virol 2019; 100:1132-1139. [PMID: 31184569 DOI: 10.1099/jgv.0.001288] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Marek's disease virus (MDV) is the most well-cited example of vaccine-driven virulence evolution. MDV induces a lymphoproliferative disease in chickens, which is currently controlled by widespread vaccination of flocks. Unfortunately, Marek's disease (MD) vaccines, while effective in preventing tumours, do not prevent viral replication and mutation, which has been hypothesized as the major driving force for increased MDV virulence of field strains during the past 40 years in US commercial flocks. To limit future virulence increases, there is interest in characterizing MDV strain genomes collected over the years and associating genetic variations with variation in virulence. In this study, we characterized 70 MDV genomes with known virulence by complete or targeted DNA sequencing, and identified genetic variants that showed association with virulence. Our results revealed a number of MDV genes as would be expected for a complex trait. In addition, phylogenetic analysis revealed a clear separation of strains that varied by virulence. Interestingly, high virulence isolates from the same farms persisted over years despite eradication attempts, which has implications on control efforts. Given the growing ability to bioengineer the MDV genome, it should be feasible to experimentally test whether these individual variants influence virulence markers alone or combinations. Once validated, these markers may provide an alternative to live bird testing for evaluating virulence of new MDV field strains.
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Affiliation(s)
- John R Dunn
- Avian Disease and Oncology Laboratory, Agricultural Research Service, United States Department of Agriculture, 4279 E. Mount Hope Road, East Lansing, MI, 48823, USA
| | - Alexis Black Pyrkosz
- Avian Disease and Oncology Laboratory, Agricultural Research Service, United States Department of Agriculture, 4279 E. Mount Hope Road, East Lansing, MI, 48823, USA
| | - Alec Steep
- Avian Disease and Oncology Laboratory, Agricultural Research Service, United States Department of Agriculture, 4279 E. Mount Hope Road, East Lansing, MI, 48823, USA.,Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, 48824, USA
| | - Hans H Cheng
- Avian Disease and Oncology Laboratory, Agricultural Research Service, United States Department of Agriculture, 4279 E. Mount Hope Road, East Lansing, MI, 48823, USA
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18
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Bertzbach LD, Kheimar A, Ali FAZ, Kaufer BB. Viral Factors Involved in Marek’s Disease Virus (MDV) Pathogenesis. CURRENT CLINICAL MICROBIOLOGY REPORTS 2018. [DOI: 10.1007/s40588-018-0104-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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19
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Wen Y, Huang Q, Yang C, Pan L, Wang G, Qi K, Liu H. Characterizing the histopathology of natural co-infection with Marek’s disease virus and subgroup J avian leucosis virus in egg-laying hens. Avian Pathol 2017; 47:83-89. [DOI: 10.1080/03079457.2017.1375079] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Yawen Wen
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, Anhui Agricultural University, Hefei, People’s Republic of China
| | - Qi Huang
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, Anhui Agricultural University, Hefei, People’s Republic of China
| | - Chengcheng Yang
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, Anhui Agricultural University, Hefei, People’s Republic of China
| | - Ling Pan
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, Anhui Agricultural University, Hefei, People’s Republic of China
| | - Guijun Wang
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, Anhui Agricultural University, Hefei, People’s Republic of China
| | - Kezong Qi
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, Anhui Agricultural University, Hefei, People’s Republic of China
| | - Hongmei Liu
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, Anhui Agricultural University, Hefei, People’s Republic of China
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20
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Marek's disease vaccines: Current status, and strategies for improvement and development of vector vaccines. Vet Microbiol 2016; 206:113-120. [PMID: 28038868 DOI: 10.1016/j.vetmic.2016.11.024] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 11/19/2016] [Accepted: 11/23/2016] [Indexed: 11/24/2022]
Abstract
Marek's disease (MD) is a lymphoproliferative viral disease of chickens, which has been controlled through vaccination since 1969. MD vaccines protect against tumors but do not provide sterilizing immunity, and thus it is generally believed that their use has contributed to increase virulence of field strains with the ability to cause MD in vaccinated chickens. Traditional methods of developing vaccines, like cell culture attenuation, have proved unsuccessful for the development of improved vaccines to protect against highly virulent MD virus (MDV) field strains. With the advent of recombinant DNA technology, it is now possible to study MDV gene function and develop rational vaccines that protect against highly pathogenic strains. In addition, the long term protection conferred by MD vaccines, their excellent safety profile, their efficacy when administered early (at hatch or in ovo), and their ability to overcome maternal antibodies, has made MDV an excellent candidate vector to protect not only against MD but also against other important viral poultry diseases. In this review we will discuss the current status of MD vaccines and their use as vector vaccines to control important viral poultry diseases.
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21
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Kumar MA, Barathidasan R, Palanivelu M, Singh S, Wani MY, Malik YS, Singh R, Dhama K. A novel recombinant Meq protein based dot-ELISA for rapid and confirmatory diagnosis of Marek’s disease induced lymphoma in poultry. J Virol Methods 2016; 236:271-280. [DOI: 10.1016/j.jviromet.2016.08.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 08/03/2016] [Accepted: 08/12/2016] [Indexed: 10/21/2022]
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22
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Pandey U, Bell AS, Renner DW, Kennedy DA, Shreve JT, Cairns CL, Jones MJ, Dunn PA, Read AF, Szpara ML. DNA from Dust: Comparative Genomics of Large DNA Viruses in Field Surveillance Samples. mSphere 2016; 1:e00132-16. [PMID: 27747299 PMCID: PMC5064450 DOI: 10.1128/msphere.00132-16] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Accepted: 08/25/2016] [Indexed: 12/12/2022] Open
Abstract
The intensification of the poultry industry over the last 60 years facilitated the evolution of increased virulence and vaccine breaks in Marek's disease virus (MDV-1). Full-genome sequences are essential for understanding why and how this evolution occurred, but what is known about genome-wide variation in MDV comes from laboratory culture. To rectify this, we developed methods for obtaining high-quality genome sequences directly from field samples without the need for sequence-based enrichment strategies prior to sequencing. We applied this to the first characterization of MDV-1 genomes from the field, without prior culture. These viruses were collected from vaccinated hosts that acquired naturally circulating field strains of MDV-1, in the absence of a disease outbreak. This reflects the current issue afflicting the poultry industry, where virulent field strains continue to circulate despite vaccination and can remain undetected due to the lack of overt disease symptoms. We found that viral genomes from adjacent field sites had high levels of overall DNA identity, and despite strong evidence of purifying selection, had coding variations in proteins associated with virulence and manipulation of host immunity. Our methods empower ecological field surveillance, make it possible to determine the basis of viral virulence and vaccine breaks, and can be used to obtain full genomes from clinical samples of other large DNA viruses, known and unknown. IMPORTANCE Despite both clinical and laboratory data that show increased virulence in field isolates of MDV-1 over the last half century, we do not yet understand the genetic basis of its pathogenicity. Our knowledge of genome-wide variation between strains of this virus comes exclusively from isolates that have been cultured in the laboratory. MDV-1 isolates tend to lose virulence during repeated cycles of replication in the laboratory, raising concerns about the ability of cultured isolates to accurately reflect virus in the field. The ability to directly sequence and compare field isolates of this virus is critical to understanding the genetic basis of rising virulence in the wild. Our approaches remove the prior requirement for cell culture and allow direct measurement of viral genomic variation within and between hosts, over time, and during adaptation to changing conditions.
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Affiliation(s)
- Utsav Pandey
- Department of Biochemistry and Molecular Biology, Center for Infectious Disease Dynamics, and the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Andrew S. Bell
- Center for Infectious Disease Dynamics, Departments of Biology and Entomology, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Daniel W. Renner
- Department of Biochemistry and Molecular Biology, Center for Infectious Disease Dynamics, and the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania, USA
| | - David A. Kennedy
- Center for Infectious Disease Dynamics, Departments of Biology and Entomology, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Jacob T. Shreve
- Department of Biochemistry and Molecular Biology, Center for Infectious Disease Dynamics, and the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Chris L. Cairns
- Center for Infectious Disease Dynamics, Departments of Biology and Entomology, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Matthew J. Jones
- Center for Infectious Disease Dynamics, Departments of Biology and Entomology, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Patricia A. Dunn
- Department of Veterinary and Biomedical Sciences, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Andrew F. Read
- Center for Infectious Disease Dynamics, Departments of Biology and Entomology, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Moriah L. Szpara
- Department of Biochemistry and Molecular Biology, Center for Infectious Disease Dynamics, and the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania, USA
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Gennart I, Coupeau D, Pejaković S, Laurent S, Rasschaert D, Muylkens B. Marek's disease: Genetic regulation of gallid herpesvirus 2 infection and latency. Vet J 2015; 205:339-48. [PMID: 26067852 DOI: 10.1016/j.tvjl.2015.04.038] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 04/27/2015] [Accepted: 04/29/2015] [Indexed: 12/12/2022]
Abstract
Gallid herpesvirus-2 (GaHV-2) is an oncogenic α-herpesvirus that causes Marek's disease (MD), a T cell lymphosarcoma (lymphoma) of domestic fowl (chickens). The GaHV-2 genome integrates by homologous recombination into the host genome and, by modulating expression of viral and cellular genes, induces transformation of latently infected cells. MD is a unique model of viral oncogenesis. Mechanisms implicated in the regulation of viral and cellular genes during GaHV-2 infection operate at transcriptional, post-transcriptional and post-translational levels, with involvement of viral and cellular transcription factors, along with epigenetic modifications, alternative splicing, microRNAs and post-translational modifications of viral proteins. Meq, the major oncogenic protein of GaHV-2, is a viral transcription factor that modulates expression of viral genes, for example by binding to the viral bidirectional promoter of the pp38-pp24/1.8 kb mRNA, and also modulates expression of cellular genes, such as Bcl-2 and matrix metalloproteinase 3. GaHV-2 expresses viral telomerase RNA subunit (vTR), which forms a complex with the cellular telomerase reverse transcriptase (TERT), thus contributing to tumorigenesis, while vTR independent of telomerase activity is implicated in metastasis. Expression of a viral interleukin 8 homologue may contribute to lymphomagenesis. Inhibition of expression of the pro-apoptotic factors JARID2 and SMAD2 by viral microRNAs may promote the survival and proliferation of GaHV-2 latently infected cells, thus enhancing tumorigenesis, while inhibition of interleukin 18 by viral microRNAs may be involved in evasion of immune surveillance. Viral envelope glycoproteins derived from glycoprotein B (gp60 and gp49), as well as glycoprotein C, may also play a role in immune evasion.
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Affiliation(s)
- Isabelle Gennart
- Veterinary Integrated Research Unit, Faculty of Sciences, Namur Research Institute for Life Sciences (NARILIS), University of Namur (UNamur), 5000 Namur, Belgium
| | - Damien Coupeau
- Veterinary Integrated Research Unit, Faculty of Sciences, Namur Research Institute for Life Sciences (NARILIS), University of Namur (UNamur), 5000 Namur, Belgium
| | - Srdan Pejaković
- Veterinary Integrated Research Unit, Faculty of Sciences, Namur Research Institute for Life Sciences (NARILIS), University of Namur (UNamur), 5000 Namur, Belgium
| | - Sylvie Laurent
- Transcription, Lymphome Viro-Induit, University François Rabelais, UFR Sciences et Techniques, Parc de Grandmont, F-37200 Tours, France
| | - Denis Rasschaert
- Transcription, Lymphome Viro-Induit, University François Rabelais, UFR Sciences et Techniques, Parc de Grandmont, F-37200 Tours, France
| | - Benoit Muylkens
- Veterinary Integrated Research Unit, Faculty of Sciences, Namur Research Institute for Life Sciences (NARILIS), University of Namur (UNamur), 5000 Namur, Belgium.
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Schat KA, Erb HN. Lack of evidence that avian oncogenic viruses are infectious for humans: a review. Avian Dis 2015; 58:345-58. [PMID: 25518427 DOI: 10.1637/10847-041514-review.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Chickens may be infected with three different oncogenic viruses: avian leukosis virus (ALV), reticuloendotheliosis virus (REV), and Marek's disease herpesvirus (MDV). Several epidemiological studies have suggested a link between these viruses and different types of cancer in people working in poultry processing plants and with multiple sclerosis. In this article, we analyze the epidemiological evidence that these viruses are causative agents for human cancer, followed by description of the relevant key characteristics of ALV, REV, and MDV. Finally, we discuss the biological evidence or lack thereof that avian tumor viruses are involved in the etiology of human cancer and multiple sclerosis (MS). The recent primary epidemiologic articles that we reviewed as examples were only hypothesis-generating studies examining massive numbers of risk factors for associations with various imprecise, non-viral-specific outcomes. The studies lacked precise evidence of exposure to the relevant viruses and the statistical methods failed to adjust for the large risks of false-positive claims. ALV subgroups A-D and J have been eradicated in the United States from the pure lines down to the parent stocks by the breeder companies, which have greatly reduced the incidence of infection in layer flocks and broilers. As a consequence, potential exposure of humans to these viruses has greatly diminished. Infection of humans working in processing plants with ALV-A and ALV-B is unlikely, because broilers are generally resistant to infection with these two subgroups. Moreover, these viruses enter cells by specific receptors present on chicken, but not on mammalian, cells. Infection of mammalian cell cultures or animals with ALV-A, ALV-B, and ALV-J has not been reported. Moreover, humans vaccinated with exogenous or endogenous ALV-contaminated vaccines against yellow fever, measles, and mumps did not become antibody- or virus-positive for ALV. The risks for human infection with REV are similarly limited. First of all, REV also has been eradicated from pure lines down to parent stock by breeder companies in the United States. Broilers can still become infected with REV through infection with fowl pox virus containing REV. However, there is no indication that REV can infect human cells. Low levels of antibodies to ALV and REV in human sera have been reported by a few groups. Absorption of sera with chicken antigens reduced the antibody titers, and there was no clear association with contacts with poultry. Possible cross-reactions with human endogenous or exogenous retroviruses were not considered in these publications. MDV is typically associated with infection of chickens, and almost all experimental data show that MDV cannot infect mammalian cells or animals, including nonhuman primates. One study reports the presence of MDV gD DNA in human sera, but this finding could not be confirmed by another group. A Medline search of the term "gene expression in human cancers" was negative for publications with avian retroviruses or MDV. In conclusion, there is no indication that avian oncogenic viruses are involved in human cancer or MS or even able to infect and replicate in humans.
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Lee LF, Kreager K, Heidari M, Zhang H, Lupiani B, Reddy SM, Fadly A. Properties of a meq-deleted rmd5 Marek's disease vaccine: protection against virulent MDV challenge and induction of lymphoid organ atrophy are simultaneously attenuated by serial passage in vitro. Avian Dis 2013; 57:491-7. [PMID: 23901766 DOI: 10.1637/10388-092612-reg.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We have previously shown that deletion of the meq gene from the genome of Cosmid-cloned rMd5 strain of Marek's disease virus (MDV-1) resulted in loss of transformation and oncogenic capacity of the virus. The rMd5deltaMeq (Meq null) virus has been shown to be an excellent vaccine in maternal antibody positive (MAb+) chickens challenged with a very virulent plus (vv+) strain of MDV, 648A. The only drawback was that it retained its ability to induce bursa and thymus atrophy (BTA) like that of the parental rMd5 in maternal antibody negative (MAb-) chickens. We recently reported that the attenuated Meq null virus did not induce BTA at the 40th cell culture passage onward. Its protective ability against challenge with vv+ MDV, strain 686 was similar to the original virus at the 19th passage in MAb- chickens. In this study, we compared the same series of attenuated meq null viruses in commercial chickens. In commercial chickens with MAb, the attenuated viruses quickly lost protection with increasing cell culture attenuation. These data suggest that although attenuation of these meq null viruses eliminated BTA, it had no influence on their protective efficacy in MAb- chickens. However, in commercial chickens (MAb+), the best protection was provided by the original 19th passage; the attenuated 40th passage was as good as one of the currently commercial CVI988/Rispens vaccine, and it did not induce BTA. Therefore, protection against virulent MDV challenge and induction of lymphoid organ atrophy are simultaneously attenuated by serial passage in vitro.
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Affiliation(s)
- Lucy F Lee
- United States Department of Agriculture-Agricultural Research Service, Avian Disease and Oncology Laboratory, East Lansing, MI 48823, USA.
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Hassanin O, Abdallah F, El-Araby IE. Molecular Characterization and Phylogenetic Analysis of Marek's Disease Virus from Clinical Cases of Marek's Disease in Egypt. Avian Dis 2013; 57:555-61. [DOI: 10.1637/10337-082912-reg.1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Characterization of Meq proteins from field isolates of Marek's disease virus in Japan. INFECTION GENETICS AND EVOLUTION 2013; 16:137-43. [PMID: 23352889 DOI: 10.1016/j.meegid.2012.12.032] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Revised: 12/18/2012] [Accepted: 12/31/2012] [Indexed: 11/23/2022]
Abstract
Serotype 1 strains of Marek's disease virus (MDV-1) cause malignant lymphomas in chickens (Marek's disease; MD). Although MD has been controlled by vaccination, field isolates of MDV-1 have tended to increase in virulence and cause MD even in vaccinated chickens. Meq, a putative MDV-1 oncoprotein, resembles the Jun/Fos family of basic leucine zipper (bZIP) transcription factors and can regulate the expression of viral and cellular genes as a homodimer or as a heterodimer with a variety of bZIP family proteins. Sequencing analysis of some of the viral genes of various MDV-1 strains revealed a distinct diversity of and point mutations in Meq, which may contribute to changes in the transcriptional activities of Meq and, consequently, to increases in MDV-1 oncogenicity. However, few reports have characterized MDV-1 strains isolated in Japan. In this study, we established the amino acid sequences of MDV-1 field isolates from Japan in order to determine whether they display a distinct diversity of and point mutations in Meq. In addition, we analyzed the transactivation activities of the Meq proteins in order to evaluate whether the observed mutations affect their functions. Japanese MDV-1 isolates displayed the distinct mutations in basic region 2 (BR2) and proline-rich repeats (PRRs) of the Meq proteins as well as some unique mutations. Reporter assays revealed that the amino acid substitutions in BR2 and the PRRs affected the Meq transactivation activity. These results suggest that the distinct mutations are also present in the Meq proteins of MDV-1 isolates from Japan and affect their transactivation activities.
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The oncogenic microRNA OncomiR-21 overexpressed during Marek's disease lymphomagenesis is transactivated by the viral oncoprotein Meq. J Virol 2012; 87:80-93. [PMID: 23055556 DOI: 10.1128/jvi.02449-12] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Gallid herpesvirus 2 (GaHV-2) is an oncogenic herpesvirus that causes T lymphoma in chicken. GaHV-2 encodes a basic leucine zipper (bZIP) protein of the AP-1 family, Meq. Upon formation of homo- or heterodimers with c-Jun, Meq may modulate the expression of viral and cellular genes involved in lymphomagenesis. GaHV-2 also encodes viral microRNAs (miRNAs) involved in latency and apoptosis escape. However, little is known about cellular miRNA deregulation during the development of GaHV-2-associated lymphoma. We determined the cellular miRNA expression profiles of chickens infected with a very virulent strain (RB-1B) or a vaccine strain (CVI988) or noninfected. Among the most deregulated cellular miRNAs, we focused our efforts on gga-miR-21, which is upregulated during GaHV-2 infection. We mapped the gga-miR-21 promoter to the 10th intron of the TMEM49 gene and found it to be driven by AP-1- and Ets-responsive elements. We show here that the viral oncoprotein Meq binds to this promoter, thereby transactivating gga-miR-21 expression. We confirmed that this miRNA targets chicken programmed death cell 4 (PDCD4) and promotes tumor cell growth and apoptosis escape. Finally, gga-miR-21 was overexpressed only during infection with a very virulent strain (RB-1B) and not during infection with a nononcogenic strain (CVI988), providing further evidence for its role in GaHV-2 lymphomagenesis. Our data therefore suggest an additional role for Meq in GaHV-2-mediated lymphomagenesis through the induction of miR-21 expression.
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Kumar S, Kunec D, Buza JJ, Chiang HI, Zhou H, Subramaniam S, Pendarvis K, Cheng HH, Burgess SC. Nuclear Factor kappa B is central to Marek's disease herpesvirus induced neoplastic transformation of CD30 expressing lymphocytes in-vivo. BMC SYSTEMS BIOLOGY 2012; 6:123. [PMID: 22979947 PMCID: PMC3472249 DOI: 10.1186/1752-0509-6-123] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Accepted: 09/04/2012] [Indexed: 12/15/2022]
Abstract
Background Marek’s Disease (MD) is a hyperproliferative, lymphomatous, neoplastic disease of chickens caused by the oncogenic Gallid herpesvirus type 2 (GaHV-2; MDV). Like several human lymphomas the neoplastic MD lymphoma cells overexpress the CD30 antigen (CD30hi) and are in minority, while the non-neoplastic cells (CD30lo) form the majority of population. MD is a unique natural in-vivo model of human CD30hi lymphomas with both natural CD30hi lymphomagenesis and spontaneous regression. The exact mechanism of neoplastic transformation from CD30lo expressing phenotype to CD30hi expressing neoplastic phenotype is unknown. Here, using microarray, proteomics and Systems Biology modeling; we compare the global gene expression of CD30lo and CD30hi cells to identify key pathways of neoplastic transformation. We propose and test a specific mechanism of neoplastic transformation, and genetic resistance, involving the MDV oncogene Meq, host gene products of the Nuclear Factor Kappa B (NF-κB) family and CD30; we also identify a novel Meq protein interactome. Results Our results show that a) CD30lo lymphocytes are pre-neoplastic precursors and not merely reactive lymphocytes; b) multiple transformation mechanisms exist and are potentially controlled by Meq; c) Meq can drive a feed-forward cycle that induces CD30 transcription, increases CD30 signaling which activates NF-κB, and, in turn, increases Meq transcription; d) Meq transcriptional repression or activation of the CD30 promoter generally correlates with polymorphisms in the CD30 promoter distinguishing MD-lymphoma resistant and susceptible chicken genotypes e) MDV oncoprotein Meq interacts with proteins involved in physiological processes central to lymphomagenesis. Conclusions In the context of the MD lymphoma microenvironment (and potentially in other CD30hi lymphomas as well), our results show that the neoplastic transformation is a continuum and the non-neoplastic cells are actually pre-neoplastic precursor cells and not merely immune bystanders. We also show that NF-κB is a central player in MDV induced neoplastic transformation of CD30-expressing lymphocytes in vivo. Our results provide insights into molecular mechanisms of neoplastic transformation in MD specifically and also herpesvirus induced lymphoma in general.
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Affiliation(s)
- Shyamesh Kumar
- Department of Pathobiology and Population Medicine, Mississippi State University, MS 39762, USA.
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Dunn JR, Silva RF. Ability of MEQ-Deleted MDV Vaccine Candidates to Adversely Affect Lymphoid Organs and Chicken Weight Gain. Avian Dis 2012; 56:494-500. [DOI: 10.1637/10062-011812-reg.1] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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31
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Kumar P, Dong H, Lenihan D, Gaddamanugu S, Katneni U, Shaikh S, Tavlarides-Hontz P, Reddy SM, Peters W, Parcells MS. Selection of a recombinant Marek's disease virus in vivo through expression of the Marek's EcoRI-Q (Meq)-encoded oncoprotein: characterization of an rMd5-based mutant expressing the Meq of strain RB-1B. Avian Dis 2012; 56:328-40. [PMID: 22856190 DOI: 10.1637/9955-100611-reg.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Marek's disease (MD) is a highly contagious viral disease of chickens (Gallus gallus domesticus) caused by MD virus (MDV), characterized by paralysis, neurologic signs, and the rapid onset of T-cell lymphomas. MDV-induced T-cell transformation requires a basic leucine zipper protein called Marek's EcoRI-Q-encoded protein (Meq). We have identified mutations in the coding sequence of Meq that correlated with virus pathotype (virulent, very virulent, and very virulent plus). The aim of this study was to determine whether recombinant viruses could be isolated based on Meq expression through in vivo selection. Chicken embryo fibroblasts (CEFs) were cotransfected with an rMd5 strain-based Meq deletion virus (rMd5deltaMeq) and meq loci from strains representing different pathotypes of MDV. Transfected CEFs were inoculated into chickens in two independent studies. We were able to isolate a single recombinant virus, rMDV-1137, in a contact-exposed chicken. rMDV-1137 had recombined two copies of the meq gene of RB-1B and was found to have pathogenicity similar to both RB-1B and rMd5 parental strains. We found the RB-1B- and rMd5-induced lymphomas showed differences in composition and that rMDV-1137-induced lymphomas were intermediate in their composition. We were able to establish cell lines from both RB-1B- (MDCC-UD35, -UD37) and rMDV-1137 (MDCC-UD36, -UD38)-induced, but not rMd5-induced, lymphomas. To date, no rMd5- or parent Md5-transformed T-cell lines have been reported. Our results suggest that 1) a recombinant MDV can be selected on the basis of oncogenicity; 2) changes in Meq sequence seem to affect tumor composition and the ability to establish cell lines; and 3) in addition to meq, other genomic loci affect MDV pathogenicity and oncogenicity.
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Affiliation(s)
- Pankaj Kumar
- Department of Animal and Food Science, University of Delaware, Newark, DE 19716, USA
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Renz KG, Cooke J, Clarke N, Cheetham BF, Hussain Z, Fakhrul Islam AFM, Tannock GA, Walkden-Brown SW. Pathotyping of Australian isolates of Marek's disease virus and association of pathogenicity with meq gene polymorphism. Avian Pathol 2012; 41:161-76. [PMID: 22515535 DOI: 10.1080/03079457.2012.656077] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
We report the pathotyping of six Australian isolates of Marek's disease virus-1 (MDV1) isolated between 1992 and 2004 and association of virulence with meq gene polymorphism. Unvaccinated and herpesvirus of turkeys (HVT)-vaccinated specific pathogen free chickens were challenged at day 5 with 500 plaque forming units of Marek's disease virus. The isolates induced gross Marek's disease lesions in 53 to 94% of unvaccinated chickens, and HVT induced a protective index ranging from 38 to 100% by 56 days post challenge. This experiment provides evidence that current Australian isolates of MDV1 vary significantly in pathogenicity. However, there was no clear evidence that the most virulent recent isolates were more pathogenic than isolates from the 1980s or that any of the isolates belong to the highest pathotype category of very virulent plus. Evidence is presented that virulence can be predicted by measurements taken as early as 13 days post challenge. The meq gene sequences of five of the isolates used in the experiment were determined. When compared with the very virulent US isolate Md5, there was a 177 base-pair insertion and distinct point mutations in each of the five isolates. There were no individual mutations in the meq sequences that correlated with levels of virulence. However, amino acid alignment of the five Australian and 14 international isolates revealed that the number of repeat sequences of four prolines (PPPP repeats) in the meq gene (overall range 2 to 8) was strongly associated with virulence across all isolates, with the most pathogenic isolates having the fewest number of repeats. The results suggest that the presence of the 177 base-pair insertion alone is not an indicator of attenuation. Rather, the number of PPPP repeats, independent of the presence of the insertion, is a better indicator of pathogenicity.
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Affiliation(s)
- Katrin G Renz
- School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, NSW 2678, Australia.
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Engel AT, Selvaraj RK, Kamil JP, Osterrieder N, Kaufer BB. Marek's disease viral interleukin-8 promotes lymphoma formation through targeted recruitment of B cells and CD4+ CD25+ T cells. J Virol 2012; 86:8536-45. [PMID: 22647701 PMCID: PMC3421702 DOI: 10.1128/jvi.00556-12] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Accepted: 05/22/2012] [Indexed: 11/20/2022] Open
Abstract
Marek's disease virus (MDV) is a cell-associated and highly oncogenic alphaherpesvirus that infects chickens. During lytic and latent MDV infection, a CXC chemokine termed viral interleukin-8 (vIL-8) is expressed. Deletion of the entire vIL-8 open reading frame (ORF) was shown to severely impair disease progression and tumor development; however, it was unclear whether this phenotype was due to loss of secreted vIL-8 or of splice variants that fuse exons II and III of vIL-8 to certain upstream open reading frames, including the viral oncoprotein Meq. To specifically examine the role of secreted vIL-8 in MDV pathogenesis, we constructed a recombinant virus, vΔMetvIL-8, in which we deleted the native start codon from the signal peptide encoding exon I. This mutant lacked secreted vIL-8 but did not affect Meq-vIL-8 splice variants. Loss of secreted vIL-8 resulted in highly reduced disease and tumor incidence in animals infected with vΔMetvIL-8 by the intra-abdominal route. Although vΔMetvIL-8 was still able to spread to naïve animals by the natural route, infection and lymphomagenesis in contact animals were severely impaired. In vitro assays showed that purified recombinant vIL-8 efficiently binds to and induces chemotaxis of B cells, which are the main target for lytic MDV replication, and also interacts with CD4(+) CD25(+) T cells, known targets of MDV transformation. Our data provide evidence that vIL-8 attracts B and CD4(+) CD25(+) T cells to recruit targets for both lytic and latent infection.
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Affiliation(s)
| | - Ramesh K. Selvaraj
- Department of Animal Sciences, The Ohio State University, Wooster, Ohio, USA
| | - Jeremy P. Kamil
- Department of Microbiology and Immunology, Louisiana State University Health Sciences Center, Shreveport, Louisiana, USA
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Lee LF, Heidari M, Zhang H, Lupiani B, Reddy SM, Fadly A. Cell culture attenuation eliminates rMd5ΔMeq-induced bursal and thymic atrophy and renders the mutant virus as an effective and safe vaccine against Marek's disease. Vaccine 2012; 30:5151-8. [PMID: 22687760 DOI: 10.1016/j.vaccine.2012.05.043] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Revised: 05/15/2012] [Accepted: 05/17/2012] [Indexed: 10/28/2022]
Abstract
Marek's disease virus (MDV) encodes a basic leucine zipper oncoprotein, Meq, which structurally resembles jun/fos family of transcriptional activators. It has been clearly demonstrated that deletion of Meq results in loss of transformation and oncogenic capacity of MDV. The rMd5ΔMeq virus provided superior protection than CVI988/Rispens vaccine in 15×7 chickens when challenged with a very virulent plus (vv+) strain of MDV, 648A. The rMd5ΔMeq construct was also shown to be an effective vaccine in commercial chickens that were challenged under field conditions by exposure to seeder chicken inoculated with MDV strain 686, a vv+ and arguably the most pathogenic strain of MDV. Although deletion of Meq gene renders the virus non-oncogenic, it still induces lymphoid organ atrophy like that of the parental rMd5, in highly susceptible MDV maternal antibody negative (MAb-) chickens. We have generated 50 cell culture passages of attenuated rMd5ΔMeq viruses and found no significant lymphoid organ atrophy beginning at 40(th) passage onward when compared with the normal control chickens. The protective ability of these attenuated Meq null viruses against challenge with vv+ MDV strain 686 is similar to the original virus at 19(th) passage in maternal antibody negative chickens. The data indicate that attenuation of these Meq null viruses has no influence on their protective efficacy, but eliminated lymphoid organ atrophy and rendered them safe to use even in MAb- chickens, a characteristic that should facilitate commercialization and licensing by vaccine manufacturers.
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Affiliation(s)
- Lucy F Lee
- United States Department of Agriculture, Agricultural Research Service, Avian Disease and Oncology Laboratory, East Lansing, MI 48823,United States.
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Epigenetic regulation of the latency-associated region of Marek's disease virus in tumor-derived T-cell lines and primary lymphoma. J Virol 2011; 86:1683-95. [PMID: 22090140 DOI: 10.1128/jvi.06113-11] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Meq is the major Marek's disease virus (MDV)-encoded oncoprotein and is essential for T-cell lymphomagenesis. Meq and several noncoding RNAs, including three microRNA (MiR) clusters, are expressed from the repeats of the MDV genome during latent infection of T cells. To investigate the state of the chromatin in this and flanking regions, we carried out chromatin immunoprecipitation (ChIP) analysis of covalent histone modifications and associated bound proteins. T-cell lines and a lymphoma were compared. The chromatin around the promoters for Meq and the noncoding RNAs in both cell lines and the lymphoma were associated with H3K9 acetylation and H3K4 trimethylation, which are marks of transcriptionally active chromatin. These correlated with bound Meq-c-Jun heterodimers. The only binding site for Meq homodimers is located at the lytic origin of replication (OriLyt), next to the lytic gene pp38. This region lacked active marks and was associated with repressive histone modifications (H3K27 and H3K9 trimethylation). DNA CpG methylation was investigated using methylated DNA precipitation (MeDP). In cell lines, DNA methylation was abundant across the repeats but noticeably reduced or absent around the active promoters. In primary tumors, CpG methylation occurred less than 2 months after infection, focused within the ICP4 gene. These data suggest that nonrandom de novo DNA methylation occurs early in lymphomagenesis. In addition, the histone data indicate a role for Meq in the epigenetic regulation of the MDV genome repeats in transformed T cells and suggest that the OriLyt region and the Meq/MiR region might be separated by chromatin boundary elements, and preliminary data on CTCF binding are consistent with this.
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36
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Xu M, Zhang H, Lee L, Gao H, Sharif S, Silva RF, Heidari M. Gene expression profiling in rMd5- and rMd5deltameq-infected chickens. Avian Dis 2011; 55:358-67. [PMID: 22017031 DOI: 10.1637/9608-120610-reg.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Marek's disease (MD) is a lymphoproliferative disorder of domestic chickens caused by a highly contagious and oncogenic alpha-herpesvirus, Marek's disease virus (MDV). MD is characterized by bursal-thymic atrophy and rapid onset of T-cell lymphomas that infiltrate lymphoid tissues, visceral organs, and peripheral nerves with severe clinical signs that include transient paralysis, anemia, weight loss, and neurologic disorders. Using overlapping cosmids- and BAC-cloned MDV, it has been shown that MDV-encoded vIL-8, pp38, vTR, vLIP, RLORF4, and meq are among the many essential genes that play critical roles in viral pathogenesis. Of all the genes investigated so far, only meq has been shown to be consistently expressed in all MDV-derived tumors and lymphoblastoid cell lines. Meq is a basic leucine-zipper protein that shares homology with the jun/fos family of transcriptional factors. There are two copies of meq gene within the MDV genome that are only present in the serotype-1 strains. It has been shown conclusively that deletion of meq results in loss of transformation of T cells in chickens, with no effect on the early cytolytic phase of infection in lymphoid organs, which is essential for induction of innate and adaptive immunity. The goal of this study was to investigate 1) the effect of the meq oncogene on the expression pattern of select chicken immune and nonimmune-related genes, and 2) its potential role in MDV-induced apoptosis. We used real-time reverse transcriptase-polymerase chain reaction to evaluate the expression profiling of a panel of chicken genes in rMd5- and rMd5deltameq-infected chickens at 5, 14, 21, and 35 days postinfection (dpi). Although the transcriptional activities of several immune-related genes, including IL-6, IL-10, cMGF, GM-CSF, iNOS, IFNbeta, and INFgamma, were higher in rMd5deltameq-infected chickens at 5 dpi when compared to the rMd5-infected birds, the differences in expression levels of the tested genes between the two viral constructs were not significant. In addition, a reduction in the transcriptional activity of Bdcl2 in recombinant fowlpox virus (rFPV)+meq-infected chicken embryonic fibroblasts suggested that meq alone did not impede FPV-induced apoptosis. The likely suppressive nature and anti-inflammatory function of the meq oncogene and its possible role in virus-induced cell death is discussed.
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Affiliation(s)
- Ming Xu
- United States Department of Agriculture, Agriculture Research Service, Avian Disease and Oncology Laboratory, East Lansing, MI 48823, USA
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Lee LF, Zhang H, Heidari M, Lupiani B, Reddy SM. Evaluation of factors affecting vaccine efficacy of recombinant Marek's disease virus lacking the Meq oncogene in chickens. Avian Dis 2011; 55:172-9. [PMID: 21793430 DOI: 10.1637/9575-101510-reg.1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We previously reported that deletion of the Meq gene from the oncogenic rMd5 virus rendered it apathogenic for chickens. Here we examined multiple factors affecting Marek's disease vaccine efficacy of this nonpathogenic recombinant Meq null rMd5 virus (rMd5deltaMeq). These factors included host genetics (MHC haplotype), strain or dose of challenge virus, vaccine challenge intervals, and maternal antibody status of the vaccinated chicks. Studies on host genetics were carried out in five chicken lines comprising four different MHC B-haplotypes. Results showed that chicken lines tested were highly protected, with protective indexes of 100% (B*2/*15), 94% (B*2/*2), 87% (B*19/*19), and 83% (B*21/*21). At a challenge dose above 8000 plaque-forming units, differences in protection were observed between the two highly virulent strains examined (648A and 686). The interval between vaccination and challenge indicated a protective efficacy from 0 to 2 days varied greatly (12%-82%) after challenge with vv+686, the most virulent virus. Less variation and significant protection began at 3 days post vaccination and reached a maximum at 5 days post vaccination with about 80%-100% protection. Taken together, our results indicate that the factors examined in this study are important for vaccine efficacy and need to be considered in comparative evaluations of vaccines.
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Affiliation(s)
- Lucy F Lee
- United States Department of Agriculture, Agricultural Research Service, Avian Disease and Oncology Laboratory, East Lansing, MI 48823, USA.
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38
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Analysis of transcriptional activities of the Meq proteins present in highly virulent Marek's disease virus strains, RB1B and Md5. Virus Genes 2011; 43:66-71. [PMID: 21503681 DOI: 10.1007/s11262-011-0612-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2010] [Accepted: 04/05/2011] [Indexed: 10/18/2022]
Abstract
Marek's disease virus (MDV) is an oncogenic herpesvirus that causes malignant lymphomas in chickens. Recent field isolates of MDV have tended to exhibit increasing virulence, and MDV strains are currently classified into four categories based on their relative virulence. Meq, a putative MDV oncoprotein, resembles the Jun/Fos family of basic leucine zipper (bZIP) transcription factors and can regulate the expression of viral and cellular genes as a homodimer or as a heterodimer with a variety of bZIP family proteins. MDV isolates display distinct diversity and point mutations in Meq, which may contribute to changes in the transcriptional activities of Meq and subsequently, to observed increases in MDV oncogenicity. In this study, we introduced mutations into the meq gene and used dual luciferase reporter assays to analyze the transcriptional activities of the resulting Meq proteins to determine whether distinct mutations in Meq could be responsible for differences in transcriptional activity among MDV strains. A proline-to-alanine substitution at position 217, the second position of one of the proline direct repeats in the transactivation domain, enhanced the transactivation activity of Meq. In addition, we found that two substitutions at positions 283 and 320 affected transactivation activity. These results suggest that the distinct diversity of and point mutations in the Meq proteins are responsible for differences in transactivation activity among MDV strains.
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Reinke AW, Grigoryan G, Keating AE. Identification of bZIP interaction partners of viral proteins HBZ, MEQ, BZLF1, and K-bZIP using coiled-coil arrays. Biochemistry 2010; 49:1985-97. [PMID: 20102225 DOI: 10.1021/bi902065k] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Basic-region leucine-zipper transcription factors (bZIPs) contain a segment rich in basic amino acids that can bind DNA, followed by a leucine zipper that can interact with other leucine zippers to form coiled-coil homo- or heterodimers. Several viruses encode proteins containing bZIP domains, including four that encode bZIPs lacking significant homology to any human protein. We investigated the interaction specificity of these four viral bZIPs by using coiled-coil arrays to assess self-associations as well as heterointeractions with 33 representative human bZIPs. The arrays recapitulated reported viral-human interactions and also uncovered new associations. MEQ and HBZ interacted with multiple human partners and had unique interaction profiles compared to any human bZIPs, whereas K-bZIP and BZLF1 displayed homospecificity. New interactions detected included HBZ with MAFB, MAFG, ATF2, CEBPG, and CREBZF and MEQ with NFIL3. These were confirmed in solution using circular dichroism. HBZ can heteroassociate with MAFB and MAFG in the presence of MARE-site DNA, and this interaction is dependent on the basic region of HBZ. NFIL3 and MEQ have different yet overlapping DNA-binding specificities and can form a heterocomplex with DNA. Computational design considering both affinity for MEQ and specificity with respect to other undesired bZIP-type interactions was used to generate a MEQ dimerization inhibitor. This peptide, anti-MEQ, bound MEQ both stably and specifically, as assayed using coiled-coil arrays and circular dichroism in solution. Anti-MEQ also inhibited MEQ binding to DNA. These studies can guide further investigation of the function of viral and human bZIP complexes.
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Affiliation(s)
- Aaron W Reinke
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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40
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Lee LF, Kreager K, Arango J, Paraguassu A, Beckman B, Zhang H, Fadly A, Lupiani B, Reddy S. Comparative evaluation of vaccine efficacy of recombinant Marek's disease virus vaccine lacking Meq oncogene in commercial chickens. Vaccine 2010; 28:1294-9. [DOI: 10.1016/j.vaccine.2009.11.022] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Revised: 11/03/2009] [Accepted: 11/06/2009] [Indexed: 11/27/2022]
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41
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Homodimerization of the Meq viral oncoprotein is necessary for induction of T-cell lymphoma by Marek's disease virus. J Virol 2009; 83:11142-51. [PMID: 19692466 DOI: 10.1128/jvi.01393-09] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Marek's disease virus (MDV) is a lymphotropic alphaherpesvirus that induces fatal rapid-onset T-cell lymphomas in chickens, its natural host. The MDV-encoded nuclear oncoprotein Meq is essential for lymphomagenesis and acts as a regulator of transcription. Meq has structural features, including a basic domain adjacent to a leucine zipper motif (B-ZIP), that suggest it is related to the Jun/Fos family of transcription factors. Via the leucine zipper, Meq can form homodimers or heterodimerize with c-Jun. Meq/Meq homodimers are associated with transrepression, and Meq/Jun heterodimers can transactivate target genes carrying an AP-1-like binding site. In order to determine the role of the leucine zipper and of Meq dimerization in T lymphomagenesis, specific point mutations were engineered into the highly oncogenic RB-1B strain of MDV to produce virus completely lacking a functional Meq leucine zipper (RB-1B Meq(BZIP/BZIP)) or virus encoding Meq that cannot homodimerize but can still bind to c-Jun and an AP-1-like site on DNA (RB-1B Meq(Hom/Hom)). Both of these mutant viruses were capable of replication in cultured chicken embryo fibroblasts. However both mutations resulted in a complete loss of oncogenicity, since no lymphomas were produced up to 90 days postinfection in experimentally infected chicks. We conclude that the leucine zipper is necessary for the oncogenic activity of Meq and/or the efficient establishment of long-term MDV latency in T cells. Moreover, it appears that the ability to form homodimers is an absolute requirement and the ability to bind c-Jun alone is insufficient for the T-cell lymphomagenesis associated with virulent MDV.
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42
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McCarthy FM, Mahony TJ, Parcells MS, Burgess SC. Understanding animal viruses using the Gene Ontology. Trends Microbiol 2009; 17:328-35. [PMID: 19577474 DOI: 10.1016/j.tim.2009.04.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Revised: 04/27/2009] [Accepted: 04/29/2009] [Indexed: 11/18/2022]
Abstract
Understanding the effects of viral infection has typically focused on specific virus-host interactions such as tissue tropism, immune responses and histopathology. However, modeling viral pathogenesis requires information about the functions of gene products from both virus and host, and how these products interact. Recent developments in the functional annotation of genomes using Gene Ontology (GO) and in modeling functional interactions among gene products, together with an increased interest in systems biology, provide an excellent opportunity to generate global interaction models for viral infection. Here, we review how the GO is being used to model viral pathogenesis, with a focus on animal viruses.
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Affiliation(s)
- Fiona M McCarthy
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762, USA.
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43
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Ajithdoss DK, Reddy SM, Suchodolski PF, Lee LF, Kung HJ, Lupiani B. In vitro characterization of the Meq proteins of Marek's disease virus vaccine strain CVI988. Virus Res 2009; 142:57-67. [PMID: 19189855 DOI: 10.1016/j.virusres.2009.01.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2008] [Revised: 01/06/2009] [Accepted: 01/13/2009] [Indexed: 11/19/2022]
Affiliation(s)
- Dharani K Ajithdoss
- Department of Poultry Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX 77843, USA
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44
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Lee LF, Silva RF, Cui X, Zhang H, Heidari M, Reddy SM. Characterization of LORF11, a unique gene common to the three Marek's disease virus serotypes. Avian Dis 2008; 51:851-7. [PMID: 18251393 DOI: 10.1637/7956-022307-regr.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The unique open reading frame 11 (LORF11) of Marek's disease virus (MDV) is present in all three serotypes of MDV and is located in the unique long region of the MDV genome. In the serotype 1 Md5 genome, LORF11 comprises 2711 nucleotides and encodes a predicted protein of 903 amino acids. In order to study the biological function of LORF11 we deleted it from the MDV cosmid A6 by using the RecA-assisted restriction endonuclease cleavage method. The recombinant cosmid, A6DeltaLORF11, was transfected into duck embryo fibroblasts (DEF) in conjunction with parental SN5, P89, SN16, and B40 cosmid clones. Recombinant rMd5DeltaLORF11 plaques were evident at 12-13 days after transfection. Polymerase chain reaction amplification of DEF cells infected with rMd5DeltaLORF11 viruses confirmed the deletion of a 2.57-kb fragment resulting in a 296-bp fragment. Three rMd5DeltaLORF11 mutants were generated and their biological functions were studied in vitro and in vivo. In vitro growth characteristics of rMd5DeltaLORF11 viruses were similar to those of parental rMd5, indicating that LORF11 is not essential for replication in vitro. In vivo studies of rMd5DeltaLORF11 mutants showed that they were impaired in viral replication in the lymphoid organs and had 100x lower viremia than chickens infected with the parental rMd5 virus. Furthermore, rMd5-infected chickens horizontally transmitted the virus to contact controls whereas no horizontal transmission occurred in rMd5DeltaLORF11-infected chickens. Three independent deletion mutants were tested and showed the same phenotypes, so it is unlikely that the observed phenotype is because of any random mutation in the genome. Therefore the LORF11 gene of MDV is essential for normal virus replication in chickens and deletion of LORF11 renders an attenuated virus.
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Affiliation(s)
- Lucy F Lee
- U.S. Department of Agriculture, Agricultural Research Service, Avian Disease and Oncology Laboratory, East Lansing, MI 48823, USA.
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45
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Venugopal K, Payne LN. Molecular pathogenesis of Marek's disease—recent developments. Avian Pathol 2007; 24:597-609. [DOI: 10.1080/03079459508419100] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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46
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Okada T, Takagi M, Murata S, Onuma M, Ohashi K. Identification and characterization of a novel spliced form of the meq transcript in lymphoblastoid cell lines derived from Marek's disease tumours. J Gen Virol 2007; 88:2111-2120. [PMID: 17622612 DOI: 10.1099/vir.0.82744-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In tumour cell lines established from Marek's disease (MD) lymphomas L-meq is consistently expressed. It contains a 180 bp insertion encoding additional copies of the proline-rich repeat in the meq open reading frame and its product may contribute to the maintenance of MD virus (MDV) latency. In this study, we identified a novel spliced form of the meq transcript in MD-derived lymphoblastoid cell lines and in MDV-infected cells. This transcript, termed Deltameq, encodes an N-terminal 98 aa of the Meq protein and lacks part of the basic leucine zipper (bZIP) and transactivation domains. In MD cell lines, transcription of L-meq was significantly downregulated, while that of the Deltameq transcript was upregulated during apoptosis. These observations were also confirmed at the protein expression level. Reporter assays using meq- and interleukin-2 (IL-2)-promoter-driven luciferase vectors revealed that DeltaMeq suppressed transactivation by L-Meq or Meq in a dose-dependent manner. Immunoprecipitation confirmed that DeltaMeq was associated with L-Meq or Meq physically. These results suggest that DeltaMeq could be involved in apoptosis in MD cell lines as it works as a negative regulator of L-Meq and Meq by direct interaction.
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Affiliation(s)
- Tsukasa Okada
- Department of Microbiology and Immunology, Faculty of Agriculture, Kobe University, 1-1, Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
- Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Kita-18, Nishi-9, Kita-ku, Sapporo 060-0818, Japan
| | - Michihiro Takagi
- Department of Microbiology and Immunology, Faculty of Agriculture, Kobe University, 1-1, Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
| | - Shiro Murata
- Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Kita-18, Nishi-9, Kita-ku, Sapporo 060-0818, Japan
| | - Misao Onuma
- Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Kita-18, Nishi-9, Kita-ku, Sapporo 060-0818, Japan
| | - Kazuhiko Ohashi
- Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Kita-18, Nishi-9, Kita-ku, Sapporo 060-0818, Japan
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47
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Kang JW, Cho SH, Mo IP, Lee DW, Kwon HJ. Prevalence and molecular characterization of meq in feather follicular epithelial cells of Korean broiler chickens. Virus Genes 2007; 35:339-45. [PMID: 17516161 DOI: 10.1007/s11262-007-0104-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2007] [Accepted: 04/12/2007] [Indexed: 11/29/2022]
Abstract
Marek's disease (MD) is a highly contagious lymphoproliferative disease of chickens. Meq is the relevant oncogene and four isoforms, long (L)-meq, meq, short (S)-meq and very short (VS)-meq, have been identified. Although MD is important in the poultry industry, the prevalence and molecular properties of Korean MD virus (MDV) among broiler chickens remain unclear. Therefore, we characterized meq in pooled feather tips sampled at 3- and 5-week-old chickens from 21 unvaccinated and 22 vaccinated broiler farms via nested-PCR and nucleotide sequence analysis. Multiple bands consisting of L-meq, meq, and S-meq amplicons were observed in a commercial vaccine (CVI988 + HVT), 1 (4.8%) and 5 samples (22.7%) from unvaccinated and vaccinated farms, respectively. A strong meq amplicon was observed in a MD-related tumor tissue, 6 (28.6%) and 1 (4.5%) samples from unvaccinated and vaccinated farms, respectively. Six and one amplicons from unvaccinated (28.6%) and vaccinated farms (4.5%), respectively, were differentiated from CVI988 by nucleotide sequence analysis. Therefore, the relatively high rate of meq in the unvaccinated broiler farms constitutes support for vaccination. However, the existence of CVI988-related meq in unvaccinated chickens necessitates further study regarding the origins and pathoimmunological effects of the viruses on chickens.
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Affiliation(s)
- Jung-Won Kang
- Department of Microbiology, Seoul National University, Seoul 151-742, Korea
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48
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Jarosinski KW, Tischer BK, Trapp S, Osterrieder N. Marek's disease virus: lytic replication, oncogenesis and control. Expert Rev Vaccines 2007; 5:761-72. [PMID: 17184215 DOI: 10.1586/14760584.5.6.761] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Marek's disease (MD) is caused by a ubiquitous, lymphotropic alphaherpesvirus, MD virus (MDV). MD has been a major concern in the poultry industry owing to the emergence of increasingly virulent strains over the last few decades that were isolated in the face of comprehensive vaccination. The disease is characterized by a variety of clinical signs; among them are neurological symptoms, chronic wasting and, most notably, the development of multiple lymphomas that manifest as solid tumors in the viscera and musculature. Much work has been devoted to study MD-induced oncogenesis and the genes involved in this process. Among the many genes encoded by MDV, a number have been shown recently to affect the development of tumors in chickens, one protein directly causing transformation of cells (Meq) and another being involved in maintaining transformed cells (vTR). Other MDV gene products modulate and are involved in early lytic in vivo replication, thereby increasing the chance of transformation occurring. In this review, we will summarize specific genes encoded by MDV that are involved in the initiation and/or maintenance of transformation and will focus mostly on current vaccination and control strategies against MD, particularly how modern molecular biological methods may be used to improve strategies to combat the disease in the future.
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Affiliation(s)
- Keith W Jarosinski
- Cornell University, Department of Microbiology and Immunology, College of Veterinary Medicine, Ithaca, NY 14853, USA.
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49
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Osterrieder N, Kamil JP, Schumacher D, Tischer BK, Trapp S. Marek's disease virus: from miasma to model. Nat Rev Microbiol 2006; 4:283-94. [PMID: 16541136 DOI: 10.1038/nrmicro1382] [Citation(s) in RCA: 302] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Marek's disease virus (MDV) is an oncogenic herpesvirus that causes various clinical syndromes in its natural host, the chicken. MDV has long been of interest as a model organism, particularly with respect to the pathogenesis and immune control of virus-induced lymphoma in an easily accessible small-animal system. Recent advances in MDV genetics and the determination of the chicken genome sequence, aided by functional genomics, have begun to dramatically increase our understanding not only of lytic MDV replication, but also of the factors and mechanisms leading to latency and tumour formation. This new information is helping to elucidate cellular signalling pathways that have undergone convergent evolution and are perturbed by different viruses, and emphasizes the value of MDV as a comparative biomedical model. Furthermore, the door is now open for rational and efficient engineering of new vaccines against one of the most important and widespread infectious diseases in chickens.
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Affiliation(s)
- Nikolaus Osterrieder
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA.
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50
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Anobile JM, Arumugaswami V, Downs D, Czymmek K, Parcells M, Schmidt CJ. Nuclear localization and dynamic properties of the Marek's disease virus oncogene products Meq and Meq/vIL8. J Virol 2006; 80:1160-6. [PMID: 16414993 PMCID: PMC1346918 DOI: 10.1128/jvi.80.3.1160-1166.2006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Marek's disease virus (MDV) is an avian herpesvirus that causes T-cell lymphomas and immune suppression in susceptible chickens. At least one gene product, MDV Eco Q-encoded protein (Meq), is essential for the oncogenicity of MDV. Alternative splicing permits the meq gene to give rise to two major transcripts encoding proteins designated Meq and Meq/vIL8. Meq is a basic leucine zipper protein capable of modulating transcription. The Meq/vIL8 protein retains a modified leucine zipper, along with the mature receptor-binding portion of vIL8, but lacks the domain of Meq responsible for transcriptional modulation. In this report, we describe studies using fusions between either Meq or Meq/vIL8 and fluorescent proteins to characterize the distribution and properties of these products in chicken embryo fibroblasts (CEFs). Meq and Meq/vIL8 both localized to the nucleoplasm, nucleoli, and Cajal bodies of transfected cells. Similar distributions were found for fluorescent fusion proteins and native Meq or Meq/vIL8. Fluorescence recovery after photobleaching and photoactivatable green fluorescent protein revealed that Meq exhibited mobility properties similar to those of other transcription factors, while Meq/vIL8 was far less mobile. In addition, fluorescence resonance energy transfer studies indicated the formation of Meq/vIL8 homodimers in CEFs. Time lapse studies revealed the coordinated elimination of a portion of Meq and Meq/vIL8 from the nucleus. Our data provide new insight regarding the dynamic cellular properties of two forms of a herpesvirus-encoded oncoprotein and suggest that these forms may have fundamentally different functions in MDV-infected cells.
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Affiliation(s)
- Jonathan M Anobile
- Department of Animal and Food Sciences, University of Delaware, Newark, DE 19717, USA
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