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Emad A, El-Kenawy AA, El-Tholoth M. Molecular characterization of Marek's Disease virus reveals reticuloendotheliosis virus-long terminal repeat integration in the genome of the field isolates in Egypt. Poult Sci 2024; 103:103722. [PMID: 38626691 PMCID: PMC11036097 DOI: 10.1016/j.psj.2024.103722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 03/02/2024] [Accepted: 03/31/2024] [Indexed: 04/18/2024] Open
Abstract
The highly contagious, immunosuppressive, and cancer-causing Marek's disease virus (MDV) infects chickens. The financial costs of Marek's disease (MD) are significant for the chicken industry. In this study, a total of 180 samples from chicken farms suspected to be MDV-infected were collected. The chickens were sampled during the period between the months of October 2016 and February 2018 at Dakahlia and Damietta Governorates, Egypt. A total of 36 pooled samples were created. The prepared samples were inoculated into embryonated chicken eggs (ECEs). Indirect fluorescent antibody technique (IFAT) and ICP4 gene-based polymerase chain reaction (PCR) were used for MDV identification. For the genetic characterization of the identified virus, The ICP4 gene sequence was identified and compared with the sequences available from various regions of the world. Furthermore, the genomes of all detected MDVs were screened for the long terminal repeat (LTR) region of reticuloendotheliosis (REV) in their genomes. The results showed that 31 out of 36 pooled samples (86.1%) inoculated into ECEs displayed the characteristic pock lesions. By using IFAT and PCR to identify MDV in ECEs, positive results were found in 27 samples (75%). The Egyptian virus is thought to be genetically closely related to MDVs circulating in Ethiopia, China, and India. REV-LTR was amplified from 6 out of 27 field isolates genomes (22.2 %) while MDV vaccine strains were free from REV-LTR insertion. The integrated REV-LTRs depicted a close genetic relationship with those integrated in fowl poxvirus (FWPV) circulating in Egypt as well as those integrated in FWPVs and MDVs from China, USA, South Africa, and Australia. To the best of our knowledge, this investigation represents the first identification and characterization of REV-LTR insertions in Egyptian MDV field isolates. Given the findings above, additional research in the future seems crucial to determine how the REV-LTR insertions affect MDV pathogenesis, virulence, and insufficient vaccination protection.
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Affiliation(s)
- Aya Emad
- Department of Virology, Faculty of Veterinary Medicine, Mansoura University, Mansoura 35516, Egypt
| | - Ali A. El-Kenawy
- Department of Virology, Faculty of Veterinary Medicine, Mansoura University, Mansoura 35516, Egypt
| | - Mohamed El-Tholoth
- Department of Virology, Faculty of Veterinary Medicine, Mansoura University, Mansoura 35516, Egypt
- Veterinary Science Program, Faculty of Health Sciences, Al Ain Men's Campus, Higher Colleges of Technology, 17155, UAE
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Zhang F, Luo Y, Wei Q, Xiong L, Xie Q, Tan J, Wu C, Li N, Kang Z. Research Note: Pathogenetic characteristics of avian encephalomyelitis virus in Guangdong and Jiangxi Provinces, China. Poult Sci 2024; 103:103264. [PMID: 38035474 PMCID: PMC10697995 DOI: 10.1016/j.psj.2023.103264] [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: 08/19/2023] [Revised: 10/21/2023] [Accepted: 11/02/2023] [Indexed: 12/02/2023] Open
Abstract
In recent years, the infection rate of avian encephalomyelitis virus (AEV) infection in chickens has risen significantly, seriously endangering the development of the chicken industry. In order to study the current epidemiological status of AEV in China as well as the genetic and evolutionary patterns of the virus, we conducted a survey and genomic analysis of chicken AEV. The results showed that 46.26% (136/294) of the tissue samples tested (n = 294) were positive for AEV, with the highest positivity rate of 62.24% (61/98) among tissue samples from chickens aged 13 to 18 wk. The complete genomes of 2 representative AEV strains were determined, and the VP1 evolutionary tree results revealed that the 2 representative strains belonged to a novel AEV strain. Multiple alignment analysis showed that the ORF1 genes of the 2 representative strains differed by 82.3 to 99.9% at the amino acid level compared with the reference AEV strain, and the mutations at the key amino acid loci of VP2 and VP3 were the same as those in the chick embryo-adapted strain. The analysis makes up for the molecular epidemiological data and genetic variation of the 2 representative strains. The analysis makes up for the molecular epidemiological data and genetic variation of AEV and provides a basis for further understanding the spread of AEV in China.
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Affiliation(s)
- Fanfan Zhang
- Institute of Animal Husbandry and Veterinary Medicine, Jiangxi Academy of Agricultural Sciences, Nanchang, Jiangxi 330200, China
| | - Yangyang Luo
- Wen's Foodstuff Group Co.,Ltd., Wen's Group Research Institute, YunFu, Guangdong 527400, China
| | - Qipeng Wei
- Institute of Animal Husbandry and Veterinary Medicine, Jiangxi Academy of Agricultural Sciences, Nanchang, Jiangxi 330200, China
| | - Ligen Xiong
- Institute of Animal Husbandry and Veterinary Medicine, Jiangxi Academy of Agricultural Sciences, Nanchang, Jiangxi 330200, China
| | - Quan Xie
- Key Laboratory of Jiangsu Preventive Veterinary Medicine, Key Laboratory for Avian Preventive Medicine, Ministry of Education, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, China
| | - Jia Tan
- Institute of Animal Husbandry and Veterinary Medicine, Jiangxi Academy of Agricultural Sciences, Nanchang, Jiangxi 330200, China
| | - Chengcheng Wu
- Institute of Animal Husbandry and Veterinary Medicine, Jiangxi Academy of Agricultural Sciences, Nanchang, Jiangxi 330200, China
| | - Na Li
- Institute of Animal Husbandry and Veterinary Medicine, Jiangxi Academy of Agricultural Sciences, Nanchang, Jiangxi 330200, China
| | - Zhaofeng Kang
- Institute of Animal Husbandry and Veterinary Medicine, Jiangxi Academy of Agricultural Sciences, Nanchang, Jiangxi 330200, China.
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Li W, Meng H, Liang X, Peng J, Irwin DM, Shen X, Shen Y. The genome evolution of Marek's disease viruses in chickens and turkeys in China. Virus Genes 2023; 59:845-851. [PMID: 37851282 DOI: 10.1007/s11262-023-02034-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 09/25/2023] [Indexed: 10/19/2023]
Abstract
The virus that causes Marek's disease (MD) is globally ubiquitous in chickens, continuously evolving, and poses a significant threat to the poultry industry. Although vaccines are extensively used, MD still occurs frequently and the virus has evolved increased virulence in China. Here, we report an outbreak of MD in vaccinated chickens and unvaccinated turkeys in a backyard farm in Guangdong province, China, in 2018. Phylogenetic analysis revealed two lineages of MDVs at this farm, with one lineage, containing isolates from two turkeys and five chickens, clustering with virulent Chinese strains and displays a relatively high genetic divergence from the vaccine strains. These new isolates appear to have broken through vaccine immunity, yielding this outbreak of MD in chickens and turkeys. The second lineage included four chicken isolates that clustered with the CVI988 and 814 vaccine strains. The large diversity of MDVs in this single outbreak reveals a complex circulation of MDVs in China. Poor breeding conditions and the weak application of disease prevention and control measures make backyard farms a hotbed for the evolution of viruses that cause infectious diseases. This is especially important in MDV as the MD vaccines do not provide sterilizing immunity, which allows the replication and shedding of virulent field viruses by vaccinated individuals and supporting the continuous evolution of MDVs. Hence, constant monitoring of the evolution of MDVs is necessary to understand the evolution of these field viruses and potential expansions of their host range.
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Affiliation(s)
- Wen Li
- Guangdong Laboratory for Lingnan Modern Agriculture, State Key Laboratory for Animal Disease Control and Prevention, Center for Emerging and Zoonotic Diseases, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, People's Republic of China
| | - Huifang Meng
- Guangdong Laboratory for Lingnan Modern Agriculture, State Key Laboratory for Animal Disease Control and Prevention, Center for Emerging and Zoonotic Diseases, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, People's Republic of China
| | - Xianghui Liang
- Guangdong Laboratory for Lingnan Modern Agriculture, State Key Laboratory for Animal Disease Control and Prevention, Center for Emerging and Zoonotic Diseases, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, People's Republic of China
| | - Jinyu Peng
- Guangdong Laboratory for Lingnan Modern Agriculture, State Key Laboratory for Animal Disease Control and Prevention, Center for Emerging and Zoonotic Diseases, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, People's Republic of China
| | - David M Irwin
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, M5S 1A8, Canada
- Banting and Best Diabetes Centre, University of Toronto, Toronto, M5S 1A8, Canada
| | - Xuejuan Shen
- Guangdong Laboratory for Lingnan Modern Agriculture, State Key Laboratory for Animal Disease Control and Prevention, Center for Emerging and Zoonotic Diseases, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, People's Republic of China
| | - Yongyi Shen
- Guangdong Laboratory for Lingnan Modern Agriculture, State Key Laboratory for Animal Disease Control and Prevention, Center for Emerging and Zoonotic Diseases, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, People's Republic of China.
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, 510642, People's Republic of China.
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Wang Q, Shi B, Yang G, Zhu X, Shao H, Qian K, Ye J, Qin A. Metabolomic profiling of Marek's disease virus infection in host cell based on untargeted LC-MS. Front Microbiol 2023; 14:1270762. [PMID: 38029131 PMCID: PMC10666056 DOI: 10.3389/fmicb.2023.1270762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 10/26/2023] [Indexed: 12/01/2023] Open
Abstract
Marek's disease (MD) caused by Marek's disease virus (MDV), poses a serious threat to the poultry industry by inducing neurological disease and malignant lymphoma in infected chickens. However, the underlying mechanisms how MDV disrupts host cells and causes damage still remain elusive. Recently, the application of metabolomics has shown great potential for uncovering the complex mechanisms during virus-host interactions. In this study, chicken embryo fibroblasts (CEFs) infected with MDV were subjected to ultrahigh-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UHPLC-QTOF-MS) and multivariate statistical analysis. The results showed that 261 metabolites were significantly altered upon MDV infection, with most changes occurring in amino acid metabolism, energy metabolism, nucleotide metabolism, and lipid metabolism. Notably, MDV infection induces an up-regulation of amino acids in host cells during the early stages of infection to provide the energy and intermediary metabolites necessary for efficient multiplication of its own replication. Taken together, these data not only hold promise in identifying the biochemical molecules utilized by MDV replication in host cells, but also provides a new insight into understanding MDV-host interactions.
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Affiliation(s)
- Qingsen Wang
- The International Joint Laboratory for Cooperation in Agriculture and Agricultural Product Safety, Ministry of Education, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu, China
- Jiangsu Key Laboratory of Zoonosis, Yangzhou, Jiangsu, China
| | - Bin Shi
- The International Joint Laboratory for Cooperation in Agriculture and Agricultural Product Safety, Ministry of Education, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu, China
- Jiangsu Key Laboratory of Zoonosis, Yangzhou, Jiangsu, China
| | - Guifu Yang
- The International Joint Laboratory for Cooperation in Agriculture and Agricultural Product Safety, Ministry of Education, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu, China
- Jiangsu Key Laboratory of Zoonosis, Yangzhou, Jiangsu, China
| | - Xueying Zhu
- The International Joint Laboratory for Cooperation in Agriculture and Agricultural Product Safety, Ministry of Education, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu, China
- Jiangsu Key Laboratory of Zoonosis, Yangzhou, Jiangsu, China
| | - Hongxia Shao
- The International Joint Laboratory for Cooperation in Agriculture and Agricultural Product Safety, Ministry of Education, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu, China
- Jiangsu Key Laboratory of Zoonosis, Yangzhou, Jiangsu, China
| | - Kun Qian
- The International Joint Laboratory for Cooperation in Agriculture and Agricultural Product Safety, Ministry of Education, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu, China
- Jiangsu Key Laboratory of Zoonosis, Yangzhou, Jiangsu, China
| | - Jianqiang Ye
- The International Joint Laboratory for Cooperation in Agriculture and Agricultural Product Safety, Ministry of Education, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu, China
- Jiangsu Key Laboratory of Zoonosis, Yangzhou, Jiangsu, China
| | - Aijian Qin
- The International Joint Laboratory for Cooperation in Agriculture and Agricultural Product Safety, Ministry of Education, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu, China
- Jiangsu Key Laboratory of Zoonosis, Yangzhou, Jiangsu, China
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Liu JL, Teng M, Zheng LP, Zhu FX, Ma SX, Li LY, Zhang ZH, Chai SJ, Yao Y, Luo J. Emerging Hypervirulent Marek's Disease Virus Variants Significantly Overcome Protection Conferred by Commercial Vaccines. Viruses 2023; 15:1434. [PMID: 37515122 PMCID: PMC10385823 DOI: 10.3390/v15071434] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 06/20/2023] [Accepted: 06/23/2023] [Indexed: 07/30/2023] Open
Abstract
As one of the most important avian immunosuppressive and neoplastic diseases, Marek's disease (MD), caused by oncogenic Marek's disease virus (MDV), has caused huge economic losses worldwide over the past five decades. In recent years, MD outbreaks have occurred frequently in MD-vaccinated chicken flocks, but the key pathogenic determinants and influencing factors remain unclear. Herein, we analyzed the pathogenicity of seven newly isolated MDV strains from tumor-bearing chickens in China and found that all of them were pathogenic to chicken hosts, among which four MDV isolates, SDCW01, HNXZ05, HNSQ05 and HNSQ01, were considered to be hypervirulent MDV (HV-MDV) strains. At 73 days of the virus infection experiment, the cumulative incidences of MD were 100%, 93.3%, 90% and 100%, with mortalities of 83.3%, 73.3%, 60% and 86.7%, respectively, for the four viruses. The gross occurrences of tumors were 50%, 33.3%, 30% and 63.3%, respectively, accompanied by significant hepatosplenomegaly and serious atrophy of the immune organs. Furthermore, the immune protection effects of four commercial MD vaccines against SDCW01, CVI988, HVT, CVI988+HVT, and 814 were explored. Unexpectedly, during the 67 days of post-virus challenge, the protection indices (PIs) of these four MD vaccines were only 46.2%, 38.5%, 50%, and 28%, respectively, and the birds that received the monovalent CVI988 or HVT still developed tumors with cumulative incidences of 7.7% and 11.5%, respectively. To our knowledge, this is the first demonstration of the simultaneous comparison of the immune protection efficacy of multiple commercial MD vaccines with different vaccine strains. Our study revealed that the HV-MDV variants circulating in China could significantly break through the immune protection of the classical MD vaccines currently widely used. For future work, there is an urgent need to develop novel, more effective MD vaccines for tackling the new challenge of emerging HV-MDV strains or variants for the sustainable control of MD.
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Affiliation(s)
- Jin-Ling Liu
- Key Laboratory of Animal Immunology, Ministry of Agriculture and Rural Affairs of China & Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China
- UK-China Centre of Excellence for Research on Avian Diseases, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China
| | - Man Teng
- Key Laboratory of Animal Immunology, Ministry of Agriculture and Rural Affairs of China & Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China
- UK-China Centre of Excellence for Research on Avian Diseases, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China
| | - Lu-Ping Zheng
- Key Laboratory of Animal Immunology, Ministry of Agriculture and Rural Affairs of China & Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China
- UK-China Centre of Excellence for Research on Avian Diseases, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China
| | - Feng-Xia Zhu
- Zhumadian Center for Animal Disease Control and Prevention, Zhumadian 463000, China
| | - Shu-Xue Ma
- Suiping Center for Animal Disease Control and Prevention, Zhumadian 463100, China
| | - Lin-Yan Li
- Key Laboratory of Animal Immunology, Ministry of Agriculture and Rural Affairs of China & Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China
- UK-China Centre of Excellence for Research on Avian Diseases, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471003, China
| | - Zhi-Hui Zhang
- Key Laboratory of Animal Immunology, Ministry of Agriculture and Rural Affairs of China & Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China
- UK-China Centre of Excellence for Research on Avian Diseases, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China
| | - Shu-Jun Chai
- Key Laboratory of Animal Immunology, Ministry of Agriculture and Rural Affairs of China & Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China
- UK-China Centre of Excellence for Research on Avian Diseases, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China
| | - Yongxiu Yao
- The Pirbright Institute & UK-China Centre of Excellence for Research on Avian Diseases, Pirbright, Ash Road, Guildford GU24 0NF, Surrey, UK
| | - Jun Luo
- Key Laboratory of Animal Immunology, Ministry of Agriculture and Rural Affairs of China & Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China
- UK-China Centre of Excellence for Research on Avian Diseases, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471003, China
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Current Epidemiology and Co-Infections of Avian Immunosuppressive and Neoplastic Diseases in Chicken Flocks in Central China. Viruses 2022; 14:v14122599. [PMID: 36560601 PMCID: PMC9784009 DOI: 10.3390/v14122599] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/19/2022] [Accepted: 11/20/2022] [Indexed: 11/25/2022] Open
Abstract
The avian immunosuppressive and neoplastic diseases caused by Marek's disease virus (MDV), avian leucosis virus (ALV), and reticuloendotheliosis virus (REV) are seriously harmful to the global poultry industry. In recent years, particularly in 2020-2022, outbreaks of such diseases in chicken flocks frequently occurred in China. Herein, we collected live diseased birds from 30 poultry farms, out of 42 farms with tumour-bearing chicken flocks distributed in central China, to investigate the current epidemiology and co-infections of these viruses. The results showed that in individual diseased birds, the positive infection rates of MDV, ALV, and REV were 69.5% (203/292), 14.4% (42/292), and 4.7% (13/277), respectively, while for the flocks, the positive infection rates were 96.7% (29/30), 36.7% (11/30), and 20% (6/30), respectively. For chicken flocks, monoinfection of MDV, ALV, or REV was 53.3% (16/30), 3.3% (1/30), and 0% (0/30), respectively, but a total of 43.3% (13/30) co-infections was observed, which includes 23.3% (7/30) of MDV+ALV, 10.0% (3/30) of MDV+REV, and 10.0% (3/30) of MDV+ALV+REV co-infections. Interestingly, no ALV+REV co-infection or REV monoinfection was observed in the selected poultry farms. Our data indicate that the prevalence of virulent MDV strains, partially accompanied with ALV and/or REV co-infections, is the main reason for current outbreaks of avian neoplastic diseases in central China, providing an important reference for the future control of disease.
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Kurokawa A, Yamamoto Y. Development of monoclonal antibodies specific to Marek disease virus- EcoRI-Q (Meq) for the immunohistochemical diagnosis of Marek disease using formalin-fixed, paraffin-embedded samples. J Vet Diagn Invest 2022; 34:458-464. [PMID: 35260010 PMCID: PMC9254047 DOI: 10.1177/10406387221080444] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Marek disease (MD) is a viral disease characterized by the development of lymphoma in poultry. Although morphologic confirmation of lymphoma is used to diagnose MD, immunohistochemical detection of MD virus-EcoRI-Q (Meq), which is a viral protein that is expressed exclusively in MD tumor cells, would further improve the accuracy of diagnosis. We developed monoclonal antibodies (mAbs) that specifically detect Meq by immunohistochemistry (IHC) using formalin-fixed, paraffin-embedded (FFPE) sections. We evaluated the sensitivity and specificity of 14 mAbs that we produced, using FFPE samples of MDCC-MSB1 cells, MD tumor tissues, and tissues of uninfected chickens. Four different antigen retrieval conditions were investigated. Thirteen mAbs reacted with Meq in FFPE sections, but immunohistochemical reactivity and specificity varied depending on the mAb and antigen retrieval condition; heat-induced antigen retrieval (HIAR) was more effective at detecting Meq than the other tested conditions. HIAR pH 9 tended to increase immunoreactivity and decrease specificity. Of the 5 mAbs that immunoreacted strongly with Meq without nonspecific reactions under the optimal antigen retrieval conditions, 3 mAbs (1C1-121, 3A3-112, 5F7-82) did not produce background staining of tumor or non-tumor tissues; 2 mAbs (2C5-11, 4A5-54) produced background staining. The mAb 6B5-128 reacted moderately with Meq without nonspecific reactions and background staining. The remaining mAbs showed weak immunoreactivity or problematic nonspecific reactions. Our results suggest that some of our developed mAbs can be used in IHC to detect Meq in FFPE sections with high specificity, and that the use of IHC may greatly improve the diagnosis of MD.
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Affiliation(s)
- Aoi Kurokawa
- National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan
| | - Yu Yamamoto
- National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan
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Song B, Zeb J, Hussain S, Aziz MU, Circella E, Casalino G, Camarda A, Yang G, Buchon N, Sparagano O. A Review on the Marek's Disease Outbreak and Its Virulence-Related meq Genovariation in Asia between 2011 and 2021. Animals (Basel) 2022; 12:ani12050540. [PMID: 35268107 PMCID: PMC8908813 DOI: 10.3390/ani12050540] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Revised: 02/17/2022] [Accepted: 02/18/2022] [Indexed: 02/01/2023] Open
Abstract
Simple Summary Marek’s disease is continuously causing an economic loss in Asia, despite the wide use of vaccines in the last decade. This review aims at summarizing the outbreak, the virulence-related meq gene variation, and the pathological information of Marek’s disease in the last decade in Asia. We found that a total of 132 viral strains emerged in 12 countries with different meq sequences. Among the evidence we have collected, 12 strains found in China were vaccine-resistant, reaching a mortality rate of 30% and above. This evidence requires the related region in China to consider the renewal of its vaccination type; however, more studies regarding the vaccination efficiency in other Asian countries are recommended, as the current information is not enough. The visceral tumor is the most common pathological type (13 in 16 studies) in Asia, while it is possible that a neural type may exist. We suggest that farmers monitor the behavioral changes of chickens to identify this harmful disease at the early stage. The phylogenetic analysis shows interconnection between Middle Eastern, South Asian, and East Asian countries that are geologically connected—poultry trading managers should consider the potential of viral transmitting. Abstract Marek’s disease is an infectious disease in poultry that usually appears in neural and visceral tumors. This disease is caused by Gallid alphaherpesvirus 2 infection in lymphocytes, and its meq gene is commonly used in virulent studies for coding the key protein functional in oncogenic transformation of the lymphocytes. Although vaccines have been introduced in many countries to control its spread and are proven to be efficient, recent records show a decline of such efficiency due to viral evolution. In this study, we reviewed the outbreak of Marek’s disease in Asia for the last 10 years, together with associated meq sequences, finding a total of 36 studies recording outbreaks with 132 viral strains in 12 countries. The visceral type is the most common (13 in 16 studies) form of Marek’s disease, but additional unobserved neural changes may exist. MD induces liver lymphoma most frequently (11 in 14 studies), and tumors were also found in spleen, kidney, heart, gizzard, skin, intestine, lung, and sciatic nerve. Twelve viral strains distributed in China have been reported to escape the CVI988 vaccine, reaching a mortality rate of more than 30%. Phylogenetic analyses show the internal connection between the Middle East (Turkey, Iraq, Iran, Saudi Arabia), South Asia (India, Indonesia), and East Asia (China and Japan), while external viral communications might occasionally occur. In 18 strains with both sequential and mortality data, amino acid alignment showed several point substitutions that may be related to its virulence. We suggest more behavioral monitoring in Marek’s disease-endemic regions and further studies on strain virulence, together with its Meq protein structural changes.
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Affiliation(s)
- Baolin Song
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong 999077, China; (B.S.); (J.Z.); (S.H.); (M.U.A.); (G.Y.)
| | - Jehan Zeb
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong 999077, China; (B.S.); (J.Z.); (S.H.); (M.U.A.); (G.Y.)
| | - Sabir Hussain
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong 999077, China; (B.S.); (J.Z.); (S.H.); (M.U.A.); (G.Y.)
| | - Muhammad Umair Aziz
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong 999077, China; (B.S.); (J.Z.); (S.H.); (M.U.A.); (G.Y.)
| | - Elena Circella
- Department of Veterinary Medicine, University of Bari, S.P. Casamassima km. 3, 70010 Valenzano, Italy; (E.C.); (G.C.); (A.C.)
| | - Gaia Casalino
- Department of Veterinary Medicine, University of Bari, S.P. Casamassima km. 3, 70010 Valenzano, Italy; (E.C.); (G.C.); (A.C.)
| | - Antonio Camarda
- Department of Veterinary Medicine, University of Bari, S.P. Casamassima km. 3, 70010 Valenzano, Italy; (E.C.); (G.C.); (A.C.)
| | - Guan Yang
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong 999077, China; (B.S.); (J.Z.); (S.H.); (M.U.A.); (G.Y.)
| | - Nicolas Buchon
- Department of Entomology, Cornell Institute of Host-Microbe Interactions and Disease, Cornell University, Ithaca, NY 14853, USA;
| | - Olivier Sparagano
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong 999077, China; (B.S.); (J.Z.); (S.H.); (M.U.A.); (G.Y.)
- Correspondence:
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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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10
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He H, Qiao D, Zhang L, Yao Y, Shao H, Qin A, Qian K. Antiviral Effect of Lithium Chloride on Replication of Marek's Disease Virus in Chicken Embryonic Fibroblasts. Int J Mol Sci 2021; 22:12375. [PMID: 34830257 PMCID: PMC8623539 DOI: 10.3390/ijms222212375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Revised: 11/09/2021] [Accepted: 11/15/2021] [Indexed: 11/16/2022] Open
Abstract
To investigate the antiviral effect of lithium chloride (LiCl) on the replication of Marek's disease virus (MDV) in chicken embryonic fibroblast (CEF) cells, real-time PCR, Western blotting, plaque counting, and indirect immunofluorescence experiments were performed at different time points of LiCl treated CEF cells with virus infection. The results demonstrated that LiCl could affect multiple steps of virus replication and inhibit viral gene expression and protein synthesis in a dose- and time-dependent manner. Moreover, LiCl could directly affect viral infectivity as well. In addition, LiCl significantly affected the gene expression of IFN-β related genes in virus-infected cells. These results indicate that LiCl significantly inhibits MDV replication and proliferation in CEF cells and it has the potential to be used as an antiviral agent against MDV.
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Affiliation(s)
- Huifeng He
- Ministry of Education Key Lab for Avian Preventive Medicine, Yangzhou University, No. 48 East Wenhui Road, Yangzhou 225009, China; (H.H.); (L.Z.); (H.S.); (A.Q.)
- Jiangsu Key Lab of Preventive Veterinary Medicine, Yangzhou University, No. 48 East Wenhui Road, Yangzhou 225009, China;
| | - Dandan Qiao
- Jiangsu Key Lab of Preventive Veterinary Medicine, Yangzhou University, No. 48 East Wenhui Road, Yangzhou 225009, China;
| | - Lu Zhang
- Ministry of Education Key Lab for Avian Preventive Medicine, Yangzhou University, No. 48 East Wenhui Road, Yangzhou 225009, China; (H.H.); (L.Z.); (H.S.); (A.Q.)
- Jiangsu Key Lab of Preventive Veterinary Medicine, Yangzhou University, No. 48 East Wenhui Road, Yangzhou 225009, China;
| | - Yongxiu Yao
- The Pirbright Institute & UK-China Centre of Excellence for Research on Avian Diseases, Pirbright, Surrey GU24 0NF, UK;
| | - Hongxia Shao
- Ministry of Education Key Lab for Avian Preventive Medicine, Yangzhou University, No. 48 East Wenhui Road, Yangzhou 225009, China; (H.H.); (L.Z.); (H.S.); (A.Q.)
- Jiangsu Key Lab of Preventive Veterinary Medicine, Yangzhou University, No. 48 East Wenhui Road, Yangzhou 225009, China;
| | - Aijian Qin
- Ministry of Education Key Lab for Avian Preventive Medicine, Yangzhou University, No. 48 East Wenhui Road, Yangzhou 225009, China; (H.H.); (L.Z.); (H.S.); (A.Q.)
- Jiangsu Key Lab of Preventive Veterinary Medicine, Yangzhou University, No. 48 East Wenhui Road, Yangzhou 225009, China;
| | - Kun Qian
- Ministry of Education Key Lab for Avian Preventive Medicine, Yangzhou University, No. 48 East Wenhui Road, Yangzhou 225009, China; (H.H.); (L.Z.); (H.S.); (A.Q.)
- Jiangsu Key Lab of Preventive Veterinary Medicine, Yangzhou University, No. 48 East Wenhui Road, Yangzhou 225009, China;
- The International Joint Laboratory for Cooperation in Agriculture and Agricultural Product Safety, Ministry of Education, Yangzhou University, Yangzhou 225009, China
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11
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Lounas A, Besbaci M, Akkou M, Tali O. Occurrence of Marek's disease in vaccinated Algerian broiler breeder flocks: A histopathological survey. Vet World 2021; 14:3021-3027. [PMID: 35017852 PMCID: PMC8743772 DOI: 10.14202/vetworld.2021.3021-3027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 10/27/2021] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND AND AIM Marek's disease (MD) is a lymphoproliferative disease that occurs in chickens. In the absence of control measures, MD causes devastating losses to commercial poultry flocks. Vaccination has enabled dramatic success in the prevention and control of MD. However, the MD vaccination program has failed frequently, and occasional clinical outbreaks have been reported in the vaccinated flocks as well. The present study aimed to describe the clinical and histopathological characteristics of the field cases of MD in broiler breeder flocks. MATERIALS AND METHODS A survey on the update of MD occurrence in Algerian broiler breeder flocks was conducted from June 2020 to September 2020. Ten vaccinated broiler breeder flocks located in Central Algeria and having progressive tumors in different visceral organs were evaluated for MD virus infection by conducting a histopathological examination of the birds. RESULTS The age of the birds affected with MD ranged from 13 to 22 weeks. The mortality rate varied sensitively from 4% to 10%. The clinical symptoms reported in the affected flocks included locomotor, nervous, digestive, and respiratory symptoms. Necropsy of the dead or euthanized birds revealed visceral lymphomatosis in several organs and macroscopic changes in the peripheral nerves (including loss of longitudinal striation, color change [grayish], and volume increase). The histopathological findings included the infiltration and proliferation of lymphocytes and blast cells (lymphoblasts) in various organs of the birds, which are the typical characteristics of MD and, therefore, confirmed the field infection of MD in these birds. CONCLUSION The present study provided evidence for the high prevalence of MD in the broiler breeder flocks vaccinated with a bivalent vaccine (turkey herpesvirus+Rispens) at the hatchery. The findings of the present study may indicate high-level failure of vaccination in these birds.
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Affiliation(s)
- Abdelaziz Lounas
- Veterinary Sciences Institute, University of Blida 1, Blida, Algeria
| | - Mohamed Besbaci
- Veterinary Sciences Institute, University of Blida 1, Blida, Algeria
| | - Madjid Akkou
- Veterinary Sciences Institute, University of Blida 1, Blida, Algeria
| | - Oumennoune Tali
- Veterinary Sciences Institute, University of Blida 1, Blida, Algeria
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12
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Murata S, Yamamoto E, Sakashita N, Maekawa N, Okagawa T, Konnai S, Ohashi K. Research Note: Characterization of S-Meq containing the deletion in Meq protein's transactivation domain in a Marek's disease virus strain in Japan. Poult Sci 2021; 100:101461. [PMID: 34601441 PMCID: PMC8531842 DOI: 10.1016/j.psj.2021.101461] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/18/2021] [Accepted: 08/26/2021] [Indexed: 11/28/2022] Open
Abstract
Marek's disease virus (MDV) causes malignant lymphomas in chickens (Marek's disease; MD). Although MD has caused significant economic losses to the poultry industry, currently, its occurrence in the field is effectively controlled by vaccination. However, the genetic characteristics of MDV strains have changed, and the poultry industry has experienced MD outbreaks in vaccinated chickens because of enhanced virulence. Meq, an oncoprotein of MDV, is a key transcription factor correlated with the tumorigenesis in MD. Animal experiments using recombinant MDV revealed that distinct polymorphisms in Meq affect the virulence of MDV strains. Meq containing an insertion or deletion is present in some MDV strains. In the 2010s, field strains that encode Meq containing the deletion (S-Meq) were reported. In this study, we characterized the genetic features of S-Meq detected in a Japanese MDV strain and analyzed its transactivation activity to investigate S-Meq's protein function. S-Meq lacked 41 amino acids, and the deletion was at the same position as those observed in other countries. In addition, S-Meq exhibited higher transactivation activity than Meq from other MDV strains circulating in Japan. These results suggest that the deletion in the transactivation domain may enhance the Meq protein's function. Further investigation is needed to clarify whether the deletion in the transactivation domain of Meq affects MDV's virulence.
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Affiliation(s)
- Shiro Murata
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan; Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan.
| | - Eiji Yamamoto
- Western Livestock Hygiene Service Center, Kagawa Prefectural Government, Zentsuji, Japan
| | | | - Naoya Maekawa
- Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Tomohiro Okagawa
- Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Satoru Konnai
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan; Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Kazuhiko Ohashi
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan; Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan
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13
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Kannaki TR, Priyanka E, Nishitha Y, Krishna SV, Haunshi S, Subbiah M. Molecular detection and phylogenetic analysis of Marek's disease virus virulence-associated genes from vaccinated flocks in southern India reveals circulation of virulent MDV genotype. Transbound Emerg Dis 2021; 69:e244-e253. [PMID: 34403565 DOI: 10.1111/tbed.14289] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 08/12/2021] [Accepted: 08/15/2021] [Indexed: 11/30/2022]
Abstract
Marek's disease (MD) is a re-emerging viral disease of chickens and a serious economic threat to the poultry industry worldwide. Continuous surveillance with molecular investigation is essential to monitor the emergence of virulent Marek's disease virus (MDV) strains and to devise any appropriate vaccination strategy and implement bio-security programmes. In the present study, we investigated the cases of MD outbreaks in vaccinated poultry flocks. The MD outbreak was confirmed through necropsy (mainly visceral tumours), histopathology and viral gene specific PCR. The pathotypes of the field MDV strains were assessed by molecular analysis of three virulence-associated genes, meq, pp38 and vIL-8. The Meq sequence of the field strains analyzed in this study lacked the 59 aa unique to mild strains, indicating that they are potentially virulent strains. Mutation at position 71 and the presence of five proline rich repeats in the transactivation domain, both associated with virulence were observed in these strains; however, the signature sequences specific to very virulent plus strains were absent. Phylogenetic analysis of meq oncogene sequences revealed clustering of the field strains with North Indian strains and with a very virulent plus ATE 2539 strain from Hungary. Analyses of pp38 protein at positions 107 and 109 and vIL-8 protein at positions 4 and 31 showed signatures of virulence. Sequence and phylogenetic analysis of oncogene and virulence-associated genes of field MDVs from vaccinated flock indicated that these strains possessed molecular features of virulent strains.
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Affiliation(s)
- T R Kannaki
- ICAR-Directorate of Poultry Research, Hyderabad, Telangana, India
| | - E Priyanka
- ICAR-Directorate of Poultry Research, Hyderabad, Telangana, India
| | - Y Nishitha
- Department of Veterinary Microbiology, P. V. Narasimha Rao Telangana Veterinary University, Hyderabad, Telangana, India
| | - S Vamshi Krishna
- Department of Veterinary Microbiology, P. V. Narasimha Rao Telangana Veterinary University, Hyderabad, Telangana, India
| | - Santosh Haunshi
- ICAR-Directorate of Poultry Research, Hyderabad, Telangana, India
| | - Madhuri Subbiah
- National Institute of Animal Biotechnology, Hyderabad, Telangana, India
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14
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Hao X, Li S, Li J, Yang Y, Qin A, Shang S. An Anti-Tumor Vaccine Against Marek's Disease Virus Induces Differential Activation and Memory Response of γδ T Cells and CD8 T Cells in Chickens. Front Immunol 2021; 12:645426. [PMID: 33659011 PMCID: PMC7917234 DOI: 10.3389/fimmu.2021.645426] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 01/26/2021] [Indexed: 02/06/2023] Open
Abstract
Marek's disease virus (MDV) is a highly oncogenic alphaherpesvirus that causes deadly T-cell lymphomas and serves as a natural virus-induced tumor model in chickens. The most efficacious vaccine, CVI988/Rispens (CVI988), against MD has been used for several decades. However, the mechanisms leading to protective immunity following vaccination are not fully understood. In this study, employing multi-parameter flow cytometry, we performed a comprehensive analysis of T cell responses in CVI988-vaccinated chickens. CVI988 vaccination induced significant expansion of γδ T cells and CD8α+ T cells but not CD4+ T cells in spleen, lung and blood at early time-points. The expansion of these cells was CVI988-specific as infection with very virulent MDV RB1B did not elicit expansion of either γδ or CD8α+ T cells. Phenotypic analysis showed that CVI988 vaccination elicited preferential proliferation of CD8α+ γδ T cells and CD8αα co-receptor expression was upregulated on γδ T cells and CD8α+ T cells after immunization. Additionally, cell sorting and quantitative RT-PCR showed that CVI988 vaccination activated γδ T cells and CD8α+ T cells which exhibited differential expression of cytotoxic and T cell-related cytokines. Lastly, secondary immunization with CVI988 induced the expansion of CD8+ T cells but not γδ T cells at higher magnitude, compared to primary immunization, suggesting CVI988 did induce memory CD8+ T cells but not γδ T cells in chickens. Our results, for the first time, reveal a potential role of γδ T cells in CVI988-induced immune protection and provide new insights into the mechanism of immune protection against oncogenic MDV.
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Affiliation(s)
- Xiaoli Hao
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China.,Institute of Comparative Medicine, Yangzhou University, Yangzhou, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou University, Yangzhou, China
| | - Shuai Li
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China
| | - Jiaqi Li
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China
| | - Yi Yang
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China.,Institute of Comparative Medicine, Yangzhou University, Yangzhou, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou University, Yangzhou, China
| | - Aijian Qin
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou University, Yangzhou, China.,International Corporation Laboratory of Agriculture and Agricultural Products Safety, Yangzhou University, Yangzhou, China.,Ministry of Education Key Laboratory for Avian Preventive Medicine, Yangzhou University, Yangzhou, China
| | - Shaobin Shang
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China.,Institute of Comparative Medicine, Yangzhou University, Yangzhou, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou University, Yangzhou, China.,International Corporation Laboratory of Agriculture and Agricultural Products Safety, Yangzhou University, Yangzhou, China
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15
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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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16
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Yang F, Feng C, Yao Y, Qin A, Shao H, Qian K. Antiviral effect of baicalin on Marek's disease virus in CEF cells. BMC Vet Res 2020; 16:371. [PMID: 33008383 PMCID: PMC7532598 DOI: 10.1186/s12917-020-02595-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 09/28/2020] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Baicalin, the main metabolic component of Scutellaria baicalensis Georgi, has various pharmacological properties including anti-inflammatory, anti-oxidant, anti-apoptotic, anti-bactericidal and anti-viral. The purpose of this study was to investigate the anti-Marek's disease virus (MDV) activities of baicalin in CEF cells. RESULTS Here, we showed that baicalin could inhibit viral mRNA, protein levels and overall plaque formation in a time-dependent manner. We also found that baicalin could consistently inhibit MDV replication and directly affect the virus infectivity. Moreover, baicalin treatment has no effect on expression level of antiviral cytokine and inflammatory cytokines in MDV infected CEFs. CONCLUSIONS These results demonstrate that baicalin could be a potential drug against MDV infection.
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Affiliation(s)
- Fan Yang
- Ministry of Education Key Lab for Avian Preventive Medicine, Yangzhou University, No.48 East Wenhui Road, Yangzhou, Jiangsu, 225009, P.R. China.,Jiangsu Key Lab of Preventive Veterinary Medicine, Yangzhou University, No.48 East Wenhui Road, Yangzhou, Jiangsu, 225009, P.R. China.,The International Joint Laboratory for Cooperation in Agriculture and Agricultural Product Safety, Ministry of Education, Yangzhou University, Yangzhou, 225009, P.R. China
| | - Chun Feng
- Ministry of Education Key Lab for Avian Preventive Medicine, Yangzhou University, No.48 East Wenhui Road, Yangzhou, Jiangsu, 225009, P.R. China.,Jiangsu Key Lab of Preventive Veterinary Medicine, Yangzhou University, No.48 East Wenhui Road, Yangzhou, Jiangsu, 225009, P.R. China.,The International Joint Laboratory for Cooperation in Agriculture and Agricultural Product Safety, Ministry of Education, Yangzhou University, Yangzhou, 225009, P.R. China
| | - Yongxiu Yao
- The Pirbright Institute & UK-China Centre of Excellence for Research on Avian Diseases, Pirbright, Surrey, GU24 0NF, UK
| | - Aijian Qin
- Ministry of Education Key Lab for Avian Preventive Medicine, Yangzhou University, No.48 East Wenhui Road, Yangzhou, Jiangsu, 225009, P.R. China.,Jiangsu Key Lab of Preventive Veterinary Medicine, Yangzhou University, No.48 East Wenhui Road, Yangzhou, Jiangsu, 225009, P.R. China.,The International Joint Laboratory for Cooperation in Agriculture and Agricultural Product Safety, Ministry of Education, Yangzhou University, Yangzhou, 225009, P.R. China
| | - Hongxia Shao
- Ministry of Education Key Lab for Avian Preventive Medicine, Yangzhou University, No.48 East Wenhui Road, Yangzhou, Jiangsu, 225009, P.R. China.,Jiangsu Key Lab of Preventive Veterinary Medicine, Yangzhou University, No.48 East Wenhui Road, Yangzhou, Jiangsu, 225009, P.R. China.,The International Joint Laboratory for Cooperation in Agriculture and Agricultural Product Safety, Ministry of Education, Yangzhou University, Yangzhou, 225009, P.R. China
| | - Kun Qian
- Ministry of Education Key Lab for Avian Preventive Medicine, Yangzhou University, No.48 East Wenhui Road, Yangzhou, Jiangsu, 225009, P.R. China. .,Jiangsu Key Lab of Preventive Veterinary Medicine, Yangzhou University, No.48 East Wenhui Road, Yangzhou, Jiangsu, 225009, P.R. China. .,The International Joint Laboratory for Cooperation in Agriculture and Agricultural Product Safety, Ministry of Education, Yangzhou University, Yangzhou, 225009, P.R. China. .,Institute of Comparative Medicine, Yangzhou University, Yangzhou, Jiangsu, 225009, P.R. China. .,, Yangzhou, P. R. China.
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17
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Yang Y, Dong M, Hao X, Qin A, Shang S. Revisiting cellular immune response to oncogenic Marek's disease virus: the rising of avian T-cell immunity. Cell Mol Life Sci 2020; 77:3103-3116. [PMID: 32080753 PMCID: PMC7391395 DOI: 10.1007/s00018-020-03477-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Revised: 02/06/2020] [Accepted: 02/07/2020] [Indexed: 12/21/2022]
Abstract
Marek's disease virus (MDV) is a highly oncogenic alphaherpesvirus that causes deadly T-cell lymphomas and serves as a natural virus-induced tumor model in chickens. Although Marek's disease (MD) is well controlled by current vaccines, the evolution of MDV field viruses towards increasing virulence is concerning as a better vaccine to combat very virulent plus MDV is still lacking. Our understanding of molecular and cellular immunity to MDV and its immunopathogenesis has significantly improved, but those findings about cellular immunity to MDV are largely out-of-date, hampering the development of more effective vaccines against MD. T-cell-mediated cellular immunity was thought to be of paramount importance against MDV. However, MDV also infects macrophages, B cells and T cells, leading to immunosuppression and T-cell lymphoma. Additionally, there is limited information about how uninfected immune cells respond to MDV infection or vaccination, specifically, the mechanisms by which T cells are activated and recognize MDV antigens and how the function and properties of activated T cells correlate with immune protection against MDV or MD tumor. The current review revisits the roles of each immune cell subset and its effector mechanisms in the host immune response to MDV infection or vaccination from the point of view of comparative immunology. We particularly emphasize areas of research requiring further investigation and provide useful information for rational design and development of novel MDV vaccines.
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Affiliation(s)
- Yi Yang
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou University, Yangzhou, 225009, China
| | - Maoli Dong
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, China
| | - Xiaoli Hao
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, China
| | - Aijian Qin
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou University, Yangzhou, 225009, China.
- International Corporation Laboratory of Agriculture and Agricultural Products Safety, Yangzhou University, Yangzhou, 225009, China.
- Ministry of Education Key Laboratory for Avian Preventive Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, China.
- Key Laboratory of Jiangsu Preventive Veterinary Medicine, Yangzhou University, Yangzhou, 225009, China.
| | - Shaobin Shang
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, China.
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou University, Yangzhou, 225009, China.
- International Corporation Laboratory of Agriculture and Agricultural Products Safety, Yangzhou University, Yangzhou, 225009, China.
- Ministry of Education Key Laboratory for Avian Preventive Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, China.
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Morphological and Immunohistochemical Examination of Lymphoproliferative Lesions Caused by Marek's Disease Virus in Breeder Chickens. Animals (Basel) 2020; 10:ani10081280. [PMID: 32727058 PMCID: PMC7460422 DOI: 10.3390/ani10081280] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 07/17/2020] [Accepted: 07/22/2020] [Indexed: 12/24/2022] Open
Abstract
Simple Summary The poultry industry is the most intensive and fastest growing among all livestock production systems, and, in the last decades, it has expanded exponentially due to an increasing demand for meat and eggs. Marek’s disease is a highly contagious and rapidly progressive lymphoproliferative disease. It is one of the most dangerous diseases of those affecting the sector because it causes important economic losses. Although widely controlled by vaccination programs, sometimes chickens are not totally protected, and the presence of virulent field strains can allow outbreaks. This case describes the occurrence of Marek’s disease observed in a breeder chicken flock that reported an increase in mortality rate (+0.4–0.6%) after the 32nd week. Histological analysis has highlighted severe lesions on visceral organs of chickens caused by Marek’s disease, especially in the intestinal tract of a hen that had a tumor mass in the distal part of the cloaca. Immunohistochemical staining confirmed the disease-associated tumor. The aim of this study was to underline the importance of vaccine administration related to the maintenance of proper biosecurity practice, especially in the first week of the raising cycle. In addition, monitoring for disease even after vaccination is crucial to minimize economic loss. Abstract Marek’s disease is widely controlled by vaccination programs; however, chickens are not totally protected, especially immediately after the vaccination when a strong challenge could interfere with the effectiveness of vaccination in the absence of proper biosecurity practice. This case report describes the occurrence of Marek’s disease (MD) observed in a breeder chicken flock reared southeast of Sicily. MD outbreak occurred from 32 to 47 weeks with an increase in weekly mortality rate (+0.4–0.6%). Overall, mortality rate related to Marek’s disease was about 6% at the end of the cycle. Carcasses of chickens found during the occurrence of disease underwent necropsy, and tissues were collected to confirm the infection. Gizzard, cecal tonsil, intestine, spleen and tumor mass were collected and analyzed from a carcass of one hen, 32 weeks old and apparently asymptomatic. Multiplex real-time PCR performed on spleen tissues detected the presence of MD virus pathogenic strain. Macroscopic and microscopic evaluation of the rest of the samples confirmed the neoplastic disease. Moreover, the immunophenotype of the tumor cells was identified as CD3 positive by immunohistochemical (IHC) staining. The vaccinated flock had become rapidly infected with the MD virus, which proves that the challenge of the MD virus was too strong in the rearing house at the beginning of the cycle, causing the outbreak.
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Li X, Zhang K, Pei Y, Xue J, Ruan S, Zhang G. Development and Application of an MRT-qPCR Assay for Detecting Coinfection of Six Vertically Transmitted or Immunosuppressive Avian Viruses. Front Microbiol 2020; 11:1581. [PMID: 32765453 PMCID: PMC7379340 DOI: 10.3389/fmicb.2020.01581] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 06/17/2020] [Indexed: 01/19/2023] Open
Abstract
Marek's disease virus (MDV), reticuloendotheliosis virus (REV), avian reovirus (ARV), chicken infectious anemia virus (CIAV), infectious bursal disease virus (IBDV), and fowl adenovirus (FAdV) are important causes of disease in poultry. To investigate the infection status of the above six viruses in chickens in China, 1,187 samples from chicken flocks were collected and tested using a newly developed multiplex reverse-transcription quantitative real-time PCR (MRT-qPCR) assay in the study. A series of validation tests confirmed that the MRT-qPCR assay has high specificity, sensitivity, and repeatability. As for six detected pathogens, CIAV had the highest detection ratio, while ARV was not detected in any samples. In the spleen samples, the coinfection rate for MDV and CIAV was 1.6%, and that for REV and CIAV was 0.4%. In the bursa samples, the coinfection rate for FAdV and CIAV was 0.3%, and that for IBDV and CIAV was 1%. In the thymus samples, the coinfection rates for MDV and CIAV and for REV and CIAV were both 0.8%. Our study indicates that the coinfection of these viruses was existing in chickens in China. Through the detection of clinical samples, this study provides data on the coinfections of the above six pathogens and provides a basis for the further study of viral coinfection in chickens.
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Affiliation(s)
- Xiao Li
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Keran Zhang
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Yu Pei
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Jia Xue
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Sifan Ruan
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Guozhong Zhang
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
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20
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Bertzbach LD, Conradie AM, You Y, Kaufer BB. Latest Insights into Marek's Disease Virus Pathogenesis and Tumorigenesis. Cancers (Basel) 2020; 12:cancers12030647. [PMID: 32164311 PMCID: PMC7139298 DOI: 10.3390/cancers12030647] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 03/06/2020] [Accepted: 03/07/2020] [Indexed: 12/14/2022] Open
Abstract
Marek’s disease virus (MDV) infects chickens and causes one of the most frequent cancers in animals. Over 100 years of research on this oncogenic alphaherpesvirus has led to a profound understanding of virus-induced tumor development. Live-attenuated vaccines against MDV were the first that prevented cancer and minimized the losses in the poultry industry. Even though the current gold standard vaccine efficiently protects against clinical disease, the virus continuously evolves towards higher virulence. Emerging field strains were able to overcome the protection provided by the previous two vaccine generations. Research over the last few years revealed important insights into the virus life cycle, cellular tropism, and tumor development that are summarized in this review. In addition, we discuss recent data on the MDV transcriptome, the constant evolution of this highly oncogenic virus towards higher virulence, and future perspectives in MDV research.
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21
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Yu Z, Zhang Y, Lan X, Wang Y, Zhang F, Gao Y, Li K, Gao L, Pan Q, Qi X, Cui H, Zhou L, Sun G, Wang X, Liu C. Natural co-infection with two virulent wild strains of Marek's disease virus in a commercial layer flock. Vet Microbiol 2019; 240:108501. [PMID: 31902513 DOI: 10.1016/j.vetmic.2019.108501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 11/02/2019] [Accepted: 11/04/2019] [Indexed: 01/13/2023]
Abstract
Marek's disease (MD) is a highly contagious lymphoproliferative poultry disease caused by the oncogenic herpesvirus, Marek's disease virus (MDV). MDV strains have shown a continued evolution of virulence leading to immune failure, and MD cases continue to occur. Co-infection of virulent MDV strains is an important factor leading to viral evolution and host immune failure. This study conducted a laboratory diagnosis and analysis of a MDV infected flock. Testing showed that all samples were MDV positive. PCR detection identified a variable 132-base pair repeat (132-bpr) sequence copy number. This indicated that two virulent strains of MDV were co-infecting the flock. Therefore, we performed homology, sequence alignment, and phylogenetic tree analysis of MDV variant genes including meq, pp38, and RLORF4. Two MDV strains had co-infected the flock; one was the 132bpr two-copy characteristic strain (AH2C) and the other was a 132bpr three-copy characteristic strain (AH3C). Specific mutations in AH3C were found, suggesting that it is a new variant strain. Furthermore, the viral load of the two strains in vivo indicated that both strains had high and similar replication ability. There was no significant difference in the proportion of positive samples of the two strains causing disease. In the whole flock, neither strain displayed an obvious advantage. However, there was a dominant strain in individual chickens, with the exception of one sample. This study reported the co-infection regularity of two virulent MDV strains in the same flock, and even in the same chicken in field conditions. In the context of overall epidemiology, this study is a useful reference.
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Affiliation(s)
- Zhenghao Yu
- Division of Avian Immunosuppressive Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150069, China
| | - Yanping Zhang
- Division of Avian Immunosuppressive Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150069, China
| | - Xingge Lan
- Division of Avian Immunosuppressive Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150069, China
| | - Yanan Wang
- Division of Avian Immunosuppressive Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150069, China
| | - Feng Zhang
- Division of Avian Immunosuppressive Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150069, China
| | - Yulong Gao
- Division of Avian Immunosuppressive Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150069, China
| | - Kai Li
- Division of Avian Immunosuppressive Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150069, China
| | - Li Gao
- Division of Avian Immunosuppressive Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150069, China
| | - Qing Pan
- Division of Avian Immunosuppressive Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150069, China
| | - Xiaole Qi
- Division of Avian Immunosuppressive Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150069, China
| | - Hongyu Cui
- Division of Avian Immunosuppressive Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150069, China
| | - Linyi Zhou
- Division of Avian Immunosuppressive Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150069, China
| | - Guorong Sun
- Division of Avian Immunosuppressive Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150069, China
| | - Xiaomei Wang
- Division of Avian Immunosuppressive Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150069, China.
| | - Changjun Liu
- Division of Avian Immunosuppressive Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150069, China.
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22
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Li T, Xie J, Liang G, Ren D, Sun S, Lv L, Xie Q, Shao H, Gao W, Qin A, Ye J. Co-infection of vvMDV with multiple subgroups of avian leukosis viruses in indigenous chicken flocks in China. BMC Vet Res 2019; 15:288. [PMID: 31409367 PMCID: PMC6691527 DOI: 10.1186/s12917-019-2041-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 08/05/2019] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND In China, although the ALV eradication program and the MD vaccination strategy greatly reduce the disease burdens caused by the infection of ALV and MDV, the frequent emergence of novel ALV-K or vvMDV in the vaccinated chicken flock challenges the current control strategies for both diseases. RESULTS In Guangdong Province, an indigenous chicken flock was infected with neoplastic disease. Hematoxylin-eosin staining of the tissues showed the typical characteristics of MDV and classical ALV infection. The PCR and sequencing data demonstrated that the identified MDV was clustered into a very virulent MDV strain endemic in domestic chickens in China. Moreover, subgroups ALV-A and ALV-K were efficiently recovered from two samples. The full genome sequence revealed that the ALV-K isolate was phylogenetically close to the ALV TW3593 isolate from Taiwan Province. CONCLUSIONS A co-infection of vvMDV with multiple ALV subgroups emerged in a chicken flock with neoplastic disease in Guangdong Province. The co-infection with different subgroups of ALV with vvMDV in one chicken flock poses the risk for the emergence of novel ALVs and heavily burdens the control strategy for MDV.
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Affiliation(s)
- Tuofan Li
- Key Laboratory of Jiangsu Preventive Veterinary Medicine, Key Laboratory for Avian Preventive Medicine, Ministry of Education, College of Veterinary Medicine, Yangzhou University, No. 12 East Wenhui Road, Yangzhou, Jiangsu, 225009, People's Republic of China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, Jiangsu, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Jing Xie
- Key Laboratory of Jiangsu Preventive Veterinary Medicine, Key Laboratory for Avian Preventive Medicine, Ministry of Education, College of Veterinary Medicine, Yangzhou University, No. 12 East Wenhui Road, Yangzhou, Jiangsu, 225009, People's Republic of China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, Jiangsu, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Guangcheng Liang
- Key Laboratory of Jiangsu Preventive Veterinary Medicine, Key Laboratory for Avian Preventive Medicine, Ministry of Education, College of Veterinary Medicine, Yangzhou University, No. 12 East Wenhui Road, Yangzhou, Jiangsu, 225009, People's Republic of China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, Jiangsu, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Dan Ren
- Key Laboratory of Jiangsu Preventive Veterinary Medicine, Key Laboratory for Avian Preventive Medicine, Ministry of Education, College of Veterinary Medicine, Yangzhou University, No. 12 East Wenhui Road, Yangzhou, Jiangsu, 225009, People's Republic of China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, Jiangsu, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Shu Sun
- Key Laboratory of Jiangsu Preventive Veterinary Medicine, Key Laboratory for Avian Preventive Medicine, Ministry of Education, College of Veterinary Medicine, Yangzhou University, No. 12 East Wenhui Road, Yangzhou, Jiangsu, 225009, People's Republic of China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, Jiangsu, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Lu Lv
- Key Laboratory of Jiangsu Preventive Veterinary Medicine, Key Laboratory for Avian Preventive Medicine, Ministry of Education, College of Veterinary Medicine, Yangzhou University, No. 12 East Wenhui Road, Yangzhou, Jiangsu, 225009, People's Republic of China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, Jiangsu, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Quan Xie
- Key Laboratory of Jiangsu Preventive Veterinary Medicine, Key Laboratory for Avian Preventive Medicine, Ministry of Education, College of Veterinary Medicine, Yangzhou University, No. 12 East Wenhui Road, Yangzhou, Jiangsu, 225009, People's Republic of China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, Jiangsu, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Hongxia Shao
- Key Laboratory of Jiangsu Preventive Veterinary Medicine, Key Laboratory for Avian Preventive Medicine, Ministry of Education, College of Veterinary Medicine, Yangzhou University, No. 12 East Wenhui Road, Yangzhou, Jiangsu, 225009, People's Republic of China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, Jiangsu, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, 225009, Jiangsu, China.,Institutes of Agricultural Science and Technology Development, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Wei Gao
- Key Laboratory of Jiangsu Preventive Veterinary Medicine, Key Laboratory for Avian Preventive Medicine, Ministry of Education, College of Veterinary Medicine, Yangzhou University, No. 12 East Wenhui Road, Yangzhou, Jiangsu, 225009, People's Republic of China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, Jiangsu, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Aijian Qin
- Key Laboratory of Jiangsu Preventive Veterinary Medicine, Key Laboratory for Avian Preventive Medicine, Ministry of Education, College of Veterinary Medicine, Yangzhou University, No. 12 East Wenhui Road, Yangzhou, Jiangsu, 225009, People's Republic of China. .,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, Jiangsu, China. .,Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, 225009, Jiangsu, China. .,Institutes of Agricultural Science and Technology Development, Yangzhou University, Yangzhou, 225009, Jiangsu, China.
| | - Jianqiang Ye
- Key Laboratory of Jiangsu Preventive Veterinary Medicine, Key Laboratory for Avian Preventive Medicine, Ministry of Education, College of Veterinary Medicine, Yangzhou University, No. 12 East Wenhui Road, Yangzhou, Jiangsu, 225009, People's Republic of China. .,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, Jiangsu, China. .,Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, 225009, Jiangsu, China. .,Institutes of Agricultural Science and Technology Development, Yangzhou University, Yangzhou, 225009, Jiangsu, China.
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23
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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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Sun GR, Zhang YP, Lv HC, Zhou LY, Cui HY, Gao YL, Qi XL, Wang YQ, Li K, Gao L, Pan Q, Wang XM, Liu CJ. A Chinese Variant Marek's Disease Virus Strain with Divergence between Virulence and Vaccine Resistance. Viruses 2017; 9:E71. [PMID: 28368367 PMCID: PMC5408677 DOI: 10.3390/v9040071] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 03/25/2017] [Accepted: 03/30/2017] [Indexed: 11/17/2022] Open
Abstract
Marek's disease (MD) virus (MDV) has been evolving continuously, leading to increasing vaccination failure. Here, the MDV field strain BS/15 was isolated from a severely diseased Chinese chicken flock previously vaccinated with CVI988. To explore the causes of vaccination failure, specific-pathogen free (SPF) chickens vaccinated with CVI988 or 814 and unvaccinated controls were challenged with either BS/15 or the reference strain Md5. Both strains induced MD lesions in unvaccinated chickens with similar mortality rates of 85.7% and 80.0% during the experimental period, respectively. However, unvaccinated chickens inoculated with BS/15 exhibited a higher tumor development rate (64.3% vs. 40.0%), but prolonged survival and diminished immune defects compared to Md5-challenged counterparts. These results suggest that BS/15 and Md5 show a similar virulence but manifest with different pathogenic characteristics. Moreover, the protective indices of CVI988 and 814 were 33.3 and 66.7 for BS/15, and 92.9 and 100 for Md5, respectively, indicating that neither vaccine could provide efficient protection against BS/15. Taken together, these data suggest that MD vaccination failure is probably due to the existence of variant MDV strains with known virulence and unexpected vaccine resistance. Our findings should be helpful for understanding the pathogenicity and evolution of MDV strains prevalent in China.
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Affiliation(s)
- Guo-Rong Sun
- Division of Avian Immunosuppressive Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China.
| | - Yan-Ping Zhang
- Division of Avian Immunosuppressive Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China.
| | - Hong-Chao Lv
- Division of Avian Immunosuppressive Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China.
| | - Lin-Yi Zhou
- Division of Avian Immunosuppressive Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China.
| | - Hong-Yu Cui
- Division of Avian Immunosuppressive Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China.
| | - Yu-Long Gao
- Division of Avian Immunosuppressive Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China.
| | - Xiao-le Qi
- Division of Avian Immunosuppressive Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China.
| | - Yong-Qiang Wang
- Division of Avian Immunosuppressive Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China.
| | - Kai Li
- Division of Avian Immunosuppressive Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China.
| | - Li Gao
- Division of Avian Immunosuppressive Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China.
| | - Qing Pan
- Division of Avian Immunosuppressive Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China.
| | - Xiao-Mei Wang
- Division of Avian Immunosuppressive Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China.
| | - Chang-Jun Liu
- Division of Avian Immunosuppressive Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China.
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25
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Lv H, Zhang Y, Sun G, Bao K, Gao Y, Qi X, Cui H, Wang Y, Li K, Gao L, Pan Q, Wang X, Liu C. Genetic evolution of Gallid herpesvirus 2 isolated in China. INFECTION GENETICS AND EVOLUTION 2016; 51:263-274. [PMID: 27112385 DOI: 10.1016/j.meegid.2016.04.027] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 04/20/2016] [Accepted: 04/21/2016] [Indexed: 01/12/2023]
Abstract
Gallid herpesvirus 2 (GaHV-2), which causes Marek's disease in chickens and has caused extensive economic losses, has recently evolved increased virulence in China. To better understand the genetic basis of the pathogenic characteristics changed and increased virulence, we sequenced the genomes of six new GaHV-2 strains (LCC, LTS, WC/1203, JL/1404, CC/1409, and HS/1412) isolated from chickens with failed immunisation as well as one previously isolated Chinese GaHV-2 strain, J-1. Based on a multiple sequence alignment, several characteristic point mutations were detected in the open reading frames of the Chinese isolates. In addition, two deletions and an insertion were identified at the unique short region and terminal repeat short region junctions in Chinese isolates, and the insertion was a characteristic of the new Chinese isolates. According to a phylogenetic analysis, the GaHV-2 genome diverged substantially over the last two decades in China. Based on the internal repeat long region, the new isolates were closely related to very virulent or very virulent plus strains. Additionally, the new Chinese isolates diverged from the previously isolated strains J-1 and 814. In conclusion, our results provide evidence that Chinese GaHV-2 strains contain characteristic sequences, especially the new isolates. The observed genetic divergence in the new Chinese GaHV-2 strains over the last two decades may be related to observed changes in pathogenic characteristics and virulence.
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Affiliation(s)
- Hongchao Lv
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin 150001, PR China
| | - Yanping Zhang
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin 150001, PR China
| | - Guorong Sun
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin 150001, PR China
| | - Keyan Bao
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin 150001, PR China
| | - Yulong Gao
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin 150001, PR China
| | - Xiaole Qi
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin 150001, PR China
| | - Hongyu Cui
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin 150001, PR China
| | - Yongqiang Wang
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin 150001, PR China
| | - Kai Li
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin 150001, PR China
| | - Li Gao
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin 150001, PR China
| | - Qing Pan
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin 150001, PR China
| | - Xiaomei Wang
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin 150001, PR China.
| | - Changjun Liu
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin 150001, PR China.
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