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Park SW, Park IB, Kang SJ, Bae J, Chun T. Interaction between host cell proteins and open reading frames of porcine circovirus type 2. JOURNAL OF ANIMAL SCIENCE AND TECHNOLOGY 2023; 65:698-719. [PMID: 37970506 PMCID: PMC10640953 DOI: 10.5187/jast.2023.e67] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 06/28/2023] [Accepted: 07/09/2023] [Indexed: 11/17/2023]
Abstract
Postweaning multisystemic wasting syndrome (PMWS) is caused by a systemic inflammation after porcine circovirus type 2 (PCV2) infection. It was one of the most economically important pathogens affecting pig production worldwide before PCV2 vaccine was first introduced in 2006. After the development of a vaccine against PCV2a type, pig farms gradually restored enormous economic losses from PMWS. However, vaccine against PCV2a type could not be fully effective against several different PCV2 genotypes (PCV2b - PCV2h). In addition, PCV2a vaccine itself could generate antigenic drift of PCV2 capsid. Therefore, PCV2 infection still threats pig industry worldwide. PCV2 infection was initially found in local tissues including reproductive, respiratory, and digestive tracks. However, PCV2 infection often leads to a systemic inflammation which can cause severe immunosuppression by depleting peripheral lymphocytes in secondary lymphoid tissues. Subsequently, a secondary infection with other microorganisms can cause PMWS. Eleven putative open reading frames (ORFs) have been predicted to encode PCV2 genome. Among them, gene products of six ORFs from ORF1 to ORF6 have been identified and characterized to estimate its functional role during PCV2 infection. Acquiring knowledge about the specific interaction between each PCV2 ORF protein and host protein might be a key to develop preventive or therapeutic tools to control PCV2 infection. In this article, we reviewed current understanding of how each ORF of PCV2 manipulates host cell signaling related to immune suppression caused by PCV2.
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Affiliation(s)
- Si-Won Park
- Department of Biotechnology, School of
Life Sciences and Biotechnology, Korea University, Seoul
02841, Korea
| | - In-Byung Park
- Department of Biotechnology, School of
Life Sciences and Biotechnology, Korea University, Seoul
02841, Korea
| | - Seok-Jin Kang
- Department of Biotechnology, School of
Life Sciences and Biotechnology, Korea University, Seoul
02841, Korea
| | - Joonbeom Bae
- Department of Biotechnology, School of
Life Sciences and Biotechnology, Korea University, Seoul
02841, Korea
| | - Taehoon Chun
- Department of Biotechnology, School of
Life Sciences and Biotechnology, Korea University, Seoul
02841, Korea
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Udenze D, Trus I, Munyanduki H, Berube N, Karniychuk U. The Isolated in Utero Environment Is Conducive to the Emergence of RNA and DNA Virus Variants. Viruses 2021; 13:v13091827. [PMID: 34578408 PMCID: PMC8473323 DOI: 10.3390/v13091827] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 09/06/2021] [Accepted: 09/11/2021] [Indexed: 01/04/2023] Open
Abstract
The host’s immune status may affect virus evolution. Little is known about how developing fetal and placental immune milieus affect virus heterogeneity. This knowledge will help us better understand intra-host virus evolution and how new virus variants emerge. The goal of our study was to find out whether the isolated in utero environment—an environment with specialized placental immunity and developing fetal immunity—supports the emergence of RNA and DNA virus variants. We used well-established porcine models for isolated Zika virus (RNA virus) and porcine circovirus 2 (DNA virus) fetal infections. We found that the isolated in utero environment was conducive to the emergence of RNA and DNA virus variants. Next-generation sequencing of nearly whole virus genomes and validated bioinformatics pipelines identified both unique and convergent single nucleotide variations in virus genomes isolated from different fetuses. Zika virus and PCV2 in utero evolution also resulted in single nucleotide variations previously reported in the human and porcine field samples. These findings should encourage further studies on virus evolution in placenta and fetuses, to better understand how virus variants emerge and how in utero viral evolution affects congenital virus transmission and pathogenicity.
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Affiliation(s)
- Daniel Udenze
- Vaccine and Infectious Disease Organization (VIDO), University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada; (D.U.); (I.T.); (H.M.); (N.B.)
- School of Public Health, University of Saskatchewan, Saskatoon, SK S7N 2Z4, Canada
| | - Ivan Trus
- Vaccine and Infectious Disease Organization (VIDO), University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada; (D.U.); (I.T.); (H.M.); (N.B.)
| | - Henry Munyanduki
- Vaccine and Infectious Disease Organization (VIDO), University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada; (D.U.); (I.T.); (H.M.); (N.B.)
| | - Nathalie Berube
- Vaccine and Infectious Disease Organization (VIDO), University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada; (D.U.); (I.T.); (H.M.); (N.B.)
| | - Uladzimir Karniychuk
- Vaccine and Infectious Disease Organization (VIDO), University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada; (D.U.); (I.T.); (H.M.); (N.B.)
- School of Public Health, University of Saskatchewan, Saskatoon, SK S7N 2Z4, Canada
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada
- Correspondence: ; Tel.: +1-306-966-5510
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Nath BK, Das S, Roby JA, Sarker S, Luque D, Raidal SR, Forwood JK. Structural Perspectives of Beak and Feather Disease Virus and Porcine Circovirus Proteins. Viral Immunol 2020; 34:49-59. [PMID: 33275868 DOI: 10.1089/vim.2020.0097] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Circoviruses represent a rapidly expanding group of viruses that infect both vertebrate and invertebrate hosts. Members are responsible for diseases of veterinary and economic importance, including postweaning multisystemic wasting syndrome in pigs, and beak and feather disease (BFD) in birds. These viruses are associated with lymphoid depletion and immunosuppressive conditions in infected animals leading to systemic illness. Circoviruses are small nonenveloped DNA viruses containing a single-stranded circular genome, encoding two major proteins: the capsid-associated protein (Cap), comprising the entirety of the viral capsid, and the replication-associated protein (Rep). Cap is the only protein component of the virion and plays crucial roles throughout the virus replication cycle, including viral attachment, cell entry, genome uncoating, and packaging of newly formed viral particles. Rep mediates recognition of replication origin motifs in the viral genome sequence and is responsible for endonuclease activity enabling nicking of the circular DNA and initiation of rolling-circle replication (RCR). Porcine circovirus 2 (PCV2) was the first circovirus capsid structure to be solved at atomic resolution using X-ray crystallography. The structure revealed an assembly comprising 60 monomeric subunits to form virus-like particles. Each Cap monomer harbors a canonical viral jelly roll domain composed of two, four-stranded antiparallel β-sheets. Crystal structures of two distinct macromolecular assemblies from BFD virus Cap were also resolved at high resolution. In these structures, the exposure of the N-terminal arginine-rich motif, responsible for DNA binding and nuclear localization is reversed. Additional structural investigations have also elucidated a PCV2 type-specific neutralizing epitope, and interaction between the PCV2 capsid and polymers such as heparin. In this review, we provide a snapshot of the structural and functional aspects of circovirus proteins.
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Affiliation(s)
- Babu Kanti Nath
- School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, Australia
| | - Shubhagata Das
- School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, Australia
| | - Justin A Roby
- School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, Australia
| | - Subir Sarker
- Department of Physiology, Anatomy and Microbiology, School of Life Sciences, La Trobe University, Melbourne, Australia
| | - Daniel Luque
- Centro Nacional de Microbiología/ISCIII, Majadahonda, Madrid, Spain
| | - Shane R Raidal
- School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, Australia
| | - Jade K Forwood
- School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, Australia
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Wei R, Xie J, Theuns S, Nauwynck HJ. Changes on the viral capsid surface during the evolution of porcine circovirus type 2 (PCV2) from 2009 till 2018 may lead to a better receptor binding. Virus Evol 2019; 5:vez026. [PMID: 31392030 PMCID: PMC6676070 DOI: 10.1093/ve/vez026] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Porcine circovirus type 2 (PCV2) is the primary causative agent of porcine circovirus-associated diseases (PCVAD). Three major PCV2 genotypes (PCV2a, PCV2b, and PCV2d) have been identified globally. Despite their worldwide distribution, the prevalence and genetic evolution of PCV2 in Belgium has not previously been determined. In this study, 319 samples from animals suffering from diseases likely to be associated with PCV2 were collected from 2009 to 2018 and analysed by virus titration. The overall prevalence of PCV2 in PCVAD-suspected cases was 15.7 per cent (50/319). The phylogenetic analysis demonstrated that at least three genotypes (PCV2a, PCV2b, and PCV2d) circulated in Belgium from 2009 till 2018, and that PCV2 evolved from PCV2a to PCV2b and from PCV2d-1 to PCV2d-2. Sequence comparison among the forty-three PCV2 isolates showed that they had 89.7–100 per cent nucleotide-sequence and 88.5–100 per cent amino-acid-sequence identities. Three amino acid sites were under positive selection. Three-dimensional analysis of genotype-specific amino acids revealed that most of the mutations were on the outside of the cap protein with a few conserved mutations present on the inner side. Mutations toward more basic amino acids were found on the upper and tail parts of two connecting capsid proteins which form one big contact region, most probably involved in receptor binding. The lower part was relatively conserved. This polarity change together with the formation of an extruding part drive the virus to a more efficient GAG receptor binding. Taken together, these results showed a genotype shift from PCV2a to PCV2b and later on from PCV2d-1 to PCV2d-2, and a PCV2 evolution toward a better receptor binding capacity.
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Affiliation(s)
- Ruifang Wei
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, Belgium
| | - Jiexiong Xie
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, Belgium
| | - Sebastiaan Theuns
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, Belgium
| | - Hans J Nauwynck
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, Belgium
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Huang L, Wei Y, Xia D, Liu D, Zhu H, Wu H, Feng L, Liu C. A broad spectrum monoclonal antibody against porcine circovirus type 2 for antigen and antibody detection. Appl Microbiol Biotechnol 2019; 103:3453-3464. [PMID: 30863876 DOI: 10.1007/s00253-019-09715-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 02/20/2019] [Accepted: 02/23/2019] [Indexed: 10/27/2022]
Abstract
This study described the production, characterization, and application of monoclonal antibodies (mAbs) against porcine circovirus type 2 (PCV2). Twelve stable hybridomas were produced by immunization with purified PCV2a/LG strain and characterized by immunoperoxidase monolayer assay (IPMA), Western blotting, and neutralization assays. All mAbs could react with the PCV2 Cap protein and neutralize PCV2a/LG strain. One of them, mAb 3A5, reacted to all PCV2 strains from PCV2a, PCV2b, and PCV2d and it could be applied to detect PCV2 antigen and antibodies. It was shown that the mAb 3A5 could be used to locate PCV2 antigen in PK15 cells and the inguinal lymph nodes of PCV2b/YJ stain-infected piglets. Furthermore, this mAb could immunoprecipitate the Cap protein in PCV2-infected PK15 cells. Meanwhile, a capture ELISA based on mAb 3A5 was developed and used to specifically test PCV2 antigen from cultures; a linear relationship was observed between the optical density at 405 nm of the ELISA and viral titers (200-12,800 TCID50/mL), with a correlation coefficient of 0.9999. Finally, a competitive ELISA based on mAb 3A5 was developed to specifically detect antibodies in PCV2-infected and immunized pigs, and its sensitivity was higher than that of the blocking ELISA. This study suggested that the mAb 3A5 could be used in several convenient and efficient methods for PCV2 clinical and pathological studies, as well as surveillance in pigs and seroconversion monitoring in the vaccinated pigs.
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Affiliation(s)
- Liping Huang
- Swine Digestive System Infectious Diseases Research Team, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 678 Haping Street, Xiangfang District, Harbin, 150069, China
| | - Yanwu Wei
- Swine Digestive System Infectious Diseases Research Team, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 678 Haping Street, Xiangfang District, Harbin, 150069, China
| | - Deli Xia
- Swine Digestive System Infectious Diseases Research Team, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 678 Haping Street, Xiangfang District, Harbin, 150069, China
| | - Dan Liu
- Swine Digestive System Infectious Diseases Research Team, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 678 Haping Street, Xiangfang District, Harbin, 150069, China
| | - Hongzhen Zhu
- Swine Digestive System Infectious Diseases Research Team, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 678 Haping Street, Xiangfang District, Harbin, 150069, China
| | - Hongli Wu
- Swine Digestive System Infectious Diseases Research Team, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 678 Haping Street, Xiangfang District, Harbin, 150069, China
| | - Li Feng
- Swine Digestive System Infectious Diseases Research Team, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 678 Haping Street, Xiangfang District, Harbin, 150069, China
| | - Changming Liu
- Swine Digestive System Infectious Diseases Research Team, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 678 Haping Street, Xiangfang District, Harbin, 150069, China.
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Darbellay J, Cox B, Lai K, Delgado-Ortega M, Wheler C, Wilson D, Walker S, Starrak G, Hockley D, Huang Y, Mutwiri G, Potter A, Gilmour M, Safronetz D, Gerdts V, Karniychuk U. Zika Virus Causes Persistent Infection in Porcine Conceptuses and may Impair Health in Offspring. EBioMedicine 2017; 25:73-86. [PMID: 29097124 PMCID: PMC5704061 DOI: 10.1016/j.ebiom.2017.09.021] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 09/11/2017] [Accepted: 09/15/2017] [Indexed: 12/26/2022] Open
Abstract
Outcomes of Zika virus (ZIKV) infection in pregnant women vary from the birth of asymptomatic offspring to abnormal development and severe brain lesions in fetuses and infants. There are concerns that offspring affected in utero and born without apparent symptoms may develop mental illnesses. Therefore, animal models are important to test interventions against in utero infection and health sequelae in symptomatic and likely more widespread asymptomatic offspring. To partially reproduce in utero infection in humans, we directly inoculated selected porcine conceptuses with ZIKV. Inoculation resulted in rapid trans-fetal infections, persistent infection in conceptuses, molecular pathology in fetal brains, fetal antibody and type I interferon responses. Offspring infected in utero showed ZIKV in their fetal membranes collected after birth. Some in utero affected piglets were small, depressed, had undersized brains, and showed seizures. Some piglets showed potentially increased activity. Our data suggest that porcine model of persistent in utero ZIKV infection has a strong potential for translational research and can be used to test therapeutic interventions in vivo.
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Affiliation(s)
- Joseph Darbellay
- Vaccine and Infectious Disease Organization-International Vaccine Centre (VIDO-InterVac), University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada
| | - Brian Cox
- Department of Physiology, Department of Obstetrics and Gynaecology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Kenneth Lai
- Vaccine and Infectious Disease Organization-International Vaccine Centre (VIDO-InterVac), University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada
| | - Mario Delgado-Ortega
- Vaccine and Infectious Disease Organization-International Vaccine Centre (VIDO-InterVac), University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada
| | - Colette Wheler
- Vaccine and Infectious Disease Organization-International Vaccine Centre (VIDO-InterVac), University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada
| | - Donald Wilson
- Vaccine and Infectious Disease Organization-International Vaccine Centre (VIDO-InterVac), University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada
| | - Stewart Walker
- Vaccine and Infectious Disease Organization-International Vaccine Centre (VIDO-InterVac), University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada
| | - Gregory Starrak
- Department of Small Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada
| | - Duncan Hockley
- Department of Small Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada
| | - Yanyun Huang
- Prairie Diagnostic Services, Saskatoon, SK S7N 5B4, Canada
| | - George Mutwiri
- School of Public Health, University of Saskatchewan, Saskatoon, SK, Canada
| | - Andrew Potter
- Vaccine and Infectious Disease Organization-International Vaccine Centre (VIDO-InterVac), University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada; Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada
| | - Matthew Gilmour
- Canada National Microbiology Laboratory, Public Health Agency of Canada, 1015 Arlington Street, Winnipeg, MB R3E 3R2, Canada
| | - David Safronetz
- Canada National Microbiology Laboratory, Public Health Agency of Canada, 1015 Arlington Street, Winnipeg, MB R3E 3R2, Canada
| | - Volker Gerdts
- Vaccine and Infectious Disease Organization-International Vaccine Centre (VIDO-InterVac), University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada; Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada
| | - Uladzimir Karniychuk
- Vaccine and Infectious Disease Organization-International Vaccine Centre (VIDO-InterVac), University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada; Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada; School of Public Health, University of Saskatchewan, Saskatoon, SK, Canada.
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Kekarainen T, Segalés J. Porcine circovirus 2 immunology and viral evolution. Porcine Health Manag 2015; 1:17. [PMID: 28405423 PMCID: PMC5382452 DOI: 10.1186/s40813-015-0012-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 11/11/2015] [Indexed: 02/08/2023] Open
Abstract
Porcine circovirus 2 (PCV2) has and is still causing important economic losses to pig industry. This is due to PCV2-systemic disease (PCV2-SD), formerly known as postweaning multi-systemic wasting syndrome (PMWS), which increases mortality rates and slows down the growth of the animals, as well as other conditions collectively included within the so-called porcine circovirus diseases (PCVD). PCV2-SD affected pigs are considered to be immunosuppressed, with severe lymphocyte depletion and evidence of secondary infections. However, PCV2-infected pigs not developing the disease are able to mount humoral and cellular immune responses and clear the virus or limit the infection. On the contrary, insufficient amounts of neutralizing antibodies have been linked to increased PCV2 replication, severe lymphoid lesions and development of PCV2-SD. Central role in controlling PCV2 infection are played by the antigen specific memory T cells. These cells persist long term post-infection or vaccination and are able to expand rapidly after recall antigen recognition. Most farms in the main pig producing countries are applying vaccination against PCV2 to prevent the disease and improve the farm performance. Vaccines do not induce sterilizing immunity and PCV2 keeps on circulating even in farms applying vaccination. This, together with the high mutation rate of PCV2, world-wide fluctuations in the genotype dominance and emergence of novel genetic variants, warrant close molecular survey of the virus in the field.
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Affiliation(s)
- Tuija Kekarainen
- Centre de Recerca en Sanitat Animal (CReSA), Institute of Agrifood Research and Technology (IRTA), Bellaterra, Cerdanyola del Vallès, Spain
| | - Joaquim Segalés
- Centre de Recerca en Sanitat Animal (CReSA), Institute of Agrifood Research and Technology (IRTA), Bellaterra, Cerdanyola del Vallès, Spain.,Departament de Sanitat i Anatomia Animals, Universitat Autònoma de Barcelona, Bellaterra, Cerdanyola del Vallès, Spain
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Huang L, Van Renne N, Liu C, Nauwynck HJ. A sequence of basic residues in the porcine circovirus type 2 capsid protein is crucial for its co-expression and co-localization with the replication protein. J Gen Virol 2015; 96:3566-3576. [PMID: 26415571 DOI: 10.1099/jgv.0.000302] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Porcine circovirus type 2 (PCV2) encodes two major proteins: the replication protein (Rep) and the capsid protein (Cap). Cap displays a conserved stretch of basic residues situated on the inside of the capsid, whose role is so far unknown. We used a reverse-genetics approach to investigate its function and found that mutations in these amino acids hindered Cap mRNA translation and hampered Cap/Rep co-localization, yielding unfit viruses. Intriguingly, co-transfection with a WT PCV2 of a different genotype partially rescued mutant Cap expression, showing the importance of this basic pattern for efficient translation of Cap mRNA into protein. Our results show that Cap and Rep are expressed independently of each other, and that this amino acid sequence of Cap is vital for virus propagation. This study provides a method for studying unfit PCV2 virions and offers new insights into the intracellular modus vivendi of PCV2.
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Affiliation(s)
- Liping Huang
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium.,Division of Swine Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, The Chinese Academy of Agricultural Sciences, Maduan Street 427, Harbin 150001, PR China
| | - Nicolaas Van Renne
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium
| | - Changming Liu
- Division of Swine Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, The Chinese Academy of Agricultural Sciences, Maduan Street 427, Harbin 150001, PR China
| | - Hans J Nauwynck
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium
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Anti-porcine circovirus type 2 (PCV2) antibody placental barrier leakage from sow to fetus: impact on the diagnosis of intra-uterine PCV2 infection. Virol Sin 2014; 29:136-8. [PMID: 24643939 DOI: 10.1007/s12250-014-3432-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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10
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Saha D, Karniychuk UU, Huang L, Geldhof M, Vanhee M, Lefebvre DJ, Meerts P, Ducatelle R, Doorsselaere JV, Nauwynck HJ. Unusual outcome of in utero infection and subsequent postnatal super-infection with different PCV2b strains. Virol Sin 2014; 29:176-82. [PMID: 24950783 DOI: 10.1007/s12250-014-3431-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 06/05/2014] [Indexed: 10/25/2022] Open
Abstract
VC2002, isolated from postweaning multisystemic wasting syndrome (PMWS)-affected pig, is a mixture of two porcine circovirus genotype 2b (PCV2b) viruses, K2 and K39. Preliminary experiments disclosed short-term adverse effects of K39, but not K2, on porcine foetuses. These findings led to the hypothesis that infection of immuno-incompetent foetuses with K2 confers a status of immunotolerance, and postnatal super-infection with K39 triggers PMWS. To explore this hypothesis, nine 55-day-old foetuses were inoculated in utero (three with K2-10(4.3)TCID50, three with K39-10(4.3)TCID50 and three with medium), and foeto-pathogenicity examined. At 21 days post-inoculation (dpi), K2 did not induce pathology, whereas pathological effects of K39 were evident. Twenty-four 45-day-old foetuses were subsequently inoculated to examine the long-term effect of K2, including six with K2-high dose-10(4.3)TCID50, six with K2-low dose-10(2.3)TCID50 and 12 mock-inoculated controls. Both doses resulted in five mummified foetuses and one live-born piglet each (69dpi). K2 was recovered from all mummies. K2 and K2-specific antibodies were not detected in serum of the two live-born piglets at birth, indicating full control of K2 infection. The K2-low dose-infected piglet was immunostimulated at day 2, but not the K2-high dose-infected piglet. Both non-stimulated and stimulated K2-infected piglets were super-inoculated with K39 at day 6 or 8 (taken as 0 days post super-inoculation). Low viral replication was observed in the non-stimulated K2-K39 piglet (up to 10(3.3)TCID50/g; identified as K39). In contrast, viral replication was extremely high in the stimulated K2-K39 piglet (up to 10(5.6)TCID50/g) and identified as K2, indicating that K2 infection is controlled during foetal life, but emerges after birth upon immunostimulation. However, none of the piglets showed any signs of PMWS.
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Affiliation(s)
- Dipongkor Saha
- Laboratory of Virology, Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
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11
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Liu J, Huang L, Wei Y, Tang Q, Liu D, Wang Y, Li S, Guo L, Wu H, Liu C. Amino acid mutations in the capsid protein produce novel porcine circovirus type 2 neutralizing epitopes. Vet Microbiol 2013; 165:260-7. [DOI: 10.1016/j.vetmic.2013.03.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2013] [Revised: 03/07/2013] [Accepted: 03/14/2013] [Indexed: 11/16/2022]
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12
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Wang C, Pang VF, Lee F, Liao PC, Huang YL, Lin YL, Lai SS, Jeng CR. Development and evaluation of a loop-mediated isothermal amplification method for rapid detection and differentiation of two genotypes of porcine circovirus type 2. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2013; 47:363-70. [PMID: 23845855 DOI: 10.1016/j.jmii.2013.05.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2012] [Revised: 04/19/2013] [Accepted: 05/08/2013] [Indexed: 11/26/2022]
Abstract
BACKGROUND Porcine circovirus type 2 (PCV2) is one of the major swine viral diseases and has caused significant economic loss to pig producers. PCV2 has been divided into two major genotypes: PCV2a, PCV2b. A loop-mediated isothermal amplification (LAMP) method was developed for the detection and differentiation of PCV2a and PCV2b in clinical samples. METHODS LAMP-specific primer sets were designed based on six PCV2a and six PCV2b reference isolates. To determine the analytical specificity of LAMP, DNA samples extracted from 36 porcine virus isolates were tested by LAMP, including eight PCV2a, 11 PCV2b, four PCV type 1, two porcine parvovirus, three pseudorabies virus, and eight porcine reproductive and respiratory virus. To evaluate the analytical sensitivity of the assay, 10-fold serial dilutions of PCV2a and PCV2b recombinant plasmids were performed to prepare the dilutions at concentration from 10(6) to 1 copy(ies)/μL, and each dilution was tested by both LAMP and nested polymerase chain reaction (nested PCR). A total of 168 clinical samples were analyzed by both LAMP and nested PCR, and the relative sensitivity and specificity of LAMP compared to nested PCR were calculated. RESULTS Using different primer sets of LAMP, LAMP could be completed within 50 minutes. This method was found to be highly analytically specific for PCV2a and PCV2b; only the target gene was detected without cross-reaction. The analytical sensitivity of LAMP for PCV2a and PCV2b were 10 copies/μL, demonstrating analytical sensitivity comparable to that obtained using nested PCR. In addition, the sensitivity and specificity of LAMP relative to those of nested PCR were 97.7% and 100.0%, respectively. The percentage of observed agreement was 98.2%, and the κ statistic was 0.949. CONCLUSION LAMP is a rapid, specific, and sensitive diagnostic method for the detection and differentiation of PCV2a and PCV2b in clinical samples.
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Affiliation(s)
- Chun Wang
- Animal Health Research Institute, Council of Agriculture, Executive Yuan, No. 376, Chung-Cheng Road, Tamsui, New Taipei City 251, Taiwan; Graduate Institute of Veterinary Medicine, School of Veterinary Medicine, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan
| | - Victor Fei Pang
- Graduate Institute of Molecular and Comparative Pathobiology, School of Veterinary Medicine, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan
| | - Fan Lee
- Animal Health Research Institute, Council of Agriculture, Executive Yuan, No. 376, Chung-Cheng Road, Tamsui, New Taipei City 251, Taiwan
| | - Pei-Chih Liao
- Animal Disease Control Centre of Yunlin County, No. 517, Sec. 2, Yunlin Road, Douliou City, Yunlin County 640, Taiwan
| | - Yu-Liang Huang
- Animal Health Research Institute, Council of Agriculture, Executive Yuan, No. 376, Chung-Cheng Road, Tamsui, New Taipei City 251, Taiwan
| | - Yeou-Liang Lin
- Animal Health Research Institute, Council of Agriculture, Executive Yuan, No. 376, Chung-Cheng Road, Tamsui, New Taipei City 251, Taiwan
| | - Shiow-Suey Lai
- Graduate Institute of Veterinary Medicine, School of Veterinary Medicine, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan.
| | - Chian-Ren Jeng
- Graduate Institute of Molecular and Comparative Pathobiology, School of Veterinary Medicine, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan.
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Wang C, Pang VF, Lee F, Huang TS, Lee SH, Lin YJ, Lin YL, Lai SS, Jeng CR. Prevalence and genetic variation of porcine circovirus type 2 in Taiwan from 2001 to 2011. Res Vet Sci 2012; 94:789-95. [PMID: 23260863 DOI: 10.1016/j.rvsc.2012.11.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Revised: 11/22/2012] [Accepted: 11/26/2012] [Indexed: 11/26/2022]
Abstract
Porcine circovirus type 2 (PCV2) is the major causative agent of postweaning multisystemic wasting syndrome (PMWS) in Taiwanese pig farms. We analyzed the complete genomes of 571 Taiwanese PCV2 isolates in Taiwan from 2001 to 2011 and divided the isolates into 2 distinct genotypes (PCV2a and PCV2b) with 6 clusters (1A, 1B, 1C, 2B, 2D, and 2E). Of the 571 Taiwanese PCV2 isolates, 22.9% (131/571) belonged to PCV2a and 77.1% (440/571) to PCV2b. In this study, PCV2a isolates were the most common in 2001, and then PCV2b isolates became predominate thereafter and widely distributed in pig farms since 2003. Sequence comparisons among the 571 isolates indicated that 89.6-100% had nucleotide identity for complete genome and 87.3-100% for open reading frames 2 (ORF2). The results suggest that a higher genetic variation and shift occurred among PCV2 isolates collected from 2001 to 2011 in Taiwan.
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Affiliation(s)
- Chun Wang
- Animal Health Research Institute, Council of Agriculture, Executive Yuan, No. 376, Chung-Cheng Rd., Tansui, New Taipei City 251, Taiwan, ROC
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Sarli G, Morandi F, Panarese S, Bacci B, Ferrara D, Bianco C, Fusaro L, Bacci ML, Galeati G, Dottori M, Bonilauri P, Lelli D, Leotti G, Vila T, Joisel F, Allan G, Benazzi C, Ostanello F. Reproduction in porcine circovirus type 2 (PCV2) seropositive gilts inseminated with PCV2b spiked semen. Acta Vet Scand 2012; 54:51. [PMID: 22935352 PMCID: PMC3509407 DOI: 10.1186/1751-0147-54-51] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Accepted: 08/08/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Since 1999, field evidence of transplacental infection by porcine circovirus type 2 (PCV2) and reproductive failure has been reported in pigs. The objective of this study was to evaluate the clinical and pathological consequences of PCV2 infection in conventional PCV2-seropositive gilts by insemination with PCV2b-spiked semen. RESULTS Six PCV2 seropositive gilts were inseminated with PCV2b-supplemented semen (infected) and three animals with semen and cell culture medium (controls). Only three out of the six infected animals were pregnant by ultrasonography on day 29 after insemination, while two out of the three controls were pregnant. One control gilt aborted on day 23 after insemination but not due to PVC2. Viraemia was demonstrated in four out of six infected and in one control gilt that became infected with PCV2a. Anti-PCV2 antibody titres showed dynamic variations in the infected group throughout the study. Among infected gilts, the animal with the lowest anti-PCV2 titre (1/100) at the beginning of the experiment and another that reached a similar low value during the experiment showed evident seroconversion over time and had also PCV2 positive foetuses. One placenta displayed mild focal necrosis of the chorionic epithelium positively stained by immunohistochemistry for PCV2 antigen. CONCLUSIONS PCV2-seropositive gilts can be infected with PCV2 after intrauterine exposure and low maternal antibody titre may increase the probability of a foetal infection.
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Saha D, Lefebvre DJ, Ooms K, Huang L, Delputte PL, Van Doorsselaere J, Nauwynck HJ. Single amino acid mutations in the capsid switch the neutralization phenotype of porcine circovirus 2. J Gen Virol 2012; 93:1548-1555. [DOI: 10.1099/vir.0.042085-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
Abstract
Porcine circovirus 2 (PCV2) is the causative agent of porcine circovirus-associated diseases in pigs. Previously, it was demonstrated that mAbs 16G12, 38C1, 63H3 and 94H8 directed against the PCV2 capsid protein recognize PCV2 strains Stoon-1010 (PCV2a), 48285 (PCV2b), 1121 (PCV2a), 1147 (PCV2b) and II9F (PCV2b), but only neutralize Stoon-1010 and 48285. This points to the existence of two distinct PCV2 neutralization phenotypes: phenotype α (mAb recognition with neutralization; Stoon-1010 and 48285) and phenotype β (mAb recognition without neutralization; 1121, 1147 and II9F). In the present study, amino acids that are important in determining the neutralization phenotype were identified in the capsid. Mutation of T at position 190 to A in strain 48285 (phenotype α) resulted in a capsid resembling that of strain 1147 (phenotype β) and caused a loss of neutralization (switch from α to β). Mutations of P at position 151 to T and A at position 190 to T in strain II9F (phenotype β) resulted in a capsid resembling that of strain 48285 (phenotype α) and gave a gain of neutralization (switch from β to α). Mutations of T at position 131 to P and of E at position 191 to R in Stoon-1010 (phenotype α) changed the capsid into that of 1121 (phenotype β) and reduced neutralization (switch from α to β). This study demonstrated that single amino acid changes in the capsid result in a phenotypic switch from α to β or β to α.
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Affiliation(s)
- Dipongkor Saha
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | | | - Karen Ooms
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - Liping Huang
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - Peter L. Delputte
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - Jan Van Doorsselaere
- Department of Health Care and Biotechnology, KATHO Catholic University College of South-West Flanders, Wilgenstraat 32, 8800 Roeselare, Belgium
| | - Hans J. Nauwynck
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
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Segalés J. Porcine circovirus type 2 (PCV2) infections: Clinical signs, pathology and laboratory diagnosis. Virus Res 2012; 164:10-9. [DOI: 10.1016/j.virusres.2011.10.007] [Citation(s) in RCA: 384] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Revised: 10/10/2011] [Accepted: 10/11/2011] [Indexed: 12/18/2022]
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Nauwynck H, Sanchez R, Meerts P, Lefebvre D, Saha D, Huang L, Misinzo G. Cell tropism and entry of porcine circovirus 2. Virus Res 2012; 164:43-5. [DOI: 10.1016/j.virusres.2011.11.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Revised: 11/04/2011] [Accepted: 11/05/2011] [Indexed: 11/27/2022]
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18
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Saha D, Doorsselaere JV, Nauwynck HJ. Instability in vitro of a PCV2 infectious clone containing an insertion between ORF1 and ORF2. Virus Genes 2011; 44:258-61. [DOI: 10.1007/s11262-011-0693-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Accepted: 11/14/2011] [Indexed: 10/15/2022]
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Saha D, Lefebvre DJ, Ducatelle R, Doorsselaere JV, Nauwynck HJ. Outcome of experimental porcine circovirus type 1 infections in mid-gestational porcine foetuses. BMC Vet Res 2011; 7:64. [PMID: 22018436 PMCID: PMC3216242 DOI: 10.1186/1746-6148-7-64] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Accepted: 10/21/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Porcine circovirus type 1 (PCV1) has been described as a non-cytopathic contaminant of the PK-15 cell line. Several experimental infections with PCV1 failed to reproduce disease in pigs. Therefore, PCV1 is generally accepted as non-pathogenic to pigs. To our knowledge, nothing is known about the outcome of PCV1 infections in porcine foetuses. This was examined in the present study. RESULTS Nine foetuses from three sows were inoculated at 55 days of gestation: three with 10(4.3) TCID(50) of the PCV1 cell culture strain ATCC-CCL33, three with 10(4.3) TCID(50) of the PCV1 field strain 3384 and three with cell culture medium (mock-inoculated). At 21 days post-inoculation, all 6 PCV1-inoculated and all 3 mock-inoculated foetuses had a normal external appearance. Microscopic lesions characterized by severe haemorrhages were observed in the lungs of two foetuses inoculated with CCL33. High PCV1 titres (up to 10(4.7) TCID(50)/g tissue) were found in the lungs of the CCL33-inoculated foetuses. All other organs of the CCL33-inoculated foetuses and all the organs of the 3384-inoculated foetuses were negative (< 10(1.7) TCID(50)/g tissue) by virus titration. PCV1-positive cells (up to 121 cells/10 mm(2) in CCL33-inoculated foetuses and up to 13 cells/10 mm(2) in 3384-inoculated foetuses) were found in the heart, lungs, spleen, liver, thymus and tonsils. PCR and DNA sequencing of Rep recovered CCL33 or 3384 sequences from CCL33- or 3384-inoculated foetuses, respectively. CONCLUSIONS From this study, it can be concluded that cell culture PCV1 can replicate efficiently and produce pathology in the lungs of porcine foetuses inoculated at 55 days of foetal life.
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Affiliation(s)
- Dipongkor Saha
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Belgium
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