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Fang Z, Sun M, Cai X, An T, Tu Y, Wang H. Identification of a conserved B-cell epitope on the capsid protein of porcine circovirus type 4. mSphere 2024; 9:e0022524. [PMID: 38926905 PMCID: PMC11288031 DOI: 10.1128/msphere.00225-24] [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: 03/17/2024] [Accepted: 05/24/2024] [Indexed: 06/28/2024] Open
Abstract
Porcine circovirus type 4 (PCV4), a recently identified circovirus, is prevalent in numerous provinces in China, as well as in South Korea, Thailand, and Europe. PCV4 virus rescued from an infectious clone showed pathogenicity, suggesting the economic impact of PCV4. However, there remains a lack of understanding regarding the immunogenicity and epitopes of PCV4. This study generated a monoclonal antibody (MAb) 1D8 by immunizing mice with PCV4 virus-like particles (VLPs). Subsequently, the epitope recognized by the MAb 1D8 was identified by truncated protein expression and alanine scanning mutagenesis analysis. Results showed that the 225PKQG228 located at the C-terminus of the PCV4 Cap protein is the minimal motif binding to the MAb. Homology modeling analysis and immunoelectron microscopy revealed that the epitope extends beyond the outer surface of the PCV4 VLP. Moreover, the epitope is highly conserved among PCV4 strains and does not react with other PCVs. Together, the MAb 1D8 recognized epitope shows potential for detecting PCV4. These findings significantly contribute to the design of antigens for PCV4 detection and control strategies. IMPORTANCE Porcine circovirus type 4 (PCV4) is a novel circovirus. Although PCV4 has been identified in several countries, including China, Korea, Thailand, and Spain, no vaccine is available. Given the potential pathogenic effects of PCV4 on pigs, PCV4 could threaten the global pig farming industry, highlighting the urgency for further investigation. Thus, epitopes of PCV4 remain to be determined. Our finding of a conserved epitope significantly advances vaccine development and pathogen detection.
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Affiliation(s)
- Zheng Fang
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin, China
| | - Mingxia Sun
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin, China
| | - Xuehui Cai
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin, China
- Heilongjiang Veterinary Biopharmaceutical Engineering Technology Research Center, Harbin, China
| | - Tongqing An
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin, China
- Heilongjiang Provincial Key Laboratory of Veterinary Immunology, Harbin, China
| | - Yabin Tu
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin, China
| | - Haiwei Wang
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin, China
- Heilongjiang Provincial Key Laboratory of Veterinary Immunology, Harbin, China
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2
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Cao Z, Ling X, Haseeb A, Sun P, Zhang H, Yin W, Fan K, Yang H, Zhang Z, Zhong J, Sun Y, Sun N, Li H. Analysis of the anti-PCV2 mechanism of Lactobacillus acidophilus based on non-target metabolomics and high-throughput molecular docking. Front Microbiol 2024; 15:1416235. [PMID: 38860222 PMCID: PMC11163031 DOI: 10.3389/fmicb.2024.1416235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Accepted: 05/13/2024] [Indexed: 06/12/2024] Open
Abstract
Our previous studies have revealed that L. acidophilus possesses inhibitory effects on PCV2 proliferation in vivo, although the underlying mechanisms remain elusive. Probiotics like L. acidophilus are known to exert antiviral through their metabolites. Therefore, in this study, non-targeted metabolomics was used to detect the changes in metabolites of L. acidophilus after 24 h of proliferation. Subsequently, high-throughput molecular docking was utilized to analyze the docking scores of these metabolites with PCV2 Cap and Rep, aiming to identify compounds with potential anti-PCV2 effects. The results demonstrated that 128 compounds such as Dl-lactate were significantly increased. The results of high-throughput molecular docking indicated that compounds such as ergocristine, and telmisartan formed complexes with Cap and Rep, suggesting their potential anti-PCV2 properties. Furthermore, compounds like vitamin C, exhibit pharmacological effects consistent with L. acidophilus adding credence to the idea that L. acidophilus may exert pharmacological effects through its metabolites. These results will provide a foundation for the study of L. acidophilus.
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Affiliation(s)
- Zhigang Cao
- Shanxi Key Laboratory for Modernization of TCVM, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, Shanxi, China
| | - Xiaoya Ling
- Shanxi Key Laboratory for Modernization of TCVM, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, Shanxi, China
| | - Abdul Haseeb
- Shanxi Key Laboratory for Modernization of TCVM, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, Shanxi, China
| | - Panpan Sun
- Shanxi Key Laboratory for Modernization of TCVM, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, Shanxi, China
| | - Hua Zhang
- Shanxi Key Laboratory for Modernization of TCVM, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, Shanxi, China
| | - Wei Yin
- Shanxi Key Laboratory for Modernization of TCVM, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, Shanxi, China
| | - Kuohai Fan
- Laboratory Animal Center, Shanxi Agricultural University, Jinzhong, Shanxi, China
| | - Huizhen Yang
- Shanxi Key Laboratory for Modernization of TCVM, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, Shanxi, China
| | - Zhenbiao Zhang
- Shanxi Key Laboratory for Modernization of TCVM, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, Shanxi, China
| | - Jia Zhong
- Shanxi Key Laboratory for Modernization of TCVM, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, Shanxi, China
| | - Yaogui Sun
- Shanxi Key Laboratory for Modernization of TCVM, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, Shanxi, China
| | - Na Sun
- Shanxi Key Laboratory for Modernization of TCVM, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, Shanxi, China
| | - Hongquan Li
- Shanxi Key Laboratory for Modernization of TCVM, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, Shanxi, China
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Arrieta-Mendoza D, Garces B, Hidalgo AA, Neira V, Ramirez G, Neira-Carrillo A, Bucarey SA. Design of a New Vaccine Prototype against Porcine Circovirus Type 2 (PCV2), M. hyopneumoniae and M. hyorhinis Based on Multiple Antigens Microencapsulation with Sulfated Chitosan. Vaccines (Basel) 2024; 12:550. [PMID: 38793801 PMCID: PMC11125950 DOI: 10.3390/vaccines12050550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 04/16/2024] [Accepted: 04/17/2024] [Indexed: 05/26/2024] Open
Abstract
This work evaluated in vivo an experimental-multivalent-vaccine (EMV) based on three Porcine Respiratory Complex (PRC)-associated antigens: Porcine Circovirus Type 2 (PCV2), M. hyopneumoniae (Mhyop) and M. hyorhinis (Mhyor), microencapsulated with sulfated chitosan (M- ChS + PRC-antigens), postulating chitosan sulphate (ChS) as a mimetic of the heparan sulfate receptor used by these pathogens for cell invasion. The EMV was evaluated physicochemically by SEM (Scanning-Electron-Microscopy), EDS (Energy-Dispersive-Spectroscopy), Pdi (Polydispersity-Index) and zeta potential. Twenty weaned pigs, distributed in four groups, were evaluated for 12 weeks. The groups 1 through 4 were as follows: 1-EMV intramuscular-route (IM), 2-EMV oral-nasal-route (O/N), 3-Placebo O/N (M-ChS without antigens), 4-Commercial-vaccine PCV2-Mhyop. qPCR was used to evaluate viral/bacterial load from serum, nasal and bronchial swab and from inguinal lymphoid samples. Specific humoral immunity was evaluated by ELISA. M-ChS + PRC-antigens measured between 1.3-10 μm and presented low Pdi and negative zeta potential, probably due to S (4.26%). Importantly, the 1-EMV protected 90% of challenged animals against PCV2 and Mhyop and 100% against Mhyor. A significant increase in antibody was observed for Mhyor (1-EMV and 2-EMV) and Mhyop (2-EMV), compared with 4-Commercial-vaccine. No difference in antibody levels between 1-EMV and 4-Commercial-vaccine for PCV2-Mhyop was observed. Conclusion: The results demonstrated the effectiveness of the first EMV with M-ChS + PRC-antigens in pigs, which were challenged with Mhyor, PCV2 and Mhyop, evidencing high protection for Mhyor, which has no commercial vaccine available.
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Affiliation(s)
- Darwuin Arrieta-Mendoza
- Doctoral Program in Forestry, Agricultural and Veterinary Sciences, South Campus, University of Chile, Av. Santa Rosa 11315, La Pintana, Santiago 8820808, Chile;
| | - Bruno Garces
- Escuela de Química y Farmacia, Facultad de Medicina, Universidad Andres Bello, 2320 Sazié, Santiago 8320000, Chile; (B.G.); (A.A.H.)
| | - Alejandro A. Hidalgo
- Escuela de Química y Farmacia, Facultad de Medicina, Universidad Andres Bello, 2320 Sazié, Santiago 8320000, Chile; (B.G.); (A.A.H.)
| | - Victor Neira
- Departamento de Medicina Preventiva, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Av. Santa Rosa 11735, La Pintana, Santiago 8320000, Chile; (V.N.); (G.R.)
| | - Galia Ramirez
- Departamento de Medicina Preventiva, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Av. Santa Rosa 11735, La Pintana, Santiago 8320000, Chile; (V.N.); (G.R.)
| | - Andrónico Neira-Carrillo
- Laboratorio Polyforms, Departamento de Ciencias Biológicas, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Av. Santa Rosa 11735, La Pintana, Santiago 8320000, Chile;
| | - Sergio A. Bucarey
- Centro Biotecnológico Veterinario, Biovetec, Departamento de Ciencias Biológicas, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Av. Santa Rosa 11735, La Pintana, Santiago 8320000, Chile
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4
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Ouyang Y, Nauwynck HJ. Molecular basis for the different PCV2 susceptibility of T-lymphoblasts in Landrace and Piétrain pigs. Vet Res 2024; 55:22. [PMID: 38374131 PMCID: PMC10875804 DOI: 10.1186/s13567-024-01275-0] [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: 11/09/2023] [Accepted: 01/29/2024] [Indexed: 02/21/2024] Open
Abstract
Clinically, Landrace pigs are more susceptible to porcine circovirus-associated diseases (PCVADs) than Piétrain pigs. We previously found that porcine circovirus type 2 (PCV2) can infect T-lymphoblasts. The present study examined the replication kinetics of six PCV2 strains in the lymphoblasts of Landrace and Piétrain pigs. The results showed that T-lymphoblasts from Landrace pigs are much more susceptible to PCV2 infection than those from Piétrain pigs. In addition, PCV2 replication was strain-dependent. PCV2 binding to T-lymphoblasts was partially mediated by chondroitin sulfate (CS) and dermatan sulfate (DS). Phosphacan, an effective internalization mediator in monocytes that contains several CS chains, was also demonstrated to be involved in PCV2 internalization. Viral binding and internalization were not different between the two breeds, however, the subsequent step, the disassembly was. Although inhibition of serine proteases blocked PCV2 replication in both Landrace and Piétrain pigs, this only occurred at a neutral pH in Piétrain pigs, whereas this occurred also at a low pH in Landrace. This suggested that more proteases can cleave PCV2 in Landrace lymphoblasts than in Piétrain lymphoblasts, explaining the better replication. Through co-localization studies of viral particles with endo-lysosomal markers, and quantitative analysis of organelle sizes during viral internalization, it was observed that PCV2 may exhibit a higher propensity for viral escape from late endosomes in Landrace pigs (smaller) compared to Piétrain pigs. These results provide new understandings of the different PCV2 susceptibility in Landrace and Piétrain pigs.
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Affiliation(s)
- Yueling Ouyang
- Laboratory of Virology, Department of Translational Physiology, Infectiology and Public Health, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium.
| | - Hans J Nauwynck
- Laboratory of Virology, Department of Translational Physiology, Infectiology and Public Health, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
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5
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Qu M, Zhang H, Cheng P, Wubshet AK, Yin X, Wang X, Sun Y. Histone deacetylase 6's function in viral infection, innate immunity, and disease: latest advances. Front Immunol 2023; 14:1216548. [PMID: 37638049 PMCID: PMC10450946 DOI: 10.3389/fimmu.2023.1216548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 07/14/2023] [Indexed: 08/29/2023] Open
Abstract
In the family of histone-deacetylases, histone deacetylase 6 (HDAC6) stands out. The cytoplasmic class IIb histone deacetylase (HDAC) family is essential for many cellular functions. It plays a crucial and debatable regulatory role in innate antiviral immunity. This review summarises the current state of our understanding of HDAC6's structure and function in light of the three mechanisms by which it controls DNA and RNA virus infection: cytoskeleton regulation, host innate immune response, and autophagy degradation of host or viral proteins. In addition, we summed up how HDAC6 inhibitors are used to treat a wide range of diseases, and how its upstream signaling plays a role in the antiviral mechanism. Together, the findings of this review highlight HDAC6's importance as a new therapeutic target in antiviral immunity, innate immune response, and some diseases, all of which offer promising new avenues for the development of drugs targeting the immune response.
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Affiliation(s)
- Min Qu
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Huijun Zhang
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Pengyuan Cheng
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Ashenafi Kiros Wubshet
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
- Department of Basic and Diagnostic Sciences, College of Veterinary Science, Mekelle University, Mekelle, Tigray, Ethiopia
| | - Xiangping Yin
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Xiangwei Wang
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Yuefeng Sun
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
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6
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Maity HK, Samanta K, Deb R, Gupta VK. Revisiting Porcine Circovirus Infection: Recent Insights and Its Significance in the Piggery Sector. Vaccines (Basel) 2023; 11:1308. [PMID: 37631876 PMCID: PMC10457769 DOI: 10.3390/vaccines11081308] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 07/29/2023] [Accepted: 07/29/2023] [Indexed: 08/27/2023] Open
Abstract
Porcine circovirus (PCV), a member of the Circoviridae family within the genus Circovirus, poses a significant economic risk to the global swine industry. PCV2, which has nine identified genotypes (a-i), has emerged as the predominant genotype worldwide, particularly PCV2d. PCV2 has been commonly found in both domestic pigs and wild boars, and sporadically in non-porcine animals. The virus spreads among swine populations through horizontal and vertical transmission routes. Despite the availability of commercial vaccines for controlling porcine circovirus infections and associated diseases, the continuous genotypic shifts from a to b, and subsequently from b to d, have maintained PCV2 as a significant pathogen with substantial economic implications. This review aims to provide an updated understanding of the biology, genetic variation, distribution, and preventive strategies concerning porcine circoviruses and their associated diseases in swine.
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Affiliation(s)
- Hemanta Kumar Maity
- Department of Avian Science, Faculty of Veterinary & Animal Science, West Bengal University of Animal & Fishery Sciences, Kolkata 700037, West Bengal, India
| | - Kartik Samanta
- Department of Avian Science, Faculty of Veterinary & Animal Science, West Bengal University of Animal & Fishery Sciences, Kolkata 700037, West Bengal, India
| | - Rajib Deb
- ICAR-National Research Center on Pig, Rani, Guwahati 781131, Assam, India
| | - Vivek Kumar Gupta
- ICAR-National Research Center on Pig, Rani, Guwahati 781131, Assam, India
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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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Zhao M, Bao S, Xu D, He J, Zhang H, Ji L, Yang S, Wang X, Shen Q, Liu J, Zhang Q, Ma X, Zhang W, Shan T. Virome of wild rats (Rattus norvegicus) captured far from pig farms in Jiangsu province of China reveals novel porcine circovirus type 2d (PCV2d) sequences. Virol J 2023; 20:46. [PMID: 36894948 PMCID: PMC9997004 DOI: 10.1186/s12985-023-02005-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 03/03/2023] [Indexed: 03/11/2023] Open
Abstract
BACKGROUND Porcine circovirus type 2 (PCV2) has caused great economic losses in the global pig industry. There have been published records of wild rats acting as the reservoirs of PCV2 (only PCV2a and PCV2b), but almost all of which were related to the PCV2-infected swine herds. RESULTS In this study, we carried out the detection, amplification, and characterization of novel PCV2 strains in wild rats that were captured far from pig farms. Nested PCR assay demonstrated that the kidney, heart, lung, liver, pancreas, and large and small intestines of rats were screened positive for PCV2. We subsequently sequenced two full genomes of PCV2 in positive sample pools, designated as js2021-Rt001 and js2021-Rt002. Genome sequence analysis indicated that they had the highest similarity to nucleotide sequences of porcine-origin PCV2 isolates in Vietnam. Phylogenetically, js2021-Rt001 and js2021-Rt002 were a part of the PCV2d genotype cluster, which is a predominant genotype circulating worldwide in recent years. The antibody recognition regions, immunodominant decoy epitope, and heparin sulfate binding motif of the two complete genome sequences coincided with those previously reported. CONCLUSIONS Our research reported the genomic characterization of two novel PCV2 strains (js2021-Rt001 and js2021-Rt002) and provided the first supported evidence that PCV2d could naturally infect wild rats in China. However, whether the newly identified strains have potential for circulating in nature in vertical and horizontal transmission or inter-species jumping between rats and pigs needs further research.
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Affiliation(s)
- Min Zhao
- Department of Microbiology, School of Medicine, Jiangsu University, Zhenjiang, 212003, Jiangsu, China
| | - Siwen Bao
- Department of Microbiology, School of Medicine, Jiangsu University, Zhenjiang, 212003, Jiangsu, China
| | - Diandian Xu
- Department of Microbiology, School of Medicine, Jiangsu University, Zhenjiang, 212003, Jiangsu, China
| | - Jingxian He
- School of Medicine, Suzhou University, Suzhou, 215031, Jiangsu, China
| | - Han Zhang
- Department of Microbiology, School of Medicine, Jiangsu University, Zhenjiang, 212003, Jiangsu, China
| | - Likai Ji
- Department of Microbiology, School of Medicine, Jiangsu University, Zhenjiang, 212003, Jiangsu, China
| | - Shixing Yang
- Department of Microbiology, School of Medicine, Jiangsu University, Zhenjiang, 212003, Jiangsu, China
| | - Xiaochun Wang
- Department of Microbiology, School of Medicine, Jiangsu University, Zhenjiang, 212003, Jiangsu, China
| | - Quan Shen
- Department of Microbiology, School of Medicine, Jiangsu University, Zhenjiang, 212003, Jiangsu, China
| | - Jia Liu
- Qinghai Institute of Endemic Disease Prevention and Control, Xining, 811602, Qinghai, China
| | - Qing Zhang
- Qinghai Institute of Endemic Disease Prevention and Control, Xining, 811602, Qinghai, China
| | - Xiao Ma
- Qinghai Institute of Endemic Disease Prevention and Control, Xining, 811602, Qinghai, China.
| | - Wen Zhang
- Department of Microbiology, School of Medicine, Jiangsu University, Zhenjiang, 212003, Jiangsu, China.
| | - Tongling Shan
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China.
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9
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Ouyang Y, Nauwynck HJ. PCV2 Uptake by Porcine Monocytes Is Strain-Dependent and Is Associated with Amino Acid Characteristics on the Capsid Surface. Microbiol Spectr 2023; 11:e0380522. [PMID: 36719220 PMCID: PMC10100887 DOI: 10.1128/spectrum.03805-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 01/13/2023] [Indexed: 02/01/2023] Open
Abstract
Porcine circovirus type 2 (PCV2) is associated with several economically important diseases that are described as PCV2-associated diseases (PCVADs). PCV2 is replicating in lymphoblasts, and PCV2 particles are taken up by monocytes without effective replication or complete degradation. Glycosaminoglycans (GAGs) have been demonstrated to be important receptors for PCV2 binding and entry in T-lymphocytes and continuous cell lines. The objective of this study was to determine whether differences exist in viral uptake and outcome among six PCV2 strains from different disease outbreaks in primary porcine monocytes: Stoon-1010 (PCV2a; PMWS), 1121 (PCV2a; abortion), 1147 (PCV2b; PDNS), 09V448 (PCV2d-1; PCVAD with high viral load in lymphoid tissues [PCVADhigh]), DE222-13 (PCV2d-2; PCVADhigh), and 19V245 (PCV2d-2; PCVADhigh). The uptake of PCV2 in peripheral blood monocytes was different among the PCV2 strains. A large number of PCV2 particles were found in the monocytes for Stoon-1010, DE222-13, and 19V245, while a low number was found for 1121, 1147, and 09V448. Competition with, and removal of GAGs on the cell surface, demonstrated an important role of chondroitin sulfate (CS) and dermatan sulfate (DS) in PCV2 entry into monocytes. The mapping of positively/negatively charged amino acids exposed on the surface of PCV2 capsids revealed that their number and distribution could have an impact on the binding of the capsids to GAGs, and the internalization into monocytes. Based on the distribution of positively charged amino acids on PCV2 capsids, phosphacan was hypothesized, and further demonstrated, as an effective candidate to mediate virus attachment to, and internalization in, monocytes. IMPORTANCE PCV2 is present on almost every pig farm in the world and is associated with a high number of diseases (PCV2-associated diseases [PCVADs]). It causes severe economic losses. Although vaccination is successfully applied in the field, there are still a lot of unanswered questions on the pathogenesis of PCV2 infections. This article reports on the uptake difference of various PCV2 strains by peripheral blood monocytes, and reveals the mechanism of the strong viral uptake ability of monocytes of Piétrain pigs. We further demonstrated that: (i) GAGs mediate the uptake of PCV2 particles by monocytes, (ii) positively charged three-wings-windmill-like amino acid patterns on the capsid outer surface are activating PCV2 uptake, and (iii) phosphacan is one of the potential candidates for PCV2 internalization. These results provide new insights into the mechanisms involved in PCVAD and contribute to a better understanding of PCV2 evolution. This may lead to the development of resistant pigs.
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Affiliation(s)
- Yueling Ouyang
- Laboratory of Virology, Department of Translational Physiology, Infectiology and Public Health, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Hans J. Nauwynck
- Laboratory of Virology, Department of Translational Physiology, Infectiology and Public Health, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
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10
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Porcine Circovirus Type 2 Hijacks Host IPO5 to Sustain the Intracytoplasmic Stability of Its Capsid Protein. J Virol 2022; 96:e0152222. [PMID: 36409110 PMCID: PMC9749456 DOI: 10.1128/jvi.01522-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Nuclear entrance and stability of porcine circovirus type 2 (PCV2), the smallest virus in mammals, are crucial for its infection and replication. However, the mechanisms are not fully understood. Here, we found that the PCV2 virion maintains self-stability via the host importin 5 (IPO5) during infection. Coimmunoprecipitation combined with mass spectrometry and glutathione S-transferase pulldown assays showed that the capsid protein (Cap) of PCV2 binds directly to IPO5. Fine identification demonstrated that the N-terminal residue arginine24 of Cap is the most critical to efficient binding to the proline709 residue of IPO5. Detection of replication ability further showed that IPO5 supports PCV2 replication by promoting the nuclear import of incoming PCV2 virions. Knockdown of IPO5 delayed the nuclear transport of incoming PCV2 virions and significantly decreased the intracellular levels of overexpressed PCV2 Cap, which was reversed by treatment with a proteasome inhibitor or by rescuing IPO5 expression. Cycloheximide treatment showed that IPO5 increases the stability of the PCV2 Cap protein. Taken together, our findings demonstrated that during infection, IPO5 facilitates PCV2 replication by directly binding to the nuclear localization signal of Cap to block proteasome degradation. IMPORTANCE Circovirus is the smallest virus to cause immune suppression in pigs. The capsid protein (Cap) is the only viral structural protein that is closely related to viral infection. The nuclear entry and stability of Cap are necessary for PCV2 replication. However, the molecular mechanism maintaining the stability of Cap during nuclear trafficking of PCV2 is unknown. Here, we report that IPO5 aggregates within the nuclear periphery and combines with incoming PCV2 capsids to promote their nuclear entry. Concurrently, IPO5 inhibits the degradation of newly synthesized Cap protein, which facilitates the synthesis of virus proteins and virus replication. These findings highlight a mechanism whereby IPO5 plays a dual role in PCV2 infection, which not only enriches our understanding of the virus replication cycle but also lays the foundation for the subsequent development of antiviral drugs.
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Ye N, Wang B, Feng W, Tang D, Zeng Z. PRRS virus receptors and an alternative pathway for viral invasion. Virus Res 2022; 320:198885. [PMID: 35948131 DOI: 10.1016/j.virusres.2022.198885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 08/05/2022] [Accepted: 08/06/2022] [Indexed: 11/25/2022]
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) has a highly restricted cell tropism, which is closely related to the specific receptors associated with PRRSV infection. At least nine cellular molecules have been identified as putative receptors for PRRSV, including CD163, a cysteine-rich scavenger receptor. With the participation of the CD163 receptor and other cofactors, PRRSV invades cells via low pH-dependent clathrin-mediated endocytosis. In addition, PRRSV utilizes viral apoptotic mimicry to infect cells though macropinocytosis as an alternative pathway. In this review, we discuss recent advances in the studies on receptors and pathways that play an important role in PRRSV invasion, and simultaneously explore the use of specific antibodies, small molecules, and blockers targeting receptor-ligand interactions, as a potential strategy for controlling PRRSV infection. Novel antiviral strategies against PRRSV could be developed by identifying the interaction between receptors and ligands.
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Affiliation(s)
- Ni Ye
- College of Animal Science, Guizhou University, Guiyang 550025, China
| | - Bin Wang
- College of Animal Science, Guizhou University, Guiyang 550025, China.
| | - Wei Feng
- College of Animal Science, Guizhou University, Guiyang 550025, China
| | - Deyuan Tang
- College of Animal Science, Guizhou University, Guiyang 550025, China
| | - Zhiyong Zeng
- College of Animal Science, Guizhou University, Guiyang 550025, China
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12
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Advances in Crosstalk between Porcine Circoviruses and Host. Viruses 2022; 14:v14071419. [PMID: 35891399 PMCID: PMC9315664 DOI: 10.3390/v14071419] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 06/20/2022] [Accepted: 06/27/2022] [Indexed: 02/06/2023] Open
Abstract
Porcine circoviruses (PCVs), including PCV1 to PCV4, are non-enveloped DNA viruses with a diameter of about 20 nm, belonging to the genus Circovirus in the family Circoviridae. PCV2 is an important causative agent of porcine circovirus disease or porcine circovirus-associated disease (PCVD/PCVAD), which is highly prevalent in pigs and seriously affects the swine industry globally. Furthermore, PCV2 mainly causes subclinical symptoms and immunosuppression, and PCV3 and PCV4 were detected in healthy pigs, sick pigs, and other animals. Although the pathogenicity of PCV3 and PCV4 in the field is still controversial, the infection rates of PCV3 and PCV4 in pigs are increasing. Moreover, PCV3 and PCV4 rescued from infected clones were pathogenic in vivo. It is worth noting that the interaction between virus and host is crucial to the infection and pathogenicity of the virus. This review discusses the latest research progress on the molecular mechanism of PCVs–host interaction, which may provide a scientific basis for disease prevention and control.
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Wang D, Mai J, Yang Y, Xiao CT, Wang N. Current knowledge on epidemiology and evolution of novel porcine circovirus 4. Vet Res 2022; 53:38. [PMID: 35642044 PMCID: PMC9158299 DOI: 10.1186/s13567-022-01053-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 03/10/2022] [Indexed: 11/15/2022] Open
Abstract
Porcine circovirus type 4 (PCV4) is a newly emerging virus, with both PCV4 genomic DNA and specific antibodies detected in swine herds in several provinces in China and South Korea. Although the virus was first identified in 2019 in Hunan, China, retrospective research suggests that serum samples collected as early as 2008 were positive for PCV4 antibody. Infections with only PCV4 or co-infections with other pathogens have been associated with several clinical manifestations, but its pathogenesis remains to be determined. The purpose of this review was the following: (1) to characterize PCV4 epidemiology by assessing evolutionary dynamics and genetic diversity of PCV4 strains circulating in swine herds; (2) to reconstruct a computerized 3D model to analyze PCV4 Cap properties; (3) and to summarize the current evidence of PCV4-associated clinical-pathological manifestations. The origin of PCV4 is apparently distinct from other PCV, based on analysis of phylogenetic trees. Of note, PCV4 shares an ancient common ancestor with mink circoviruses. Furthermore, the amino acid residue at position 27 of the PCV4 Cap is a key benchmark to distinguish PCV4a (27S) from PCV4b (27 N), based on PCV4 strains currently available, and variation of this residue may alter Cap antigenicity. In addition, the capsid surface of PCV4 has characteristics of increased polar residues, compared to PCV2, which raises the possibility that PCV4 may target negatively charged host receptors to promote virus infection. Further studies are required, including virus isolation and culture, and more detailed characterization of molecular epidemiology and genetic diversity of PCV4 in swine herds.
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Affiliation(s)
- Dongliang Wang
- Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, Laboratory of Functional Proteomics (LFP), Research Center of Reverse Vaccinology (RCRV), College of Veterinary Medicine, Hunan Agricultural University, Changsha, 410128, China
| | - Jinhui Mai
- Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, Laboratory of Functional Proteomics (LFP), Research Center of Reverse Vaccinology (RCRV), College of Veterinary Medicine, Hunan Agricultural University, Changsha, 410128, China
| | - Yi Yang
- Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, Laboratory of Functional Proteomics (LFP), Research Center of Reverse Vaccinology (RCRV), College of Veterinary Medicine, Hunan Agricultural University, Changsha, 410128, China
| | - Chao-Ting Xiao
- Institute of Pathogen Biology and Immunology, College of Biology, Hunan University, Changsha, China.
| | - Naidong Wang
- Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, Laboratory of Functional Proteomics (LFP), Research Center of Reverse Vaccinology (RCRV), College of Veterinary Medicine, Hunan Agricultural University, Changsha, 410128, China.
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Five years of porcine circovirus 3: what have we learned about the clinical disease, immune pathogenesis, and diagnosis. Virus Res 2022; 314:198764. [DOI: 10.1016/j.virusres.2022.198764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 03/25/2022] [Accepted: 03/26/2022] [Indexed: 11/24/2022]
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Jiménez-Arriagada D, Hidalgo AA, Neira V, Neira-Carrillo A, Bucarey SA. Low molecular weight sulfated chitosan efficiently reduces infection capacity of porcine circovirus type 2 (PCV2) in PK15 cells. Virol J 2022; 19:52. [PMID: 35331290 PMCID: PMC8943519 DOI: 10.1186/s12985-022-01781-7] [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: 12/07/2021] [Accepted: 03/10/2022] [Indexed: 11/15/2022] Open
Abstract
Background Porcine circovirus type 2 (PCV2)-associated diseases are a major problem for the swine industry worldwide. In addition to vaccines, the availability of antiviral polymers provides an efficient and safe option for reducing the impact of these diseases. By virtue of their molecular weight and repetitious structure, polymers possess properties not found in small-molecule drugs. In this perspective, we focus on chitosan, a ubiquitous biopolymer, that adjusts the molecular weight and sulfated-mediated functionality can act as an efficient antiviral polymer by mimicking PCV2-cell receptor interactions. Methods Sulfated chitosan (Chi-S) polymers of two molecular weights were synthesized and characterized by FTIR, SEM–EDS and elemental analysis. The Chi-S solutions were tested against PCV2 infection in PK15 cells in vitro and antiviral activity was evaluated by measuring the PCV2 DNA copy number, TCID50 and capsid protein expression, upon application of different molecular weights, sulfate functionalization, and concentrations of polymer. In addition, to explore the mode of action of the Chi-S against PCV2 infection, experiments were designed to elucidate whether the antiviral activity of the Chi-S would be influenced by when it was added to the cells, relative to the time and stage of viral infection. Results Chi-S significantly reduced genomic copies, TCID50 titers and capsid protein of PCV2, showing specific antiviral effects depending on its molecular weight, concentration, and chemical functionalization. Assays designed to explore the mode of action of the low molecular weight Chi-S revealed that it exerted antiviral activity through impeding viral attachment and penetration into cells. Conclusions These findings help better understanding the interactions of PCV2 and porcine cells and reinforce the idea that sulfated polymers, such as Chi-S, represent a promising candidates for use in antiviral therapies against PCV2-associated diseases. Further studies in swine are warranted.
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Affiliation(s)
- Daniela Jiménez-Arriagada
- Programa de Doctorado en Ciencias Silvoagropecuarias y Veterinarias, Campus Sur Universidad de Chile, Santa Rosa 11315, La Pintana, CP: 8820808, Santiago, Chile
| | - Alejandro A Hidalgo
- Escuela de Química y Farmacia, Facultad de Medicina, Universidad Andres Bello, Sazié 2320, Santiago, Chile
| | - Victor Neira
- Unidad de Virología, Departamento de Medicina Preventiva, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santa Rosa 11735, La Pintana, Santiago, Chile
| | - Andrónico Neira-Carrillo
- Laboratorio Polyform, Departamento de Ciencias Biológicas, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Av. Sta. Rosa 11735, La Pintana, Santiago, Chile.
| | - Sergio A Bucarey
- Departamento de Ciencias Biológicas, Centro Biotecnológico Veterinario, Biovetec, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santa Rosa 11735, La Pintana, Santiago, Chile.
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Ning Y, Wei L, Lin S, Jiang Y, Wang N, Xiao L. Dissection the endocytic routes of viral capsid proteins-coated upconversion nanoparticles by single-particle tracking. CHINESE CHEM LETT 2022. [DOI: 10.1016/j.cclet.2021.12.084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Purification of Porcine Circovirus Type 2 Using an Affinity Chromatography Based on a Neutralizing Monoclonal Antibody against Viral Capsid Protein. Pathogens 2021; 10:pathogens10121564. [PMID: 34959519 PMCID: PMC8708674 DOI: 10.3390/pathogens10121564] [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: 10/29/2021] [Revised: 11/21/2021] [Accepted: 11/29/2021] [Indexed: 12/01/2022] Open
Abstract
Porcine circovirus type 2 (PCV2) is a DNA virus without an envelope. The viral particle is icosahedral and has a diameter of approximately 17 nm. In order to obtain the purified virus, a broad-spectrum monoclonal antibody 3A5 against PCV2 was coupled to CNBr-activated SepharoseTM 4B, and an affinity chromatography was established for PCV2 purification. A total of 6.5 mg of purified PCV2a/LG with 97% purity was obtained from 120 mL of the viral culture medium, and only PCV2 was detected by electron microscopy. No significant changes in the antigenic characteristics of the purified virus were detected by a capture enzyme-linked immunosorbent assay (ELISA). Furthermore, the titer of the purified PCV2 was 100 times higher than that of the unpurified virus. This affinity chromatography method was also used to purify PCV2b/LN590516 and PCV2d/SD446F16, and the purified viruses were detected by electron microscopy, capture ELISA, and virus titration, respectively. The results showed that these two strains can be successfully purified, but the yield is lower than that of the PCV2a strain. In addition, the purified virus could be used to study the viral adsorption and invasion of PK15 cells using indirect immunofluorescence assays. A large number of PCV2 signals were detected to transfer from the cellular surface to the periphery of the nucleus of the PK15 cells after 30 min of adsorption of the PCV2 to the PK15 cells. The affinity chromatography is a simple and convenient tool to obtain PCV2 with high purity. It could be applied for virus structure analysis, antibody preparation, and viral adsorption and invasion research.
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Abstract
AbstractPorcine circovirus type 2 (PCV2), which serves as a major causative agent of PCV2-associated diseases and causes severe loss to the pig industry worldwide, can dysregulate the immune response and induce immunosuppression in PCV2-infected pigs. Similar to PCV2, porcine circovirus type 3 (PCV3), a newly identified swine circovirus which might be closely associated with porcine dermatitis and nephropathy syndrome, reproductive disorder, and multisystemic inflammatory responses, also interferes with host immune defense. Interaction between host immune system and PCVs is considered to be a crucial determinant of pathogenicity in pigs. Here, we sought to briefly discuss the current knowledge regarding the interaction of porcine circovirus type 2 and/or 3 with host immune cells and immune responses to better depict the viral immunomodulatory capacity, pathogenic mechanisms, and the future research direction in host immune responses to infection with PCV2 and PCV3.
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Wang Z, Chen J, Wu X, Ma D, Zhang X, Li R, Han C, Liu H, Yin X, Du Q, Tong D, Huang Y. PCV2 targets cGAS to inhibit type I interferon induction to promote other DNA virus infection. PLoS Pathog 2021; 17:e1009940. [PMID: 34543359 PMCID: PMC8483418 DOI: 10.1371/journal.ppat.1009940] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 09/30/2021] [Accepted: 09/03/2021] [Indexed: 01/28/2023] Open
Abstract
Viruses use diverse strategies to impair the antiviral immunity of host in order to promote infection and pathogenesis. Herein, we found that PCV2 infection promotes the infection of DNA viruses through inhibiting IFN-β induction in vivo and in vitro. In the early phase of infection, PCV2 promotes the phosphorylation of cGAS at S278 via activation of PI3K/Akt signaling, which directly silences the catalytic activity of cGAS. Subsequently, phosphorylation of cGAS at S278 can facilitate the K48-linked poly-ubiquitination of cGAS at K389, which can been served as a signal for recognizing by the ubiquitin-binding domain of histone deacetylase 6 (HDAC6), to promote the translocation of K48-ubiquitinated-cGAS from cytosol to autolysosome depending on the deacetylase activity of HDAC6, thereby eventually resulting in a markedly increased cGAS degradation in PCV2 infection-induced autophagic cells relative to Earle’s Balanced Salt Solution (EBSS)-induced autophagic cells (a typical starving autophagy). Importantly, we found that PCV2 Cap and its binding protein gC1qR act as predominant regulators to promote porcine cGAS phosphorylation and HDAC6 activation through mediating PI3K/AKT signaling and PKCδ signaling activation. Based on this finding, gC1qR-binding activity deficient PCV2 mutant (PCV2RmA) indeed shows a weakened inhibitory effect on IFN-β induction and a weaker boost effect for other DNA viruses infection compared to wild-type PCV2. Collectively, our findings illuminate a systematic regulation mechanism by which porcine circovirus counteracts the cGAS-STING signaling pathway to inhibit the type I interferon induction and promote DNA virus infection, and identify gC1qR as an important regulator for the immunosuppression induced by PCV2. PCV2 is well known for its ability to induce immunosuppression in pigs. However, how PCV2 infection interferes cGAS-STING signaling is still poorly understood. Herein, we demonstrate that PCV2 infection can phosphorylate porcine cGAS via gC1qR-mediated PI3K/AKT signaling to silence the catalytic activity of cGAS, while activates PKCδ signaling to promote histone deacetylase 6 (HDAC6) activation depending on the assistance of gC1qR. Subsequently, phosphorylation of cGAS facilitates the poly-ubiquitination of cGAS, then ubiquitinated-cGAS proteins are recruited and transported to autolysosome by activated HDAC6 depending on its deacetylase activity and ubiquitin-binding function, thereby eventually resulting in the autophagic degradation of cGAS in PCV2-infected cells. This study reveals that PCV2 can inhibit the activation of cGAS signaling pathway through two different mechanisms at different stages of infection and clarifies the internal relationship and cooperation model between these two mechanisms.
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Affiliation(s)
- Zhenyu Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Jing Chen
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Xingchen Wu
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Dan Ma
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Xiaohua Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Ruizhen Li
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Cong Han
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Haixin Liu
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Xiangrui Yin
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Qian Du
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Dewen Tong
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
- * E-mail: (DT); (YH)
| | - Yong Huang
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
- * E-mail: (DT); (YH)
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Su CM, Rowland RRR, Yoo D. Recent Advances in PRRS Virus Receptors and the Targeting of Receptor-Ligand for Control. Vaccines (Basel) 2021; 9:vaccines9040354. [PMID: 33916997 PMCID: PMC8067724 DOI: 10.3390/vaccines9040354] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Revised: 04/02/2021] [Accepted: 04/05/2021] [Indexed: 12/21/2022] Open
Abstract
Cellular receptors play a critical role in viral infection. At least seven cellular molecules have been identified as putative viral entry mediators for porcine reproductive and respiratory syndrome virus (PRRSV). Accumulating data indicate that among these candidates, CD163, a cysteine-rich scavenger receptor on macrophages, is the major receptor for PRRSV. This review discusses the recent advances and understanding of the entry of PRRSV into cells, viral pathogenesis in CD163 gene-edited swine, and CD163 as a potential target of receptor–ligand for the control of PRRS.
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21
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Shi R, Hou L, Wei L, Quan R, Zhou B, Jiang H, Wang J, Zhu S, Song J, Wang D, Liu J. Porcine Circovirus Type 3 Enters Into PK15 Cells Through Clathrin- and Dynamin-2-Mediated Endocytosis in a Rab5/Rab7 and pH-Dependent Fashion. Front Microbiol 2021; 12:636307. [PMID: 33679671 PMCID: PMC7928314 DOI: 10.3389/fmicb.2021.636307] [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: 12/01/2020] [Accepted: 01/26/2021] [Indexed: 01/20/2023] Open
Abstract
Porcine circovirus type 3 (PCV3) invades multiple tissues and organs of pigs of different ages and are widely spread throughout pig farms, emerging as an important viral pathogen that can potentially damage the pig industry worldwide. Since PCV3 is a newly discovered virus, many aspects of its life cycle remain unknown. Porcine kidney epithelial cells are important host targets for PCV3. Here, we used systematic approaches to dissect the molecular mechanisms underlying the cell entry and intracellular trafficking of PCV3 in PK15 cells, a cell line of porcine kidney epithelial origin. A large number of PCV3 viral particles were found to colocalize with clathrin but not caveolin-1 after entry, and PCV3 infection was significantly decreased when treated with chlorpromazine, dynasore, knockdown of clathrin heavy chain expression via RNA interference, or overexpression of a dominant-negative mutant of EPS15 in PCV3-infected cells. After internalization, the viral particles were further observed to colocalize with Rab5 and Rab7, and knockdown of both expression by RNA interference significantly inhibited PCV3 replication. We also found that PCV3 infection was impeded by ammonium chloride treatment, which indicated the requirement of an acidic environment for viral entry. Taken together, our findings demonstrate that PCV3 enters PK15 cells through a clathrin- and dynamin-2-mediated endocytic pathway, which requires early and late endosomal trafficking, as well as an acidic environment, providing an insightful theoretical basis for further understanding the PCV3 life cycle and its pathogenesis.
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Affiliation(s)
- Ruihan Shi
- Beijing Key Laboratory for Prevention and Control of Infectious Diseases in Livestock and Poultry, Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Lei Hou
- Beijing Key Laboratory for Prevention and Control of Infectious Diseases in Livestock and Poultry, Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China.,College of Veterinary Medicine, Yangzhou University, Yangzhou, China.,Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China
| | - Li Wei
- Beijing Key Laboratory for Prevention and Control of Infectious Diseases in Livestock and Poultry, Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Rong Quan
- Beijing Key Laboratory for Prevention and Control of Infectious Diseases in Livestock and Poultry, Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Bin Zhou
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Haijun Jiang
- Beijing Key Laboratory for Prevention and Control of Infectious Diseases in Livestock and Poultry, Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Jing Wang
- Beijing Key Laboratory for Prevention and Control of Infectious Diseases in Livestock and Poultry, Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Shanshan Zhu
- Beijing Key Laboratory for Prevention and Control of Infectious Diseases in Livestock and Poultry, Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Jiangwei Song
- Beijing Key Laboratory for Prevention and Control of Infectious Diseases in Livestock and Poultry, Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Dan Wang
- Beijing Key Laboratory for Prevention and Control of Infectious Diseases in Livestock and Poultry, Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Jue Liu
- Beijing Key Laboratory for Prevention and Control of Infectious Diseases in Livestock and Poultry, Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China.,College of Veterinary Medicine, Yangzhou University, Yangzhou, China.,Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China
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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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Is PBFD Simptomatology Species Specific Rather then Strain Specific? – A Case of 8 Lovebirds. ACTA VET-BEOGRAD 2020. [DOI: 10.2478/acve-2020-0029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
Eight lovebirds of both sexes and different age were admitted showing alterations in behaviour and apathy. During the initial examination delamination of the beak was noted in all birds and discrete areas of alopecia in three of eight birds. Based on clinical experience, molecular diagnostic on PBFD, sequencing of obtained amplicons, and histopathological examination were performed. All birds tested positive on the presence of PBFD virus, despite the fact they did not exhibit expected clinical signs for PBFD. Sequencing results showed 100% match with sequences previously isolated from parrots with PBFD exhibiting classical PBFD manifestation. Histopathological examination showed similar findings as in previously described cases of PBFD in parrots. Other studies on psittacine birds correlate clinical manifestations and nucleotide variations with geographic localization. Our results indicate that the clinical manifestation of the disease is more dependent on bird species than on the genetic variation of the virus or the geographical distribution.
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Li J, Gu J, Lin C, Zhou J, Wang S, Lei J, Wen F, Sun B, Zhou J. Conformational Dynamics of Nonenveloped Circovirus Capsid to the Host Cell Receptor. iScience 2020; 23:101547. [PMID: 33083716 PMCID: PMC7519355 DOI: 10.1016/j.isci.2020.101547] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 02/12/2020] [Accepted: 09/07/2020] [Indexed: 10/25/2022] Open
Abstract
Circovirus, comprising one capsid protein, is the smallest nonenveloped virus and induces lymphopenia. Circovirus can be used to explore the cell adhesion mechanism of nonenveloped viruses. We developed a single-molecule fluorescence resonance energy transfer (smFRET) assay to directly visualize the capsid's conformational feature. The capsid underwent reversible dynamic transformation between three conformations. The cell surface receptor heparan sulfate (HS) altered the dynamic equilibrium of the capsid to the high-FRET state, revealing the HS-binding region. Neutralizing antibodies restricted capsid transition to a low-FRET state, masking the HS-binding domain. The lack of positively charged amino acids in the HS-binding site reduced cell surface affinity and attenuated virus infectivity via conformational changes. These intrinsic characteristics of the capsid suggested that conformational dynamics is critical for the structural changes occurring upon cell surface receptor binding, supporting a dynamics-based mechanism of receptor binding.
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Affiliation(s)
- Jiarong Li
- MOA Key Laboratory of Animal Virology, Center for Veterinary Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Jinyan Gu
- MOA Key Laboratory of Animal Virology, Center for Veterinary Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Cui Lin
- MOA Key Laboratory of Animal Virology, Center for Veterinary Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Jianwei Zhou
- MOA Key Laboratory of Animal Virology, Center for Veterinary Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Shengnan Wang
- MOA Key Laboratory of Animal Virology, Center for Veterinary Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Jin Lei
- Institute of Immunology and College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Fengcai Wen
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Bo Sun
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Jiyong Zhou
- MOA Key Laboratory of Animal Virology, Center for Veterinary Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China.,Collaborative Innovation Center and State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University, Hangzhou, Zhejiang 310058, China
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25
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Zhu X, Wen L, Wang W, Xiao Q, Li B, He K. PCV2 inhibits the Wnt signalling pathway in vivo and in vitro. Vet Microbiol 2020; 247:108787. [PMID: 32768231 DOI: 10.1016/j.vetmic.2020.108787] [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: 04/03/2020] [Revised: 07/01/2020] [Accepted: 07/05/2020] [Indexed: 11/16/2022]
Abstract
Porcine circovirus type 2 (PCV2) is an important pathogen of the current pig industry. The Wnt signalling pathway plays an important role in the growth of young animals. In this study, we mainly elucidated the relationship between PCV2 and the Wnt signalling pathway. In an in vivo experiment in mice, we demonstrated the downregulatory effects of PCV2 infection on expression levels of downstream components of the Wnt signalling pathway. Weight loss in mice was reversed by activating the Wnt signalling pathway, and the body weight was still significantly higher than that in mice infected with PCV2. We detected levels of growth hormone (GH) in the liver and sera, which showed that GH was also downregulated in mice challenged with PCV2. Lithium chloride, the activator of Wnt signalling, upregulated GH, albeit to a significantly lesser degree than that in corresponding non-stimulated mock mice. In vitro studies showed that PCV2 infection downregulated protein expression of β-catenin and mRNA expression of matrix metallopeptidase-2 (Mmp2), downregulated protein expression of β-catenin in the cytoplasm and nucleus, and reduced the activity of the TCF/LEF promoter, demonstrating that PCV2 inhibited activation of the Wnt signalling pathway in vitro. Finally, we found that Rep protein of PCV2 might be responsible for the inhibitory effect.
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Affiliation(s)
- Xuejiao Zhu
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, Nanjing 210014, Jiangsu Province, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China; Jiangsu Key Laboratory for Food Quality and Safety - State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, China
| | - Libin Wen
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, Nanjing 210014, Jiangsu Province, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China; Jiangsu Key Laboratory for Food Quality and Safety - State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, China
| | - Wei Wang
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, Nanjing 210014, Jiangsu Province, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China; Jiangsu Key Laboratory for Food Quality and Safety - State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, China
| | - Qi Xiao
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, Nanjing 210014, Jiangsu Province, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China; Jiangsu Key Laboratory for Food Quality and Safety - State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, China
| | - Bin Li
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, Nanjing 210014, Jiangsu Province, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China; Jiangsu Key Laboratory for Food Quality and Safety - State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, China
| | - Kongwang He
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, Nanjing 210014, Jiangsu Province, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China; Jiangsu Key Laboratory for Food Quality and Safety - State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, China.
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26
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Neutralization Mechanism of a Monoclonal Antibody Targeting a Porcine Circovirus Type 2 Cap Protein Conformational Epitope. J Virol 2020; 94:JVI.01836-19. [PMID: 32075932 DOI: 10.1128/jvi.01836-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 01/22/2020] [Indexed: 12/31/2022] Open
Abstract
Porcine circovirus type 2 (PCV2) is an important pathogen in swine herds, and its infection of pigs has caused severe economic losses to the pig industry worldwide. The capsid protein of PCV2 is the only structural protein that is associated with PCV2 infection and immunity. Here, we report a neutralizing monoclonal antibody (MAb), MAb 3A5, that binds to intact PCV2 virions of the PCV2a, PCV2b, and PCV2d genotypes. MAb 3A5 neutralized PCV2 by blocking viral attachment to PK15 cells. To further explore the neutralization mechanism, we resolved the structure of the PCV2 virion in complex with MAb 3A5 Fab fragments by using cryo-electron microscopy single-particle analysis. The binding sites were located at the topmost edges around 5-fold icosahedral symmetry axes, with each footprint covering amino acids from two adjacent capsid proteins. Most of the epitope residues (15/18 residues) were conserved among 2,273 PCV2 strains. Mutations of some amino acids within the epitope had significant effects on the neutralizing activity of MAb 3A5. This study reveals the molecular and structural bases of this PCV2-neutralizing antibody and provides new and important information for vaccine design and therapeutic antibody development against PCV2 infections.IMPORTANCE PCV2 is associated with several clinical manifestations collectively known as PCV2-associated diseases (PCVADs). Neutralizing antibodies play a crucial role in the prevention of PCVADs. We demonstrated previously that a MAb, MAb 3A5, neutralizes the PCV2a, PCV2b, and PCV2d genotypes with different degrees of efficiency, but the underlying mechanism remains elusive. Here, we report the neutralization mechanism of this MAb and the structure of the PCV2 virion in complex with MAb 3A5 Fabs, showing a binding mode in which one Fab interacted with more than two loops from two adjacent capsid proteins. This binding mode has not been observed previously for PCV2-neutralizing antibodies. Our work provides new and important information for vaccine design and therapeutic antibody development against PCV2 infections.
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The Carboxyl Terminus of the Porcine Circovirus Type 2 Capsid Protein Is Critical to Virus-Like Particle Assembly, Cell Entry, and Propagation. J Virol 2020; 94:JVI.00042-20. [PMID: 32075927 DOI: 10.1128/jvi.00042-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 02/11/2020] [Indexed: 11/20/2022] Open
Abstract
The capsid protein (Cap) is the sole structural protein and the main antigen of porcine circovirus type 2 (PCV2). Structural loops of the Cap play crucial roles in viral genome packaging, capsid assembly, and virus-host interactions. Although the molecular mechanisms are yet unknown, the carboxyl terminus (CT) of the PCV2 Cap is known to play critical roles in the evolution, pathogenesis, and proliferation of this virus. In this study, we investigated functions of CT. Removal of this loop leads to abrogation of the in vitro Cap self-assembly into virus-like particles (VLPs). Likewise, the mutated virus resists rescue from PK15 cell culture. A conserved PXXP motif in the CT is dispensable for VLP assembly and subsequent cell entry. However, its removal leads to the subsequent failure of virus rescued from PK15 cells. Furthermore, substituting either the PCV1 counterpart or an AXXA for the PXXP motif still supports virus rescue from cell culture but results in a dramatic decrease in viral titers compared with wild type. In particular, a strictly conserved residue (227K) in the CT is essential for VLP entry into PK15 cells, and its mutation to alanine greatly attenuates cell entry of the VLPs, supporting a mechanism for the failure to rescue a mutated PCV2 infectious DNA clone (K227A) from PK15 cell culture. These results suggest the CT of the PCV2 Cap plays critical roles in virus assembly, viral-host cell interaction(s), and virus propagation in vitro IMPORTANCE The carboxyl terminus (CT) of porcine circovirus type 2 (PCV2) capsid protein (Cap) was previously reported to be associated with immunorecognition, alterations of viral titer in swine sera, and pathogenicity. However, the molecular mechanisms underlying these effects remain unknown. In this study, roles of the critical residues and motifs of the CT are investigated with respect to virus-like particle (VLP) assembly, cell entry, and viral proliferation. The results revealed that the positively charged 227K of the CT is essential for both cell entry of PCV2 VLPs and virus proliferation. Our findings, therefore, suggest that the CT should be considered one of the key epitopes, recognized by neutralizing antibodies, for vaccine design and a target for drug development to prevent PCV2-associated diseases (PCVADs). Furthermore, it is important to respect the function of 227K for its role in cell entry if using either PCV2 VLPs for nanoscale DNA/drug cell delivery or using PCV2 VLPs to display a variety of foreign epitopes for immunization.
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28
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Dai X, Zhang X, Ostrikov K, Abrahamyan L. Host receptors: the key to establishing cells with broad viral tropism for vaccine production. Crit Rev Microbiol 2020; 46:147-168. [PMID: 32202955 PMCID: PMC7113910 DOI: 10.1080/1040841x.2020.1735992] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Cell culture-based vaccine technology is a flexible and convenient approach for vaccine production that requires adaptation of the vaccine strains to the new cells. Driven by the motivation to develop a broadly permissive cell line for infection with a wide range of viruses, we identified a set of the most relevant host receptors involved in viral attachment and entry. This identification was done through a review of different viral entry pathways and host cell lines, and in the context of the Baltimore classification of viruses. In addition, we indicated the potential technical problems and proposed some solutions regarding how to modify the host cell genome in order to meet industrial requirements for mass production of antiviral vaccines. Our work contributes to a finer understanding of the importance of breaking the host–virus recognition specificities for the possibility of creating a cell line feasible for the production of vaccines against a broad spectrum of viruses.
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Affiliation(s)
- Xiaofeng Dai
- Wuxi School of Medicine, Jiangnan University, Wuxi, China
| | - Xuanhao Zhang
- School of Biotechnology, Jiangnan University, Wuxi, China
| | - Kostya Ostrikov
- School of Chemistry and Physics and Institute for Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia
| | - Levon Abrahamyan
- Faculty of Veterinary Medicine, Swine and Poultry Infectious Diseases Research Center (CRIPA), Research Group on Infectious Diseases in Production Animals (GREMIP), Université de Montréal, Saint-Hyacinthe, Canada
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29
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Li J, Song D, Wang S, Dai Y, Zhou J, Gu J. Antiviral Effect of Epigallocatechin Gallate via Impairing Porcine Circovirus Type 2 Attachment to Host Cell Receptor. Viruses 2020; 12:v12020176. [PMID: 32033244 PMCID: PMC7077276 DOI: 10.3390/v12020176] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 02/02/2020] [Accepted: 02/02/2020] [Indexed: 12/18/2022] Open
Abstract
The green tea catechin epigallocatechin gallate (EGCG) exhibits antiviral activity against various viruses. Whether EGCG also inhibits the infectivity of circovirus remains unclear. In this study, we demonstrated the antiviral effect of EGCG on porcine circovirus type 2 (PCV2). EGCG targets PCV2 virions directly and blocks the attachment of virions to host cells. The microscale thermophoresis assay showed EGCG could interact with PCV2 capsid protein in vitro with considerable affinity (Kd = 98.03 ± 4.76 μM), thereby interfering with the binding of the capsid to the cell surface receptor heparan sulfate. The molecular docking analysis of capsid–EGCG interaction identified the key amino acids which formed the binding pocket accommodating EGCG. Amino acids ARG51, ASP70, ARG73 and ASP78 of capsid were found to be critical for maintaining the binding, and the arginine residues were also essential for the electrostatic interaction with heparan sulfate. The rescued mutant viruses also confirm the importance of the key amino acids of the capsid to the antiviral effect of EGCG. Our findings suggest that catechins could act as anti-infective agents against circovirus invasion, as well as provide the basic information for the development and synthesis of structure-based anti-circovirus drugs.
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Affiliation(s)
- Jiarong Li
- Institute of Immunology, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; (J.L.); (D.S.); (S.W.)
| | - Dongfeng Song
- Institute of Immunology, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; (J.L.); (D.S.); (S.W.)
| | - Shengnan Wang
- Institute of Immunology, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; (J.L.); (D.S.); (S.W.)
- MOA Key Laboratory of Animal Virology, Institute of Preventive Veterinary Sciences and Department of Veterinary Medicine, Zhejiang University, Hangzhou 310058, China; (Y.D.); (J.Z.)
| | - Yadong Dai
- MOA Key Laboratory of Animal Virology, Institute of Preventive Veterinary Sciences and Department of Veterinary Medicine, Zhejiang University, Hangzhou 310058, China; (Y.D.); (J.Z.)
- Center of Veterinary Medical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Jiyong Zhou
- MOA Key Laboratory of Animal Virology, Institute of Preventive Veterinary Sciences and Department of Veterinary Medicine, Zhejiang University, Hangzhou 310058, China; (Y.D.); (J.Z.)
- Center of Veterinary Medical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Jinyan Gu
- Institute of Immunology, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; (J.L.); (D.S.); (S.W.)
- Correspondence:
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30
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Wu S, Wu Z, Wu Y, Wang T, Wang M, Jia R, Zhu D, Liu M, Zhao X, Yang Q, Wu Y, Zhang S, Liu Y, Zhang L, Yu Y, Pan L, Chen S, Cheng A. Heparin sulfate is the attachment factor of duck Tembus virus on both BHK21 and DEF cells. Virol J 2019; 16:134. [PMID: 31718685 PMCID: PMC6852980 DOI: 10.1186/s12985-019-1246-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Accepted: 10/23/2019] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Duck tembusu virus (DTMUV, genus Flaviviruses, family Flaviviridae) is an emerging flavivirus that can infect a wide range of cells and cell lines in vitro, though the initial step of virus invasion remains obscure. METHODS In this study, drug treatments that including heparin, chondroitin sulfate, heparinase I, chondroitinase ABC and trypsin were applied to detect the influence of DTMUV absorption, subsequently, the copy number of viral genome RNA was analyzed by quantitative real-time PCR. The inhibition process of viral absorption or entry by heparin was determined by western blotting, and the cytotoxicity of drug treated cells was detected by cell counting kit-8. RESULTS We found that the desulfation of glycosaminoglycans (GAGs) with sodium chlorate had a significant effect on the adsorption of DTMUV in both BHK21 and DEF cells. Based on this result, we incubated cells with a mixture of DTMUV and GAGs competition inhibitors or pre-treated cells with inhibitors, after incubation with the virus, the NS5 expression of DTMUV and viral titers were detected. The data suggested that heparin can significantly inhibit the absorption of DTMUV in a dose dependent manner but not at the step of viral entry in BHK21 and DEF cells. Meanwhile, heparinase I can significantly inhibit DTMUV attachment step. CONCLUSIONS Our results clearly proved that heparin sulfate plays an important role in the first step of DTMUV entry, viral attachment, in both BHK21 and DEF cells, which sheds light on the entry mechanism of DTMUV.
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Affiliation(s)
- Shaoxiong Wu
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang District, Chengdu City, 611130, Sichuan Province, China
| | - Zhen Wu
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang District, Chengdu City, 611130, Sichuan Province, China
| | - Yuanyuan Wu
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang District, Chengdu City, 611130, Sichuan Province, China
| | - Tao Wang
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang District, Chengdu City, 611130, Sichuan Province, China
| | - Mingshu Wang
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang District, Chengdu City, 611130, Sichuan Province, China.,Institute of Preventive Veterinary Medicine, College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu City, 611130, Sichuan Province, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Wenjiang District, Chengdu City, 611130, Sichuan Province, China
| | - Renyong Jia
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang District, Chengdu City, 611130, Sichuan Province, China.,Institute of Preventive Veterinary Medicine, College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu City, 611130, Sichuan Province, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Wenjiang District, Chengdu City, 611130, Sichuan Province, China
| | - Dekang Zhu
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang District, Chengdu City, 611130, Sichuan Province, China.,Institute of Preventive Veterinary Medicine, College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu City, 611130, Sichuan Province, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Wenjiang District, Chengdu City, 611130, Sichuan Province, China
| | - Mafeng Liu
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang District, Chengdu City, 611130, Sichuan Province, China.,Institute of Preventive Veterinary Medicine, College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu City, 611130, Sichuan Province, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Wenjiang District, Chengdu City, 611130, Sichuan Province, China
| | - Xinxin Zhao
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang District, Chengdu City, 611130, Sichuan Province, China.,Institute of Preventive Veterinary Medicine, College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu City, 611130, Sichuan Province, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Wenjiang District, Chengdu City, 611130, Sichuan Province, China
| | - Qiao Yang
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang District, Chengdu City, 611130, Sichuan Province, China.,Institute of Preventive Veterinary Medicine, College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu City, 611130, Sichuan Province, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Wenjiang District, Chengdu City, 611130, Sichuan Province, China
| | - Ying Wu
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang District, Chengdu City, 611130, Sichuan Province, China.,Institute of Preventive Veterinary Medicine, College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu City, 611130, Sichuan Province, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Wenjiang District, Chengdu City, 611130, Sichuan Province, China
| | - Shaqiu Zhang
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang District, Chengdu City, 611130, Sichuan Province, China.,Institute of Preventive Veterinary Medicine, College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu City, 611130, Sichuan Province, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Wenjiang District, Chengdu City, 611130, Sichuan Province, China
| | - Yunya Liu
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang District, Chengdu City, 611130, Sichuan Province, China
| | - Ling Zhang
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang District, Chengdu City, 611130, Sichuan Province, China
| | - Yanling Yu
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang District, Chengdu City, 611130, Sichuan Province, China
| | - Leichang Pan
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang District, Chengdu City, 611130, Sichuan Province, China
| | - Shun Chen
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang District, Chengdu City, 611130, Sichuan Province, China. .,Institute of Preventive Veterinary Medicine, College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu City, 611130, Sichuan Province, China. .,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Wenjiang District, Chengdu City, 611130, Sichuan Province, China.
| | - Anchun Cheng
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang District, Chengdu City, 611130, Sichuan Province, China. .,Institute of Preventive Veterinary Medicine, College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu City, 611130, Sichuan Province, China. .,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Wenjiang District, Chengdu City, 611130, Sichuan Province, China.
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31
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Ilha M, Nara P, Ramamoorthy S. Early antibody responses map to non-protective, PCV2 capsid protein epitopes. Virology 2019; 540:23-29. [PMID: 31734380 DOI: 10.1016/j.virol.2019.11.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 11/06/2019] [Accepted: 11/06/2019] [Indexed: 11/19/2022]
Abstract
Porcine circovirus type 2 (PCV2) is an economically important cause of post-weaning multisystemic wasting syndrome (PMWS) in weanling piglets. Current commercial vaccines against PCV2 are highly effective. Yet, a recurring emergence of new genotypes in vaccinated herds necessitates a better understanding of protective immunity. The study objectives were to identify previously unrecognized decoy epitopes in the PCV2 capsid and test the hypothesis that early antibody responses would map to decoy epitopes and vice versa. Using a peptide library spanning the PCV2a capsid and weekly sera collections from PCV2a infected animals, three major immunodominant regions mapping the early responses to decoy epitopes were identified. Regions with potential decoy activity were mapped using peptide blocking fluorescent focus inhibition assays to residues 55 YTVKATTVRTPSWAVDMM 72, 106 WPCSPITQGDRGVGSTAV 123 and 124 ILDDNFVTKATALTYDPY 141. Post-vaccination responses largely recognized these same three identified regions and dominated the antibody responses to PCV2 in both infection and vaccination.
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Affiliation(s)
- M Ilha
- Veterinary Diagnostic and Investigational Laboratory, College of Veterinary Medicine, University of Georgia, Tifton, GA, USA
| | - P Nara
- Biological Mimetics, Frederick, MD, USA
| | - S Ramamoorthy
- Department of Microbiological Sciences, North Dakota State University, Dakota State University, Fargo, ND, USA.
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32
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Cao W, Cao H, Yi X, Zhuang Y. Development of a simple and high-yielding fed-batch process for the production of porcine circovirus type 2 virus-like particle subunit vaccine. AMB Express 2019; 9:164. [PMID: 31605297 PMCID: PMC6789058 DOI: 10.1186/s13568-019-0880-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 09/17/2019] [Indexed: 12/25/2022] Open
Abstract
The cap protein is encoded by the orf2 gene of porcine circovirus type 2 (PCV2) has the main antigen epitope of PCV2 and can form virus-like particles (VLPs), which are expressed in insect cells. PCV2-VLPs can effectively inhibit PCV2 replication as a subunit vaccine. In this study, a robust and reliable fed-batch process was successfully developed for the production of PCV2-VLPs by Sf9 cells. The feeding solution, feeding strategy, and cell density at infection were optimized to maximize the final PCV2-VLPs production yields. The cell density at infection and the volumetric PCV2-VLPs production reached 12 × 106 cells/mL and 110 mg/L, respectively, which yielded 3- and 3.6-fold enhancements compared to the batch culture. The PCV2-VLPs produced in fed-batch culture were not different from the PCV2-VLPs produced in a batch culture in an immunity test. A highly efficient production process was produced for PCV2-VLPs subunit vaccines, which could provide an effective means for the industrial production of PCV2 vaccines.
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Affiliation(s)
- Wenlong Cao
- School of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China
| | - Hui Cao
- Zhejiang EBVAC Biotech Co., Ltd., Hangzhou, 310018, Zhejiang, China
| | - Xiaoping Yi
- School of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China.
| | - Yingping Zhuang
- School of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China
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Strain-Dependent Porcine Circovirus Type 2 (PCV2) Entry and Replication in T-Lymphoblasts. Viruses 2019; 11:v11090813. [PMID: 31480752 PMCID: PMC6783876 DOI: 10.3390/v11090813] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 08/29/2019] [Accepted: 08/31/2019] [Indexed: 12/25/2022] Open
Abstract
Porcine circovirus type 2 (PCV2) is the etiological agent of PCV2-associated diseases (PCVAD). PCV2 targets lymphoblasts, and pigs suffering from PCVAD display lymphocyte depletion in lymphoid tissues. PCV2 infection of lymphoblasts has not been studied. Here, the replication cycle of PCV2 (abortion strain 1121 and PMWS strain Stoon1010) in T-lymphoblasts was examined. The expression of Rep and Cap were found for both viral strains, while progeny virus was detected for Stoon1010 but not for 1121. PCV2 attached to 11–26% (1121-Stoon1010) of the T-lymphoblasts while 2.6–12.7% of cells showed virus internalization. Chondroitin sulfate (CS) was present on 25% of T-lymphoblasts, and colocalized with PCV2 on 31–32% of the PCV2+ cells. Enzymatic removal of CS reduced PCV2 infection. PCV2 infection was decreased by chlorpromazine, cytochalasin D and Clostridium difficile toxin B for both viral strains and by amiloride for 1121 but not for Stoon1010. Inhibiting either endosome acidification or serine proteases strongly reduced PCV2 infection. Three-dimensional analysis of Cap structure demonstrated a better Cap-nucleic acid affinity for Stoon1010 than for 1121. Taken together, PCV2 binds to T-lymphoblasts partially via CS, enters via clathrin-mediated endocytosis, and disassembles under functions of a pH-drop and serine proteases. Strain Stoon1010 displayed an enhanced viral binding, a specific receptor-mediated endocytosis, an increased Cap-nucleic acid affinity, and a more productive infection in T-lymphoblasts than 1121 did, indicating an evolution from 1121 to Stoon1010.
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Aints A, Mölder S, Salumets A. EXTL3-interacting endometriosis-specific serum factors induce colony formation of endometrial stromal cells. Sci Rep 2019; 9:12562. [PMID: 31467315 PMCID: PMC6715673 DOI: 10.1038/s41598-019-48840-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 08/12/2019] [Indexed: 12/30/2022] Open
Abstract
Endometriosis is a benign chronic condition characterized by the existence of endometrial-like stroma and glandular tissue in extrauterine locations. The molecular mechanisms of its pathogenesis have not been elucidated. We have studied the role of EXTL3 (exostosin-like 3) in endometriosis and found that it is expressed in endometrial tissue as well as endometriosis lesions. We have found that serum from endometriosis patients contains a factor or factors, which interact with EXTL3 resulting in strongly increased colony formation in regenerating cell culture. We also found increased anti-EXTL3 antibodies in endometriosis patients’ sera. EXTL3 is an N-acetyl glucosamine (GlcNAc) transferase, performing a key step in heparan sulfate (HS) glucosaminoglycan synthesis. Many viruses replicate in regenerating epithelial cells and use HS as a receptor for cell entry. We measured antibody titres to viruses, which use HS as a receptor for cell entry, and found rarely increased titres for these viruses in endometriosis sera, whereas titres to viruses using other receptors were equally distributed in study groups. The data indicate that perturbation of HS metabolism is associated with endometriosis.
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Affiliation(s)
- Alar Aints
- Institute of Clinical Medicine, Department of Obstetrics and Gynecology, University of Tartu, Tartu, 51014, Estonia. .,Kvintest OÜ, Tartu, 50410, Estonia.
| | - Signe Mölder
- Competence Centre on Health Technologies AS, Tartu, 50410, Estonia
| | - Andres Salumets
- Institute of Clinical Medicine, Department of Obstetrics and Gynecology, University of Tartu, Tartu, 51014, Estonia.,Competence Centre on Health Technologies AS, Tartu, 50410, Estonia.,Institute of Bio- and Translational Medicine, University of Tartu, Tartu, 50411, Estonia.,Department of Obstetrics and Gynecology, University of Helsinki and Helsinki University Hospital, Helsinki, 00014, Finland
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Dhindwal S, Feng S, Khayat R. The Arginines in the N-Terminus of the Porcine Circovirus 2 Virus-like Particles Are Responsible for Disrupting the Membranes at Neutral and Acidic pH. J Mol Biol 2019; 431:3261-3274. [PMID: 31173778 PMCID: PMC6697213 DOI: 10.1016/j.jmb.2019.05.044] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 05/21/2019] [Accepted: 05/27/2019] [Indexed: 12/23/2022]
Abstract
Non-enveloped viruses that are endocytosed employ numerous mechanisms to disrupt endosomal membranes for escape into the cellular cytoplasm. These include the use of amphipathic helices or sheets, hydrophobic loops, myristoylated peptides, and proteins with phospholipase activity. Some mechanisms result in immediate deterioration of the endosome, while others form pores in the membrane causing osmolysis to disrupt the endosome and allow viral escape. We describe an additional mechanism by a non-enveloped virus to disrupt endosomal membranes. Porcine circovirus 2 (PCV2) possesses a 41-amino acid arginine-rich motif (ARM) at the N-terminus of its capsid protein that appears to be in the interior of the virus-like particle (VLP). Using in vitro membrane disruption assays, we demonstrate that PCV2 VLP, unassembled capsid, and ARM peptide possess the ability to disrupt endosomal-like membranes, whereas VLP lacking the ARM sequence does not possess this capability. Membrane disruption by VLP is insensitive to pH, but unassembled capsid protein and ARM peptide exhibit diminished activity at low pH. Our liposome disruption assays, circular dichroism, and intrinsic tryptophan fluorescence assays allow us to propose a model for PCV2-endosomal membrane interaction wherein the ARM peptide externalizes from the capsid, its C-terminus (amino acids 28-40) anchors into the membrane, and the arginine-rich N-terminus (amino acids 1-27) drives membrane disruption. To our knowledge, this is the first example of a non-enveloped virus using the arginines of an ARM to disrupt membranes. Also, this is the first example of such study for the Circoviridae family of viruses.
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Affiliation(s)
- Sonali Dhindwal
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY 10031, USA
| | - Shanshan Feng
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY 10031, USA; Graduate Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY 10016, USA
| | - Reza Khayat
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY 10031, USA; Graduate Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY 10016, USA.
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Mukherjee P, Karam A, Chakraborty A, Baruah S, Pegu R, Das S, Milton A, Puro K, Sanjukta R, Ghatak S, Shakuntala I, Laha R, Sen A. Identification of a novel cluster of PCV2 isolates from Meghalaya, India indicates possible recombination along with changes in capsid protein. INFECTION GENETICS AND EVOLUTION 2019; 71:7-15. [DOI: 10.1016/j.meegid.2019.02.026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 02/13/2019] [Accepted: 02/22/2019] [Indexed: 10/27/2022]
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Cagno V, Tseligka ED, Jones ST, Tapparel C. Heparan Sulfate Proteoglycans and Viral Attachment: True Receptors or Adaptation Bias? Viruses 2019; 11:v11070596. [PMID: 31266258 PMCID: PMC6669472 DOI: 10.3390/v11070596] [Citation(s) in RCA: 239] [Impact Index Per Article: 47.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 06/28/2019] [Accepted: 06/29/2019] [Indexed: 12/12/2022] Open
Abstract
Heparan sulfate proteoglycans (HSPG) are composed of unbranched, negatively charged heparan sulfate (HS) polysaccharides attached to a variety of cell surface or extracellular matrix proteins. Widely expressed, they mediate many biological activities, including angiogenesis, blood coagulation, developmental processes, and cell homeostasis. HSPG are highly sulfated and broadly used by a range of pathogens, especially viruses, to attach to the cell surface.
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Affiliation(s)
- Valeria Cagno
- Department of Microbiology and Molecular Medicine, University of Geneva Medical School, 1205 Geneva, Switzerland.
| | - Eirini D Tseligka
- Department of Microbiology and Molecular Medicine, University of Geneva Medical School, 1205 Geneva, Switzerland
| | - Samuel T Jones
- School of Materials, University of Manchester, Manchester, M13 9PL, UK
| | - Caroline Tapparel
- Department of Microbiology and Molecular Medicine, University of Geneva Medical School, 1205 Geneva, Switzerland
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Ouyang T, Niu G, Zhang Y, Liu X, Zhang X, Zhang S, Geng Y, Pang D, Ouyang H, Ren L. Porcine HMGCR Inhibits Porcine Circovirus Type 2 Infection by Directly Interacting with the Viral Proteins. Viruses 2019; 11:v11060544. [PMID: 31212640 PMCID: PMC6630565 DOI: 10.3390/v11060544] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 06/03/2019] [Accepted: 06/10/2019] [Indexed: 12/29/2022] Open
Abstract
Porcine circovirus type 2 (PCV2) is the etiological agent of porcine circovirus diseases and porcine circovirus-associated diseases (PCVDs/PCVADs). However, the pathogenesis of PCV2 is not fully understood. We previously found that 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) is negatively associated with PCV2 infection in vitro and in vivo. HMGCR inhibits the early stages of PCV2 infection, while PCV2 infection induces the phosphorylation of HMGCR to inactivate the protein. In this study, we investigated the possibility that adenosine 5′-monophosphate (AMP)-activated protein kinase (AMPK), and protein phosphatase 2 (PP2A) participate in HMGCR-mediated inhibition of PCV2 infection and the interaction of porcine HMGCR with PCV2 proteins. The results showed that AMPK activity fluctuated in cells during the early stage of PCV2 infection, while PP2A had little effect on PCV2 infection and HMGCR activity. Furthermore, PCV2 infection may enhance or maintain the level of phosphorylated HMGCR by directly interacting with the protein in PK-15 cells. These findings may provide a better understanding of PCV2 pathogenesis, and HMGCR may be a novel PCV2 antiviral target.
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Affiliation(s)
- Ting Ouyang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, 5333 Xi'an Road, Changchun 130062, China.
| | - Guyu Niu
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, 5333 Xi'an Road, Changchun 130062, China.
| | - Yifang Zhang
- College of Animal Medicine, Yunnan Agricultural University, Black Dragon Pool, Kunming 650201, China.
| | - Xiaohua Liu
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, 5333 Xi'an Road, Changchun 130062, China.
| | - Xinwei Zhang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, 5333 Xi'an Road, Changchun 130062, China.
| | - Shiqi Zhang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, 5333 Xi'an Road, Changchun 130062, China.
| | - Yulu Geng
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, 5333 Xi'an Road, Changchun 130062, China.
| | - Daxin Pang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, 5333 Xi'an Road, Changchun 130062, China.
| | - Hongsheng Ouyang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, 5333 Xi'an Road, Changchun 130062, China.
| | - Linzhu Ren
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, 5333 Xi'an Road, Changchun 130062, China.
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Human cells are permissive for the productive infection of porcine circovirus type 2 in vitro. Sci Rep 2019; 9:5638. [PMID: 30948762 PMCID: PMC6449348 DOI: 10.1038/s41598-019-42210-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 03/27/2019] [Indexed: 11/19/2022] Open
Abstract
Porcine circovirus 2 (PCV2) is the main pathogen of porcine circovirus diseases and porcine circovirus-associated diseases, which are widespread in swine-producing countries. However, there is controversy regarding the susceptibility of human cells to PCV2 infection. In this study, human cell lines were infected with PCV2 and blind passaged several times. PCV2 entered and replicated in human cells, and infectious virions were generated, indicating that human cell lines were permissive to PCV2 replication. Furthermore, PCV2 replication in human cell lines was enhanced by D-glucosamine or concanavalin A (ConA). However, the infection efficiency of PCV2 was lower in human cells than in PK-15 cells, suggesting that PCV2 infection was limited in human cells. Our study reveals that human cells are permissive for the productive infection of porcine circovirus type 2 in vitro.
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40
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Liu Q, Somiya M, Iijima M, Tatematsu K, Kuroda S. A hepatitis B virus-derived human hepatic cell-specific heparin-binding peptide: identification and application to a drug delivery system. Biomater Sci 2019; 7:322-335. [PMID: 30474653 DOI: 10.1039/c8bm01134f] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Viruses are naturally evolved nanocarriers that can evade host immune systems, attach specifically to the surfaces of target cells, enter the cells through endocytosis, escape from endosomes efficiently, and then transfer their genomes to host cells. Hepatitis B virus (HBV) is a ∼42 nm enveloped DNA virus that can specifically infect human hepatic cells. To utilize the HBV-derived early infection machinery in synthetic nanocarriers, the human hepatic cell-binding site (i.e., the sodium taurocholate co-transporting polypeptide (NTCP)-binding site, with myristoylated pre-S1(2-47)) and the low pH-dependent fusogenic domain (pre-S1(9-24)) are indispensable for targeting and endosomal escape, respectively. However, cell-surface NTCP has recently been shown not to be involved in the initial attachment of HBV. In this study, we identified a novel heparin-binding site (pre-S1(30-42)) in the N-terminal half of the pre-S1 region, which presumably interacts with cell-surface heparan sulfate proteoglycan (HSPG) and plays a pivotal role in the initial attachment of HBV to human hepatic cells. The evolutionarily conserved amino acid residues Asp-31, Trp-32, and Asp-33 are indispensable for the heparin-binding activity. Liposomes (LPs) displaying the peptide were endocytosed by human hepatic cells in a cell-surface heparin-dependent manner and delivered doxorubicin to human hepatic cells more efficiently than myristoylated pre-S1(2-47)-displaying LPs. These results demonstrated that the pre-S1(30-42) peptide is the most promising HBV-derived targeting peptide for synthetic nanocarriers, and that this peptide exhibits high specificity for human hepatic cells and efficiently induces endocytosis.
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Affiliation(s)
- Qiushi Liu
- The Institute of Scientific and Industrial Research, Osaka University, Osaka 567-0047, Japan.
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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: 14] [Impact Index Per Article: 2.8] [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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Porcine Circovirus 2 Uses a Multitude of Weak Binding Sites To Interact with Heparan Sulfate, and the Interactions Do Not Follow the Symmetry of the Capsid. J Virol 2019; 93:JVI.02222-18. [PMID: 30602608 DOI: 10.1128/jvi.02222-18] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 12/12/2018] [Indexed: 12/24/2022] Open
Abstract
Porcine circovirus 2 (PCV2) is the smallest pathogenic virus capable of autonomous replication within its host. Infections result in immunosuppression and subsequent death of the host and are initiated via the attachment of the PCV2 icosahedral capsid to heparan sulfate (HS) and chondroitin sulfate B (CSB) glycosaminoglycans on the cell surface. However, the underlying mechanism of structural recognition remains to be explored. Using heparin, a routinely used analog of heparan sulfate, we demonstrate that increasing lengths of heparin exhibit a greater affinity toward PCV2. Our competition assays indicate that dextran sulfate (8 kDa) has a higher affinity for PCV2 than heparin (12 kDa), chondroitin sulfate B (41 kDa), hyaluronic acid (1.6 MDa), and dextran (6 kDa). This suggests that polymers high in sulfate content are capable of competing with the PCV2-heparan sulfate interaction and, thus, have the potential to inhibit PCV2 infection. Finally, we visualized the interaction between heparin and the PCV2 capsid using cryo-electron microscopy single-particle analysis, symmetry expansion, and focused classification. The image reconstructions provide the first example of an asymmetric distribution of heparin on the surface of an icosahedral virus capsid. We demonstrate that each of the 60 capsid subunits that generate the T=1 capsid can bind heparin via one of five binding sites. However, not all of the binding sites were occupied by heparin, and only one-third to two-thirds of the binding sites were occupied. The binding sites are defined by arginine, lysine, and polar amino acids. Mutating the arginine, lysine, and polar amino acids to alanine diminished the binding capacity of PCV2 to heparin.IMPORTANCE It has been demonstrated that porcine circovirus 2 (PCV2) attaches to cells via heparan sulfate (HS) and chondroitin sulfate B (CSB) glycosaminoglycans; however, the underlying structural mechanism describing the HS/CSB recognition by PCV2 remains to be explored. We used cryo-electron microscopy with single-particle analysis, symmetry expansion, and focused classification to visualize the interaction between the PCV2 capsid and heparin, an analog of heparan sulfate, to better than 3.6-Å resolution. We observed that the interaction between PCV2 and heparin does not adhere to the icosahedral symmetry of the capsid. To the best of our knowledge, this is the first example where the interaction between heparin and an icosahedral capsid does not follow the symmetry elements of the capsid. Our findings also suggest that anionic polymers, such as dextran sulfate, may act to inhibit PCV2 infection.
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Structural roles of PCV2 capsid protein N-terminus in PCV2 particle assembly and identification of PCV2 type-specific neutralizing epitope. PLoS Pathog 2019; 15:e1007562. [PMID: 30822338 PMCID: PMC6415871 DOI: 10.1371/journal.ppat.1007562] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 03/13/2019] [Accepted: 01/04/2019] [Indexed: 11/19/2022] Open
Abstract
Postweaning multisystemic wasting disease (PMWS) in piglets caused by porcine circovirus type 2 (PCV2) is one of the major threats to most pig farms worldwide. Among all the PCV types, PCV2 is the dominant genotype causing PMWS and associated diseases. Considerable efforts were made to study the virus-like-particle (VLP) assembly and the specific PCV2-associated epitope(s) in order to establish the solid foundation for engineered PCV2 vaccine development. Although the N-terminal fragment including Nuclear Localization Signal (NLS) sequence seems important for recombinant PCV2 capsid protein expression and VLP assembly, the detailed structural and functional information regarding this important fragment are largely unknown. In this study, we report crystal structure of PCV2 VLP assembled from N-terminal NLS truncated PCV2 capsid protein at 2.8 Å resolution and cryo-EM structure of PCV2 VLP assembled from full-length PCV2 capsid protein at 4.1Å resolution. Our in vitro PCV2 VLP assembly results show that NLS-truncated PCV2 capsid protein only forms instable VLPs which were easily disassembled in solution, whereas full-length PCV2 capsid protein forms stable VLPs due to interaction between 15PRSHLGQILRRRP27(α-helix) and 33RHRYRWRRKN42(NLS-B) in a repeated manner. In addition, our results also showed that N-terminal truncation of PCV2 capsid protein up to 27 residues still forms PCV2 particles in solution with similar size and immunogenicity, while N-terminal truncation of PCV2 capsid protein with more than 30 residues is not able to form stable PCV2 particles in solution, demonstrating the importance of interaction between the α-helix at N-terminal and NLS-B in PCV2 VLP formation. Moreover, we also report the cryo-EM structure of PCV2 VLP in complex with 3H11-Fab, a PCV2 type-specific neutralizing antibody, at 15 Å resolution. MAb-3H11 specifically recognizes one exposed epitope located on the VLP surface EF-loop (residues 128–143), which is further confirmed by PCV1-PCV2 epitope swapping assay. Hence, our results have revealed the structural roles of N-terminal fragment of PCV2 capsid protein in PCV2 particle assembly and pinpointed one PCV2 type-specific neutralizing epitope for the first time, which could provide clear clue for next generation PCV2 vaccine and diagnostic kits development. Porcine circovirus type 2 (PCV2) is considered as one of the most wide-spread pathogens threatening swine production by causing postweaning multisystemic wasting disease (PMWS) in piglets worldwide. Several VLP-based PCV2 vaccines are commercially available which significantly reduce the viral burden and virally induced lesions. However, prophylactic efficacy of VLP-based PCV2 vaccine largely relies on the correct VLP assembly from the individual PCV2 capsid protein. Notably, limited structural information of PCV2 N-terminal fragment containing arginine-rich patches significantly delays our understanding of PCV2 assembly at the molecular level, and the lack of solid evidence in identification of PCV2 type-specific epitope delays the development of PCV2 type-specific diagnosis kits. In this study, through the combination of structural and immunological approaches, we are able, for the first time, to disclose the structural details of the N-terminal Nuclear Localization Signal (NLS) region of PCV2 capsid protein. We show that the interaction between the α-helix from one capsid protein and the NLS-B from an adjacent capsid protein within the pentamer stabilizes the assembled PCV2 VLP in solution. Moreover, by the combination of structural determination and biochemical mapping, we have identified that a short linear sequence (134KATALT139) located within PCV2 EF-loop is a unique PCV2 type-specific neutralizing epitope. Therefore, our work has revealed the detailed structural information of PCV2 particle assembly and a PCV2 type-specific neutralizing epitope, which should provide insightful information for virus-host interaction studies and next-generation PCV2 vaccine and type-specific diagnostic kits development.
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Zepeda-Cervantes J, Cruz-Reséndiz A, Sampieri A, Carreón-Nápoles R, Sánchez-Betancourt JI, Vaca L. Incorporation of ORF2 from Porcine Circovirus Type 2(PCV2) into genetically encoded nanoparticles as a novel vaccine using a self-aggregating peptide. Vaccine 2019; 37:1928-1937. [PMID: 30824359 DOI: 10.1016/j.vaccine.2019.02.044] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 02/11/2019] [Accepted: 02/17/2019] [Indexed: 02/07/2023]
Abstract
Porcine Circovirus Type 2 (PCV2) is one of the most important pathogens in pigs around the world. PCV2 is a non-enveloped virus and its capsid is formed by a single protein known as open reading frame 2 (ORF2). The aim of this study was to evaluate the antigenicity and immunogenicity of genetically-encoded protein nanoparticles (NPs) containing ORF2 from PCV2 fused to the first 110 amino acids of the N-terminus of polyhedrin from the insect virus Autographa californica nucleopolyhedrovirus (PH(1 -1 1 0)). Our group has previously described that some polyhedrin fragments self-aggregate forming polyhedra-like particles. We identified a self-aggregating signal within the first 110 amino acids from polyhedrin (PH(1 -1 1 0)). Fusing the ORF2 from PCV2 to the carboxyl terminus from PH(1 -1 1 0) results in the formation of NPs which incorporate the antigen of interest. Using this system we synthesized NPs containing PH(1 -1 1 0) fused to ORF2 (PH(1 -1 1 0)PCV2) and purify them to immunize pigs and evaluate the humoral immune response generated by these NPs comparing them to a commercially available vaccine. Pigs immunized with PH(1 -1 1 0)PCV2 NPs produced antibodies against ORF2 from PCV2 as indicated by western blot and ELISA analysis. Antibodies obtained with PH(1 -1 1 0)PCV2 NPs were comparable to those obtained using a commercial PCV2 vaccine. These antibodies neutralized the infection of a recombinant PCV2 expressing the green fluorescent protein (GFP). These results together suggest that the self-aggregating peptide PH(1 -1 1 0) can be used for the synthesis of subunit vaccines against PCV2.
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Affiliation(s)
- Jesús Zepeda-Cervantes
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad Universitaria, CDMX, Coyoacán 04510, Mexico; Programa de Doctorado en Ciencias Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, México, CDMX, Coyoacán 04510, Mexico
| | - Adolfo Cruz-Reséndiz
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad Universitaria, CDMX, Coyoacán 04510, Mexico
| | - Alicia Sampieri
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad Universitaria, CDMX, Coyoacán 04510, Mexico.
| | - Rosalba Carreón-Nápoles
- Departamento de Medicina y Zootecnia de Cerdos, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Ciudad Universitaria, CDMX, Coyoacán 04510, Mexico.
| | - José Iván Sánchez-Betancourt
- Departamento de Medicina y Zootecnia de Cerdos, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Ciudad Universitaria, CDMX, Coyoacán 04510, Mexico
| | - Luis Vaca
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad Universitaria, CDMX, Coyoacán 04510, Mexico.
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Affiliation(s)
- Yashpal Singh Malik
- ICAR-Indian Veterinary Research Institute (ICAR-IVRI), Izatnagar, Uttar Pradesh India
| | - Raj Kumar Singh
- ICAR-Indian Veterinary Research Institute (ICAR-IVRI), Izatnagar, Uttar Pradesh India
| | - Mahendra Pal Yadav
- ICAR-Indian Veterinary Research Institute (ICAR-IVRI), Izatnagar, Uttar Pradesh, India, Sardar Vallabhbhai Patel University of Agriculture and Technology, Meerut, India
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Lambert C, Braxton C, Charlebois RL, Deyati A, Duncan P, La Neve F, Malicki HD, Ribrioux S, Rozelle DK, Michaels B, Sun W, Yang Z, Khan AS. Considerations for Optimization of High-Throughput Sequencing Bioinformatics Pipelines for Virus Detection. Viruses 2018; 10:E528. [PMID: 30262776 PMCID: PMC6213042 DOI: 10.3390/v10100528] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 09/19/2018] [Accepted: 09/25/2018] [Indexed: 02/07/2023] Open
Abstract
High-throughput sequencing (HTS) has demonstrated capabilities for broad virus detection based upon discovery of known and novel viruses in a variety of samples, including clinical, environmental, and biological. An important goal for HTS applications in biologics is to establish parameter settings that can afford adequate sensitivity at an acceptable computational cost (computation time, computer memory, storage, expense or/and efficiency), at critical steps in the bioinformatics pipeline, including initial data quality assessment, trimming/cleaning, and assembly (to reduce data volume and increase likelihood of appropriate sequence identification). Additionally, the quality and reliability of the results depend on the availability of a complete and curated viral database for obtaining accurate results; selection of sequence alignment programs and their configuration, that retains specificity for broad virus detection with reduced false-positive signals; removal of host sequences without loss of endogenous viral sequences of interest; and use of a meaningful reporting format, which can retain critical information of the analysis for presentation of readily interpretable data and actionable results. Furthermore, after alignment, both automated and manual evaluation may be needed to verify the results and help assign a potential risk level to residual, unmapped reads. We hope that the collective considerations discussed in this paper aid toward optimization of data analysis pipelines for virus detection by HTS.
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Affiliation(s)
| | | | - Robert L Charlebois
- Analytical Research and Development, Sanofi Pasteur, Toronto, ON M2R 3T4, Canada.
| | | | - Paul Duncan
- Merck & Co. Inc., West Point, PA 19486, USA.
| | | | | | | | | | - Brandye Michaels
- Analytical Research and Development: Microbiology, Pfizer Inc., Andover, MA 01810, USA.
| | | | - Zhihui Yang
- Office of Applied Research and Safety Assessment, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, Laurel, MD 20708, USA.
| | - Arifa S Khan
- Office of Vaccines Research and Review, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD 20993, USA.
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Yu W, Zhan Y, Xue B, Dong Y, Wang Y, Jiang P, Wang A, Sun Y, Yang Y. Highly efficient cellular uptake of a cell-penetrating peptide (CPP) derived from the capsid protein of porcine circovirus type 2. J Biol Chem 2018; 293:15221-15232. [PMID: 30108178 DOI: 10.1074/jbc.ra118.004823] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 08/09/2018] [Indexed: 12/24/2022] Open
Abstract
Porcine circovirus type 2 (PCV2) is one of the smallest, nonenveloped, single-stranded DNA viruses. The PCV2 capsid protein (Cap) is the sole viral structural protein and main antigenic determinant. Previous sequence analysis has revealed that the N terminus of the PCV2 Cap contains a nuclear localization signal (NLS) enriched in positively charged residues. Here, we report that PCV2's NLS can function as a cell-penetrating peptide (CPP). We observed that this NLS can carry macromolecules, e.g. enhanced GFP (EGFP), into cells when they are fused to the NLS, indicating that it can function as a CPP, similar to the classical CPP derived from HIV type 1 transactivator of transcription protein (HIV TAT). We also found that the first 17 residues of the NLS (NLS-A) have a key role in cellular uptake. In addition to entering cells via multiple endocytic processes, NLS-A was also rapidly internalized via direct translocation enabled by increased membrane permeability and was evenly distributed throughout cells when its concentration in cell cultures was ≥10 μm Of note, cellular NLS-A uptake was ∼10 times more efficient than that of HIV TAT. We inferred that the externalized NLS of the PCV2 Cap may accumulate to a high concentration (≥10 μm) at a local membrane area, increasing membrane permeability to facilitate viral entry into the cell to release its genome into a viral DNA reproduction center. We conclude that NLS-A has potential as a versatile vehicle for shuttling foreign molecules into cells, including pharmaceuticals for therapeutic interventions.
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Affiliation(s)
- Wanting Yu
- From the Key Laboratory of Animal Vaccine and Protein Engineering and.,Laboratory of Functional Proteomics (LFP) and Research Center of Reverse Vaccinology (RCRV), College of Veterinary Medicine, Hunan Agricultural University, Changsha 410128, China
| | - Yang Zhan
- From the Key Laboratory of Animal Vaccine and Protein Engineering and.,Laboratory of Functional Proteomics (LFP) and Research Center of Reverse Vaccinology (RCRV), College of Veterinary Medicine, Hunan Agricultural University, Changsha 410128, China
| | - Boxin Xue
- State Key Laboratory of Membrane Biology, Biodynamic Optical Imaging Center (BIOPIC), School of Life Sciences, Peking University, Beijing 100871, China
| | - Yanpeng Dong
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China, and
| | - Yanfeng Wang
- Tsinghua-Peking Joint Center for Life Science, Tsinghua University, Beijing 100084, China
| | - Ping Jiang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China, and
| | - Aibing Wang
- From the Key Laboratory of Animal Vaccine and Protein Engineering and.,Laboratory of Functional Proteomics (LFP) and Research Center of Reverse Vaccinology (RCRV), College of Veterinary Medicine, Hunan Agricultural University, Changsha 410128, China
| | - Yujie Sun
- State Key Laboratory of Membrane Biology, Biodynamic Optical Imaging Center (BIOPIC), School of Life Sciences, Peking University, Beijing 100871, China,
| | - Yi Yang
- From the Key Laboratory of Animal Vaccine and Protein Engineering and .,Laboratory of Functional Proteomics (LFP) and Research Center of Reverse Vaccinology (RCRV), College of Veterinary Medicine, Hunan Agricultural University, Changsha 410128, China
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Wang D, Zhang S, Zou Y, Yu W, Jiang Y, Zhan Y, Wang N, Dong Y, Yang Y. Structure-Based Design of Porcine Circovirus Type 2 Chimeric VLPs (cVLPs) Displays Foreign Peptides on the Capsid Surface. Front Cell Infect Microbiol 2018; 8:232. [PMID: 30038901 PMCID: PMC6046401 DOI: 10.3389/fcimb.2018.00232] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 06/19/2018] [Indexed: 11/13/2022] Open
Abstract
Although porcine circovirus-like particles can function as a vector to carry foreign peptides into host cells, displaying foreign peptides on the surface of virus-like particles (VLPs) remains challenging. In this study, a plateau, consisting of the middle portion of Loop CD (MP-Lcd) from two neighboring subunits of PCV2 capsid protein (Cap), was identified as an ideal site to insert various foreign peptides or epitopes and display them on the surface of PCV2 VLPs. One of the goals of this work is to determine if the surface pattern of this plateau can be altered without compromising the neutralizing activity against PCV2 infections. Therefore, biological roles of MP-Lcd regarding VLPs assembly, cell entry, and antigenicity were investigated to determine whether this was a universal site for insertion of foreign functional peptides. Three-dimensional (3D) structure simulations and mutation assays revealed MP-Lcd was dispensable for PCV2 Cap assembly into VLPs and their entry into host cells. Notably, substitution of MP-Lcd with a foreign peptide, caused surface pattern changes around two-fold axes of PCV2 VLPs based on 3D structure simulation, but was not detrimental to VLPs assembly and cell entry. Moreover, this substitution had no adverse effect on eliciting neutralizing antibodies (NAbs) against PCV2 infection in pigs. In conclusion, MP-Lcd of the PCV2 Cap was a promising site to accommodate and display foreign epitopes or functional peptides on the surface of PCV2 VLPs. Furthermore, chimeric VLPs (cVLPs) would have potential as bivalent or multivalent vaccines and carriers to deliver functional peptides to target cells.
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Affiliation(s)
- Dongliang Wang
- Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, Laboratory of Functional Proteomics, Research Center of Reverse Vaccinology, College of Veterinary Medicine, Hunan Agricultural University, Changsha, China
| | - Sujiao Zhang
- Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, Laboratory of Functional Proteomics, Research Center of Reverse Vaccinology, College of Veterinary Medicine, Hunan Agricultural University, Changsha, China
| | - Yawen Zou
- Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, Laboratory of Functional Proteomics, Research Center of Reverse Vaccinology, College of Veterinary Medicine, Hunan Agricultural University, Changsha, China
| | - Wanting Yu
- Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, Laboratory of Functional Proteomics, Research Center of Reverse Vaccinology, College of Veterinary Medicine, Hunan Agricultural University, Changsha, China
| | - Yifan Jiang
- Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, Laboratory of Functional Proteomics, Research Center of Reverse Vaccinology, College of Veterinary Medicine, Hunan Agricultural University, Changsha, China
| | - Yang Zhan
- Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, Laboratory of Functional Proteomics, Research Center of Reverse Vaccinology, College of Veterinary Medicine, Hunan Agricultural University, Changsha, China
| | - Naidong Wang
- Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, Laboratory of Functional Proteomics, Research Center of Reverse Vaccinology, College of Veterinary Medicine, Hunan Agricultural University, Changsha, China
| | - Yanpeng Dong
- Jiangsu Nannong Hi-Tech Co., Ltd, Jiangyin, China
| | - Yi Yang
- Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, Laboratory of Functional Proteomics, Research Center of Reverse Vaccinology, College of Veterinary Medicine, Hunan Agricultural University, Changsha, China
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Mukherjee P, Karam A, Barkalita L, Borah P, Chakraborty AK, Das S, Puro K, Sanjukta R, Ghatak S, Shakuntala I, Laha RG, Sen A, Sharma I. Porcine circovirus 2 in the North Eastern region of India: Disease prevalence and genetic variation among the isolates from areas of intensive pig rearing. Acta Trop 2018; 182:166-172. [PMID: 29470945 DOI: 10.1016/j.actatropica.2018.02.025] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 02/16/2018] [Accepted: 02/17/2018] [Indexed: 11/26/2022]
Abstract
Porcine Circovirus type-2 (PCV-2) is considered as a major threat to the piggery sector in India. To ascertain the epidemiological status and infection level of PCV2, a pilot study was undertaken to find out the prevalence of PCV2 in swine population by ELISA and PCR in the interior and border areas of Meghalaya which includes the area where accessibility and medical aid is a rare phenomenon. A total of 249 serum samples were collected from October 2014 to February 2016 from three divisions of Meghalaya: Khasi, Jaintia and Garo Hills Divisions. The mean positivity of PCV-2 antibodies in suspected sera was 83.93% whereas 62.25% of the suspected samples respectively were found to contain PCV2 as detected by PCR. Additional 190 tissue samples were collected during necropsy from both symptomatic and asymptomatic animals following reported outbreak in this region, which indicated a mean positivity of 18.94% (36/190); out of which 13 samples were subjected to sequencing to find out the genetic diversity of PCV2 amongst the field isolates. Molecular characterization and phylogenetic analysis of PCV2 isolates based on cap gene depicted genetic diversity among the strains in pig population of Meghalaya as the isolates belonged to PCV2a, PCV2b-1c and PCV2d genotypes; identification of the PCV2d genotype is probably the first report from Meghalaya. Four isolates forming an outlier group in the phylogenetic tree were arising out of natural inter-genotypic recombination between PCV2a and PCV2b. PCV2 being immunosuppressive in nature impairs the host immune response increasing the susceptibility to other co-infections leading to disease severity and high mortality in pig population. This baseline data gives a brief epidemiological status of PCV2 infection and circulating PCV2 genotype in this region which will be useful in the formulation of control and eradication programs in remotes areas of Meghalaya where accessibility is less and vaccination is a rare practice.
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Cruz TF, Magro AJ, de Castro AMMG, Pedraza-Ordoñez FJ, Tsunemi MH, Perahia D, Araujo JP. In vitro and in silico studies reveal capsid-mutant Porcine circovirus 2b with novel cytopathogenic and structural characteristics. Virus Res 2018; 251:22-33. [PMID: 29730308 DOI: 10.1016/j.virusres.2018.04.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Revised: 04/27/2018] [Accepted: 04/27/2018] [Indexed: 12/20/2022]
Abstract
Porcine circovirus 2 (PCV2) is an icosahedral, non-enveloped, and single-stranded circular DNA virus that belongs to the family Circoviridae, genus Circovirus, and is responsible for a complex of different diseases defined as porcine circovirus diseases (PCVDs). These diseases - including postweaning multisystemic wasting syndrome (PMWS), enteric disease, respiratory disease, porcine dermatitis and nephropathy syndrome (PDNS), and reproductive failure - are responsible for large economic losses in the pig industry. After serial passages in swine testicle (ST) cells of a wild-type virus isolated from an animal with PMWS, we identified three PCV2b viruses with capsid protein (known as Cap protein) cumulative mutations, including two novel mutants. The mutant viruses were introduced into new ST cell cultures for reisolation and showed, in comparison to the wild-type PCV2b, remarkable viral replication efficiency (> 1011 DNA copies/ml) and cell death via necrosis, which were clearly related to the accretion of capsid protein mutations. The analysis of a Cap protein/capsid model showed that the mutated residues were located in solvent-accessible positions on the external PCV2b surface. Additionally, the mutated residues were found in linear epitopes and participated in pockets on the capsid surface, indicating that these residues could also be involved in antibody recognition. Taking into account the likely natural emergence of PCV2b variants, it is possible to consider that the results of this work increase knowledge of Circovirus biology and could help to prevent future serious cases of vaccine failure that could lead to heavy losses to the swine industry.
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Affiliation(s)
- Taís Fukuta Cruz
- Departamento de Microbiologia e Imunologia, Instituto de Biociências (IB), Universidade Estadual Paulista (Unesp), Botucatu, São Paulo, Brazil; Instituto de Biotecnologia (IBTEC), Universidade Estadual Paulista (Unesp), Botucatu, São Paulo, Brazil.
| | - Angelo José Magro
- Instituto de Biotecnologia (IBTEC), Universidade Estadual Paulista (Unesp), Botucatu, São Paulo, Brazil; Departamento de Bioprocessos e Biotecnologia, Faculdade de Ciências Agronômicas (FCA), Universidade Estadual Paulista (Unesp), Botucatu, São Paulo, Brazil.
| | - Alessandra M M G de Castro
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Universidade de São Paulo (USP), São Paulo, São Paulo, Brazil
| | | | - Miriam Harumi Tsunemi
- Departamento de Bioestatística, Instituto de Biociências (IB), Universidade Estadual Paulista (Unesp), Botucatu, São Paulo, Brazil
| | - David Perahia
- Laboratoire de Biologie et de Pharmacologie Appliquée, ENS Cachan/Université Paris-Saclay, Cachan, France.
| | - João Pessoa Araujo
- Departamento de Microbiologia e Imunologia, Instituto de Biociências (IB), Universidade Estadual Paulista (Unesp), Botucatu, São Paulo, Brazil; Instituto de Biotecnologia (IBTEC), Universidade Estadual Paulista (Unesp), Botucatu, São Paulo, Brazil.
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