1
|
Sun YY, Liu KS, Zhang C, Ni Z, Zhu YC, Bao HL, Chen L, Ye WC, Hua JG, Huo SX, Wang HY, Yun T, Bao ED. Recombinant pseudorabies virus (PRV) expressing stabilized E2 of classical swine fever virus (CSFV) protects against both PRV and CSFV. Antiviral Res 2023; 211:105548. [PMID: 36702445 DOI: 10.1016/j.antiviral.2023.105548] [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: 11/30/2022] [Revised: 01/05/2023] [Accepted: 01/19/2023] [Indexed: 01/25/2023]
Abstract
Pseudorabies (PR) and classical swine fever (CSF) are economically important infectious diseases of pigs. Most pig farms in China are immunized against these two diseases. Here, we describe a stabilized E2 protein as an immunogen inserted into the PRV genome as a bivalent live virus-vectored vaccine. The E2 protein has 48 variant sites, there are 2-5 candidate amino acids per variant site, and the relative energy contribution of each amino acid to E2 energy was calculated. Combined substitutions of amino acids at the neighbor variant site (neighbor substitution) were performed to obtain the E2 protein sequence with the lowest energy (stabilized E2). Multiple amino acid substitutions at 48 variant sites were performed, and the results were consistent with neighbor substitutions. The stabilized E2 sequence was obtained, and its energy decreased by 22 Rosetta Energy Units (REUs) compared with the original sequence. After the recombinant PRV expressing stabilized E2 of CSFV was constructed, the secretion efficiency of stabilized E2 was increased by 2.97 times, and the thermal stability was increased by 10.5 times. Immunization of mice resulted in a 2-fold increase in antibody production, and a balanced antibody level against subtype 1.1 and subtype 2.1d E2 was achieved. In rabbits immunized, the lethal challenge of PRV-ZJ and the fever response induced by CSFV could be prevented simultaneously. These findings suggest that rPRV-muta/287aaE2 is a promising bivalent vaccine against CSFV and PRV infections.
Collapse
Affiliation(s)
- Yang-Yang Sun
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China; Institute of Animal Husbandry and Veterinary Sciences, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China
| | - Ke-Shu Liu
- Institute of Animal Husbandry and Veterinary Sciences, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China
| | - Cun Zhang
- Institute of Animal Husbandry and Veterinary Sciences, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China
| | - Zheng Ni
- Institute of Animal Husbandry and Veterinary Sciences, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China
| | - Yin-Chu Zhu
- Institute of Animal Husbandry and Veterinary Sciences, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China
| | - Hai-Li Bao
- Fujian Provincial Key Laboratory of Reproductive Health Research, School of Medicine, Xiamen University, Xiamen, China
| | - Liu Chen
- Institute of Animal Husbandry and Veterinary Sciences, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China
| | - Wei-Cheng Ye
- Institute of Animal Husbandry and Veterinary Sciences, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China
| | - Jiong-Gang Hua
- Institute of Animal Husbandry and Veterinary Sciences, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China
| | - Su-Xin Huo
- Institute of Animal Husbandry and Veterinary Sciences, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China
| | - Hong-Yu Wang
- Institute of Animal Husbandry and Veterinary Sciences, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China
| | - Tao Yun
- Institute of Animal Husbandry and Veterinary Sciences, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China; State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Animal Husbandry and Veterinary Sciences, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China.
| | - En-Dong Bao
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China.
| |
Collapse
|
2
|
Hu M, Wang F, Li N, Xing G, Sun X, Zhang Y, Cao S, Cui N, Zhang G. An antigen display system of GEM nanoparticles based on affinity peptide ligands. Int J Biol Macromol 2021; 193:574-584. [PMID: 34699894 DOI: 10.1016/j.ijbiomac.2021.10.135] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 10/08/2021] [Accepted: 10/18/2021] [Indexed: 10/20/2022]
Abstract
Gram-positive enhancer matrix (GEM) nanoparticles are often used in mucosal immunity, preparation of subunit vaccines or as an immune adjuvant due to its good immunological activities in recent years. Here, we designed and screened out a high affinity peptide ligand PL23, which could specifically target the non-epitope region of Classic Swine Fever Virus (CSFV) E2 protein, by virtual screening technology, enzyme linked immunosorbent assay (ELISA) and surface plasmon resonance (SPR) test. The OD value of PL23 at 450 nm was reached 1.982, and the KD value of it was 90.12 nM. Its binding capacity to protein was verified by SDS-PAGE as well. PL23 was subsequently conjugated to GEM nanoparticles by dehydration synthesis generating GEM-PL23 particles, and the GEM-PL-E2 particles were assembled after incubated with CSFV E2 protein. The cytotoxic test indicated that PL23, CSFV E2 protein, GEM nanoparticles, GEM-PL23 particles and GEM-PL-E2 particles were not toxic to cells and GEM nanoparticles could significantly promote the growth of APCs at high concentration for 1 h, p<0.001. In addition, GEM nanoparticles could promote the uptake of antigen by APCs. The cytokines tests suggested that GEM-PL-E2 particles could promote innate immune responses, regulate adaptive immune responses generated by T cells and APCs, and promote the differentiation and maturation of dendritic cells without producing inflammasomes. The results of immunological activity identification showed GEM-PL-E2 particles induced higher levels of both neutralizing antibodies and anti-CSFV antibodies than CSFV E2 protein in mice. This strategy provided a new, simpler, faster and cheaper method for assembling GEM nanoparticles, using an affinity peptide ligand replaced the protein anchor (PA), and provided a better application prospect for the application of GEM particles.
Collapse
Affiliation(s)
- Man Hu
- College of Veterinary Medicine, Jilin University, Changchun, Jilin, China; Key Laboratory for Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, Henan, China
| | - Fangyu Wang
- Key Laboratory for Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, Henan, China
| | - Ning Li
- College of Food Science and Technology, Henan Agricultural University, Zhengzhou, Henan, China
| | - Guangxu Xing
- Key Laboratory for Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, Henan, China
| | - Xuefeng Sun
- Key Laboratory for Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, Henan, China
| | - Yunshang Zhang
- Key Laboratory for Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, Henan, China
| | - Shuai Cao
- College of Food Science and Technology, Henan Agricultural University, Zhengzhou, Henan, China
| | - Ningning Cui
- College of Food Science and Technology, Henan Agricultural University, Zhengzhou, Henan, China
| | - Gaiping Zhang
- College of Veterinary Medicine, Jilin University, Changchun, Jilin, China; Key Laboratory for Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, Henan, China.
| |
Collapse
|
3
|
Forner M, Cañas-Arranz R, Defaus S, de León P, Rodríguez-Pulido M, Ganges L, Blanco E, Sobrino F, Andreu D. Peptide-Based Vaccines: Foot-and-Mouth Disease Virus, a Paradigm in Animal Health. Vaccines (Basel) 2021; 9:vaccines9050477. [PMID: 34066901 PMCID: PMC8150788 DOI: 10.3390/vaccines9050477] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 04/19/2021] [Accepted: 05/02/2021] [Indexed: 02/07/2023] Open
Abstract
Vaccines are considered one of the greatest global health achievements, improving the welfare of society by saving lives and substantially reducing the burden of infectious diseases. However, few vaccines are fully effective, for reasons ranging from intrinsic limitations to more contingent shortcomings related, e.g., to cold chain transport, handling and storage. In this context, subunit vaccines where the essential antigenic traits (but not the entire pathogen) are presented in rationally designed fashion have emerged as an attractive alternative to conventional ones. In particular, this includes the option of fully synthetic peptide vaccines able to mimic well-defined B- and T-cell epitopes from the infectious agent and to induce protection against it. Although, in general, linear peptides have been associated to low immunogenicity and partial protection, there are several strategies to address such issues. In this review, we report the progress towards the development of peptide-based vaccines against foot-and-mouth disease (FMD) a highly transmissible, economically devastating animal disease. Starting from preliminary experiments using single linear B-cell epitopes, recent research has led to more complex and successful second-generation vaccines featuring peptide dendrimers containing multiple copies of B- and T-cell epitopes against FMD virus or classical swine fever virus (CSFV). The usefulness of this strategy to prevent other animal and human diseases is discussed.
Collapse
Affiliation(s)
- Mar Forner
- Departament de Ciències Experimentals i de la Salut (DCEXS-UPF), 08003 Barcelona, Spain; (M.F.); (S.D.)
| | - Rodrigo Cañas-Arranz
- Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), 28049 Madrid, Spain; (R.C.-A.); (P.d.L.); (M.R.-P.)
| | - Sira Defaus
- Departament de Ciències Experimentals i de la Salut (DCEXS-UPF), 08003 Barcelona, Spain; (M.F.); (S.D.)
| | - Patricia de León
- Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), 28049 Madrid, Spain; (R.C.-A.); (P.d.L.); (M.R.-P.)
| | - Miguel Rodríguez-Pulido
- Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), 28049 Madrid, Spain; (R.C.-A.); (P.d.L.); (M.R.-P.)
| | - Llilianne Ganges
- Centre de Recerca en Sanitat Animal (CReSA), OIE Reference Laboratory for Classical Swine Fever, Institute of Agrifood Research and Technology, 08193 Barcelona, Spain;
| | - Esther Blanco
- Centro de Investigación en Sanidad Animal (CISA-INIA), 28130 Valdeolmos, Spain;
| | - Francisco Sobrino
- Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), 28049 Madrid, Spain; (R.C.-A.); (P.d.L.); (M.R.-P.)
- Correspondence: (F.S.); (D.A.)
| | - David Andreu
- Departament de Ciències Experimentals i de la Salut (DCEXS-UPF), 08003 Barcelona, Spain; (M.F.); (S.D.)
- Correspondence: (F.S.); (D.A.)
| |
Collapse
|
4
|
Research Progress and Challenges in Vaccine Development against Classical Swine Fever Virus. Viruses 2021; 13:v13030445. [PMID: 33801868 PMCID: PMC7998128 DOI: 10.3390/v13030445] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 03/01/2021] [Accepted: 03/04/2021] [Indexed: 01/06/2023] Open
Abstract
Classical swine fever (CSF), caused by CSF virus (CSFV), is one of the most devastating viral epizootic diseases of swine in many countries. To control the disease, highly efficacious and safe live attenuated vaccines have been used for decades. However, the main drawback of these conventional vaccines is the lack of differentiability of infected from vaccinated animals (DIVA concept). Advances in biotechnology and our detailed knowledge of multiple basic science disciplines have facilitated the development of effective and safer DIVA vaccines to control CSF. To date, two types of DIVA vaccines have been developed commercially, including the subunit vaccines based on CSFV envelope glycoprotein E2 and chimeric pestivirus vaccines based on infectious cDNA clones of CSFV or bovine viral diarrhea virus (BVDV). Although inoculation of these vaccines successfully induces solid immunity against CSFV, none of them could ideally meet all demands regarding to safety, efficacy, DIVA potential, and marketability. Due to the limitations of the available choices, researchers are still striving towards the development of more advanced DIVA vaccines against CSF. This review summarizes the present status of candidate CSFV vaccines that have been developed. The strategies and approaches revealed here may also be helpful for the development of new-generation vaccines against other diseases.
Collapse
|
5
|
Xu H, Han G, Lu Y, Liu Z, Tao L, He F. Broad neutralization of CSFV with novel monoclonal antibodies in vivo. Int J Biol Macromol 2021; 173:513-523. [PMID: 33493566 DOI: 10.1016/j.ijbiomac.2021.01.142] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 01/18/2021] [Accepted: 01/20/2021] [Indexed: 12/11/2022]
Abstract
Classical swine fever is a highly contagious disease in China. Although vaccination against Classical swine fever virus (CSFV) has been widely carried out in China, CSFV cases still emerge in an endless stream. Therefore, it is necessary to take new antiviral measures to eliminate CSFV. Glycoprotein E2 of CSFV is the major vaccine candidate that confers protective immunity. Thus, in this study, a batch of neutralizing monoclonal antibodies (mAbs) against E2, as alternative antiviral strategies, were produced. Among them, mAbs 6D10, 8D8 and 3C12 presented neutralizing reactivity against CSFV in a dose-dependent manner. Based on truncated overlapping fragments of E2 and mutants, three linear neutralizing epitopes were identified highly conserved in various CSFV strains. Epitopes 8YRYAIS13 and 254HECLIG259 were reported for the first time. All the three epitopes are involved in virus internalization and attachment as shown in pre- or post-attachment neutralization. Recombinant polypeptides carrying epitopes successfully inhibit virus infection in PK-15 cells, indicating epitopes were located in receptor-binding domain (RBD). Further, both prophylactic and therapeutic functions of neutralizing antibody were evaluated in rabbits upon CSFV challenge, confirming the efficacy in vivo. These findings provide alternative antiviral strategies against CSFV and deepen the understanding in E2 function during virus entry.
Collapse
Affiliation(s)
- Huiling Xu
- Institute of Preventive Veterinary Medicine, College of Animal Science, Zhejiang University, Hangzhou, China; Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou, China
| | - Guangwei Han
- Institute of Preventive Veterinary Medicine, College of Animal Science, Zhejiang University, Hangzhou, China; Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou, China
| | - Ying Lu
- Institute of Preventive Veterinary Medicine, College of Animal Science, Zhejiang University, Hangzhou, China; Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou, China
| | - Zehui Liu
- Institute of Preventive Veterinary Medicine, College of Animal Science, Zhejiang University, Hangzhou, China; Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou, China
| | - Lina Tao
- Institute of Preventive Veterinary Medicine, College of Animal Science, Zhejiang University, Hangzhou, China; Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou, China
| | - Fang He
- Institute of Preventive Veterinary Medicine, College of Animal Science, Zhejiang University, Hangzhou, China; Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou, China.
| |
Collapse
|
6
|
Singh AP, Prabhu SN, Nagaleekar VK, Dangi SK, Prakash C, Singh VP. Immunogenicity assessment of Clostridium perfringens type D epsilon toxin epitope-based chimeric construct in mice and rabbit. 3 Biotech 2020; 10:406. [PMID: 32864287 PMCID: PMC7447850 DOI: 10.1007/s13205-020-02400-4] [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: 03/16/2020] [Accepted: 08/17/2020] [Indexed: 12/05/2022] Open
Abstract
Epsilon toxin (Etx) belongs to family of pore-forming toxin and is produced by Clostridium perfringens type D. The Etx toxin is responsible for the pathogenesis of enterotoxaemia in sheep and goats, and occasionally in other livestock animals. The present study aimed to develop a Clostridium perfringens epsilon toxin-based chimeric epitope construct having immunodominant B-cell epitope and universal T-cell epitope and its immunogenicity was evaluated in mice and rabbit. An artificial chimeric epitope construct (CEC) was prepared by joining tandem repeats of a peptide containing amino acids (aa) 134–145 of epsilon toxin B-cell epitope and universal T-cell epitopes. The CEC was expressed in the Escherichia coli following codon optimization for efficient translational efficiency and purified by affinity chromatography. The antigenic reactivity of r-CEC proteins was confirmed by western blot with rabbit anti-r-Etox hyperimmune sera. The immunogenicity of the recombinant single CEC was examined in mice and rabbit by indirect ELISA. It was found that r-CEC yielded high titers of neutralizing antibodies (≥ 1.035 IU/ml) in immunized mice and rabbit. The potency of chimeric protein immunized serum was observed to be higher than the recommended level (0.1–0.3 IU/ml) for protection in sheep and goats. This indicated the potential ability of the chimeric protein as a vaccine candidate. This further requires studying the immune response in targeted host species (sheep and goat).
Collapse
Affiliation(s)
- Ajay Pratap Singh
- Department of Veterinary Microbiology, College of Veterinary and Animal Science, COVSc.&AH, U.P. Pandit Deen Dayal Upadhyaya Pashu Chikitsa Vigyan Vishwavidyalaya Evam Go Anusandhan Sansthan (DUVASU), Mathura, UP 281001 India
| | - Shyama N. Prabhu
- Department of Veterinary Pathology, COVSc.&AH, U.P. Pandit Deen Dayal Upadhyaya Pashu Chikitsa Vigyan Vishwavidyalaya Evam Go Anusandhan Sansthan (DUVASU), Mathura, UP 281001 India
| | - Viswas K. Nagaleekar
- Division Bacteriology and Mycology, Indian Veterinary Reaserch Institute (IVRI), Izatnagar, Bareilly, Uttar Pradesh 243 122 India
| | - Saroj K. Dangi
- Division Bacteriology and Mycology, Indian Veterinary Reaserch Institute (IVRI), Izatnagar, Bareilly, Uttar Pradesh 243 122 India
| | - Chandan Prakash
- Centre for Advance Animal Research and Diagnosis, Indian Veterinary Reaserch Institute (IVRI), Izatnagar, Bareilly, Uttar Pradesh 243 122 India
| | - Vijendra Pal Singh
- National Institute of High Security Animal Disease (NISHAD), Bhopal, Madhya Pradesh 462021 India
| |
Collapse
|
7
|
Han Y, Xie L, Yuan M, Ma Y, Sun H, Sun Y, Li Y, Qiu HJ. Development of a marker vaccine candidate against classical swine fever based on the live attenuated vaccine C-strain. Vet Microbiol 2020; 247:108741. [PMID: 32768202 DOI: 10.1016/j.vetmic.2020.108741] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 05/26/2020] [Accepted: 05/26/2020] [Indexed: 12/29/2022]
Abstract
Classical swine fever (CSF) is a highly contagious and economically damaging disease. Classical swine fever virus (CSFV) lapinized vaccine C-strain against CSF worldwide lacks the capacity for the serological differentiation between infected and vaccinated animals (DIVA). To develop a marker C-strain complying with the DIVA principle, we generated and evaluated mutants rHCLV-E2F117A, rHCLV-E2G119A, and rHCLV-E2P122A, which harbor the single amino acid mutation at 117F, 119G or 122P of the monoclonal antibody HQ06-recognized epitope on the E2 glycoprotein in rabbits and pigs. Viral intravenous administration demonstrated that all the mutants retain the phenotype of C-strain in rabbits, including fever response induction and replication in the spleen. Notably, the HQ06-recognized epitope did not react with the antibodies induced by rHCLV-E2P122A in rabbits, in contrast with C-strain and other two mutants. Intramuscular administration of rHCLV-E2P122A in pigs induced anti-CSFV neutralizing antibodies but not antibodies against the HQ06-recognized epitope at 28 days post-inoculation. Collectively, our data demonstrate that rHCLV-E2P122A is a promising marker vaccine candidate against CSF.
Collapse
Affiliation(s)
- Yuying Han
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Libao Xie
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Mengqi Yuan
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Yuteng Ma
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Huimin Sun
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Yuan Sun
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Yongfeng Li
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China.
| | - Hua-Ji Qiu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China.
| |
Collapse
|
8
|
Identification of structural glycoprotein E2 domain critical to mediate replication of Classical Swine Fever Virus in SK6 cells. Virology 2018; 526:38-44. [PMID: 30340154 DOI: 10.1016/j.virol.2018.10.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 09/12/2018] [Accepted: 10/02/2018] [Indexed: 11/21/2022]
Abstract
Envelope glycoprotein E2 of Classical Swine Fever Virus (CSFV) is involved in several critical virus functions. To analyze the role of E2 in virus replication, a series of recombinant CSFVs harboring chimeric forms of E2 CSFV and Bovine viral diarrhea virus (BVDV) were created and tested for their ability to infect swine or bovine cell lines. Substitution of native CSFV E2 by BVDV E2 abrogates virus replication in both cell lines. Substitution of individual domains in CSFV Brescia E2 by the homologous from BVDV produces chimeras that efficiently replicate in SK6 cells with the exception of a chimera harboring BVDV E2 residues 93-168. Further mapping revealed a critical area in E2 required for CSFV replication in SK6 cells between protein residues 136-156. This is the first report categorically defining a discrete portion of E2 as essential to pestivirus infection in susceptible cells.
Collapse
|
9
|
Blome S, Moß C, Reimann I, König P, Beer M. Classical swine fever vaccines-State-of-the-art. Vet Microbiol 2017; 206:10-20. [PMID: 28069290 DOI: 10.1016/j.vetmic.2017.01.001] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2016] [Revised: 12/24/2016] [Accepted: 01/01/2017] [Indexed: 10/20/2022]
Abstract
Due to its impact on animal health and pig industry, classical swine fever (CSF) is still one of the most important viral diseases of pigs. To control the disease, safe and highly efficacious live attenuated vaccines exist for decades. These vaccines have usually outstanding efficacy and safety but lack differentiability of infected from vaccinated animals (DIVA or marker strategy). In contrast, the first generation of E2 subunit marker vaccines shows constraints in efficacy, application, and production. To overcome these limitations, new generations of marker vaccines are developed. A wide range of approaches have been tried including recombinant vaccines, recombinant inactivated vaccines or subunit vaccines, vector vaccines, and DNA/RNA vaccines. During the last years, especially attenuated deletion vaccines or chimeric constructs have shown potential. At present, especially two new constructs have been intensively tested, the adenovirus-delivered, Semliki Forest virus replicon-vectored marker vaccine candidate "rAdV-SFV-E2" and the pestivirus chimera "CP7_E2alf". The later was recently licensed by the European Medicines Agency. Under field conditions, all marker vaccines have to be accompanied by a potent test system. Particularly this point shows still weaknesses and it is important to embed vaccination in a well-established vaccination strategy and a suitable diagnostic workflow. In summary, conventional vaccines are a standard in terms of efficacy. However, only vaccines with DIVA will allow improved eradication strategies e.g. also under emergency vaccination conditions in free regions. To answer this demand, new generations of marker vaccines have been developed and add now to the tool box of CSF control.
Collapse
Affiliation(s)
- Sandra Blome
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Suedufer 10, 17493 Greifswald, Insel Riems, Germany
| | - Claudia Moß
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Suedufer 10, 17493 Greifswald, Insel Riems, Germany
| | - Ilona Reimann
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Suedufer 10, 17493 Greifswald, Insel Riems, Germany
| | - Patricia König
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Suedufer 10, 17493 Greifswald, Insel Riems, Germany
| | - Martin Beer
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Suedufer 10, 17493 Greifswald, Insel Riems, Germany.
| |
Collapse
|
10
|
Abstract
Pestiviruses are a group of viruses of veterinary importance infecting livestock animals like pigs, cattle, and sheep, and also wildlife animals like wild boar and different deer species. While for decades only four classical species (Classical swine fever virus, Bovine viral diarrhea virus types 1 and 2, Border disease virus), and a few so-called atypical pestiviruses were known (e.g., Giraffe virus, Pronghorn virus, HoBi virus), a series of novel pestiviruses was identified in the last years (Bungowannah virus, Bat pestivirus, Norway rat pestivirus, Atypical porcine pestivirus, LINDA virus). The Australian Bungowannah virus could be isolated and further characterized by classical sequencing, but all the other latest novel pestiviruses were identified by metagenomics using next-generation sequencing technologies. Here, we describe these new viruses and their discovery and characterization. Differentiation is made between the occurrence of classical pestiviruses in new species and novel viruses or virus types.
Collapse
Affiliation(s)
- Sandra Blome
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany.
| | - Martin Beer
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Kerstin Wernike
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| |
Collapse
|
11
|
Beer M, Wernike K, Dräger C, Höper D, Pohlmann A, Bergermann C, Schröder C, Klinkhammer S, Blome S, Hoffmann B. High Prevalence of Highly Variable Atypical Porcine Pestiviruses Found in Germany. Transbound Emerg Dis 2016; 64:e22-e26. [PMID: 27297961 DOI: 10.1111/tbed.12532] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Indexed: 11/29/2022]
Abstract
Recently, a novel atypical porcine pestivirus (APPV) with significant distribution was described in the USA. Subsequent screening of the German pig sector showed a high prevalence of APPV with high variability among strains. First indication of a cell culture isolate is provided which will allow further investigations like pathogenesis studies.
Collapse
Affiliation(s)
- M Beer
- Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany
| | - K Wernike
- Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany
| | - C Dräger
- Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany
| | - D Höper
- Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany
| | - A Pohlmann
- Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany
| | - C Bergermann
- State Office for Agriculture Food Safety and Fishery Mecklenburg-Western Pomerania, Rostock, Germany
| | - C Schröder
- Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany
| | | | - S Blome
- Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany
| | - B Hoffmann
- Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany
| |
Collapse
|
12
|
Structures and Functions of Pestivirus Glycoproteins: Not Simply Surface Matters. Viruses 2015; 7:3506-29. [PMID: 26131960 PMCID: PMC4517112 DOI: 10.3390/v7072783] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 06/11/2015] [Accepted: 06/18/2015] [Indexed: 12/21/2022] Open
Abstract
Pestiviruses, which include economically important animal pathogens such as bovine viral diarrhea virus and classical swine fever virus, possess three envelope glycoproteins, namely Erns, E1, and E2. This article discusses the structures and functions of these glycoproteins and their effects on viral pathogenicity in cells in culture and in animal hosts. E2 is the most important structural protein as it interacts with cell surface receptors that determine cell tropism and induces neutralizing antibody and cytotoxic T-lymphocyte responses. All three glycoproteins are involved in virus attachment and entry into target cells. E1-E2 heterodimers are essential for viral entry and infectivity. Erns is unique because it possesses intrinsic ribonuclease (RNase) activity that can inhibit the production of type I interferons and assist in the development of persistent infections. These glycoproteins are localized to the virion surface; however, variations in amino acids and antigenic structures, disulfide bond formation, glycosylation, and RNase activity can ultimately affect the virulence of pestiviruses in animals. Along with mutations that are driven by selection pressure, antigenic differences in glycoproteins influence the efficacy of vaccines and determine the appropriateness of the vaccines that are currently being used in the field.
Collapse
|
13
|
Kwon T, Yoon SH, Kim KW, Caetano-Anolles K, Cho S, Kim H. Time-calibrated phylogenomics of the classical swine fever viruses: genome-wide bayesian coalescent approach. PLoS One 2015; 10:e0121578. [PMID: 25815768 PMCID: PMC4376735 DOI: 10.1371/journal.pone.0121578] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2014] [Accepted: 02/13/2015] [Indexed: 01/03/2023] Open
Abstract
The phylogeny of classical swine fever virus (CSFV), the causative agent of classical swine fever (CSF), has been investigated extensively. However, no evolutionary research has been performed using the whole CSFV genome. In this study, we used 37 published genome sequences to investigate the time-calibrated phylogenomics of CSFV. In phylogenomic trees based on Bayesian inference (BI) and Maximum likelihood (ML), the 37 isolates were categorized into five genetic types (1.1, 1.2, 2.1, 2.3, and 3.4). Subgenotype 1.1 is divided into 3 groups and 1 unclassified isolate, 2.1 into 4 groups, 2.3 into 2 groups and 1 unclassified isolate, and subgenotype 1.2 and 3.4 consisted of one isolate each. We did not observe an apparent temporal or geographical relationship between isolates. Of the 14 genomic regions, NS4B showed the most powerful phylogenetic signal. Results of this evolutionary study using Bayesian coalescent approach indicate that CSFV has evolved at a rate of 13×.010-4 substitutions per site per year. The most recent common ancestor of CSFV appeared 2770.2 years ago, which was about 8000 years after pig domestication. The effective population size of CSFV underwent a slow increase until the 1950s, after which it has remained constant.
Collapse
Affiliation(s)
- Taehyung Kwon
- Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea
| | - Sook Hee Yoon
- Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea
| | - Kyu-Won Kim
- Interdisciplinary Program in Bioinformatics, Seoul National University, Seoul, 151-747, Republic of Korea
| | - Kelsey Caetano-Anolles
- Department of Animal Sciences, University of Illinois, Urbana, IL, 61801, United States of America
| | - Seoae Cho
- C&K Genomics Inc. 514 Main Bldg., Seoul National University Research Park, San 4-2 Boncheon-dong, Gwanak-gu, Seoul, 151-919, Republic of Korea
| | - Heebal Kim
- Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea
- * E-mail:
| |
Collapse
|
14
|
Bruderer U, van de Velde J, Frantzen I, De Bortoli F. Discrimination within epitope specific antibody populations against Classical swine fever virus is a new means of differentiating infection from vaccination. J Immunol Methods 2015; 420:18-23. [PMID: 25825375 DOI: 10.1016/j.jim.2015.03.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 03/18/2015] [Accepted: 03/18/2015] [Indexed: 10/23/2022]
Abstract
Serological differentiation between infection and vaccination depends on the detection of pathogen specific antibodies for an epitope that is modified or lacking in a vaccine. Here we describe a new assay principle that is based on differences in the binding properties of epitope specific antibodies. C-DIVA is a potent Classical swine fever vaccine candidate that differs from the parental C-strain life attenuated vaccine in the highly immunogenic TAVSPTTLR epitope by the deletion of two and the mutation of one amino acid (TAGSΔΔTLR). We show that C-DIVA vaccination elicits antibodies with high affinity for both the TAGSΔΔTLR and TAVSPTTLR epitope, whereas infection elicits only TAVSPTTLR specific antibodies. Differentiation is achieved with a double competition assay with negative selection for antibodies with affinity for the TAGSΔΔTLR epitope followed by positive selection for antibodies with affinity for the TAVSPTTLR epitope. Our findings add a new strategy for the development of marker vaccines and their accompanying discrimination assays and offer an alternative to the devastating stamping out policy for Classical swine fever.
Collapse
Affiliation(s)
- Urs Bruderer
- Discovery & Technology Vaccine Analysis, MSD Animal Health, Boxmeer, The Netherlands.
| | - Jan van de Velde
- Discovery & Technology Vaccine Analysis, MSD Animal Health, Boxmeer, The Netherlands
| | - Inge Frantzen
- Discovery & Technology Expression, MSD Animal Health, Boxmeer, The Netherlands
| | - Francesca De Bortoli
- Institute of Chemistry and Biochemistry, Free University of Berlin, Berlin, Germany
| |
Collapse
|
15
|
Jung M, Shin YJ, Kim J, Cha SB, Lee WJ, Shin MK, Shin SW, Yang MS, Jang YS, Kwon TH, Yoo HS. Induction of immune responses in mice and pigs by oral administration of classical swine fever virus E2 protein expressed in rice calli. Arch Virol 2014; 159:3219-30. [PMID: 25091740 DOI: 10.1007/s00705-014-2182-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 07/15/2014] [Indexed: 12/19/2022]
Abstract
Classical swine fever (CSF), caused by the CSF virus (CSFV), is a highly contagious disease in pigs. In Korea, vaccination using a live-attenuated strain (LOM strain) has been used to control the disease. However, parenteral vaccination using a live-attenuated strain still faces a number of problems related to storage, cost, injection stress, and differentiation of CSFV infected and vaccinated pigs. Therefore, two kinds of new candidates for oral vaccination have been developed based on the translation of the E2 gene of the SW03 strain, which was isolated from an outbreak of CSF in 2002 in Korea, in transgenic rice calli (TRCs) from Oriza sativa L. cv. Dongjin to express a recombinant E2 protein (rE2-TRCs). The expression of the recombinant E2 protein (rE2) in rE2-TRCs was confirmed using Northern blot, SDS-PAGE, and Western blot analysis. Immune responses to the rE2-TRC in mice and pigs were investigated after oral administration. The administration of rE2-TRCs increased E2-specific antibodies titers and antibody-secreting cells when compared to animals receiving the vector alone (p < 0.05 and p < 0.01). In addition, mice receiving rE2-TRCs had a higher level of CD8+ lymphocytes and Th1 cytokine immune responses to purified rE2 (prE2) in vitro than the controls (p < 0.05 and p < 0.01). Pigs receiving rE2-TRCs also showed an increase in IL-8, CCL2, and the CD8+ subpopulation in response to stimulation with prE2. These results suggest that oral administration of rE2-TRCs can induce E2-specific immune responses.
Collapse
Affiliation(s)
- Myunghwan Jung
- Department of Infectious diseases, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 151-742, Korea
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Huang YL, Deng MC, Wang FI, Huang CC, Chang CY. The challenges of classical swine fever control: modified live and E2 subunit vaccines. Virus Res 2013; 179:1-11. [PMID: 24211665 DOI: 10.1016/j.virusres.2013.10.025] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Revised: 10/22/2013] [Accepted: 10/25/2013] [Indexed: 01/15/2023]
Abstract
Classical swine fever (CSF) is an economically important, highly contagious disease of swine worldwide. CSF is caused by classical swine fever virus (CSFV), and domestic pigs and wild boars are its only natural hosts. The two main strategies used to control CSF epidemic are systematic prophylactic vaccination and a non-vaccination stamping-out policy. This review compares the protective efficacy of the routinely used modified live vaccine (MLV) and E2 subunit vaccines and summarizes the factors that influence the efficacy of the vaccines and the challenges that both vaccines face to CSF control. Although MLV provide earlier and more complete protection than E2 subunit vaccines, it has the drawback of not allowing differentiation between infected and vaccinated animals (DIVA). The marker vaccine of E2 protein with companion discriminatory test to detect antibodies against E(rns) allows DIVA and is a promising strategy for future control and eradication of CSF. Maternal derived antibody (MDA) is the critical factor in impairing the efficacy of both MLV and E2 subunit vaccines, so the well-designed vaccination programs of sows and piglets should be considered together. Because of the antigen variation among various genotypes of CSFV, antibodies raised by either MLV or subunit vaccine neutralize genotypically homologous strains better than heterologous ones. However, although this is not a major concern for MLV as the induced immune responses can protect pigs against the challenge of various genotypes of CSFVs, it is critical for E2 subunit vaccines. It is thus necessary to evaluate whether the E2 subunit vaccine can completely protect against the current prevalent strains in the field. An ideal new generation of vaccine should be able to maintain the high protective efficiency of MLV and overcome the problem of antigenic variations while allowing for DIVA.
Collapse
Affiliation(s)
- Yu-Liang Huang
- Animal Health Research Institute, Council of Agriculture, 376 Chung-Cheng Road, Tansui, New Taipei City 25158, Taiwan
| | - Ming-Chung Deng
- Animal Health Research Institute, Council of Agriculture, 376 Chung-Cheng Road, Tansui, New Taipei City 25158, Taiwan
| | - Fun-In Wang
- School of Veterinary Medicine, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Chin-Cheng Huang
- Pingtung Agriculture Biotechnology Park, Council of Agriculture, No. 1 Shennong Road, Dehe Village, Changjhih Township, Pingtung County 90846, Taiwan
| | - Chia-Yi Chang
- Animal Health Research Institute, Council of Agriculture, 376 Chung-Cheng Road, Tansui, New Taipei City 25158, Taiwan.
| |
Collapse
|
17
|
Identification and characterization of mimotopes of classical swine fever virus E2 glycoprotein using specific anti-E2 monoclonal antibodies. Virus Res 2013; 175:12-9. [DOI: 10.1016/j.virusres.2013.03.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 03/22/2013] [Accepted: 03/26/2013] [Indexed: 11/18/2022]
|
18
|
Jelsma H, Loeffen WLA, van Beuningen A, van Rijn PA. Preliminary mapping of non-conserved epitopes on envelope glycoprotein E2 of Bovine viral diarrhea virus type 1 and 2. Vet Microbiol 2013; 166:195-9. [PMID: 23838147 DOI: 10.1016/j.vetmic.2013.06.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2012] [Revised: 05/23/2013] [Accepted: 06/10/2013] [Indexed: 11/25/2022]
Abstract
Bovine viral diarrhea virus (BVDV) belongs together with Classical swine fever virus (CSFV) and Border disease virus (BDV) to the genus Pestivirus in the Flaviviridae family. BVDV has been subdivided into two different species, BVDV1 and BVDV2 based on phylogenetic analysis. Subsequent characterization of both strains revealed major antigenic differences. Because the envelope glycoprotein E2 is the most immunodominant protein for all pestiviruses, the present study focused on epitope mapping by constructing chimeric BVDV type 1 and 2 E2 genes in expression plasmids. These plasmids with chimeric E2-genes were transfected in SK6 cells and transient expression was studied by immunostaining with a panel of MAbs specific for E2 of BVDV1 or BVDV2, resulting in the localization of type-specific antigenic domains at similar regions. These results indicate that E2 glycoproteins of both BVDV types exhibit a comparable antigenic structure, but with type specific epitopes. In addition, the antigenic resemblance with envelope glycoprotein E2 of Classical swine fever virus is discussed.
Collapse
Affiliation(s)
- H Jelsma
- Central Veterinary Institute of Wageningen UR, P.O. Box 65, 8200 AB Lelystad, The Netherlands.
| | | | | | | |
Collapse
|
19
|
Leifer I, Ruggli N, Blome S. Approaches to define the viral genetic basis of classical swine fever virus virulence. Virology 2013; 438:51-5. [PMID: 23415391 DOI: 10.1016/j.virol.2013.01.013] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Revised: 11/20/2012] [Accepted: 01/18/2013] [Indexed: 10/27/2022]
Abstract
Classical swine fever (CSF), a highly contagious disease of pigs caused by the classical swine fever virus (CSFV), can lead to important economic losses in the pig industry. Numerous CSFV isolates with various degrees of virulence have been isolated worldwide, ranging from low virulent strains that do not result in any apparent clinical signs to highly virulent strains that cause a severe peracute hemorrhagic fever with nearly 100% mortality. Knowledge of the molecular determinants of CSFV virulence is an important issue for effective disease control and development of safe and effective marker vaccines. In this review, the latest studies in the field of CSFV virulence are discussed. The topic of virulence is addressed from different angles; nonconventional approaches like codon pair usage and quasispecies are considered. Future research approaches in the field of CSFV virulence are proposed.
Collapse
Affiliation(s)
- Immanuel Leifer
- Institute of Virology and Immunoprophylaxis (IVI), Sensemattstrasse 293, CH-3147 Mittelhäusern, Switzerland.
| | | | | |
Collapse
|
20
|
Tarradas J, Monsó M, Fraile L, de la Torre BG, Muñoz M, Rosell R, Riquelme C, Pérez LJ, Nofrarías M, Domingo M, Sobrino F, Andreu D, Ganges L. A T-cell epitope on NS3 non-structural protein enhances the B and T cell responses elicited by dendrimeric constructions against CSFV in domestic pigs. Vet Immunol Immunopathol 2012; 150:36-46. [PMID: 22959286 DOI: 10.1016/j.vetimm.2012.08.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Revised: 08/05/2012] [Accepted: 08/08/2012] [Indexed: 12/15/2022]
Abstract
It has been recently reported by our group that dendrimeric constructs combining B- and T-cell epitopes from classical swine fever virus (CSFV) provided partial protection against experimental infection. This research evaluated four newly designed constructions while taking into account our previous work, including the direct implication that a T-cell epitope from the NS3 protein contributes to the generation of the immune response against CSFV. To this end, the dendrimeric constructions, including either this NS3 T-cell epitope alone or two different B-cell epitopes without this T-cell epitope, were used to immunise pigs. Thus, construct 1, containing the NS3 T-cell epitope and four copies of a previously described B-cell epitope, significantly reduced the clinical scores and RNA viral loads after challenge relative to the control group. In three out of six animals in this group, vaccination achieved partial protection and was associated with IFN-gamma producing-cells and neutralising antibodies. In contrast, the pigs immunised with construct 2, again with four copies of the B epitope of construct 1 but lacking the T-cell motif, developed more severe clinical signs. Finally, the additional constructs 3 and 4 included four copies of a B epitope that was different from the epitope used in constructs 1 and 2 with or without the abovementioned NS3 T-cell epitope, respectively. Pigs immunised with these latter constructs developed low levels of peptide-specific antibodies that correlated with equally low levels of cellular responses, an absence of neutralising antibodies and a lack of protection. Even so, the clinical scores in the first week after the challenge were less severe for animals vaccinated with construct 3 than for those given construct 4. Our results confirm the relevant role of the B-cell epitope in residues 694-712 of the glycoprotein E2 (which is used in both constructs 1 and 2) for protection against CSFV, as well as the appropriateness of the newly used NS3 peptide as a specific T-cell epitope in domestic pigs.
Collapse
Affiliation(s)
- Joan Tarradas
- Centre de Recerca en Sanitat Animal (CReSA), IRTA-UAB, Campus de la UAB, 08193 Bellaterra, Barcelona, Spain
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Identification of conformational epitopes and antigen-specific residues at the D/A domains and the extramembrane C-terminal region of E2 glycoprotein of classical swine fever virus. Virus Res 2012; 168:56-63. [PMID: 22727685 DOI: 10.1016/j.virusres.2012.06.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Revised: 06/10/2012] [Accepted: 06/12/2012] [Indexed: 11/20/2022]
Abstract
Envelope glycoprotein E2 of classical swine fever virus (CSFV) is the major antigen that induces neutralizing antibodies in infected pigs. Previous studies revealed that both conformation-dependent and linear epitopes are most present within domains B/C/D/A in the N-terminal half of E2. However, studies of antigenicity beyond the B/C domains remain limited. This study revealed that conformational epitopes were present on the D/A domains as well as the proximal C-terminal of E2, since the mutation of cysteine abrogated their bindings to monoclonal antibodies (mAbs). The residue R845 at domain A and E902 at the C-terminal region were critical for specific binding to mAbs, further supporting the presence of antigenic determinants on these regions. Substitutions of cysteines in domains D/A not only abrogated the binding to mAbs directed to D/A, but also affected the binding of the downstream C-terminal region to its specific mAbs, suggesting a close interaction between the two conformational epitopes. Mutations on the five proximal cysteines at positions 869, 877, 893, 896 and 930 in the C-terminal region only affected the binding to its specific mAbs binding sites. In addition, mutation on the three distal C-terminal cysteines at positions 945, 966, and 983 resulted in loss of E2 homodimerization. This study demonstrates new antigenic epitopes on D/A domains and C-terminal of E2 that have not been reported before, and that the nine cysteines in the C-terminal function differently in either maintaining the antigenic structure or in intermolecular dimerization of E2.
Collapse
|
22
|
Chang CY, Huang CC, Deng MC, Huang YL, Lin YJ, Liu HM, Lin YL, Wang FI. Antigenic mimicking with cysteine-based cyclized peptides reveals a previously unknown antigenic determinant on E2 glycoprotein of classical swine fever virus. Virus Res 2012; 163:190-6. [DOI: 10.1016/j.virusres.2011.09.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2011] [Revised: 09/10/2011] [Accepted: 09/12/2011] [Indexed: 10/17/2022]
|
23
|
Zhou B, Liu K, Jiang Y, Wei JC, Chen PY. Multiple linear B-cell epitopes of classical swine fever virus glycoprotein E2 expressed in E.coli as multiple epitope vaccine induces a protective immune response. Virol J 2011; 8:378. [PMID: 21801433 PMCID: PMC3163558 DOI: 10.1186/1743-422x-8-378] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Accepted: 07/30/2011] [Indexed: 01/24/2023] Open
Abstract
Classical swine fever is a highly contagious disease of swine caused by classical swine fever virus, an OIE list A pathogen. Epitope-based vaccines is one of the current focuses in the development of new vaccines against classical swine fever virus (CSFV). Two B-cell linear epitopes rE2-ba from the E2 glycoprotein of CSFV, rE2-a (CFRREKPFPHRMDCVTTTVENED, aa844-865) and rE2-b (CKEDYRYAISSTNEIGLLGAGGLT, aa693-716), were constructed and heterologously expressed in Escherichia coli as multiple epitope vaccine. Fifteen 6-week-old specified-pathogen-free (SPF) piglets were intramuscularly immunized with epitopes twice at 2-week intervals. All epitope-vaccinated pigs could mount an anamnestic response after booster vaccination with neutralizing antibody titers ranging from 1:16 to 1:256. At this time, the pigs were subjected to challenge infection with a dose of 1 × 106 TCID50 virulent CSFV strain. After challenge infection, all of the rE2-ba-immunized pigs were alive and without symptoms or signs of CSF. In contrast, the control pigs continuously exhibited signs of CSF and had to be euthanized because of severe clinical symptoms at 5 days post challenge infection. The data from in vivo experiments shown that the multiple epitope rE2-ba shown a greater protection (similar to that of HCLV vaccine) than that of mono-epitope peptide(rE2-a or rE2-b). Therefore, The results demonstrated that this multiple epitope peptide expressed in a prokaryotic system can be used as a potential DIVA (differentiating infected from vaccinated animals) vaccine. The E.coli-expressed E2 multiple B-cell linear epitopes retains correct immunogenicity and is able to induce a protective immune response against CSFV infection.
Collapse
Affiliation(s)
- Bin Zhou
- Key Laboratory of Animal Diseases Diagnosis and Immunology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China
| | | | | | | | | |
Collapse
|
24
|
Partial protection against classical swine fever virus elicited by dendrimeric vaccine-candidate peptides in domestic pigs. Vaccine 2011; 29:4422-9. [DOI: 10.1016/j.vaccine.2011.03.095] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2010] [Revised: 03/24/2011] [Accepted: 03/28/2011] [Indexed: 11/23/2022]
|
25
|
Improved sero-monitoring assay for classical swine fever (CSF) using the recombinant E2 protein of a recent Korean isolate. Res Vet Sci 2011; 90:329-35. [DOI: 10.1016/j.rvsc.2010.06.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Revised: 05/27/2010] [Accepted: 06/04/2010] [Indexed: 11/23/2022]
|
26
|
Monsó M, Tarradas J, de la Torre BG, Sobrino F, Ganges L, Andreu D. Peptide vaccine candidates against classical swine fever virus: T cell and neutralizing antibody responses of dendrimers displaying E2 and NS2-3 epitopes. J Pept Sci 2010; 17:24-31. [DOI: 10.1002/psc.1292] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2010] [Revised: 08/03/2010] [Accepted: 08/04/2010] [Indexed: 01/03/2023]
|
27
|
Lin M, McRae H, Dan H, Tangorra E, Laverdiere A, Pasick J. High-resolution epitope mapping for monoclonal antibodies to the structural protein Erns of classical swine fever virus using peptide array and random peptide phage display approaches. J Gen Virol 2010; 91:2928-40. [PMID: 20810747 DOI: 10.1099/vir.0.023259-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The structural glycoprotein E(rns) (an envelope protein with RNase activity) of classical swine fever virus (CSFV) is not well characterized with respect to its antigenic structure and organization. Here, we investigated the antigenic sites on E(rns) by raising mAbs against the Escherichia coli expressed E(rns) of CSFV strain Alfort/187 and defined the B-cell epitopes recognized by these antibodies. Eighteen mAbs to E(rns) were identified and they were classified as either immunoglobulin subclass G1 or G2b. Using an array of overlapping 12-mer peptides, spanning aa 27-227 of E(rns), the epitopes for 12 mAbs were mapped to a high resolution of six to eight residues, which cluster in five discrete locations, ¹³GIWPEKIC³⁸ (group I), ⁶⁵NYTCCKLQ⁷² (group II), ¹²⁷QARNRPTT¹³⁴ (group III), ¹⁴⁵SFAGTVIE¹⁵² (group IV) and ¹⁶¹VEDILY¹⁶⁶ (group V). Two mAbs recognize two or more antigenic determinants, including the group II epitope. The epitopes for four other mAbs could not be mapped using the overlapping 12-mer peptides. Random peptide phage display with one mAb from each of all the groups except group V further identified some conserved residues that may be critical for binding antibodies, i.e. Trp³³ in the epitope of group I, Leu⁷¹ in the epitope of group II, Gln¹²⁷ and Apn¹³⁰ in the epitope of group III, and Ser¹⁴⁵ and Gly¹⁴⁸ in the epitope of group IV. This study has provided new insights into the structure and organization of epitopes on the CSFV E(rns) and valuable epitope information for the rational design of vaccines, drugs and diagnostic immunoassays for CSFV.
Collapse
Affiliation(s)
- Min Lin
- Canadian Food Inspection Agency, Ottawa Laboratory (Fallowfield), Ottawa, ON, Canada.
| | | | | | | | | | | |
Collapse
|
28
|
Chang CY, Huang CC, Lin YJ, Deng MC, Tsai CH, Chang WM, Wang FI. Identification of antigen-specific residues on E2 glycoprotein of classical swine fever virus. Virus Res 2010; 152:65-72. [PMID: 20558217 DOI: 10.1016/j.virusres.2010.06.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2010] [Revised: 06/02/2010] [Accepted: 06/07/2010] [Indexed: 10/19/2022]
Abstract
Envelope glycoprotein E2 of classical swine fever virus (CSFV) is the major antigen that induces neutralizing antibodies in infected pigs. Our previous study revealed that N-terminal 90 residues (domains B/C) of E2 play key roles in differentiating vaccine strain LPC/AHRI (subgroup 1.1) from the two field strains TD/96/TWN (subgroup 2.1) and 94.4/IL/94/TWN (subgroup 3.4) (Chang et al., 2010). This study further analyzed the reaction patterns between monoclonal antibodies (mAbs) and expressed hybrid N-terminal of E2 of the above-mentioned viruses, revealing that mAbs T33 and C2, mAbs V8 and T23, and mAbs L7 and L150 required binding sites specifically at residues 690-714 in domain B, residues 715-740 in domain C, and residues 741-765 in domain C, respectively. Site-directed mutagenesis further demonstrated that residues (713)E and (729)D were critical for antigenic specificity of field strain (94.4/IL/94/TWN), while residues (705)D and (761)K were specific for vaccine strain (LPC/AHRI). These specific residues likely mediated in determining the topography of mAb binding sites of E2 to allow for differentiation between strains based on the premise that the structural integrity of the conformational epitope is maintained.
Collapse
Affiliation(s)
- Chia-Yi Chang
- Animal Health Research Institute, Council of Agriculture, 376 Chung-Cheng Road, Tansui, Taipei, Taiwan
| | | | | | | | | | | | | |
Collapse
|
29
|
Reimann I, Depner K, Utke K, Leifer I, Lange E, Beer M. Characterization of a new chimeric marker vaccine candidate with a mutated antigenic E2-epitope. Vet Microbiol 2010; 142:45-50. [DOI: 10.1016/j.vetmic.2009.09.042] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
30
|
Animal health safety of fresh meat derived from pigs vaccinated against Classic Swine Fever. EFSA J 2009. [DOI: 10.2903/j.efsa.2009.933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
|
31
|
Qi Y, Zhang BQ, Shen Z, Chen YH. Candidate Vaccine Focused on a Classical Swine Fever Virus Epitope Induced Antibodies with Neutralizing Activity. Viral Immunol 2009; 22:205-13. [DOI: 10.1089/vim.2009.0007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Yun Qi
- Laboratory of Immunology, Department of Biology, Tsinghua University, Beijing Key Laboratory for Protein Therapeutics, Beijing, China
| | - Bing-Qing Zhang
- Laboratory of Immunology, Department of Biology, Tsinghua University, Beijing Key Laboratory for Protein Therapeutics, Beijing, China
| | - Zhen Shen
- Laboratory of Immunology, Department of Biology, Tsinghua University, Beijing Key Laboratory for Protein Therapeutics, Beijing, China
| | - Ying-Hua Chen
- Laboratory of Immunology, Department of Biology, Tsinghua University, Beijing Key Laboratory for Protein Therapeutics, Beijing, China
| |
Collapse
|
32
|
Antigenic differentiation of classical swine fever viruses in China by monoclonal antibodies. Virus Res 2009; 142:169-74. [PMID: 19428750 DOI: 10.1016/j.virusres.2009.02.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2008] [Revised: 02/12/2009] [Accepted: 02/13/2009] [Indexed: 11/23/2022]
Abstract
The phylogenetic diversity of classical swine fever virus (CSFV) in China has been extensively studied previously, with the report of the classification of Chinese CSFVs into four subgroups within two of the established genotypes, but the antigenic differences amongst Chinese CSF viruses still remain unknown. To address this issue, 21 CSFV field strains isolated in China between 1996 and 2006 were grown in cell culture and characterized in comparison with two Chinese reference strains: a virulent strain Shimen and a vaccine strain CSF lapinized virus (hog cholera lapinized virus in China, HCLV), by indirect immunofluorescence assay (IFA) with a panel of 28 monoclonal antibodies (mAbs) against four pestiviruses, CSFV, bovine viral diarrhoea virus-1 (BVDV-1), bovine viral diarrhoea virus-2 (BVDV-2) and border disease virus (BDV). All 23 CSFV strains reacted only with CSFV-specific mAbs, not with those raised against BVDV-1, BVDV-2 and BDV. Of the former mAbs, those directed against CSFV E2 protein recognized more isolates than those directed against E(rns) and NS2/3. Of nine CSFV E2-specific mAbs used, WH303 and WH302 reacted with all 23 strains, confirming their value in differentiating CSFV from other pestiviruses. Furthermore, different strains had different patterns of reactivity with CSFV-specific mAbs, and mAbs other than WH303 and WH302 did not recognize all strains. This study provides the first evidence for the existence of antigenic differences among Chinese CSFVs.
Collapse
|
33
|
|
34
|
Immunoglobulins in pigs vaccinated with a subunit E2 and an attenuated c strain vaccine against classical swine fever. ACTA VET-BEOGRAD 2009. [DOI: 10.2298/avb0906489t] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
|
35
|
Secretory expression of E2 main antigen domain of CSFV C strain and the establishment of indirect ELISA assay. Virol Sin 2008. [DOI: 10.1007/s12250-008-2970-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
|
36
|
Qi Y, Liu LC, Zhang BQ, Shen Z, Wang J, Chen YH. Characterization of antibody responses against a neutralizing epitope on the glycoprotein E2 of classical swine fever virus. Arch Virol 2008; 153:1593-8. [PMID: 18607674 DOI: 10.1007/s00705-008-0147-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2008] [Accepted: 05/27/2008] [Indexed: 11/27/2022]
Abstract
The sequence TAVSPTTLR is a conserved and linear neutralizing epitope on the glycoprotein E2 of classical swine fever virus. In this study, TAVSPTTLR-directed antibodies, induced either by virions or by an epitope-focused immunogen, were characterized. The results revealed that despite the same epitope specificity, the antibodies induced by different immunogens varied significantly both in the neutralizing test and in binding inhibition assays. This suggests that the protective immunity induced by this epitope is due to more than simply the epitope specificity and that this epitope might need essential contributions from its flanking context to induce functional epitope-specific antibodies.
Collapse
Affiliation(s)
- Y Qi
- Laboratory of Immunology, Department of Biology, Tsinghua University, Protein Science Laboratory of MOE, Beijing, People's Republic of China
| | | | | | | | | | | |
Collapse
|
37
|
Beer M, Reimann I, Hoffmann B, Depner K. Novel marker vaccines against classical swine fever. Vaccine 2007; 25:5665-70. [PMID: 17239502 DOI: 10.1016/j.vaccine.2006.12.036] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2006] [Revised: 12/04/2006] [Accepted: 12/13/2006] [Indexed: 11/28/2022]
Abstract
Classical swine fever (CSF) is one of the most devastating epizootic diseases of pigs worldwide. For eradication and control purposes, CSF vaccination is an important tool, and efficacious and safe attenuated vaccines have been available for many decades (for example, the C-strain vaccines). In addition to administering them parenterally, live attenuated vaccines are also administered orally for the control and eradication of CSF in wild boar populations. However, antibodies against live attenuated vaccines do not allow to differentiate infected from vaccinated animals (DIVA principle) and the mechanism responsible for attenuation is not known. Only a few years ago the first DIVA vaccines based on baculovirus-expressed E2 glycoprotein have been put on the market [Hulst MM, Westra DF, Wensvoort G, Moormann RJ. Glycoprotein E1 of hog cholera virus expressed in insect cells protects swine from hog cholera. J Virol 1993;67(9):5435-42]. However, these subunit E2 marker vaccines are less efficient and more than one parenteral application is necessary. Furthermore, oral vaccination is not possible. Taking these disadvantages into account, the development of novel CSF vaccines has been focussed on five different strategies, mainly based on genetically engineered constructs: (1) immunogenic CSFV peptides, (2) DNA vaccines, (3) viral vectors expressing CSFV proteins, (4) chimeric pestiviruses, and (5) trans-complemented deleted CSFV genomes (replicons).
Collapse
Affiliation(s)
- Martin Beer
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Boddenblick 5a, 17493 Greifswald-Insel Riems, Germany.
| | | | | | | |
Collapse
|
38
|
Dong XN, Chen YH. Marker vaccine strategies and candidate CSFV marker vaccines. Vaccine 2007; 25:205-30. [PMID: 16934915 DOI: 10.1016/j.vaccine.2006.07.033] [Citation(s) in RCA: 112] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2006] [Revised: 07/21/2006] [Accepted: 07/21/2006] [Indexed: 11/24/2022]
Abstract
Classical swine fever (CSF) is an economically important highly contagious disease of swine worldwide. Classical swine fever virus (CSFV) is its etiological agent, and the only natural hosts are domestic pigs and wild boars. Although field CSFV strains vary in the virulence, they all result in serious losses in pig industry. Highly virulent field strains generally cause acute disease and high mortality; moderately virulent field strains raise subacute or chronic infections; postnatal infection by low virulent field strains produces subclinical infection and mortality in the new-born piglets. CSFV can cross the placental barrier, and this transplacental transmission usually results in mortality of fetuses and birth of congenitally infected pigs with a late-onset disease and death. Two main strategies to control CSF epidemic are systematic prophylactic vaccination with live attenuated vaccines (such as C-strain) and non-vaccination stamping-out policy. But neither of them is satisfying enough. Marker vaccine and companion serological diagnostic test is thought to be a promising strategy for future control and eradication of CSF. During the past 15 years, various candidate marker vaccines were constructed and evaluated in the animal experiments, including recombinant chimeric vaccines, recombinant deletion vaccines, DNA vaccines, subunit vaccines and peptide vaccines. Among them, two subunit vaccines entered the large scale marker vaccine trial of EU in 1999. Although they failed to fulfil all the demands of the Scientific Veterinary Committee, they successfully induced solid immunity against CSFV in the vaccinated pigs. It can be expected that new potent marker vaccines might be commercially available and used in systematic prophylactic vaccination campaign or emergency vaccination in the next 15 years. Here, we summarized current strategies and candidate CSFV marker vaccines. These strategies and methods are also helpful for the development of new-generation vaccines against other diseases.
Collapse
Affiliation(s)
- Xiao-Nan Dong
- Laboratory of Immunology, Department of Biology, Tsinghua University, Protein Science Laboratory of the Ministry of Education, Beijing 100084, PR China.
| | | |
Collapse
|
39
|
Liu S, Yu X, Wang C, Wu J, Kong X, Tu C. Quadruple antigenic epitope peptide producing immune protection against classical swine fever virus. Vaccine 2006; 24:7175-80. [PMID: 17050046 DOI: 10.1016/j.vaccine.2006.06.042] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2006] [Revised: 06/20/2006] [Accepted: 06/20/2006] [Indexed: 11/19/2022]
Abstract
Research on epitope-based vaccines is a current focus in the development of new vaccines against classical swine fever virus (CSFV). The present study aimed to engineer a quadruple antigenic epitope peptide of the CSFV immunogen E2 glycoprotein by splice overlap extension (SOE) PCR, expressed in E. coli fused with glutathione S-transferase (GST), and named rGST-4E. Enzyme-linked immunosorbent assay (ELISA) and Western blot analysis showed that purified rGST-4E had an excellent immunoreactivity with swine anti-CSFV serum and rabbit anti-E2 serum. Animal vaccination trials showed that the rGST-4E was more immunogenic than mono-epitope peptide and was able to produce effective immune protection in rabbits against challenge with hog cholera lapinized virus, and in pigs against challenge with virulent CSFV. These data show that the recombinant repeated epitope peptide could be considered a potential epitope-based vaccine for prevention of the disease.
Collapse
Affiliation(s)
- Siguo Liu
- Institute of Military Veterinary, Academy of Military Medical Sciences, 1068 Qinglong Road, Changchun 130062, China
| | | | | | | | | | | |
Collapse
|