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Zhu J, Liu Q, Li L, Zhang R, Chang Y, Zhao J, Liu S, Zhao X, Chen X, Sun Y, Zhao Q. Nanobodies against African swine fever virus p72 and CD2v proteins as reagents for developing two cELISAs to detect viral antibodies. Virol Sin 2024; 39:478-489. [PMID: 38588947 DOI: 10.1016/j.virs.2024.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 04/01/2024] [Indexed: 04/10/2024] Open
Abstract
African swine fever virus (ASFV) poses a significant threat to the global swine industry. Currently, there are no effective vaccines or treatments available to combat ASFV infection in pigs. The primary means of controlling the spread of the disease is through rapid detection and subsequent elimination of infected pig. Recently, a lower virulent ASFV isolate with a deleted EP402R gene (CD2v-deleted) has been reported in China, which further complicates the control of ASFV infection in pig farms. Furthermore, an EP402R-deleted ASFV variant has been developed as a potential live attenuated vaccine candidate strain. Therefore, it is crucial to develop detection methods that can distinguish wild-type and EP402R-deleted ASFV infections. In this study, two recombinant ASFV-p72 and -CD2v proteins were expressed using a prokaryotic system and used to immunize Bactrian camels. Subsequently, eight nanobodies against ASFV-p72 and ten nanobodies against ASFV-CD2v were screened. Following the production of these nanobodies with horse radish peroxidase (HRP) fusion proteins, the ASFV-p72-Nb2-HRP and ASFV-CD2v-Nb22-HRP fusions were selected for the development of two competitive ELISAs (cELISAs) to detect anti-ASFV antibodies. The two cELISAs exhibited high sensitivity, good specificity, repeatability, and stability. The coincidence rate between the two cELISAs and commercial ELISA kits was 98.6% and 97.6%, respectively. Collectively, the two cELISA for detecting antibodies against ASFV demonstrated ease of operation, a low cost, and a simple production process. The two cELISAs could determine whether pigs were infected with wild-type or CD2v-deleted ASFV, and could play an important role in monitoring ASFV infections in pig farms.
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Affiliation(s)
- Jiahong Zhu
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling Observing and Experimental Station of National Data Center of Animal Health, Ministry of Agriculture, Yangling, 712100, China
| | - Qingyuan Liu
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling Observing and Experimental Station of National Data Center of Animal Health, Ministry of Agriculture, Yangling, 712100, China
| | - Liuya Li
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling Observing and Experimental Station of National Data Center of Animal Health, Ministry of Agriculture, Yangling, 712100, China
| | - Runyu Zhang
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling Observing and Experimental Station of National Data Center of Animal Health, Ministry of Agriculture, Yangling, 712100, China
| | - Yueting Chang
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling Observing and Experimental Station of National Data Center of Animal Health, Ministry of Agriculture, Yangling, 712100, China
| | - Jiakai Zhao
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling Observing and Experimental Station of National Data Center of Animal Health, Ministry of Agriculture, Yangling, 712100, China
| | - Siyu Liu
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling Observing and Experimental Station of National Data Center of Animal Health, Ministry of Agriculture, Yangling, 712100, China
| | - Xinyu Zhao
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling Observing and Experimental Station of National Data Center of Animal Health, Ministry of Agriculture, Yangling, 712100, China
| | - Xu Chen
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling Observing and Experimental Station of National Data Center of Animal Health, Ministry of Agriculture, Yangling, 712100, China
| | - Yani Sun
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling Observing and Experimental Station of National Data Center of Animal Health, Ministry of Agriculture, Yangling, 712100, China.
| | - Qin Zhao
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling Observing and Experimental Station of National Data Center of Animal Health, Ministry of Agriculture, Yangling, 712100, China.
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Fan R, Wei Z, Zhang M, Jia S, Jiang Z, Wang Y, Cai J, Chen G, Xiao H, Wei Y, Shi Y, Feng J, Shen B, Zheng Y, Huang Y, Wang J. Development of novel monoclonal antibodies for blocking NF-κB activation induced by CD2v protein in African swine fever virus. Front Immunol 2024; 15:1352404. [PMID: 38846950 PMCID: PMC11153791 DOI: 10.3389/fimmu.2024.1352404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 05/06/2024] [Indexed: 06/09/2024] Open
Abstract
Background CD2v, a critical outer envelope glycoprotein of the African swine fever virus (ASFV), plays a central role in the hemadsorption phenomenon during ASFV infection and is recognized as an essential immunoprotective protein. Monoclonal antibodies (mAbs) targeting CD2v have demonstrated promise in both diagnosing and combating African swine fever (ASF). The objective of this study was to develop specific monoclonal antibodies against CD2v. Methods In this investigation, Recombinant CD2v was expressed in eukaryotic cells, and murine mAbs were generated through meticulous screening and hybridoma cloning. Various techniques, including indirect enzyme-linked immunosorbent assay (ELISA), western blotting, immunofluorescence assay (IFA), and bio-layer interferometry (BLI), were employed to characterize the mAbs. Epitope mapping was conducted using truncation mutants and epitope peptide mapping. Results An optimal antibody pair for a highly sensitive sandwich ELISA was identified, and the antigenic structures recognized by the mAbs were elucidated. Two linear epitopes highly conserved in ASFV genotype II strains, particularly in Chinese endemic strains, were identified, along with a unique glycosylated epitope. Three mAbs, 2B25, 3G25, and 8G1, effectively blocked CD2v-induced NF-κB activation. Conclusions This study provides valuable insights into the antigenic structure of ASFV CD2v. The mAbs obtained in this study hold great potential for use in the development of ASF diagnostic strategies, and the identified epitopes may contribute to vaccine development against ASFV.
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Affiliation(s)
- Rongrong Fan
- Laboratory for Genetic Engineering of Antibodies and Functional Proteins, Beijing Institute of Pharmacology and Toxicology, Beijing, China
- Beijing Engineering Research Center of Food Environment and Public Health, Minzu University of China, Beijing, China
| | - Zeliang Wei
- Laboratory for Genetic Engineering of Antibodies and Functional Proteins, Beijing Institute of Pharmacology and Toxicology, Beijing, China
- Inner Mongolia Key Laboratory of Molecular Biology, Inner Mongolia Medical University, Hohhot, China
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital of Henan University, Henan University, Kaifeng, China
| | - Mengmeng Zhang
- BCA Bio-Breeding Center, Beijing Capital Agribusiness Co., Ltd., Beijing, China
| | - Shanshan Jia
- Laboratory for Genetic Engineering of Antibodies and Functional Proteins, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Zhiyang Jiang
- Laboratory for Genetic Engineering of Antibodies and Functional Proteins, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Yao Wang
- Inner Mongolia Key Laboratory of Molecular Biology, Inner Mongolia Medical University, Hohhot, China
| | - Junyu Cai
- Laboratory for Genetic Engineering of Antibodies and Functional Proteins, Beijing Institute of Pharmacology and Toxicology, Beijing, China
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital of Henan University, Henan University, Kaifeng, China
| | - Guojiang Chen
- Laboratory for Genetic Engineering of Antibodies and Functional Proteins, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - He Xiao
- Laboratory for Genetic Engineering of Antibodies and Functional Proteins, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Yinxiang Wei
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital of Henan University, Henan University, Kaifeng, China
| | - Yanchun Shi
- Inner Mongolia Key Laboratory of Molecular Biology, Inner Mongolia Medical University, Hohhot, China
| | - Jiannan Feng
- Laboratory for Genetic Engineering of Antibodies and Functional Proteins, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Beifen Shen
- Laboratory for Genetic Engineering of Antibodies and Functional Proteins, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Yuanqiang Zheng
- Inner Mongolia Key Laboratory of Molecular Biology, Inner Mongolia Medical University, Hohhot, China
| | - Yaojiang Huang
- Beijing Engineering Research Center of Food Environment and Public Health, Minzu University of China, Beijing, China
| | - Jing Wang
- Laboratory for Genetic Engineering of Antibodies and Functional Proteins, Beijing Institute of Pharmacology and Toxicology, Beijing, China
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Vu HLX, McVey DS. Recent progress on gene-deleted live-attenuated African swine fever virus vaccines. NPJ Vaccines 2024; 9:60. [PMID: 38480758 PMCID: PMC10937926 DOI: 10.1038/s41541-024-00845-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 02/21/2024] [Indexed: 03/17/2024] Open
Abstract
African Swine Fever (ASF) is a highly lethal viral disease in swine, with mortality rates approaching 100%. The disease has spread to many swine-producing countries, leading to significant economic losses and adversely impacting global food security. Extensive efforts have been directed toward developing effective ASF vaccines. Among the vaccinology approaches tested to date, live-attenuated virus (LAV) vaccines produced by rational deleting virulence genes from virulent African Swine Fever Virus (ASFV) strains have demonstrated promising safety and efficacy in experimental and field conditions. Many gene-deleted LAV vaccine candidates have been generated in recent years. The virulence genes targeted for deletion from the genome of virulent ASFV strains can be categorized into four groups: Genes implicated in viral genome replication and transcription, genes from the multigene family located at both 5' and 3' termini, genes participating in mediating hemadsorption and putative cellular attachment factors, and novel genes with no known functions. Some promising LAV vaccine candidates are generated by deleting a single viral virulence gene, whereas others are generated by simultaneously deleting multiple genes. This article summarizes the recent progress in developing and characterizing gene-deleted LAV vaccine candidates.
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Affiliation(s)
- Hiep L X Vu
- Department of Animal Science, and Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - D Scott McVey
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA.
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Fan J, Zhang J, Wang F, Miao F, Zhang H, Jiang Y, Qi Y, Zhang Y, Hui L, Zhang D, Yue H, Zhou X, Li Q, Wang Y, Chen T, Hu R. Identification of L11L and L7L as virulence-related genes in the African swine fever virus genome. Front Microbiol 2024; 15:1345236. [PMID: 38328426 PMCID: PMC10848158 DOI: 10.3389/fmicb.2024.1345236] [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: 11/27/2023] [Accepted: 01/08/2024] [Indexed: 02/09/2024] Open
Abstract
Introduction African swine fever (ASF) is an infectious disease that causes considerable economic losses in pig farming. The agent of this disease, African swine fever virus (ASFV), is a double-stranded DNA virus with a capsid membrane and a genome that is 170-194 kb in length encoding over 150 proteins. In recent years, several live attenuated strains of ASFV have been studied as vaccine candidates, including the SY18ΔL7-11. This strain features deletion of L7L, L8L, L9R, L10L and L11L genes and was found to exhibit significantly reduced pathogenicity in pigs, suggesting that these five genes play key roles in virulence. Methods Here, we constructed and evaluated the virulence of ASFV mutations with SY18ΔL7, SY18ΔL8, SY18ΔL9, SY18ΔL10, and SY18ΔL11L. Results Our findings did not reveal any significant differences in replication efficiency between the single-gene deletion strains and the parental strains. Pigs inoculated with SY18ΔL8L, SY18ΔL9R and SY18ΔL10L exhibited clinical signs similar to those inoculated with the parental strains. Survival rate of pigs inoculated with 103.0TCID50 of SY18ΔL7L was 25%, while all pigs inoculated with 103.0TCID50 of SY18ΔL11L survived, and 50% inoculated with 106.0TCID50 SY18ΔL11L survived. Discussion The results indicate that L8L, L9R and L10L do not affect ASFV SY18 virulence, while the L7L and L11L are associated with virulence.
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Affiliation(s)
- Jiaqi Fan
- College of Life Sciences, Ningxia University, Yinchuan, Ningxia, China
- Key Laboratory of Prevention and Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, Changchun, Jilin, China
- Chinese Academy of Agricultural Sciences Changchun Veterinary Research Institute, Changchun, Jilin, China
| | - Jingyuan Zhang
- Institute of Rare Diseases, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Fengjie Wang
- College of Life Sciences, Ningxia University, Yinchuan, Ningxia, China
- Key Laboratory of Prevention and Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, Changchun, Jilin, China
- Chinese Academy of Agricultural Sciences Changchun Veterinary Research Institute, Changchun, Jilin, China
| | - Faming Miao
- Key Laboratory of Prevention and Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, Changchun, Jilin, China
- Chinese Academy of Agricultural Sciences Changchun Veterinary Research Institute, Changchun, Jilin, China
| | - Han Zhang
- Key Laboratory of Prevention and Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, Changchun, Jilin, China
- Chinese Academy of Agricultural Sciences Changchun Veterinary Research Institute, Changchun, Jilin, China
| | - Yiqian Jiang
- Key Laboratory of Prevention and Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, Changchun, Jilin, China
- Chinese Academy of Agricultural Sciences Changchun Veterinary Research Institute, Changchun, Jilin, China
| | - Yu Qi
- Key Laboratory of Prevention and Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, Changchun, Jilin, China
- Chinese Academy of Agricultural Sciences Changchun Veterinary Research Institute, Changchun, Jilin, China
| | - Yanyan Zhang
- Key Laboratory of Prevention and Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, Changchun, Jilin, China
- Chinese Academy of Agricultural Sciences Changchun Veterinary Research Institute, Changchun, Jilin, China
| | - Lili Hui
- Key Laboratory of Prevention and Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, Changchun, Jilin, China
- Chinese Academy of Agricultural Sciences Changchun Veterinary Research Institute, Changchun, Jilin, China
| | - Dan Zhang
- Key Laboratory of Prevention and Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, Changchun, Jilin, China
- Chinese Academy of Agricultural Sciences Changchun Veterinary Research Institute, Changchun, Jilin, China
| | - Huixian Yue
- Key Laboratory of Prevention and Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, Changchun, Jilin, China
- Chinese Academy of Agricultural Sciences Changchun Veterinary Research Institute, Changchun, Jilin, China
| | - Xintao Zhou
- College of Life Sciences, Ningxia University, Yinchuan, Ningxia, China
- Key Laboratory of Prevention and Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, Changchun, Jilin, China
- Chinese Academy of Agricultural Sciences Changchun Veterinary Research Institute, Changchun, Jilin, China
| | - Qixuan Li
- Key Laboratory of Prevention and Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, Changchun, Jilin, China
- Chinese Academy of Agricultural Sciences Changchun Veterinary Research Institute, Changchun, Jilin, China
| | - Yu Wang
- Key Laboratory of Prevention and Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, Changchun, Jilin, China
- Chinese Academy of Agricultural Sciences Changchun Veterinary Research Institute, Changchun, Jilin, China
| | - Teng Chen
- Key Laboratory of Prevention and Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, Changchun, Jilin, China
- Chinese Academy of Agricultural Sciences Changchun Veterinary Research Institute, Changchun, Jilin, China
| | - Rongliang Hu
- College of Life Sciences, Ningxia University, Yinchuan, Ningxia, China
- Key Laboratory of Prevention and Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, Changchun, Jilin, China
- Chinese Academy of Agricultural Sciences Changchun Veterinary Research Institute, Changchun, Jilin, China
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Pérez-Núñez D, García-Belmonte R, Riera E, Fernández-Sesma MH, Vigara-Astillero G, Revilla Y. Signal peptide and N-glycosylation of N-terminal-CD2v determine the hemadsorption of African swine fever virus. J Virol 2023; 97:e0103023. [PMID: 37768082 PMCID: PMC10617588 DOI: 10.1128/jvi.01030-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 07/26/2023] [Indexed: 09/29/2023] Open
Abstract
IMPORTANCE African swine fever virus (ASFV) is the cause of the current major animal epidemic worldwide. This disease affects domestic pigs and wild boars, has spread since 2007 through Russia, Eastern Europe, and more recently to Western European countries, and since 2018 emerged in China, from where it spread throughout Southeast Asia. Recently, outbreaks have appeared in the Caribbean, threatening the Americas. It is estimated that more than 900,000 animals have died directly or indirectly from ASFV since 2021 alone. One of the features of ASFV infection is hemoadsorption (HAD), which has been linked to virulence, although the molecular and pathological basis of this hypothesis remains largely unknown. In this study, we have analyzed and identified the key players responsible of HAD, contributing to the identification of new determinants of ASFV virulence, the understanding of ASFV pathogenesis, and the rational development of new vaccines.
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Affiliation(s)
- Daniel Pérez-Núñez
- Microbes in Health and Welfare Department, Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Madrid, Spain
| | - Raquel García-Belmonte
- Microbes in Health and Welfare Department, Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Madrid, Spain
| | - Elena Riera
- Microbes in Health and Welfare Department, Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Madrid, Spain
| | - Marta H. Fernández-Sesma
- Microbes in Health and Welfare Department, Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Madrid, Spain
| | - Gonzalo Vigara-Astillero
- Microbes in Health and Welfare Department, Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Madrid, Spain
| | - Yolanda Revilla
- Microbes in Health and Welfare Department, Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Madrid, Spain
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Pannhorst K, Carlson J, Hölper JE, Grey F, Baillie JK, Höper D, Wöhnke E, Franzke K, Karger A, Fuchs W, Mettenleiter TC. The non-classical major histocompatibility complex II protein SLA-DM is crucial for African swine fever virus replication. Sci Rep 2023; 13:10342. [PMID: 37604847 PMCID: PMC10442341 DOI: 10.1038/s41598-023-36788-9] [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: 12/08/2022] [Accepted: 06/09/2023] [Indexed: 08/23/2023] Open
Abstract
African swine fever virus (ASFV) is a lethal animal pathogen that enters its host cells through endocytosis. So far, host factors specifically required for ASFV replication have been barely identified. In this study a genome-wide CRISPR/Cas9 knockout screen in porcine cells indicated that the genes RFXANK, RFXAP, SLA-DMA, SLA-DMB, and CIITA are important for productive ASFV infection. The proteins encoded by these genes belong to the major histocompatibility complex II (MHC II), or swine leucocyte antigen complex II (SLA II). RFXAP and CIITA are MHC II-specific transcription factors, whereas SLA-DMA/B are subunits of the non-classical MHC II molecule SLA-DM. Targeted knockout of either of these genes led to severe replication defects of different ASFV isolates, reflected by substantially reduced plating efficiency, cell-to-cell spread, progeny virus titers and viral DNA replication. Transgene-based reconstitution of SLA-DMA/B fully restored the replication capacity demonstrating that SLA-DM, which resides in late endosomes, plays a crucial role during early steps of ASFV infection.
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Affiliation(s)
- Katrin Pannhorst
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Südufer 10, 17493, Greifswald-Insel Riems, Germany.
| | - Jolene Carlson
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Südufer 10, 17493, Greifswald-Insel Riems, Germany
- Ceva Animal Health, Greifswald-Insel Riems, Germany
| | - Julia E Hölper
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Südufer 10, 17493, Greifswald-Insel Riems, Germany
| | - Finn Grey
- The Roslin Institute, University of Edinburgh, Midlothian, UK
| | | | - Dirk Höper
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Elisabeth Wöhnke
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Südufer 10, 17493, Greifswald-Insel Riems, Germany
| | - Kati Franzke
- Institute of Infectology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Axel Karger
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Südufer 10, 17493, Greifswald-Insel Riems, Germany
| | - Walter Fuchs
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Südufer 10, 17493, Greifswald-Insel Riems, Germany
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Zuo X, Peng G, Xia Y, Xu L, Zhao Q, Zhu Y, Wang C, Liu Y, Zhao J, Wang H, Zou X. A quadruple fluorescence quantitative PCR method for the identification of wild strains of african swine fever and gene-deficient strains. Virol J 2023; 20:150. [PMID: 37452402 PMCID: PMC10347796 DOI: 10.1186/s12985-023-02111-1] [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: 05/10/2023] [Accepted: 06/30/2023] [Indexed: 07/18/2023] Open
Abstract
BACKGROUND Originating in Africa, African swine fever (ASF) was introduced to China in 2018. This acute and highly virulent infectious disease affects domestic pigs. The World Organization for Animal Health has listed it as a statutory reportable disease, and China has listed it as a category A infectious disease. METHODS Primers and probes were designed for four ASFV genes (B646L, EP402R, MGF505-3R, and A137R). The primers/probes were highly conserved compared with the gene sequences of 21 ASFV strains. RESULTS After optimization, the calibration curve showed good linearity (R2 > 0.99), the minimum concentration of positive plasmids that could be detected was 50 copies/µL, and the minimum viral load detection limit was 102 HAD50/mL. Furthermore, quadruple quantitative polymerase chain reaction (qPCR) with nucleic acids from three porcine-derived DNA viruses and cDNAs from eight RNA viruses did not show amplification curves, indicating that the method was specific. In addition, 1 × 106, 1 × 105, and 1 × 104 copies/µL of mixed plasmids were used for the quadruple qPCR; the coefficient of variation for triplicate determination between groups was < 2%, indicating the method was reproducible. CONCLUSIONS The results obtained by testing clinical samples containing detectable EP402R, MGF505-3R, and A137R strains with different combinations of gene deletions were as expected. Therefore, the established quadruple qPCR method was validated for the molecular diagnosis of ASF using gene-deleted ASFV strains.
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Affiliation(s)
- Xuezhi Zuo
- College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, 030801, Shanxi, China
- China/WOAH Reference Laboratory for Classical Swine Fever, China Institute of Veterinary Drug Control, Beijing, China
| | - Guorui Peng
- College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, 030801, Shanxi, China
| | - Yingju Xia
- College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, 030801, Shanxi, China
| | - Lu Xu
- College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, 030801, Shanxi, China
| | - Qizu Zhao
- College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, 030801, Shanxi, China
| | - Yuanyuan Zhu
- College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, 030801, Shanxi, China
| | - Cheng Wang
- College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, 030801, Shanxi, China
- China/WOAH Reference Laboratory for Classical Swine Fever, China Institute of Veterinary Drug Control, Beijing, China
| | - Yebing Liu
- College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, 030801, Shanxi, China
| | - Junjie Zhao
- College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, 030801, Shanxi, China
| | - Haidong Wang
- College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, 030801, Shanxi, China.
| | - Xingqi Zou
- China/WOAH Reference Laboratory for Classical Swine Fever, China Institute of Veterinary Drug Control, Beijing, China.
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Penrith ML, Okoth E, Livio Heath. Special Issue "African Swine Fever and Other Swine Viral Diseases in Africa". Viruses 2023; 15:1438. [PMID: 37515126 PMCID: PMC10386646 DOI: 10.3390/v15071438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 06/20/2023] [Indexed: 07/30/2023] Open
Abstract
African swine fever (ASF) has become the swine disease of most global concern since its second escape from Africa in 2007 resulted in its spread to five continents and the consequent devastation of industrial to subsistence pig farming [...].
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Affiliation(s)
- Mary-Louise Penrith
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria 0110, South Africa
| | - Edward Okoth
- Biosciences, Animal and Human Health Program, International Livestock Research Institute (ILRI), Nairobi 00100, Kenya
| | - Livio Heath
- Transboundary Animal Diseases, Onderstepoort Veterinary Research, Agricultural Research Council, Pretoria 0110, South Africa
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Koltsov A, Krutko S, Kholod N, Sukher M, Belov S, Korotin A, Koltsova G. Deletion of the CD2 Gene in the Virulent ASFV Congo Strain Affects Viremia in Domestic Swine, but Not the Virulence. Animals (Basel) 2023; 13:2002. [PMID: 37370512 DOI: 10.3390/ani13122002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 06/01/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023] Open
Abstract
African swine fever (ASF) is an infectious disease that causes the most significant losses to the pig industry. One of the effective methods for combating this disease could be the development of vaccines. To date, experimental vaccines based on the use of live attenuated strains of the ASF virus (ASFV) obtained by the deletion of viral genes responsible for virulence are the most effective. Deletion of the EP402R gene encoding a CD2-like protein led to the attenuation of various strains of the ASFV, although the degree of attenuation varies among different isolates. Here we have shown that the deletion of the EP402R gene from the genome of a high-virulent Congo isolate did not change either the virulence of the virus or its ability to replicate in the swine macrophage cell cultures in vitro. However, in vivo, animals infected with ΔCongo-v_CD2v had a delay in the onset of the disease and viremia compared to animals infected with the parental strain. Thus, deletion of the CD2 gene in different isolates of the ASFV has a different effect on the virulence of the virus, depending on its genetic background.
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Affiliation(s)
- Andrey Koltsov
- Federal Research Centre for Virology and Microbiology, Academician Bakoulov Street 1, 601125 Volginsky, Russia
| | - Sergey Krutko
- Federal Research Centre for Virology and Microbiology, Academician Bakoulov Street 1, 601125 Volginsky, Russia
| | - Natalia Kholod
- Federal Research Centre for Virology and Microbiology, Academician Bakoulov Street 1, 601125 Volginsky, Russia
| | - Mikhail Sukher
- Federal Research Centre for Virology and Microbiology, Academician Bakoulov Street 1, 601125 Volginsky, Russia
| | - Sergey Belov
- Federal Research Centre for Virology and Microbiology, Academician Bakoulov Street 1, 601125 Volginsky, Russia
| | - Alexey Korotin
- Federal Research Centre for Virology and Microbiology, Academician Bakoulov Street 1, 601125 Volginsky, Russia
| | - Galina Koltsova
- Federal Research Centre for Virology and Microbiology, Academician Bakoulov Street 1, 601125 Volginsky, Russia
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10
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Sereda AD, Kazakova AS, Namsrayn SG, Vlasov ME, Sindryakova IP, Kolbasov DV. Subsequent Immunization of Pigs with African Swine Fever Virus (ASFV) Seroimmunotype IV Vaccine Strain FK-32/135 and by Recombinant Plasmid DNA Containing the CD2v Derived from MK-200 ASFV Seroimmunotype III Strain Does Not Protect from Challenge with ASFV Seroimmunotype III. Vaccines (Basel) 2023; 11:vaccines11051007. [PMID: 37243111 DOI: 10.3390/vaccines11051007] [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: 03/23/2023] [Revised: 05/15/2023] [Accepted: 05/19/2023] [Indexed: 05/28/2023] Open
Abstract
Understanding the immunological mechanisms of protection and the viral proteins involved in the induction of a protective immune response to the African swine fever virus (ASFV) is still limited. In the last years, the CD2v protein (gp110-140) of the ASFV has been proven to be a serotype-specific protein. Current work is devoted to the investigation of the possibility of creating protection against virulent ASFV strain Mozambique-78 (seroimmunotype III) in pigs previously vaccinated with vaccine strain FK-32/135 (seroimmunotype IV) and then immunized with the pUBB76A_CD2v plasmid, containing a chimeric nucleotide sequence from the CD2v protein gene (EP402R, nucleotides from 49 to 651) from the MK-200 strain (seroimmunotype III). Vaccination with the ASFV vaccine strain FK-32/135 protects pigs from the disease caused by the strain with homologous seroimmunotype-France-32 (seroimmunotype IV). Our attempt to create balanced protection against virulent strain Mozambique-78 (seroimmunotype III) by induction of both humoral factors of immunity (by vaccination with strain FK-32/135 of seroimmunotype IV) and serotype-specific cellular immunity (by immunization with the plasmid pUBB76A_CD2v of seroimmunotype III) was unsuccessful.
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Affiliation(s)
- Alexey D Sereda
- Federal Research Center for Virology and Microbiology (FRCVM), 601125 Volginsky, Petushki Area, Vladimir Region, Russia
| | - Anna S Kazakova
- Federal Research Center for Virology and Microbiology (FRCVM), 601125 Volginsky, Petushki Area, Vladimir Region, Russia
| | - Sanzhi G Namsrayn
- Federal Research Center for Virology and Microbiology (FRCVM), 601125 Volginsky, Petushki Area, Vladimir Region, Russia
| | - Mikhail E Vlasov
- Federal Research Center for Virology and Microbiology (FRCVM), 601125 Volginsky, Petushki Area, Vladimir Region, Russia
| | - Irina P Sindryakova
- Federal Research Center for Virology and Microbiology (FRCVM), 601125 Volginsky, Petushki Area, Vladimir Region, Russia
| | - Denis V Kolbasov
- Federal Research Center for Virology and Microbiology (FRCVM), 601125 Volginsky, Petushki Area, Vladimir Region, Russia
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11
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Pérez-Núñez D, Sunwoo SY, García-Belmonte R, Kim C, Vigara-Astillero G, Riera E, Kim DM, Jeong J, Tark D, Ko YS, You YK, Revilla Y. Recombinant African Swine Fever Virus Arm/07/CBM/c2 Lacking CD2v and A238L Is Attenuated and Protects Pigs against Virulent Korean Paju Strain. Vaccines (Basel) 2022; 10:vaccines10121992. [PMID: 36560402 PMCID: PMC9784410 DOI: 10.3390/vaccines10121992] [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: 10/17/2022] [Revised: 11/17/2022] [Accepted: 11/20/2022] [Indexed: 11/25/2022] Open
Abstract
African swine fever (ASF) is an obligated declaration swine disease, provoking farm isolation measures and the closing of affected country boarders. ASF virus (ASFV) is currently the cause of a pandemic across China and Eurasia. By the end of 2019, ASF was detected in nine EU Member States: Bulgaria, Romania, Slovakia, Estonia, Hungary, Latvia, Lithuania, Poland and Belgium. The affected area of the EU extended progressively, moving mostly in a southwestern direction (EFSA). Inactivated and/or subunit vaccines have proven to fail since certain virus replication is needed for protection. LAVs are thus the most realistic option, which must be safe, effective and industrially scalable. We here generated a vaccine prototype from the Arm/07/CBM/c2 genotype II strain, in which we have deleted the EP402R (CD2v) and A238L genes by CRISPR/Cas9 in COS-1 cells, without detectable further genetic changes. The successful immunization of pigs has proven this vaccine to be safe and fully protective against the circulating Korean Paju genotype II strain, opening the possibility of a new vaccine on the market in the near future.
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Affiliation(s)
- Daniel Pérez-Núñez
- Microbes in Health and Welfare Department, Centro de Biología Molecular Severo Ochoa, CSIC-UAM, c/Nicolás Cabrera 1, 28049 Madrid, Spain
| | - Sun-Young Sunwoo
- Careside Co., Ltd., Sagimakgol-ro 45 Beongil 14, Seongnam-si 13209, Gyeonggi-do, Republic of Korea
| | - Raquel García-Belmonte
- Microbes in Health and Welfare Department, Centro de Biología Molecular Severo Ochoa, CSIC-UAM, c/Nicolás Cabrera 1, 28049 Madrid, Spain
| | - Chansong Kim
- Careside Co., Ltd., Sagimakgol-ro 45 Beongil 14, Seongnam-si 13209, Gyeonggi-do, Republic of Korea
| | - Gonzalo Vigara-Astillero
- Microbes in Health and Welfare Department, Centro de Biología Molecular Severo Ochoa, CSIC-UAM, c/Nicolás Cabrera 1, 28049 Madrid, Spain
| | - Elena Riera
- Microbes in Health and Welfare Department, Centro de Biología Molecular Severo Ochoa, CSIC-UAM, c/Nicolás Cabrera 1, 28049 Madrid, Spain
| | - Dae-min Kim
- Laboratory for infectious Disease Prevention, Korea Zoonosis Research Institute, Jeonbuk National University, 79 Gobong-ro, Ma-dong, Iksan 54531, Jeollabuk-do, Republic of Korea
| | - Jiyun Jeong
- Careside Co., Ltd., Sagimakgol-ro 45 Beongil 14, Seongnam-si 13209, Gyeonggi-do, Republic of Korea
| | - Dongseob Tark
- Laboratory for infectious Disease Prevention, Korea Zoonosis Research Institute, Jeonbuk National University, 79 Gobong-ro, Ma-dong, Iksan 54531, Jeollabuk-do, Republic of Korea
| | - Young-Seung Ko
- Laboratory for infectious Disease Prevention, Korea Zoonosis Research Institute, Jeonbuk National University, 79 Gobong-ro, Ma-dong, Iksan 54531, Jeollabuk-do, Republic of Korea
| | - Young-Kook You
- Careside Co., Ltd., Sagimakgol-ro 45 Beongil 14, Seongnam-si 13209, Gyeonggi-do, Republic of Korea
| | - Yolanda Revilla
- Microbes in Health and Welfare Department, Centro de Biología Molecular Severo Ochoa, CSIC-UAM, c/Nicolás Cabrera 1, 28049 Madrid, Spain
- Correspondence: ; Tel.: +34-911964570
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12
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Penrith ML, Van Heerden J, Heath L, Abworo EO, Bastos ADS. Review of the Pig-Adapted African Swine Fever Viruses in and Outside Africa. Pathogens 2022; 11:pathogens11101190. [PMID: 36297247 PMCID: PMC9609104 DOI: 10.3390/pathogens11101190] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 10/08/2022] [Accepted: 10/11/2022] [Indexed: 12/04/2022] Open
Abstract
The region in eastern, central and southern Africa (ECSA) where African swine fever (ASF) originated in a sylvatic cycle is home to all the p72 genotypes of ASF virus identified so far. While 20 of the 24 genotypes have been isolated from outbreaks in domestic pigs in the region, only five of the genotypes (I, II, VIII, IX, X) have an extended field presence associated with domestic pigs. Of the genotypes that appear to be strongly adapted to domestic pigs, two have spread beyond the African continent and have been the focus of efforts to develop vaccines against ASF. Most of the experimental ASF vaccines described do not protect against a wider spectrum of viruses and may be less useful in the event of incursions of different strains or where multiple genotypes co-exist. The other three pig-adapted strains that are currently restricted to the ECSA region might spread, and priority should be given to understanding not only the genetic and antigenic characteristics of these viruses but also their history. We review historic and current knowledge of the distribution of these five virus genotypes, and note that as was the case for genotype II, some pig-associated viruses have the propensity for geographical range expansion. These features are valuable for prioritizing vaccine-development efforts to ensure a swift response to virus escape. However, whilst ASF vaccines are critical for high-production systems, global food security relies on parallel efforts to improve biosecurity and pig production in Africa and on continued ASFV surveillance and characterisation in the ECSA region.
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Affiliation(s)
- Mary-Louise Penrith
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria 0110, South Africa
- Correspondence: or
| | - Juanita Van Heerden
- Transboundary Animal Diseases, Onderstepoort Veterinary Research, Agricultural Research Council, Pretoria 0110, South Africa
| | - Livio Heath
- Transboundary Animal Diseases, Onderstepoort Veterinary Research, Agricultural Research Council, Pretoria 0110, South Africa
| | - Edward Okoth Abworo
- Biosciences, Animal and Human Health Program, International Livestock Research Institute (ILRI), Nairobi 00100, Kenya
| | - Armanda D. S. Bastos
- Department of Zoology and Entomology, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria 0028, South Africa
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13
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Co-Deletion of A238L and EP402R Genes from a Genotype IX African Swine Fever Virus Results in Partial Attenuation and Protection in Swine. Viruses 2022; 14:v14092024. [PMID: 36146830 PMCID: PMC9501025 DOI: 10.3390/v14092024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 08/29/2022] [Accepted: 09/09/2022] [Indexed: 11/30/2022] Open
Abstract
African swine fever virus (ASFV) is the causative agent of African swine fever (ASF), resulting in up to 100% mortality in pigs. Although endemic in most sub-Saharan African countries, where all known ASFV genotypes have been reported, the disease has caused pandemics of significant economic impact in Eurasia, and no vaccines or therapeutics are available to date. In endeavors to develop live-attenuated vaccines against ASF, deletions of several of the ~170 ASFV genes have shown contrasting results depending on the genotype of the investigated ASFV. Here, we report the in vivo outcome of a single deletion of the A238L (5EL) gene and double deletions of A238L (5EL) and EP402R (CD2v) genes from the genome of a highly virulent genotype IX ASFV isolate. Domestic pigs were intramuscularly inoculated with (i) ASFV-Ke-ΔA238L to assess the safety of A238L deletion and (ii) ASFV-Ke-ΔEP402RΔA238L to investigate protection against challenge with the virulent wildtype ASFV-Ke virus. While A238L (5EL) gene deletion did not yield complete attenuation, co-deletion of A238L (5EL) and EP402R (CD2v) improved the safety profile of the single deletions, eliciting both humoral and cellular immune responses and conferred partial protection against challenge with the virulent wildtype ASFV-Ke virus.
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