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Gladue DP, Gomez-Lucas L, Largo E, Ramirez-Medina E, Torralba J, Queralt-Martín M, Alcaraz A, Velazquez-Salinas L, Nieva JL, Borca MV. Viroporin-like activity of the hairpin transmembrane domain of African swine fever virus B169L protein. J Virol 2024; 98:e0023124. [PMID: 38980063 PMCID: PMC11334534 DOI: 10.1128/jvi.00231-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Accepted: 05/21/2024] [Indexed: 07/10/2024] Open
Abstract
African swine fever virus (ASFV) is the causative agent of a contagious disease affecting wild and domestic swine. The function of B169L protein, as a potential integral structural membrane protein, remains to be experimentally characterized. Using state-of-the-art bioinformatics tools, we confirm here earlier predictions indicating the presence of an integral membrane helical hairpin, and further suggest anchoring of this protein to the ER membrane, with both terminal ends facing the lumen of the organelle. Our evolutionary analysis confirmed the importance of purifying selection in the preservation of the identified domains during the evolution of B169L in nature. Also, we address the possible function of this hairpin transmembrane domain (HTMD) as a class IIA viroporin. Expression of GFP fusion proteins in the absence of a signal peptide supported B169L insertion into the ER as a Type III membrane protein and the formation of oligomers therein. Overlapping peptides that spanned the B169L HTMD were reconstituted into ER-like membranes and the adopted structures analyzed by infrared spectroscopy. Consistent with the predictions, B169L transmembrane sequences adopted α-helical conformations in lipid bilayers. Moreover, single vesicle permeability assays demonstrated the assembly of lytic pores in ER-like membranes by B169L transmembrane helices, a capacity confirmed by ion-channel activity measurements in planar bilayers. Emphasizing the relevance of these observations, pore-forming activities were not observed in the case of transmembrane helices derived from EP84R, another ASFV protein predicted to anchor to membranes through a α-helical HTMD. Overall, our results support predictions of viroporin-like function for the B169L HTMD.IMPORTANCEAfrican swine fever (ASF), a devastating disease affecting domestic swine, is widely spread in Eurasia, producing significant economic problems in the pork industry. Approaches to prevent/cure the disease are mainly restricted to the limited information concerning the role of most of the genes encoded by the large (160-170 kba) virus genome. In this report, we present the experimental data on the functional characterization of the African swine fever virus (ASFV) gene B169L. Data presented here indicates that the B169L gene encodes for an essential membrane-associated protein with a viroporin function.
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Affiliation(s)
- Douglas P. Gladue
- Plum Island Animal Disease Center, ARS, USDA, Greenport, New York, USA
| | - Lidia Gomez-Lucas
- Instituto Biofisika (CSIC-UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country, Bilbao, Spain
| | - Eneko Largo
- Department of Immunology, Microbiology and Parasitology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain
| | | | - Johana Torralba
- Instituto Biofisika (CSIC-UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country, Bilbao, Spain
| | - Maria Queralt-Martín
- Laboratory of Molecular Biophysics. Department of Physics, University Jaume I, Castello, Castellón, Spain
| | - Antonio Alcaraz
- Laboratory of Molecular Biophysics. Department of Physics, University Jaume I, Castello, Castellón, Spain
| | | | - Jose L. Nieva
- Instituto Biofisika (CSIC-UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country, Bilbao, Spain
| | - Manuel V. Borca
- Plum Island Animal Disease Center, ARS, USDA, Greenport, New York, USA
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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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3
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Borca MV, Ramirez-Medina E, Espinoza N, Rai A, Spinard E, Velazquez-Salinas L, Valladares A, Silva E, Burton L, Meyers A, Clark J, Wu P, Gay CG, Gladue DP. Deletion of the EP402R Gene from the Genome of African Swine Fever Vaccine Strain ASFV-G-∆I177L Provides the Potential Capability of Differentiating between Infected and Vaccinated Animals. Viruses 2024; 16:376. [PMID: 38543742 PMCID: PMC10974803 DOI: 10.3390/v16030376] [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: 12/16/2023] [Revised: 02/19/2024] [Accepted: 02/20/2024] [Indexed: 05/23/2024] Open
Abstract
The African swine fever virus (ASFV) mutant ASFV-G-∆I177L is a safe and efficacious vaccine which induces protection against the challenge of its parental virus, the Georgia 2010 isolate. Although a genetic DIVA (differentiation between infected and vaccinated animals) assay has been developed for this vaccine, still there is not a serological DIVA test for differentiating between animals vaccinated with ASFV-G-∆I177L and those infected with wild-type viruses. In this report, we describe the development of the ASFV-G-∆I177L mutant having deleted the EP402R gene, which encodes for the viral protein responsible for mediating the hemadsorption of swine erythrocytes. The resulting virus, ASFV-G-∆I177L/∆EP402R, does not have a decreased ability to replicates in swine macrophages when compared with the parental ASFV-G-∆I177L. Domestic pigs intramuscularly (IM) inoculated with either 102 or 106 HAD50 of ASFV-G-∆I177L/∆EP402R remained clinically normal, when compared with a group of mock-vaccinated animals, indicating the absence of residual virulence. Interestingly, an infectious virus could not be detected in the blood samples of the ASFV-G-∆I177L/∆EP402R-inoculated animals in either group at any of the time points tested. Furthermore, while all of the mock-inoculated animals presented a quick and lethal clinical form of ASF after the intramuscular inoculation challenge with 102 HAD50 of highly virulent parental field isolate Georgia 2010 (ASFV-G), all of the ASFV-G-∆I177L/∆EP402R-inoculated animals were protected, remaining clinically normal until the end of the observational period. Most of the ASFV-G-∆I177L/∆EP402R-inoculated pigs developed strong virus-specific antibody responses against viral antigens, reaching maximum levels at 28 days post inoculation. Importantly, all of the sera collected at that time point in the ASFV-G-∆I177L/∆EP402R-inoculated pigs did not react in a direct ELISA coated with the recombinant EP402R protein. Conversely, the EP402R protein was readily recognized by the pool of sera from the animals immunized with recombinant live attenuated vaccine candidates ASFV-G-∆I177L, ASFV-G-∆MGF, or ASFV-G-∆9GL/∆UK. Therefore, ASFV-G-∆I177L/∆EP402R is a novel, safe and efficacious candidate with potential to be used as an antigenically DIVA vaccine.
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Affiliation(s)
- Manuel V. Borca
- Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, U.S. Department of Agriculture, Agricultural Research Service, Orient, NY 11957, USA; (E.R.-M.); (N.E.); (A.R.); (E.S.); (L.V.-S.); (A.V.); (A.M.)
- Foreign Animal Disease Research Unit, U.S. Department of Agriculture, Agricultural Research Service, National Bio and Agro-Defense Facility, Manhattan, KS 66502, USA; (E.S.); (L.B.); (J.C.)
| | - Elizabeth Ramirez-Medina
- Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, U.S. Department of Agriculture, Agricultural Research Service, Orient, NY 11957, USA; (E.R.-M.); (N.E.); (A.R.); (E.S.); (L.V.-S.); (A.V.); (A.M.)
- Foreign Animal Disease Research Unit, U.S. Department of Agriculture, Agricultural Research Service, National Bio and Agro-Defense Facility, Manhattan, KS 66502, USA; (E.S.); (L.B.); (J.C.)
| | - Nallely Espinoza
- Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, U.S. Department of Agriculture, Agricultural Research Service, Orient, NY 11957, USA; (E.R.-M.); (N.E.); (A.R.); (E.S.); (L.V.-S.); (A.V.); (A.M.)
- Foreign Animal Disease Research Unit, U.S. Department of Agriculture, Agricultural Research Service, National Bio and Agro-Defense Facility, Manhattan, KS 66502, USA; (E.S.); (L.B.); (J.C.)
| | - Ayushi Rai
- Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, U.S. Department of Agriculture, Agricultural Research Service, Orient, NY 11957, USA; (E.R.-M.); (N.E.); (A.R.); (E.S.); (L.V.-S.); (A.V.); (A.M.)
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN 37830, USA
| | - Edward Spinard
- Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, U.S. Department of Agriculture, Agricultural Research Service, Orient, NY 11957, USA; (E.R.-M.); (N.E.); (A.R.); (E.S.); (L.V.-S.); (A.V.); (A.M.)
- Foreign Animal Disease Research Unit, U.S. Department of Agriculture, Agricultural Research Service, National Bio and Agro-Defense Facility, Manhattan, KS 66502, USA; (E.S.); (L.B.); (J.C.)
| | - Lauro Velazquez-Salinas
- Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, U.S. Department of Agriculture, Agricultural Research Service, Orient, NY 11957, USA; (E.R.-M.); (N.E.); (A.R.); (E.S.); (L.V.-S.); (A.V.); (A.M.)
- Foreign Animal Disease Research Unit, U.S. Department of Agriculture, Agricultural Research Service, National Bio and Agro-Defense Facility, Manhattan, KS 66502, USA; (E.S.); (L.B.); (J.C.)
| | - Alyssa Valladares
- Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, U.S. Department of Agriculture, Agricultural Research Service, Orient, NY 11957, USA; (E.R.-M.); (N.E.); (A.R.); (E.S.); (L.V.-S.); (A.V.); (A.M.)
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN 37830, USA
| | - Ediane Silva
- Foreign Animal Disease Research Unit, U.S. Department of Agriculture, Agricultural Research Service, National Bio and Agro-Defense Facility, Manhattan, KS 66502, USA; (E.S.); (L.B.); (J.C.)
| | - Leeanna Burton
- Foreign Animal Disease Research Unit, U.S. Department of Agriculture, Agricultural Research Service, National Bio and Agro-Defense Facility, Manhattan, KS 66502, USA; (E.S.); (L.B.); (J.C.)
| | - Amanda Meyers
- Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, U.S. Department of Agriculture, Agricultural Research Service, Orient, NY 11957, USA; (E.R.-M.); (N.E.); (A.R.); (E.S.); (L.V.-S.); (A.V.); (A.M.)
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN 37830, USA
| | - Jason Clark
- Foreign Animal Disease Research Unit, U.S. Department of Agriculture, Agricultural Research Service, National Bio and Agro-Defense Facility, Manhattan, KS 66502, USA; (E.S.); (L.B.); (J.C.)
| | - Ping Wu
- Plum Island Animal Disease Center, U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Orient, NY 11957, USA;
| | - Cyril G. Gay
- Agricultural Research Service, U.S. Department of Agriculture, Beltsville, MD 20705, USA;
| | - Douglas P. Gladue
- Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, U.S. Department of Agriculture, Agricultural Research Service, Orient, NY 11957, USA; (E.R.-M.); (N.E.); (A.R.); (E.S.); (L.V.-S.); (A.V.); (A.M.)
- Foreign Animal Disease Research Unit, U.S. Department of Agriculture, Agricultural Research Service, National Bio and Agro-Defense Facility, Manhattan, KS 66502, USA; (E.S.); (L.B.); (J.C.)
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Yang J, Zhu R, Zhang Y, Zhou X, Yue H, Li Q, Ke J, Wang Y, Miao F, Chen T, Zhang F, Zhang S, Qian A, Hu R. Deleting the C84L Gene from the Virulent African Swine Fever Virus SY18 Does Not Affect Its Replication in Porcine Primary Macrophages but Reduces Its Virulence in Swine. Pathogens 2024; 13:103. [PMID: 38392841 PMCID: PMC10891671 DOI: 10.3390/pathogens13020103] [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: 12/31/2023] [Revised: 01/17/2024] [Accepted: 01/18/2024] [Indexed: 02/25/2024] Open
Abstract
(1) Background: African swine fever (ASF) is a highly contagious disease that causes high pig mortality. Due to the absence of vaccines, prevention and control are relatively challenging. The pathogenic African swine fever virus (ASFV) has a complex structure and encodes over 160 proteins, many of which still need to be studied and verified for their functions. In this study, we identified one of the unknown functional genes, C84L. (2) Methods: A gene deficient strain was obtained through homologous recombination and several rounds of purification, and its replication characteristics and virulence were studied through in vitro and in vivo experiments, respectively. (3) Results: Deleting this gene from the wild-type virulent strain SY18 did not affect its replication in porcine primary macrophages but reduced its virulence in pigs. In animal experiments, we injected pigs with a 102 TCID50, 105 TCID50 deletion virus, and a 102 TCID50 wild-type strain SY18 intramuscularly. The control group pigs reached the humane endpoint on the ninth day (0/5) and were euthanized. Two pigs in the 102 TCID50(2/5) deletion virus group survived on the twenty-first day, and one in the 105 TCID50(1/5) deletion virus group survived. On the twenty-first day, the surviving pigs were euthanized, which was the end of the experiment. The necropsies of the survival group and control groups' necropsies showed that the surviving pigs' liver, spleen, lungs, kidneys, and submaxillary lymph nodes did not show significant lesions associated with the ASFV. ASFV-specific antibodies were first detected on the seventh day after immunization; (4) Conclusions: This is the first study to complete the replication and virulence functional exploration of the C84L gene of SY18. In this study, C84L gene was preliminarily found not a necessary gene for replication, gene deletion strain SY18ΔC84L has similar growth characteristics to SY18 in porcine primary alveolar macrophages. The C84L gene affects the virulence of the SY18 strain.
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Affiliation(s)
- Jinjin Yang
- College of Veterinary Medicine, Jilin Agricultural University, Changchun 130118, China
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
- Key Laboratory of Prevention & Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, Changchun 130000, China
| | - Rongnian Zhu
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
- Key Laboratory of Prevention & Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, Changchun 130000, China
| | - Yanyan Zhang
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
- Key Laboratory of Prevention & Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, Changchun 130000, China
| | - Xintao Zhou
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
- Key Laboratory of Prevention & Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, Changchun 130000, China
| | - Huixian Yue
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
- Key Laboratory of Prevention & Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, Changchun 130000, China
| | - Qixuan Li
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
- Key Laboratory of Prevention & Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, Changchun 130000, China
| | - Junnan Ke
- College of Veterinary Medicine, Jilin Agricultural University, Changchun 130118, China
| | - Yu Wang
- College of Veterinary Medicine, Jilin Agricultural University, Changchun 130118, China
| | - Faming Miao
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
- Key Laboratory of Prevention & Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, Changchun 130000, China
| | - Teng Chen
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
- Key Laboratory of Prevention & Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, Changchun 130000, China
| | - Fei Zhang
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
- Key Laboratory of Prevention & Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, Changchun 130000, China
| | - Shoufeng Zhang
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
- Key Laboratory of Prevention & Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, Changchun 130000, China
| | - Aidong Qian
- College of Veterinary Medicine, Jilin Agricultural University, Changchun 130118, China
| | - Rongliang Hu
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
- Key Laboratory of Prevention & Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, Changchun 130000, China
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Wang H, Su A, Bao C, Liang C, Xu W, Chang J, Xu S. A CRISPR/Cas12a-SERS platform for amplification-free detection of African swine fever virus genes. Talanta 2024; 267:125225. [PMID: 37741267 DOI: 10.1016/j.talanta.2023.125225] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 08/26/2023] [Accepted: 09/18/2023] [Indexed: 09/25/2023]
Abstract
A surface-enhanced Raman scattering (SERS) strategy combined with a CRISPR/Cas12a system is designed for the amplification-free gene detection of African swine fever virus (ASFV). A SERS sensing probe was fabricated by conjugating plasmonic SERS tags on the magnetic bead (MB) surface with an single-stranded DNA (ssDNA) as a linker. The target ASFV gene-activated Cas12a protein starts the trans-cleavage function on the linker ssDNA, which causes the release of SERS tags, leading to a decrease of the SERS signal detected above the collective MBs. Two signal enhancement strategies were adopted to improve the liquid-phase detection sensitivity arriving at the fM level. One is the unlimited trans-cleavage function of the Cas12a protein, and the other is the magnetic-induced collection of probes that can significantly gather the analytes from the solution to the laser spot and provide SERS hotspots during SERS measurement. Detection range is from 100 nM to 10 fM without the gene amplification steps. This sensing method achieved the SERS detection of ASFV gene in the serum system and the extracted nucleic acids in viral samples with high sensitivity and selectivity at a relative standard deviation of <8%. This sensing platform is mainly in use for site inspection and quick testing of gene samples.
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Affiliation(s)
- Huimin Wang
- School of Chemistry and Environmental Engineering, Changchun University of Science and Technology, Changchun, 130022, PR China; State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, PR China
| | - Ailing Su
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, PR China
| | - Chengxin Bao
- Institute of Frontier Medical Science, Jilin University, Changchun, 130021, PR China
| | - Chongyang Liang
- Institute of Frontier Medical Science, Jilin University, Changchun, 130021, PR China
| | - Weiqing Xu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, PR China; Theoretical Chemistry, College of Chemistry, Jilin University, Changchun, 130012, PR China
| | - Jingjing Chang
- School of Chemistry and Environmental Engineering, Changchun University of Science and Technology, Changchun, 130022, PR China.
| | - Shuping Xu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, PR China; Theoretical Chemistry, College of Chemistry, Jilin University, Changchun, 130012, PR China; Center for Supramolecular Chemical Biology, College of Chemistry, Jilin University, Changchun, 130012, PR China.
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Spinard E, Rai A, Osei-Bonsu J, O’Donnell V, Ababio PT, Tawiah-Yingar D, Arthur D, Baah D, Ramirez-Medina E, Espinoza N, Valladares A, Faburay B, Ambagala A, Odoom T, Borca MV, Gladue DP. The 2022 Outbreaks of African Swine Fever Virus Demonstrate the First Report of Genotype II in Ghana. Viruses 2023; 15:1722. [PMID: 37632064 PMCID: PMC10459280 DOI: 10.3390/v15081722] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 08/02/2023] [Accepted: 08/05/2023] [Indexed: 08/27/2023] Open
Abstract
African swine fever (ASF) is a lethal disease of domestic pigs that has been causing outbreaks for over a century in Africa ever since its first discovery in 1921. Since 1957, there have been sporadic outbreaks outside of Africa; however, no outbreak has been as devastating and as far-reaching as the current pandemic that originated from a 2007 outbreak in the Republic of Georgia. Derivatives with a high degree of similarity to the progenitor strain, ASFV-Georgia/2007, have been sequenced from various countries in Europe and Asia. However, the current strains circulating in Africa are largely unknown, and 24 different genotypes have been implicated in different outbreaks. In this study, ASF isolates were collected from samples from swine suspected of dying from ASF on farms in Ghana in early 2022. While previous studies determined that the circulating strains in Ghana were p72 Genotype I, we demonstrate here that the strains circulating in 2022 were derivatives of the p72 Genotype II pandemic strain. Therefore, this study demonstrates for the first time the emergence of Genotype II ASFV in Ghana.
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Affiliation(s)
- Edward Spinard
- U.S. Department of Agriculture, Agricultural Research Service, Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Orient, NY 11957, USA; (E.S.); (E.R.-M.); (N.E.)
- U.S. Department of Agriculture, Agricultural Research Service, Foreign Animal Disease Research Unit, National Bio and Agro-Defense Facility, Unit Name, Manhattan, KS 66502, USA
- Center of Excellence for African Swine Fever Genomics, Guilford, CT 06437, USA (A.A.); (T.O.)
| | - Ayushi Rai
- U.S. Department of Agriculture, Agricultural Research Service, Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Orient, NY 11957, USA; (E.S.); (E.R.-M.); (N.E.)
- U.S. Department of Agriculture, Agricultural Research Service, Foreign Animal Disease Research Unit, National Bio and Agro-Defense Facility, Unit Name, Manhattan, KS 66502, USA
| | - Jehadi Osei-Bonsu
- Accra Veterinary Laboratory of Veterinary Services Directorate, Accra P.O. Box GA184, Ghana (P.T.A.); (D.T.-Y.); (D.A.); (D.B.)
- Animal and Plant Inspection Service, USDA, Greenport, NY 11944, USA
| | - Vivian O’Donnell
- Departmenr of Libral Arts & Sciences, University of Illinois at Urbana-Champaign, Champaign, IL 61820, USA;
| | - Patrick T. Ababio
- Accra Veterinary Laboratory of Veterinary Services Directorate, Accra P.O. Box GA184, Ghana (P.T.A.); (D.T.-Y.); (D.A.); (D.B.)
| | - Daniel Tawiah-Yingar
- Accra Veterinary Laboratory of Veterinary Services Directorate, Accra P.O. Box GA184, Ghana (P.T.A.); (D.T.-Y.); (D.A.); (D.B.)
| | - Daniel Arthur
- Accra Veterinary Laboratory of Veterinary Services Directorate, Accra P.O. Box GA184, Ghana (P.T.A.); (D.T.-Y.); (D.A.); (D.B.)
| | - Daniel Baah
- Accra Veterinary Laboratory of Veterinary Services Directorate, Accra P.O. Box GA184, Ghana (P.T.A.); (D.T.-Y.); (D.A.); (D.B.)
| | - Elizabeth Ramirez-Medina
- U.S. Department of Agriculture, Agricultural Research Service, Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Orient, NY 11957, USA; (E.S.); (E.R.-M.); (N.E.)
- U.S. Department of Agriculture, Agricultural Research Service, Foreign Animal Disease Research Unit, National Bio and Agro-Defense Facility, Unit Name, Manhattan, KS 66502, USA
| | - Nallely Espinoza
- U.S. Department of Agriculture, Agricultural Research Service, Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Orient, NY 11957, USA; (E.S.); (E.R.-M.); (N.E.)
- U.S. Department of Agriculture, Agricultural Research Service, Foreign Animal Disease Research Unit, National Bio and Agro-Defense Facility, Unit Name, Manhattan, KS 66502, USA
| | - Alyssa Valladares
- U.S. Department of Agriculture, Agricultural Research Service, Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Orient, NY 11957, USA; (E.S.); (E.R.-M.); (N.E.)
- U.S. Department of Agriculture, Agricultural Research Service, Foreign Animal Disease Research Unit, National Bio and Agro-Defense Facility, Unit Name, Manhattan, KS 66502, USA
| | - Bonto Faburay
- Center of Excellence for African Swine Fever Genomics, Guilford, CT 06437, USA (A.A.); (T.O.)
- Animal and Plant Inspection Service, USDA, Greenport, NY 11944, USA
| | - Aruna Ambagala
- Center of Excellence for African Swine Fever Genomics, Guilford, CT 06437, USA (A.A.); (T.O.)
- Animal and Plant Inspection Service, USDA, Greenport, NY 11944, USA
| | - Theophlius Odoom
- Center of Excellence for African Swine Fever Genomics, Guilford, CT 06437, USA (A.A.); (T.O.)
- Departmenr of Libral Arts & Sciences, University of Illinois at Urbana-Champaign, Champaign, IL 61820, USA;
| | - Manuel V. Borca
- U.S. Department of Agriculture, Agricultural Research Service, Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Orient, NY 11957, USA; (E.S.); (E.R.-M.); (N.E.)
- U.S. Department of Agriculture, Agricultural Research Service, Foreign Animal Disease Research Unit, National Bio and Agro-Defense Facility, Unit Name, Manhattan, KS 66502, USA
- Center of Excellence for African Swine Fever Genomics, Guilford, CT 06437, USA (A.A.); (T.O.)
| | - Douglas P. Gladue
- U.S. Department of Agriculture, Agricultural Research Service, Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Orient, NY 11957, USA; (E.S.); (E.R.-M.); (N.E.)
- U.S. Department of Agriculture, Agricultural Research Service, Foreign Animal Disease Research Unit, National Bio and Agro-Defense Facility, Unit Name, Manhattan, KS 66502, USA
- Center of Excellence for African Swine Fever Genomics, Guilford, CT 06437, USA (A.A.); (T.O.)
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Feng W, Zhou L, Zhao P, Du H, Diao C, Zhang Y, Liu Z, Jin W, Yu J, Han J, Okoth E, Mrode R, Liu JF. Comparative Genomic Analysis of Warthog and Sus Scrofa Identifies Adaptive Genes Associated with African Swine Fever. BIOLOGY 2023; 12:1001. [PMID: 37508430 PMCID: PMC10376286 DOI: 10.3390/biology12071001] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 07/01/2023] [Accepted: 07/12/2023] [Indexed: 07/30/2023]
Abstract
BACKGROUND As warthogs (Phacochoerus africanus) have innate immunity against African swine fever (ASF), it is critical to understand the evolutionary novelty of warthogs to explain their specific ASF resistance. METHODS Here, we present two completed new genomes of one warthog and one Kenyan domestic pig as fundamental genomic references to elucidate the genetic mechanisms of ASF tolerance. RESULTS Multiple genomic variations, including gene losses, independent contraction, and the expansion of specific gene families, likely molded the warthog genome to adapt to the environment. Importantly, the analysis of the presence and absence of genomic sequences revealed that the DNA sequence of the warthog genome had an absence of the gene lactate dehydrogenase B (LDHB) on chromosome 2 compared with the reference genome. The overexpression and siRNA of LDHB inhibited the replication of the African swine fever virus. Combined with large-scale sequencing data from 42 pigs worldwide, the contraction and expansion of tripartite motif-containing (TRIM) gene families revealed that TRIM family genes in the warthog genome are potentially responsible for its tolerance to ASF. CONCLUSION Our results will help improve the understanding of genetic resistance to ASF in pigs.
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Affiliation(s)
- Wen Feng
- National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture; Frontiers Science Center for Molecular Design Breeding (MOE), College of Animal Science and Technology, China Agricultural University, Beijing 100193, China
- Shenzhen Kingsino Technology Co., Ltd., Shenzhen 518107, China
| | - Lei Zhou
- National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture; Frontiers Science Center for Molecular Design Breeding (MOE), College of Animal Science and Technology, China Agricultural University, Beijing 100193, China
| | - Pengju Zhao
- National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture; Frontiers Science Center for Molecular Design Breeding (MOE), College of Animal Science and Technology, China Agricultural University, Beijing 100193, China
| | - Heng Du
- National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture; Frontiers Science Center for Molecular Design Breeding (MOE), College of Animal Science and Technology, China Agricultural University, Beijing 100193, China
| | - Chenguang Diao
- National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture; Frontiers Science Center for Molecular Design Breeding (MOE), College of Animal Science and Technology, China Agricultural University, Beijing 100193, China
| | - Yu Zhang
- National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture; Frontiers Science Center for Molecular Design Breeding (MOE), College of Animal Science and Technology, China Agricultural University, Beijing 100193, China
| | - Zhen Liu
- National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture; Frontiers Science Center for Molecular Design Breeding (MOE), College of Animal Science and Technology, China Agricultural University, Beijing 100193, China
| | - Wenjiao Jin
- National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture; Frontiers Science Center for Molecular Design Breeding (MOE), College of Animal Science and Technology, China Agricultural University, Beijing 100193, China
| | - Jian Yu
- National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture; Frontiers Science Center for Molecular Design Breeding (MOE), College of Animal Science and Technology, China Agricultural University, Beijing 100193, China
| | - Jianlin Han
- International Livestock Research Institute (ILRI), Nairobi 00100, Kenya
- CAAS-ILRI Joint Laboratory on Livestock and Forage Genetic Resources, Institute of Animal Science, Chinese Academy of Agriculture Sciences (CAAS), Beijing 100193, China
| | - Edward Okoth
- International Livestock Research Institute (ILRI), Nairobi 00100, Kenya
| | - Raphael Mrode
- International Livestock Research Institute (ILRI), Nairobi 00100, Kenya
| | - Jian-Feng Liu
- National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture; Frontiers Science Center for Molecular Design Breeding (MOE), College of Animal Science and Technology, China Agricultural University, Beijing 100193, China
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8
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Ramirez-Medina E, Rai A, Espinoza N, Valladares A, Silva E, Velazquez-Salinas L, Borca MV, Gladue DP. Deletion of the H240R Gene in African Swine Fever Virus Partially Reduces Virus Virulence in Swine. Viruses 2023; 15:1477. [PMID: 37515164 PMCID: PMC10384018 DOI: 10.3390/v15071477] [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: 05/15/2023] [Revised: 06/14/2023] [Accepted: 06/24/2023] [Indexed: 07/30/2023] Open
Abstract
African swine fever (ASF) is a highly contagious disease that affects wild and domestic swine. Currently, the disease is present as a pandemic affecting pork production in Eurasia and the Caribbean region. The etiological agent of ASF is a large, highly complex structural virus (ASFV) harboring a double-stranded genome encoding for more than 160 proteins whose functions, in most cases, have not been experimentally characterized. We show here that deletion of the ASFV gene H240R from the genome of the highly virulent ASFV-Georgia2010 (ASFV-G) isolate partially decreases virus virulence when experimentally inoculated in domestic swine. ASFV-G-∆H240R, a recombinant virus harboring the deletion of the H240R gene, was produced to evaluate the function of the gene in the development of disease in pigs. While all animals intramuscularly inoculated with 102 HAD50 of ASFV-G developed a fatal form of the disease, forty percent of pigs receiving a similar dose of ASFV-G-∆H240R survived the infection, remaining healthy during the 28-day observational period, and the remaining sixty percent developed a protracted but fatal form of the disease compared to that induced by ASFV-G. Additionally, all animals inoculated with ASFV-G-∆H240R presented protracted viremias with reduced virus titers when compared with those found in animals inoculated with ASFV-G. Animals surviving infection with ASFV-G-∆H240R developed a strong virus-specific antibody response and were protected against the challenge of the virulent parental ASFV-G.
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Affiliation(s)
| | - Ayushi Rai
- Plum Island Animal Disease Center, ARS, USDA, Greenport, NY 11944, USA
- Oak Ridge Institute for Science and Education, Oak Ridge, TN 37830, USA
| | - Nallely Espinoza
- Plum Island Animal Disease Center, ARS, USDA, Greenport, NY 11944, USA
| | - Alyssa Valladares
- Plum Island Animal Disease Center, ARS, USDA, Greenport, NY 11944, USA
- Oak Ridge Institute for Science and Education, Oak Ridge, TN 37830, USA
| | - Ediane Silva
- Plum Island Animal Disease Center, ARS, USDA, Greenport, NY 11944, USA
| | | | - Manuel V Borca
- Plum Island Animal Disease Center, ARS, USDA, Greenport, NY 11944, USA
| | - Douglas P Gladue
- Plum Island Animal Disease Center, ARS, USDA, Greenport, NY 11944, USA
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9
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Ramirez-Medina E, Vuono EA, Rai A, Espinoza N, Valladares A, Spinard E, Velazquez-Salinas L, Gladue DP, Borca MV. Evaluation of the Function of ASFV Gene E66L in the Process of Virus Replication and Virulence in Swine. Viruses 2023; 15:v15020566. [PMID: 36851779 PMCID: PMC9965554 DOI: 10.3390/v15020566] [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: 12/28/2022] [Revised: 02/12/2023] [Accepted: 02/13/2023] [Indexed: 02/22/2023] Open
Abstract
African swine fever virus (ASFV) is the etiological agent of an economically important disease of swine currently affecting large areas of Africa, Eurasia and the Caribbean. ASFV has a complex structure harboring a large dsDNA genome which encodes for more than 160 proteins. One of the proteins, E66L, has recently been involved in arresting gene transcription in the infected host cell. Here, we investigate the role of E66L in the processes of virus replication in swine macrophages and disease production in domestic swine. A recombinant ASFV was developed (ASFV-G-∆E66L), from the virulent parental Georgia 2010 isolate (ASFV-G), harboring the deletion of the E66L gene as a tool to assess the role of the gene. ASFV-G-∆E66L showed that the E66L gene is non-essential for ASFV replication in primary swine macrophages when compared with the parental highly virulent field isolate ASFV-G. Additionally, domestic pigs infected with ASFV-G-∆E66L developed a clinical disease undistinguishable from that produced by ASFV-G. Therefore, E66L is not involved in virus replication or virulence in domestic pigs.
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Affiliation(s)
- Elizabeth Ramirez-Medina
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA
| | - Elizabeth A. Vuono
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA
| | - Ayushi Rai
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN 37830, USA
| | - Nallely Espinoza
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA
| | - Alyssa Valladares
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN 37830, USA
| | - Edward Spinard
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA
| | - Lauro Velazquez-Salinas
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA
| | - Douglas P. Gladue
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA
- Correspondence: (D.P.G.); (M.V.B.)
| | - Manuel V. Borca
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA
- Correspondence: (D.P.G.); (M.V.B.)
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10
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Deletion of an African Swine Fever Virus ATP-Dependent RNA Helicase QP509L from the Highly Virulent Georgia 2010 Strain Does Not Affect Replication or Virulence. Viruses 2022; 14:v14112548. [PMID: 36423157 PMCID: PMC9694930 DOI: 10.3390/v14112548] [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: 09/20/2022] [Revised: 10/31/2022] [Accepted: 11/08/2022] [Indexed: 11/19/2022] Open
Abstract
African swine fever virus (ASFV) produces a lethal disease (ASF) in domestic pigs, which is currently causing a pandemic deteriorating pig production across Eurasia. ASFV is a large and structurally complex virus with a large genome harboring more than 150 genes. ASFV gene QP509L has been shown to encode for an ATP-dependent RNA helicase, which appears to be important for efficient virus replication. Here, we report the development of a recombinant virus, ASFV-G-∆QP509L, having deleted the QP509L gene in the highly virulent field isolate ASFV Georgia 2010 (ASFV-G). It is shown that ASFV-G-∆QP509L replicates in primary swine macrophage cultures as efficiently as the parental virus ASFV-G. In addition, the experimental inoculation of pigs with 102 HAD50 by the intramuscular route produced a slightly protracted but lethal clinical disease when compared to that of animals inoculated with virulent parental ASFV-G. Viremia titers in animals infected with ASFV-G-∆QP509L also had slightly protracted kinetics of presentation. Therefore, ASFV gene QP509L is not critical for the processes of virus replication in swine macrophages, nor is it clearly involved in virus replication and virulence in domestic pigs.
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11
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Ramirez-Medina E, Vuono E, Pruitt S, Rai A, Espinoza N, Valladares A, Spinard E, Silva E, Velazquez-Salinas L, Gladue DP, Borca MV. ASFV Gene A151R Is Involved in the Process of Virulence in Domestic Swine. Viruses 2022; 14:v14081834. [PMID: 36016456 PMCID: PMC9413758 DOI: 10.3390/v14081834] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 08/10/2022] [Accepted: 08/15/2022] [Indexed: 11/16/2022] Open
Abstract
African swine fever virus (ASFV) is the etiological agent of a swine pandemic affecting a large geographical area extending from Central Europe to Asia. The viral disease was also recently identified in the Dominican Republic and Haiti. ASFV is a structurally complex virus with a large dsDNA genome that encodes for more than 150 genes. Most of these genes have not been experimentally characterized. One of these genes, A151R, encodes for a nonstructural protein and has been reported to be required for the replication of a Vero-cell-adapted ASFV strain. Here, we evaluated the role of the A151R gene in the context of the highly virulent field isolate Georgia 2010 (ASFV-G) during virus replication in swine macrophage cell cultures and during experimental infection in swine. We show that the recombinant virus ASFV-G-∆A151R, harboring a deletion of the A151R gene, replicated in swine macrophage cultures as efficiently as the parental virus ASFV-G, indicating that the A151R gene is not required for ASFV replication in swine macrophages. Interestingly, experimental infection of domestic pigs demonstrated that ASFV-G-∆A151R had a decreased replication rate and produced a drastic reduction in virus virulence. Animals were intramuscularly inoculated with 102 HAD50 of ASFV-G-∆A151R and compared with pigs receiving a similar dose of virulent ASFV-G. All ASFV-G-infected pigs developed an acute lethal form of the disease, while those inoculated with ASFV-G-∆A151R remained healthy during the 28-day observational period, with the exception of only one showing a protracted, but fatal, form of the disease. All ASFV-G-∆A151R surviving animals presented protracted viremias with lower virus titers than those detected in ASFV-G-infected animals. In addition, three out of the four animals surviving the infection with ASFV-G-∆A151R were protected against the challenge with the virulent parental virus ASFV-G. This is the first report indicating that the ASFV A151R gene is involved in virus virulence in domestic swine, suggesting that its deletion may be used to increase the safety profile of currently experimental vaccines.
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Affiliation(s)
| | - Elizabeth Vuono
- Plum Island Animal Disease Center, ARS, USDA, Greenport, NY 11944, USA
- Department of Pathobiology and Population Medicine, Mississippi State University, P.O. Box 6100, Starkville, MS 39762, USA
| | - Sarah Pruitt
- Plum Island Animal Disease Center, ARS, USDA, Greenport, NY 11944, USA
| | - Ayushi Rai
- Plum Island Animal Disease Center, ARS, USDA, Greenport, NY 11944, USA
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN 37830, USA
| | - Nallely Espinoza
- Plum Island Animal Disease Center, ARS, USDA, Greenport, NY 11944, USA
| | - Alyssa Valladares
- Plum Island Animal Disease Center, ARS, USDA, Greenport, NY 11944, USA
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN 37830, USA
| | - Edward Spinard
- Plum Island Animal Disease Center, ARS, USDA, Greenport, NY 11944, USA
| | - Ediane Silva
- Plum Island Animal Disease Center, ARS, USDA, Greenport, NY 11944, USA
| | | | - Douglas P. Gladue
- Plum Island Animal Disease Center, ARS, USDA, Greenport, NY 11944, USA
- Correspondence: (D.P.G.); (M.V.B.)
| | - Manuel V. Borca
- Plum Island Animal Disease Center, ARS, USDA, Greenport, NY 11944, USA
- Correspondence: (D.P.G.); (M.V.B.)
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12
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Vuono EA, Ramirez-Medina E, Pruitt S, Rai A, Espinoza N, Spinard E, Valladares A, Silva E, Velazquez-Salinas L, Borca MV, Gladue DP. Deletion of the EP296R Gene from the Genome of Highly Virulent African Swine Fever Virus Georgia 2010 Does Not Affect Virus Replication or Virulence in Domestic Pigs. Viruses 2022; 14:1682. [PMID: 36016304 PMCID: PMC9415450 DOI: 10.3390/v14081682] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 07/22/2022] [Accepted: 07/22/2022] [Indexed: 11/29/2022] Open
Abstract
African swine fever virus (ASFV) causes a lethal disease (ASF) in domestic pigs, African swine fever (ASF). ASF is currently producing a pandemic affecting pig production across Eurasia, leading to a shortage of food accessibility. ASFV is structurally complex, harboring a large genome encoding over 150 genes. One of them, EP296R, has been shown to encode for an endonuclease that is necessary for the efficient replication of the virus in swine macrophages, the natural ASFV target cell. Here, we report the development of a recombinant virus, ASFV-G-∆EP296R, harboring the deletion of the EP296R gene from the genome of the highly virulent field isolate ASFV Georgia 2010 (ASFV-G). The recombinant ASFV-G-∆EP296R replicates in primary swine macrophages with similar kinetics as the parental virus ASFV-G. Pigs experimentally infected by the intramuscular route with 102 HAD50 show a slightly protracted, although lethal, presentation of the disease when compared to that of animals inoculated with parental ASFV-G. Viremia titers in the ASFV-G-∆EP296R-infected animals closely followed the kinetics of presentation of clinical disease. Results presented here demonstrate that ASFV-G-∆EP296R is not essential for the processes of ASFV replication in swine macrophages, nor is it radically involved in the process of virus replication or disease production in domestic pigs.
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Affiliation(s)
- Elizabeth A. Vuono
- Plum Island Animal Disease Center, ARS, USDA, Greenport, New York, NY 11944, USA; (E.A.V.); (E.R.-M.); (S.P.); (A.R.); (N.E.); (E.S.); (A.V.); (E.S.); (L.V.-S.)
- Department of Pathobiology and Population Medicine, Mississippi State University, P.O. Box 6100, Oxford, MS 39762, USA
| | - Elizabeth Ramirez-Medina
- Plum Island Animal Disease Center, ARS, USDA, Greenport, New York, NY 11944, USA; (E.A.V.); (E.R.-M.); (S.P.); (A.R.); (N.E.); (E.S.); (A.V.); (E.S.); (L.V.-S.)
| | - Sarah Pruitt
- Plum Island Animal Disease Center, ARS, USDA, Greenport, New York, NY 11944, USA; (E.A.V.); (E.R.-M.); (S.P.); (A.R.); (N.E.); (E.S.); (A.V.); (E.S.); (L.V.-S.)
| | - Ayushi Rai
- Plum Island Animal Disease Center, ARS, USDA, Greenport, New York, NY 11944, USA; (E.A.V.); (E.R.-M.); (S.P.); (A.R.); (N.E.); (E.S.); (A.V.); (E.S.); (L.V.-S.)
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN 37830, USA
| | - Nallely Espinoza
- Plum Island Animal Disease Center, ARS, USDA, Greenport, New York, NY 11944, USA; (E.A.V.); (E.R.-M.); (S.P.); (A.R.); (N.E.); (E.S.); (A.V.); (E.S.); (L.V.-S.)
| | - Edward Spinard
- Plum Island Animal Disease Center, ARS, USDA, Greenport, New York, NY 11944, USA; (E.A.V.); (E.R.-M.); (S.P.); (A.R.); (N.E.); (E.S.); (A.V.); (E.S.); (L.V.-S.)
| | - Alyssa Valladares
- Plum Island Animal Disease Center, ARS, USDA, Greenport, New York, NY 11944, USA; (E.A.V.); (E.R.-M.); (S.P.); (A.R.); (N.E.); (E.S.); (A.V.); (E.S.); (L.V.-S.)
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN 37830, USA
| | - Ediane Silva
- Plum Island Animal Disease Center, ARS, USDA, Greenport, New York, NY 11944, USA; (E.A.V.); (E.R.-M.); (S.P.); (A.R.); (N.E.); (E.S.); (A.V.); (E.S.); (L.V.-S.)
| | - Lauro Velazquez-Salinas
- Plum Island Animal Disease Center, ARS, USDA, Greenport, New York, NY 11944, USA; (E.A.V.); (E.R.-M.); (S.P.); (A.R.); (N.E.); (E.S.); (A.V.); (E.S.); (L.V.-S.)
| | - Manuel V. Borca
- Plum Island Animal Disease Center, ARS, USDA, Greenport, New York, NY 11944, USA; (E.A.V.); (E.R.-M.); (S.P.); (A.R.); (N.E.); (E.S.); (A.V.); (E.S.); (L.V.-S.)
| | - Douglas P. Gladue
- Plum Island Animal Disease Center, ARS, USDA, Greenport, New York, NY 11944, USA; (E.A.V.); (E.R.-M.); (S.P.); (A.R.); (N.E.); (E.S.); (A.V.); (E.S.); (L.V.-S.)
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13
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Xie Z, Liu Y, Di D, Liu J, Gong L, Chen Z, Li Y, Yu W, Lv L, Zhong Q, Song Y, Liao X, Song Q, Wang H, Chen H. Protection Evaluation of a Five-Gene-Deleted African Swine Fever Virus Vaccine Candidate Against Homologous Challenge. Front Microbiol 2022; 13:902932. [PMID: 35966648 PMCID: PMC9374035 DOI: 10.3389/fmicb.2022.902932] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 05/09/2022] [Indexed: 11/18/2022] Open
Abstract
African swine fever virus (ASFV) represents a serious threat to the global swine industry, and there are no safe or commercially available vaccines. Previous studies have demonstrated that inactivated vaccines do not provide sufficient protection against ASFV and that attenuated vaccines are effective, but raise safety concerns. Here, we first constructed a deletion mutant in which EP153R and EP402R gene clusters were knocked out. Based on the deletion mutant, a further deletion from the MGF_360-12L, MGF_360-13L to MGF_360-14L genes was obtained. The five-genes knockout virus was designated as ASFV-ΔECM3. To investigate the efficacy and safety of the ASFV-ΔECM3 virus as a vaccine candidate, the evaluation of the virus was subsequently carried out in pigs. The results showed that the ASFV-ΔECM3 virus could induce homologous protection against the parental isolate, and no significant clinical signs or viremia were observed. These results show that the contiguous deletion mutant, ASFV-ΔECM3 encompassing the EP153R/EP402R and MGF_360-12L/13L/14L genes, could be a potential live-attenuated vaccine candidate for the prevention of ASFV infection.
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Affiliation(s)
- Zhenhua Xie
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
- Biosafety Research Center, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Yingnan Liu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
- Biosafety Research Center, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Dongdong Di
- The Spirit Jinyu Biological Pharmaceutical Co., Ltd., Hohhot, China
| | - Jingyi Liu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
- Biosafety Research Center, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Lang Gong
- Guangdong Provincial Key Laboratory of Prevention and Control for Severe Clinical Animal Diseases, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Zongyan Chen
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
- Biosafety Research Center, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Yao Li
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
- Biosafety Research Center, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Wanqi Yu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
- Biosafety Research Center, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Lu Lv
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
- Biosafety Research Center, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Qiuping Zhong
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
- Biosafety Research Center, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Yingying Song
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
- Biosafety Research Center, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Xinxin Liao
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
- Biosafety Research Center, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Qingqing Song
- The Spirit Jinyu Biological Pharmaceutical Co., Ltd., Hohhot, China
| | - Heng Wang
- Guangdong Provincial Key Laboratory of Prevention and Control for Severe Clinical Animal Diseases, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- *Correspondence: Heng Wang
| | - Hongjun Chen
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
- Biosafety Research Center, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
- Hongjun Chen
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14
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Evaluation of the Deletion of MGF110-5L-6L on Swine Virulence from the Pandemic Strain of African Swine Fever Virus and Use as a DIVA Marker in Vaccine Candidate ASFV-G-ΔI177L. J Virol 2022; 96:e0059722. [PMID: 35862688 PMCID: PMC9327674 DOI: 10.1128/jvi.00597-22] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
African swine fever virus (ASFV) is responsible for an ongoing pandemic that is affecting central Europe, Asia, and recently the Dominican Republic, the first report of the disease in the Western Hemisphere in over 40 years. ASFV is a large, complex virus with a double-stranded DNA (dsDNA) genome that carries more than 150 genes, most of which have not been studied. Here, we assessed the role of the MGF110-5L-6L gene during virus replication in cell cultures and experimental infection in swine. A recombinant virus with MGF110-5L-6L deleted (ASFV-G-ΔMGF110-5L-6L) was developed using the highly virulent ASFV Georgia (ASFV-G) isolate as a template. ASFV-G-ΔMGF110-5L-6L replicates in swine macrophage cultures as efficiently as the parental virus ASFV-G, indicating that the MGF110-5L-6L gene is nonessential for virus replication. Similarly, domestic pigs inoculated with ASFV-G-ΔMGF110-5L-6L presented with a clinical disease undistinguishable from that caused by the parental ASFV-G, confirming that the MGF110-5L-6L gene is not involved in producing disease in swine. Sera from animals inoculated with an efficacious vaccine candidate, ASFV-G-ΔMGF, strongly recognized the protein encoded by the MGF110-5L-6L gene as a potential target for the development of an antigenic marker differentiation of infected from vaccinated animals (DIVA) vaccine. To test this hypothesis, the MGF110-5L-6L gene was deleted from the highly efficacious ASFV vaccine candidate ASFV-G-ΔI177L, generating the recombinant ASFV-G-ΔI177L/ΔMGF110-5L-6L. Animals inoculated with ASFV-G-ΔI177L/ΔMGF110-5L-6L developed an ASFV-specific antibody response detected by enzyme-linked immunosorbent assay (ELISA). The sera strongly recognized ASFV p30 expressed in eukaryotic cells but did not recognize ASFV MGF110-5L-6L protein, demonstrating that deletion of the MGF110-5L-6L gene can enable DIVA capabilities in preexisting vaccine candidates. IMPORTANCE Currently, there are no African swine fever (ASF) commercial vaccines that can be used to prevent or control the spread of ASF. The only effective experimental vaccines against ASF are live-attenuated vaccines. However, these experimental vaccines, which rely on a deletion of a specific gene of the current circulating strain of ASF, make it hard to tell the difference between a vaccinated and an infected animal. In our search for a serological marker, we identified that the virus protein encoded by the MGF110-5L-6L gene induced an immune response, making a virus lacking this gene a vaccine candidate that allows the differentiation of infected from vaccinated animals (DIVA). Here, we show that deletion of MGF110-5L-6L does not affect virulence or virus replication. However, when the deletion of MGF110-5L-6L was added to vaccine candidate ASFV-G-ΔI177L, a reduction in the effectiveness of the vaccine occurred.
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Deletion of the H108R Gene Reduces Virulence of the Pandemic Eurasia Strain of African Swine Fever Virus with Surviving Animals Being Protected against Virulent Challenge. J Virol 2022; 96:e0054522. [DOI: 10.1128/jvi.00545-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Currently, there is no commercial vaccine available to prevent ASF. ASFV-Georgia2007 (ASFV-G) and its field isolate derivatives are producing a large pandemic which is drastically affecting pork production in Eurasia.
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Vuono EA, Ramirez-Medina E, Pruitt S, Rai A, Espinoza N, Silva E, Velazquez-Salinas L, Gladue DP, Borca MV. Deletion of the ASFV dUTPase Gene E165R from the Genome of Highly Virulent African Swine Fever Virus Georgia 2010 Does Not Affect Virus Replication or Virulence in Domestic Pigs. Viruses 2022; 14:v14071409. [PMID: 35891389 PMCID: PMC9320246 DOI: 10.3390/v14071409] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 06/21/2022] [Accepted: 06/24/2022] [Indexed: 02/05/2023] Open
Abstract
African swine fever (ASF) is a frequently lethal disease of domestic and wild swine currently producing a pandemic affecting pig production in Eurasia. The causative agent, ASF virus (ASFV) is a structurally complex virus with a large genome harboring over 150 genes. One of them, E165R, encodes for a protein belonging to the dUTPase family. The fine structure of the purified protein has been recently analyzed and its dUTPase activity tested. In addition, it has been reported that a BA71 mutant virus, adapted to growth in Vero cells, lacking the E165R gene presented a drastic decreased replication in swine macrophages, its natural target cell. Herein, we report the development of a recombinant virus, ASFV-G-∆E165R, harboring the deletion of the E165R gene from the genome of the highly virulent field isolate ASFV Georgia 2010 (ASFV-G). Interestingly, ASFV-G-∆E165R replicates in primary swine macrophage cultures as efficiently as the parental virus ASFV-G. In addition, ASFV-G-∆E165R also replicates in experimentally inoculated domestic pigs with equal efficacy as ASFV-G and produced a lethal disease almost indistinguishable from that induced by the parental virus. Therefore, results presented here clearly demonstrated that E165R gene is not essential or important for ASFV replication in swine macrophages nor disease production in domestic pigs.
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Affiliation(s)
- Elizabeth A. Vuono
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA; (E.A.V.); (E.R.-M.); (S.P.); (A.R.); (N.E.); (E.S.); (L.V.-S.)
- Department of Pathobiology and Population Medicine, Mississippi State University, Starkville, MS 39762, USA
| | - Elizabeth Ramirez-Medina
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA; (E.A.V.); (E.R.-M.); (S.P.); (A.R.); (N.E.); (E.S.); (L.V.-S.)
| | - Sarah Pruitt
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA; (E.A.V.); (E.R.-M.); (S.P.); (A.R.); (N.E.); (E.S.); (L.V.-S.)
| | - Ayushi Rai
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA; (E.A.V.); (E.R.-M.); (S.P.); (A.R.); (N.E.); (E.S.); (L.V.-S.)
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN 37830, USA
| | - Nallely Espinoza
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA; (E.A.V.); (E.R.-M.); (S.P.); (A.R.); (N.E.); (E.S.); (L.V.-S.)
| | - Ediane Silva
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA; (E.A.V.); (E.R.-M.); (S.P.); (A.R.); (N.E.); (E.S.); (L.V.-S.)
| | - Lauro Velazquez-Salinas
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA; (E.A.V.); (E.R.-M.); (S.P.); (A.R.); (N.E.); (E.S.); (L.V.-S.)
| | - Douglas P. Gladue
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA; (E.A.V.); (E.R.-M.); (S.P.); (A.R.); (N.E.); (E.S.); (L.V.-S.)
- Correspondence: (D.P.G.); (M.V.B.)
| | - Manuel V. Borca
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA; (E.A.V.); (E.R.-M.); (S.P.); (A.R.); (N.E.); (E.S.); (L.V.-S.)
- Correspondence: (D.P.G.); (M.V.B.)
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Huang Z, Xu Z, Cao H, Zeng F, Wang H, Gong L, Zhang S, Cao S, Zhang G, Zheng Z. A Triplex PCR Method for Distinguishing the Wild-Type African Swine Fever Virus From the Deletion Strains by Detecting the Gene Insertion. Front Vet Sci 2022; 9:921907. [PMID: 35836498 PMCID: PMC9274085 DOI: 10.3389/fvets.2022.921907] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Accepted: 06/03/2022] [Indexed: 11/23/2022] Open
Abstract
To date, there is no effective vaccine or antiviral therapy available to prevent or treat African swine fever virus (ASFV) infections. ASFV gene deletion strains have been proposed as promising anti-ASFV vaccine candidates. In recent years, most ASFV gene deletion strains worldwide have been recombinant strains expressing EGFP or mCherry as markers. Therefore, in this study, a new triplex real-time PCR (RT-PCR) method was established for the broad and accurate differentiation of ASFV wild-type vs. gene deletion strains. We designed three pairs of primers and probes to target B646L, EGFP, and mCherry, and RT-PCR was used to detect these three genes simultaneously. The detection method prevented non-specific amplification of porcine reproductive and respiratory syndrome virus, porcine epidemic diarrhea virus, circovirus type 2, pseudorabies virus, and classical swine fever virus genes. The minimum copy number of standard plasmid DNA detected using triplex RT-PCR was 9.49, 15.60, and 9.60 copies for B646L, EGFP, and mCherry, respectively. Importantly, of the 1646 samples analyzed in this study, 67 were positive for ASFV, all corresponding to the wild-type virus. Overall, our data show that the triplex RT-PCR method established in this study can specifically identify both ASFV wild-type and gene deletion strains.
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Affiliation(s)
- Zhao Huang
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- African Swine Fever Regional Laboratory of China, Guangzhou, China
| | - Zhiying Xu
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- African Swine Fever Regional Laboratory of China, Guangzhou, China
| | - Haoxuan Cao
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- African Swine Fever Regional Laboratory of China, Guangzhou, China
| | - Fanliang Zeng
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- African Swine Fever Regional Laboratory of China, Guangzhou, China
| | - Heng Wang
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- African Swine Fever Regional Laboratory of China, Guangzhou, China
- Research Center for African Swine Fever Prevention and Control, South China Agricultural University, Guangzhou, China
| | - Lang Gong
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- African Swine Fever Regional Laboratory of China, Guangzhou, China
| | | | - Sen Cao
- Haifeng Animal Disease Prevention and Control Center, Shanwei, China
| | - Guihong Zhang
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Research Center for African Swine Fever Prevention and Control, South China Agricultural University, Guangzhou, China
- Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong, China
- Key Laboratory of Animal Vaccine Development, Ministry of Agriculture and Rural Affairs, Guangzhou, China
- Guihong Zhang
| | - Zezhong Zheng
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Research Center for African Swine Fever Prevention and Control, South China Agricultural University, Guangzhou, China
- *Correspondence: Zezhong Zheng
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18
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Canter JA, Aponte T, Ramirez-Medina E, Pruitt S, Gladue DP, Borca MV, Zhu JJ. Serum Neutralizing and Enhancing Effects on African Swine Fever Virus Infectivity in Adherent Pig PBMC. Viruses 2022; 14:v14061249. [PMID: 35746720 PMCID: PMC9229155 DOI: 10.3390/v14061249] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 06/03/2022] [Accepted: 06/07/2022] [Indexed: 12/28/2022] Open
Abstract
African swine fever virus (ASFV) causes hemorrhagic fever with mortality rates of up to 100% in domestic pigs. Currently, there are no commercial vaccines for the disease. Only some live-attenuated viruses have been able to protect pigs from ASFV infection. The immune mechanisms involved in the protection are unclear. Immune sera can neutralize ASFV but incompletely. The mechanisms involved are not fully understood. Currently, there is no standardized protocol for ASFV neutralization assays. In this study, a flow cytometry-based ASFV neutralization assay was developed and tested in pig adherent PBMC using a virulent ASFV containing a fluorescent protein gene as a substrate for neutralization. As with previous studies, the percentage of infected macrophages was approximately five time higher than that of infected monocytes, and nearly all infected cells displayed no staining with anti-CD16 antibodies. Sera from naïve pigs and pigs immunized with a live-attenuated ASFV and fully protected against parental virus were used in the assay. The sera displayed incomplete neutralization with MOI-dependent neutralizing efficacies. Extracellular, but not intracellular, virions suspended in naïve serum were more infectious than those in the culture medium, as reported for some enveloped viruses, suggesting a novel mechanism of ASFV infection in macrophages. Both the intracellular and extracellular virions could not be completely neutralized.
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Affiliation(s)
- Jessica A. Canter
- Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Orient, NY 11957, USA; (J.A.C.); (T.A.); (E.R.-M.); (S.P.)
- Plum Island Animal Disease Center, Oak Ridge Institute for Science and Education, Oak Ridge, TN 37830, USA
| | - Theresa Aponte
- Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Orient, NY 11957, USA; (J.A.C.); (T.A.); (E.R.-M.); (S.P.)
- Plum Island Animal Disease Center, Oak Ridge Institute for Science and Education, Oak Ridge, TN 37830, USA
| | - Elizabeth Ramirez-Medina
- Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Orient, NY 11957, USA; (J.A.C.); (T.A.); (E.R.-M.); (S.P.)
| | - Sarah Pruitt
- Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Orient, NY 11957, USA; (J.A.C.); (T.A.); (E.R.-M.); (S.P.)
| | - Douglas P. Gladue
- Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Orient, NY 11957, USA; (J.A.C.); (T.A.); (E.R.-M.); (S.P.)
- Correspondence: (D.P.G.); (M.V.B.); (J.J.Z.); Tel.: +1-631-323-3131 (D.P.G.); +1-631-323-3035 (M.V.B.); +1-631-323-3186 (J.J.Z.)
| | - Manuel V. Borca
- Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Orient, NY 11957, USA; (J.A.C.); (T.A.); (E.R.-M.); (S.P.)
- Correspondence: (D.P.G.); (M.V.B.); (J.J.Z.); Tel.: +1-631-323-3131 (D.P.G.); +1-631-323-3035 (M.V.B.); +1-631-323-3186 (J.J.Z.)
| | - James J. Zhu
- Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Orient, NY 11957, USA; (J.A.C.); (T.A.); (E.R.-M.); (S.P.)
- Correspondence: (D.P.G.); (M.V.B.); (J.J.Z.); Tel.: +1-631-323-3131 (D.P.G.); +1-631-323-3035 (M.V.B.); +1-631-323-3186 (J.J.Z.)
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19
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Ramirez-Medina E, Vuono EA, Pruitt S, Rai A, Espinoza N, Valladares A, Silva E, Velazquez-Salinas L, Borca MV, Gladue DP. Deletion of African Swine Fever Virus Histone-like Protein, A104R from the Georgia Isolate Drastically Reduces Virus Virulence in Domestic Pigs. Viruses 2022; 14:v14051112. [PMID: 35632853 PMCID: PMC9146580 DOI: 10.3390/v14051112] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 05/10/2022] [Accepted: 05/17/2022] [Indexed: 02/06/2023] Open
Abstract
African swine fever virus (ASFV) is the etiological agent of a frequently lethal disease, ASF, affecting domestic and wild swine. Currently, ASF is causing a pandemic affecting pig production in Eurasia. There are no vaccines available, and therefore control of the disease is based on culling infected animals. We report here that deletion of the ASFV gene A104R, a virus histone-like protein, from the genome of the highly virulent ASFV-Georgia2010 (ASFV-G) strain induces a clear decrease in virus virulence when experimentally inoculated in domestic swine. A recombinant virus lacking the A104R gene, ASFV-G-∆A104R, was developed to assess the role of the A104R gene in disease production in swine. Domestic pigs were intramuscularly inoculated with 102 HAD50 of ASFV-G-∆A104R, and compared with animals that received a similar dose of virulent ASFV-G. While all ASFV-G inoculated animals developed a fatal form of the disease, animals receiving ASFV-G-∆A104R survived the challenge, remaining healthy during the 28-day observational period, with the exception of only one showing a protracted but fatal form of the disease. ASFV-G-∆A104R surviving animals presented protracted viremias with reduced virus titers when compared with those found in animals inoculated with ASFV-G, and all of them developed a strong virus-specific antibody response. This is the first report demonstrating that the A104R gene is involved in ASFV virulence in domestic swine, suggesting that A104R deletion may be used to increase the safety profile of currently experimental vaccines.
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Affiliation(s)
- Elizabeth Ramirez-Medina
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture Greenport, Greenport, NY 11944, USA; (E.R.-M.); (E.A.V.); (S.P.); (A.R.); (N.E.); (A.V.); (E.S.); (L.V.-S.)
| | - Elizabeth A. Vuono
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture Greenport, Greenport, NY 11944, USA; (E.R.-M.); (E.A.V.); (S.P.); (A.R.); (N.E.); (A.V.); (E.S.); (L.V.-S.)
- Department of Pathobiology and Population Medicine, Mississippi State University, P.O. Box 6100, Starkville, MS 39762, USA
| | - Sarah Pruitt
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture Greenport, Greenport, NY 11944, USA; (E.R.-M.); (E.A.V.); (S.P.); (A.R.); (N.E.); (A.V.); (E.S.); (L.V.-S.)
| | - Ayushi Rai
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture Greenport, Greenport, NY 11944, USA; (E.R.-M.); (E.A.V.); (S.P.); (A.R.); (N.E.); (A.V.); (E.S.); (L.V.-S.)
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN 37830, USA
| | - Nallely Espinoza
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture Greenport, Greenport, NY 11944, USA; (E.R.-M.); (E.A.V.); (S.P.); (A.R.); (N.E.); (A.V.); (E.S.); (L.V.-S.)
| | - Alyssa Valladares
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture Greenport, Greenport, NY 11944, USA; (E.R.-M.); (E.A.V.); (S.P.); (A.R.); (N.E.); (A.V.); (E.S.); (L.V.-S.)
- College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA
| | - Ediane Silva
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture Greenport, Greenport, NY 11944, USA; (E.R.-M.); (E.A.V.); (S.P.); (A.R.); (N.E.); (A.V.); (E.S.); (L.V.-S.)
| | - Lauro Velazquez-Salinas
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture Greenport, Greenport, NY 11944, USA; (E.R.-M.); (E.A.V.); (S.P.); (A.R.); (N.E.); (A.V.); (E.S.); (L.V.-S.)
| | - Manuel V. Borca
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture Greenport, Greenport, NY 11944, USA; (E.R.-M.); (E.A.V.); (S.P.); (A.R.); (N.E.); (A.V.); (E.S.); (L.V.-S.)
- Correspondence: (M.V.B.); (D.P.G.)
| | - Douglas P. Gladue
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture Greenport, Greenport, NY 11944, USA; (E.R.-M.); (E.A.V.); (S.P.); (A.R.); (N.E.); (A.V.); (E.S.); (L.V.-S.)
- Correspondence: (M.V.B.); (D.P.G.)
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20
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Tran XH, Phuong LTT, Huy NQ, Thuy DT, Nguyen VD, Quang PH, Ngôn QV, Rai A, Gay CG, Gladue DP, Borca MV. Evaluation of the Safety Profile of the ASFV Vaccine Candidate ASFV-G-ΔI177L. Viruses 2022; 14:v14050896. [PMID: 35632638 PMCID: PMC9147362 DOI: 10.3390/v14050896] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Revised: 04/20/2022] [Accepted: 04/20/2022] [Indexed: 01/09/2023] Open
Abstract
African swine fever (ASF) is the cause of a recent pandemic that is posing a threat to much of the world swine production. The etiological agent, ASF virus (ASFV), infects domestic and wild swine, producing a variety of clinical presentations depending on the virus strain and the genetic background of the pigs infected. No commercial vaccine is currently available, although recombinant live attenuated vaccine candidates have been shown to be efficacious. In addition to determining efficacy, it is paramount to evaluate the safety profile of a live attenuated vaccine. The presence of residual virulence and the possibility of reversion to virulence are two of the concerns that must be evaluated in the development of live attenuated vaccines. Here we evaluate the safety profile of an efficacious live attenuated vaccine candidate, ASFV-G-ΔI177L. Results from safety studies showed that ASFV-G-ΔI177L remains genetically stable and phenotypically attenuated during a five-passage reversion to virulence study in domestic swine. In addition, large-scale experiments to detect virus shedding and transmission confirmed that even under varying conditions, ASFV-G-ΔI177L is a safe live attenuated vaccine.
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Affiliation(s)
- Xuan Hanh Tran
- National Veterinary Joint Stock Company (NAVETCO), Ho Chi Minh City 70000, Vietnam; (L.T.T.P.); (N.Q.H.); (D.T.T.); (N.V.D.); (P.H.Q.); (Q.V.N.)
- Correspondence: (X.H.T.); (D.P.G.); (M.V.B.)
| | - Le Thi Thu Phuong
- National Veterinary Joint Stock Company (NAVETCO), Ho Chi Minh City 70000, Vietnam; (L.T.T.P.); (N.Q.H.); (D.T.T.); (N.V.D.); (P.H.Q.); (Q.V.N.)
| | - Nguyen Quang Huy
- National Veterinary Joint Stock Company (NAVETCO), Ho Chi Minh City 70000, Vietnam; (L.T.T.P.); (N.Q.H.); (D.T.T.); (N.V.D.); (P.H.Q.); (Q.V.N.)
| | - Do Thanh Thuy
- National Veterinary Joint Stock Company (NAVETCO), Ho Chi Minh City 70000, Vietnam; (L.T.T.P.); (N.Q.H.); (D.T.T.); (N.V.D.); (P.H.Q.); (Q.V.N.)
| | - Van Dung Nguyen
- National Veterinary Joint Stock Company (NAVETCO), Ho Chi Minh City 70000, Vietnam; (L.T.T.P.); (N.Q.H.); (D.T.T.); (N.V.D.); (P.H.Q.); (Q.V.N.)
| | - Pham Hào Quang
- National Veterinary Joint Stock Company (NAVETCO), Ho Chi Minh City 70000, Vietnam; (L.T.T.P.); (N.Q.H.); (D.T.T.); (N.V.D.); (P.H.Q.); (Q.V.N.)
| | - Quách Võ Ngôn
- National Veterinary Joint Stock Company (NAVETCO), Ho Chi Minh City 70000, Vietnam; (L.T.T.P.); (N.Q.H.); (D.T.T.); (N.V.D.); (P.H.Q.); (Q.V.N.)
| | - Ayushi Rai
- Plum Island Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Greenport, NY 11944, USA;
| | - Cyril G. Gay
- Agricultural Research Service, U.S. Department of Agriculture, Beltsville, MD 20705, USA;
| | - Douglas Paul Gladue
- Plum Island Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Greenport, NY 11944, USA;
- Correspondence: (X.H.T.); (D.P.G.); (M.V.B.)
| | - Manuel Victor Borca
- Plum Island Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Greenport, NY 11944, USA;
- Correspondence: (X.H.T.); (D.P.G.); (M.V.B.)
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21
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Gladue DP, Borca MV. Recombinant ASF Live Attenuated Virus Strains as Experimental Vaccine Candidates. Viruses 2022; 14:v14050878. [PMID: 35632620 PMCID: PMC9146452 DOI: 10.3390/v14050878] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 04/17/2022] [Accepted: 04/21/2022] [Indexed: 11/16/2022] Open
Abstract
African swine fever (ASF) is causing a pandemic affecting swine in a large geographical area of the Eastern Hemisphere, from Central Europe to East and Southeast Asia, and recently in the Americas, the Dominican Republic and Haiti. The etiological agent, ASF virus (ASFV), infects both domestic and wild swine and produces a variety of clinical presentations depending on the virus strain and the genetics of the pigs infected. No commercial vaccines are currently available, although experimental recombinant live attenuated vaccine candidates have been shown to be efficacious in protecting animals against disease when challenged with homologous virulent strains. This review attempts to systematically provide an overview of all the live attenuated strains that have been shown to be experimental vaccine candidates. Moreover, it aims to analyze the development of these vaccine candidates, obtained by deleting specific genes or group of genes, and their efficacy in preventing virus infection and clinical disease after being challenged with virulent isolates. This report summarizes all the experimental vaccine strains that have shown promise against the contemporary pandemic strain of African swine fever.
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Differential Effect of Deleting Members of African Swine Fever Virus Multigene Families 360 and 505 from the Genotype II Georgia 2007/1 Isolate on Virus Replication, Virulence, and Induction of Protection. J Virol 2022; 96:e0189921. [PMID: 35044212 PMCID: PMC8941908 DOI: 10.1128/jvi.01899-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
African swine fever virus multigene family (MGF) 360 and 505 genes have roles in suppressing the type I interferon response and in virulence in pigs. The role of the individual genes is poorly understood. Different combinations of these genes were deleted from the virulent genotype II Georgia 2007/1 isolate. Deletion of five copies of MGF 360 genes, MGF360-10L, -11L, -12L, -13L, and -14L, and three copies of MGF505-1R, -2R, and -3R reduced virus replication in macrophages and attenuated virus in pigs. However, only 25% of the immunized pigs were protected against challenge. Deletion of MGF360-12L, -13L, and -14L and MGF505-1R in combination with a negative serology marker, K145R (GeorgiaΔK145RΔMGF(A)), reduced virus replication in macrophages and virulence in pigs, since no clinical signs or virus genome in blood were observed following immunization. Four of six pigs were protected after challenge. In contrast, deletion of MGF360-13L and -14L, MGF505-2R and -3R, and K145R (GeorgiaΔK145RΔMGF(B)) did not reduce virus replication in macrophages. Following immunization of pigs, clinical signs were delayed, but all pigs reached the humane endpoint. Deletion of genes MGF360-12L, MGF505-1R, and K145R reduced replication in macrophages and attenuated virulence in pigs since no clinical signs or virus genome in blood were observed following immunization. Thus, the deletion of MGF360-12L and MGF505-1R, in combination with K145R, was sufficient to dramatically attenuate virus infection in pigs. However, only two of six pigs were protected, suggesting that deletion of additional MGF genes is required to induce a protective immune response. Deletion of MGF360-12L, but not MGF505-1R, from the GeorgiaΔK145R virus reduced virus replication in macrophages, indicating that MGF360-12L was most critical for maintaining high levels of virus replication in macrophages. IMPORTANCE African swine fever has a high socioeconomic impact and no vaccines to aid control. The African swine fever virus (ASFV) has many genes that inhibit the host's interferon response. These include related genes that are grouped into multigene families, including MGF360 and 505. Here, we investigated which MGF360 and 505 genes were most important for viral attenuation and protection against genotype II strains circulating in Europe and Asia. We compared viruses with deletions of MGF genes. Deletion of just two MGF genes in combination with a third gene, K145R, a possible marker for vaccination, is sufficient for virus attenuation in pigs. Deletion of additional MGF360 genes was required to induce higher levels of protection. Furthermore, we showed that the deletion of MGF360-12L, combined with K145R, impairs virus replication in macrophages in culture. Our results have important implications for understanding the roles of the ASFV MGF genes and for vaccine development.
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Wang Y, Cui S, Xin T, Wang X, Yu H, Chen S, Jiang Y, Gao X, Jiang Y, Guo X, Jia H, Zhu H. African Swine Fever Virus MGF360-14L Negatively Regulates Type I Interferon Signaling by Targeting IRF3. Front Cell Infect Microbiol 2022; 11:818969. [PMID: 35096660 PMCID: PMC8790226 DOI: 10.3389/fcimb.2021.818969] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Accepted: 12/22/2021] [Indexed: 12/16/2022] Open
Abstract
African swine fever (ASF) is a devastating infectious disease caused by African swine fever virus (ASFV). The ASFV genome encodes multiple structural and non-structural proteins that contribute to evasion of host immunity. In this study, we determined that the viral non-structural protein MGF360-14L inhibits interferon-β (IFN-β) promoter activity induced by cGAS-STING signaling. MGF360-14L was also found to downregulate expression of the IRF3 protein and promote its degradation through ubiquitin-meditated proteolysis. Moreover, MGF360-14L was shown to interact with and destabilize IRF3 by facilitating E3 ligase TRIM21-mediated K63-linked ubiquitination of IRF3. Overall, our study revealed that MGF360-14L promotes degradation of IRF3 through TRIM21, thereby inhibiting type I interferon production. These findings provide new insights into the mechanisms underlying ASFV immune evasion.
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Affiliation(s)
- Yang Wang
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Shuai Cui
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Ting Xin
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xixi Wang
- Institute of Microbiology, Chinese Academy of Sciences (CAS), Beijing, China
| | - Hainan Yu
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Shiyu Chen
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yajun Jiang
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xintao Gao
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Beijing, China
| | - Yitong Jiang
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xiaoyu Guo
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Hong Jia
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Hongfei Zhu
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
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24
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Rathakrishnan A, Reis AL, Moffat K, Dixon LK. Isolation of Porcine Bone Marrow Cells and Generation of Recombinant African Swine Fever Viruses. Methods Mol Biol 2022; 2503:73-94. [PMID: 35575887 DOI: 10.1007/978-1-0716-2333-6_5] [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] [Indexed: 06/15/2023]
Abstract
Genetic manipulation of ASFV has been increasingly used not only for the development of live attenuated vaccines but also as an indispensable tool to further our understanding of the virus-host interactions. Here we present methods for isolation of porcine bone marrow cells and purification of recombinant ASFV using both chromogenic and fluorescent reporters. We also describe in detail a newly developed method to purify genetically modified ASFV using fluorescence-activated cell sorting (FACS).
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Affiliation(s)
| | | | - Katy Moffat
- The Pirbright Institute, Pirbright, Woking, UK
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25
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Zhang Y, Ke J, Zhang J, Yue H, Chen T, Li Q, Zhou X, Qi Y, Zhu R, Wang S, Miao F, Zhang S, Li N, Mi L, Yang J, Yang J, Han X, Wang L, Li Y, Hu R. I267L Is Neither the Virulence- Nor the Replication-Related Gene of African Swine Fever Virus and Its Deletant Is an Ideal Fluorescent-Tagged Virulence Strain. Viruses 2021; 14:v14010053. [PMID: 35062257 PMCID: PMC8777747 DOI: 10.3390/v14010053] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 12/22/2021] [Accepted: 12/27/2021] [Indexed: 12/29/2022] Open
Abstract
African swine fever virus (ASFV) is the causative agent of African swine fever (ASF) which reaches up to 100% case fatality in domestic pigs and wild boar and causes significant economic losses in the swine industry. Lack of knowledge of the function of ASFV genes is a serious impediment to the development of the safe and effective vaccine. Herein, I267L was identified as a relative conserved gene and an early expressed gene. A recombinant virus (SY18ΔI267L) with I267L gene deletion was produced by replacing I267L of the virulent ASFV SY18 with enhanced green fluorescent protein (EGFP) cassette. The replication kinetics of SY18ΔI267L is similar to that of the parental isolate in vitro. Moreover, the doses of 102.0 TCID50 (n = 5) and 105.0 TCID50 (n = 5) SY18ΔI267L caused virulent phenotype, severe clinical signs, viremia, high viral load, and mortality in domestic pigs inoculated intramuscularly as the virulent parental virus strain. Therefore, the deletion of I267L does not affect the replication or the virulence of ASFV. Utilizing the fluorescent-tagged virulence deletant can be easy to gain a visual result in related research such as the inactivation effect of some drugs, disinfectants, extracts, etc. on ASFV.
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Affiliation(s)
- Yanyan Zhang
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China; (Y.Z.); (J.Z.); (H.Y.); (T.C.); (Q.L.); (X.Z.); (Y.Q.); (R.Z.); (S.W.); (F.M.); (S.Z.); (N.L.); (L.M.); (J.Y.); (X.H.); (L.W.)
| | - Junnan Ke
- College of Animal Science and Technology, College of Veterinary Medicine, Jilin Agricultural University, Changchun 130118, China; (J.K.); (J.Y.)
| | - Jingyuan Zhang
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China; (Y.Z.); (J.Z.); (H.Y.); (T.C.); (Q.L.); (X.Z.); (Y.Q.); (R.Z.); (S.W.); (F.M.); (S.Z.); (N.L.); (L.M.); (J.Y.); (X.H.); (L.W.)
| | - Huixian Yue
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China; (Y.Z.); (J.Z.); (H.Y.); (T.C.); (Q.L.); (X.Z.); (Y.Q.); (R.Z.); (S.W.); (F.M.); (S.Z.); (N.L.); (L.M.); (J.Y.); (X.H.); (L.W.)
| | - Teng Chen
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China; (Y.Z.); (J.Z.); (H.Y.); (T.C.); (Q.L.); (X.Z.); (Y.Q.); (R.Z.); (S.W.); (F.M.); (S.Z.); (N.L.); (L.M.); (J.Y.); (X.H.); (L.W.)
| | - Qian Li
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China; (Y.Z.); (J.Z.); (H.Y.); (T.C.); (Q.L.); (X.Z.); (Y.Q.); (R.Z.); (S.W.); (F.M.); (S.Z.); (N.L.); (L.M.); (J.Y.); (X.H.); (L.W.)
| | - Xintao Zhou
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China; (Y.Z.); (J.Z.); (H.Y.); (T.C.); (Q.L.); (X.Z.); (Y.Q.); (R.Z.); (S.W.); (F.M.); (S.Z.); (N.L.); (L.M.); (J.Y.); (X.H.); (L.W.)
| | - Yu Qi
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China; (Y.Z.); (J.Z.); (H.Y.); (T.C.); (Q.L.); (X.Z.); (Y.Q.); (R.Z.); (S.W.); (F.M.); (S.Z.); (N.L.); (L.M.); (J.Y.); (X.H.); (L.W.)
| | - Rongnian Zhu
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China; (Y.Z.); (J.Z.); (H.Y.); (T.C.); (Q.L.); (X.Z.); (Y.Q.); (R.Z.); (S.W.); (F.M.); (S.Z.); (N.L.); (L.M.); (J.Y.); (X.H.); (L.W.)
| | - Shuchao Wang
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China; (Y.Z.); (J.Z.); (H.Y.); (T.C.); (Q.L.); (X.Z.); (Y.Q.); (R.Z.); (S.W.); (F.M.); (S.Z.); (N.L.); (L.M.); (J.Y.); (X.H.); (L.W.)
| | - Faming Miao
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China; (Y.Z.); (J.Z.); (H.Y.); (T.C.); (Q.L.); (X.Z.); (Y.Q.); (R.Z.); (S.W.); (F.M.); (S.Z.); (N.L.); (L.M.); (J.Y.); (X.H.); (L.W.)
| | - Shoufeng Zhang
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China; (Y.Z.); (J.Z.); (H.Y.); (T.C.); (Q.L.); (X.Z.); (Y.Q.); (R.Z.); (S.W.); (F.M.); (S.Z.); (N.L.); (L.M.); (J.Y.); (X.H.); (L.W.)
| | - Nan Li
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China; (Y.Z.); (J.Z.); (H.Y.); (T.C.); (Q.L.); (X.Z.); (Y.Q.); (R.Z.); (S.W.); (F.M.); (S.Z.); (N.L.); (L.M.); (J.Y.); (X.H.); (L.W.)
| | - Lijuan Mi
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China; (Y.Z.); (J.Z.); (H.Y.); (T.C.); (Q.L.); (X.Z.); (Y.Q.); (R.Z.); (S.W.); (F.M.); (S.Z.); (N.L.); (L.M.); (J.Y.); (X.H.); (L.W.)
| | - Jinjin Yang
- College of Animal Science and Technology, College of Veterinary Medicine, Jilin Agricultural University, Changchun 130118, China; (J.K.); (J.Y.)
| | - Jinmei Yang
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China; (Y.Z.); (J.Z.); (H.Y.); (T.C.); (Q.L.); (X.Z.); (Y.Q.); (R.Z.); (S.W.); (F.M.); (S.Z.); (N.L.); (L.M.); (J.Y.); (X.H.); (L.W.)
| | - Xun Han
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China; (Y.Z.); (J.Z.); (H.Y.); (T.C.); (Q.L.); (X.Z.); (Y.Q.); (R.Z.); (S.W.); (F.M.); (S.Z.); (N.L.); (L.M.); (J.Y.); (X.H.); (L.W.)
| | - Lidong Wang
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China; (Y.Z.); (J.Z.); (H.Y.); (T.C.); (Q.L.); (X.Z.); (Y.Q.); (R.Z.); (S.W.); (F.M.); (S.Z.); (N.L.); (L.M.); (J.Y.); (X.H.); (L.W.)
| | - Ying Li
- College of Animal Science and Technology, College of Veterinary Medicine, Jilin Agricultural University, Changchun 130118, China; (J.K.); (J.Y.)
- Correspondence: (Y.L.); (R.H.)
| | - Rongliang Hu
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China; (Y.Z.); (J.Z.); (H.Y.); (T.C.); (Q.L.); (X.Z.); (Y.Q.); (R.Z.); (S.W.); (F.M.); (S.Z.); (N.L.); (L.M.); (J.Y.); (X.H.); (L.W.)
- Correspondence: (Y.L.); (R.H.)
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26
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Ramirez-Medina E, Vuono EA, Pruitt S, Rai A, Espinoza N, Velazquez-Salinas L, Gladue DP, Borca MV. Evaluation of an ASFV RNA Helicase Gene A859L for Virus Replication and Swine Virulence. Viruses 2021; 14:v14010010. [PMID: 35062213 PMCID: PMC8777736 DOI: 10.3390/v14010010] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 12/10/2021] [Accepted: 12/15/2021] [Indexed: 12/31/2022] Open
Abstract
African swine fever virus (ASFV) is producing a devastating pandemic that, since 2007, has spread to a contiguous geographical area from central Europe to Asia. In July 2021, ASFV was detected in the Dominican Republic, the first report of the disease in the Americas in more than 40 years. ASFV is a large, highly complex virus harboring a large dsDNA genome that encodes for more than 150 genes. The majority of these genes have not been functionally characterized. Bioinformatics analysis predicts that ASFV gene A859L encodes for an RNA helicase, although its function has not yet been experimentally assessed. Here, we evaluated the role of the A859L gene during virus replication in cell cultures and during infection in swine. For that purpose, a recombinant virus (ASFV-G-∆A859L) harboring a deletion of the A859L gene was developed using the highly virulent ASFV Georgia (ASFV-G) isolate as a template. Recombinant ASFV-G-∆A859L replicates in swine macrophage cultures as efficiently as the parental virus ASFV-G, demonstrating that the A859L gene is non-essential for ASFV replication. Experimental infection of domestic pigs demonstrated that ASFV-G-∆A859L replicates as efficiently and induces a clinical disease indistinguishable from that caused by the parental ASFV-G. These studies conclude that the predicted RNA helicase gene A859L is not involved in the processes of virus replication or disease production in swine.
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Affiliation(s)
- Elizabeth Ramirez-Medina
- Plum Island Animal Disease Center, USDA, Agricultural Research Service, Orient, NY 11944, USA; (E.R.-M.); (E.A.V.); (S.P.); (A.R.); (N.E.); (L.V.-S.)
| | - Elizabeth A. Vuono
- Plum Island Animal Disease Center, USDA, Agricultural Research Service, Orient, NY 11944, USA; (E.R.-M.); (E.A.V.); (S.P.); (A.R.); (N.E.); (L.V.-S.)
- Department of Pathobiology and Population Medicine, Mississippi State University, Starkville, MS 39762, USA
| | - Sarah Pruitt
- Plum Island Animal Disease Center, USDA, Agricultural Research Service, Orient, NY 11944, USA; (E.R.-M.); (E.A.V.); (S.P.); (A.R.); (N.E.); (L.V.-S.)
| | - Ayushi Rai
- Plum Island Animal Disease Center, USDA, Agricultural Research Service, Orient, NY 11944, USA; (E.R.-M.); (E.A.V.); (S.P.); (A.R.); (N.E.); (L.V.-S.)
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN 37830, USA
| | - Nallely Espinoza
- Plum Island Animal Disease Center, USDA, Agricultural Research Service, Orient, NY 11944, USA; (E.R.-M.); (E.A.V.); (S.P.); (A.R.); (N.E.); (L.V.-S.)
| | - Lauro Velazquez-Salinas
- Plum Island Animal Disease Center, USDA, Agricultural Research Service, Orient, NY 11944, USA; (E.R.-M.); (E.A.V.); (S.P.); (A.R.); (N.E.); (L.V.-S.)
| | - Douglas P. Gladue
- Plum Island Animal Disease Center, USDA, Agricultural Research Service, Orient, NY 11944, USA; (E.R.-M.); (E.A.V.); (S.P.); (A.R.); (N.E.); (L.V.-S.)
- Correspondence: (D.P.G.); (M.V.B.)
| | - Manuel V. Borca
- Plum Island Animal Disease Center, USDA, Agricultural Research Service, Orient, NY 11944, USA; (E.R.-M.); (E.A.V.); (S.P.); (A.R.); (N.E.); (L.V.-S.)
- Correspondence: (D.P.G.); (M.V.B.)
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27
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African Swine Fever Virus Bearing an I226R Gene Deletion Elicits Robust Immunity in Pigs to African Swine Fever. J Virol 2021; 95:e0119921. [PMID: 34495696 PMCID: PMC8577359 DOI: 10.1128/jvi.01199-21] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
African swine fever (ASF) is a severe hemorrhagic infectious disease in pigs caused by African swine fever virus (ASFV), leading to devastating economic losses in epidemic regions. Its control currently depends on thorough culling and clearance of the diseased and surrounding suspected pigs. An ASF vaccine has been extensively explored for years worldwide, especially in hog-intensive areas where it is highly desired, but it is still unavailable for numerous reasons. Here, we report another ASF vaccine candidate, named SY18ΔI226R, bearing a deletion of the I226R gene with a replacement of an enhanced green fluorescent protein (eGFP) expression cassette at the right end of the viral genome. This deletion results in the complete loss of virulence of SY18 as the gene-deleted strain does not cause any clinical symptoms in all pigs inoculated with a dosage of either 104.0 or 107.0 50% tissue culture infective doses (TCID50). Apparent viremia with a gradual decline was monitored, while virus shedding was detected only occasionally in oral or anal swabs. ASFV-specific antibody appeared at 9 days postinoculation. After intramuscular challenge with its parental strain ASFV SY18 at 21 days postinoculation, all the challenged pigs survived, without obvious febrile or abnormal clinical signs. No viral DNA could be detected upon the dissection of any tissue when viremia disappeared. These results indicated that SY18ΔI226R is safe in swine and elicits robust immunity to virulent ASFV infection. IMPORTANCE Outbreaks of African swine fever have resulted in devastating losses to the swine industry worldwide, but there is currently no commercial vaccine available. Although several vaccine candidates have been reported, none has been approved for use for several reasons, especially ones concerning biosafety. Here, we identified a new undescribed functional gene, I226R. When deleted from the ASFV genome, the virus completely loses its virulence in swine. Importantly, pigs infected with this gene-deleted virus were resistant to infection by intramuscular challenge with 102.5 or 104.0 TCID50 of its virulent parental virus. Furthermore, the nucleic acid of the gene-deleted virus and its virulent parental virus was rarely detected from oral or anal swabs. Viruses could not be detected in any tissues after necropsy when viremia became negative, indicating that robust immunity was achieved. Therefore, SY18ΔI226R is a novel, ideal, and efficacious vaccine candidate for genotype II ASF.
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Deletion of E184L, a putative DIVA target from the pandemic strain of African swine fever virus, produces a reduction in virulence and protection against virulent challenge. J Virol 2021; 96:e0141921. [PMID: 34668772 DOI: 10.1128/jvi.01419-21] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
African swine fever (ASF) is currently causing a major pandemic affecting the swine industry and protein availability from Central Europe to East and South Asia. No commercial vaccines are available, making disease control dependent on the elimination of affected animals. Here, we show that the deletion of the ASFV E184L gene from the highly virulent ASFV-Georgia2010 (ASFV-G) isolate produces a reduction in virus virulence during the infection in swine. Forty percent (40%) of domestic pigs intramuscularly inoculated with a recombinant virus lacking the E184L gene (ASFV-G-ΔE184L) experienced a significantly (5 days) delayed presentation of clinical disease and, overall, had a 60% rate of survival when compared to animals inoculated with the virulent parental ASFV-G. Importantly, all animals surviving ASFV-G-ΔE184L infection developed a strong antibody response and were protected when challenged with ASFV-G. As expected, a pool of sera from ASFV-G-ΔE184L-inoculated animals lacked any detectable antibody response to peptides partially representing the E184L protein, while sera from animals inoculated with an efficacious vaccine candidate, ASFV-G-ΔMGF, strongly recognize the same set of peptides. These results support the potential use of the E184L deletion for the development of vaccines able to differentiate infected from vaccinated animals (DIVA). Therefore, it is shown here that the E184L gene is a novel ASFV determinant of virulence that can potentially be used to increase safety in pre-existing vaccine candidates as well as to provide them with DIVA capabilities. To our knowledge, E184L is the first ASFV gene product experimentally shown to be a functional DIVA antigenic marker. Importance: No commercial vaccines are available to prevent African swine fever. The ASF pandemic caused by the Georgia (ASFV-G) strain is seriously affecting pork production in a contiguous geographical area from Central Europe to East Asia. The only effective experimental vaccines are viruses attenuated by deleting ASFV genes associated with virus virulence. Therefore, identification of such genes is of critical importance for vaccine development. Here we report the discovery of a novel determinant of ASFV virulence, the E184L gene. Deletion of the E184L gene from the ASFV-G genome (ASFV-G-ΔE184L) produced a reduction in virus virulence and, importantly, animals surviving infection with ASFV-G-ΔE184L were protected from developing ASF after challenge with the virulent parental virus ASFV-G. Importantly, the virus protein encoded by E184L is highly immunogenic, making a virus lacking this gene a DIVA vaccine candidate that allows the differentiation of infected from vaccinated animals. Here we show that unlike what is observed in animals inoculated with the vaccine candidate ASFV-G-ΔMGF, ASFV-G-ΔE184L-inoculated animals do not mount a E184L-specific antibody response, indicating the feasibility of using the E184L deletion as the antigenic marker for the development of a DIVA vaccine in ASFV.
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Deletion of the A137R Gene from the Pandemic Strain of African Swine Fever Virus Attenuates the Strain and Offers Protection against the Virulent Pandemic Virus. J Virol 2021; 95:e0113921. [PMID: 34406865 DOI: 10.1128/jvi.01139-21] [Citation(s) in RCA: 69] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
African swine fever virus (ASFV) is causing a devastating pandemic in domestic and wild swine within an extended geographical area from Central Europe to East Asia, resulting in economic losses for the regional swine industry. There are no commercial vaccines; therefore, disease control relies on identification and culling of infected animals. We report here that the deletion of the ASFV gene A137R from the highly virulent ASFV-Georgia2010 (ASFV-G) isolate induces a significant attenuation of virus virulence in swine. A recombinant virus lacking the A137R gene, ASFV-G-ΔA137R, was developed to assess the role of this gene in ASFV virulence in domestic swine. Animals inoculated intramuscularly with 102 50% hemadsorption doses (HAD50) of ASFV-G-ΔA137R remained clinically healthy during the 28-day observational period. All animals inoculated with ASFV-G-ΔA137R had medium to high viremia titers and developed a strong virus-specific antibody response. Importantly, all ASFV-G-ΔA137R-inoculated animals were protected when challenged with the virulent parental strain ASFV-G. No evidence of replication of challenge virus was observed in the ASFV-G-ΔA137R-inoculated animals. Therefore, ASFV-G-ΔA137R is a novel potential live attenuated vaccine candidate and one of the few experimental vaccine strains reported to induce protection against the highly virulent ASFV Georgia virus that is the cause of the current Eurasian pandemic. IMPORTANCE No commercial vaccine is available to prevent African swine fever. The ASF pandemic caused by ASFV Georgia2007 strain (ASFV-G) is seriously affecting pork production in a contiguous area from Central Europe to East Asia. Here we report the rational development of a potential live attenuated vaccine strain by deleting a virus-specific gene, A137R, from the genome of ASFV-G. The resulting virus presented a completely attenuated phenotype and, importantly, animals infected with this genetically modified virus were protected from developing ASF after challenge with the virulent parental virus. ASFV-G-ΔA137R confers protection even at low doses (102 HAD50), demonstrating its potential as a vaccine candidate. Therefore, ASFV-G-ΔA137R is a novel experimental ASF vaccine protecting pigs from the epidemiologically relevant ASFV Georgia isolate.
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Abkallo HM, Svitek N, Oduor B, Awino E, Henson SP, Oyola SO, Mwalimu S, Assad-Garcia N, Fuchs W, Vashee S, Steinaa L. Rapid CRISPR/Cas9 Editing of Genotype IX African Swine Fever Virus Circulating in Eastern and Central Africa. Front Genet 2021; 12:733674. [PMID: 34527025 PMCID: PMC8435729 DOI: 10.3389/fgene.2021.733674] [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: 06/30/2021] [Accepted: 08/10/2021] [Indexed: 11/17/2022] Open
Abstract
African swine fever virus (ASFV) is the etiological agent of a contagious and fatal disease of domestic pigs that has significant economic consequences for the global swine industry. Due to the lack of effective treatment and vaccines against African swine fever, there is an urgent need to leverage cutting-edge technologies and cost-effective approaches for generating and purifying recombinant virus to fast-track the development of live-attenuated ASFV vaccines. Here, we describe the use of the CRISPR/Cas9 gene editing and a cost-effective cloning system to produce recombinant ASFVs. Combining these approaches, we developed a recombinant virus lacking the non-essential gene A238L (5EL) in the highly virulent genotype IX ASFV (ASFV-Kenya-IX-1033) genome in less than 2 months as opposed to the standard homologous recombination with conventional purification techniques which takes up to 6 months on average. Our approach could therefore be a method of choice for less resourced laboratories in developing nations.
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Affiliation(s)
- Hussein M Abkallo
- Animal and Human Health Program, International Livestock Research Institute (ILRI), Nairobi, Kenya
| | - Nicholas Svitek
- Animal and Human Health Program, International Livestock Research Institute (ILRI), Nairobi, Kenya
| | - Bernard Oduor
- Animal and Human Health Program, International Livestock Research Institute (ILRI), Nairobi, Kenya
| | - Elias Awino
- Animal and Human Health Program, International Livestock Research Institute (ILRI), Nairobi, Kenya
| | - Sonal P Henson
- Animal and Human Health Program, International Livestock Research Institute (ILRI), Nairobi, Kenya
| | - Samuel O Oyola
- Animal and Human Health Program, International Livestock Research Institute (ILRI), Nairobi, Kenya
| | - Stephen Mwalimu
- Animal and Human Health Program, International Livestock Research Institute (ILRI), Nairobi, Kenya
| | - Nacrya Assad-Garcia
- Department of Synthetic Biology and Bioenergy, J. Craig Venter Institute, Rockville, MD, United States
| | - Walter Fuchs
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
| | - Sanjay Vashee
- Department of Synthetic Biology and Bioenergy, J. Craig Venter Institute, Rockville, MD, United States
| | - Lucilla Steinaa
- Animal and Human Health Program, International Livestock Research Institute (ILRI), Nairobi, Kenya
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Lopez E, Bosch-Camós L, Ramirez-Medina E, Vuono E, Navas MJ, Muñoz M, Accensi F, Zhang J, Alonso U, Argilaguet J, Salas ML, Anachkov N, Gladue DP, Borca MV, Pina-Pedrero S, Rodriguez F. Deletion Mutants of the Attenuated Recombinant ASF Virus, BA71ΔCD2, Show Decreased Vaccine Efficacy. Viruses 2021; 13:v13091678. [PMID: 34578263 PMCID: PMC8473413 DOI: 10.3390/v13091678] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 08/04/2021] [Accepted: 08/06/2021] [Indexed: 11/20/2022] Open
Abstract
African swine fever (ASF) has become the major threat to the global swine industry. Lack of available commercial vaccines complicates the implementation of global control strategies. So far, only live attenuated ASF viruses (ASFV) have demonstrated solid protection efficacy at the experimental level. The implementation of molecular techniques has allowed the generation of a collection of deletion mutants lacking ASFV-specific virulence factors, some of them with promising potential as vaccine candidates against the pandemic genotype II ASFV strain currently circulating in Africa, Europe, Asia and Oceania. Despite promising results, there is room for improvement, mainly from the biosafety point of view. Aiming to improve the safety of BA71∆CD2, a cross-protective recombinant live attenuated virus (LAV) lacking the ASFV CD2v gene (encoding β-glucuronidase as a reporter gene) available in our laboratory, three new recombinants were generated using BA71∆CD2 as a template: the single mutant BA71∆CD2f, this time containing the fluorescent mCherry reporter gene instead of CD2v, and two double recombinants lacking CD2v and either the lectin gene (EP153R) or the uridine kinase (UK) gene (DP96R). Comparative in vivo experiments using BA71∆CD2f, BA71∆CD2DP96R and BA71∆CD2EP153R recombinant viruses as immunogens, demonstrated that deletion of either DP96R or EP153R from BA71∆CD2f decreases vaccine efficacy and does not improve safety. Our results additionally confirm ASFV challenge as the only available method today to evaluate the protective efficacy of any experimental vaccine. We believe that understanding the fine equilibrium between attenuation and inducing protection in vivo deserves further study and might contribute to more rational vaccine designs in the future.
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Affiliation(s)
- Elisabeth Lopez
- IRTA, Centre de Recerca en Sanitat Animal (IRTA-CReSA), Campus de la Universitat Autonoma de Barcelona, 08193 Bellaterra, Spain; (E.L.); (L.B.-C.); (M.J.N.); (M.M.); (F.A.); (J.Z.); (U.A.); (J.A.)
| | - Laia Bosch-Camós
- IRTA, Centre de Recerca en Sanitat Animal (IRTA-CReSA), Campus de la Universitat Autonoma de Barcelona, 08193 Bellaterra, Spain; (E.L.); (L.B.-C.); (M.J.N.); (M.M.); (F.A.); (J.Z.); (U.A.); (J.A.)
| | - Elizabeth Ramirez-Medina
- USDA Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA; (E.R.-M.); (E.V.); (D.P.G.); (M.V.B.)
| | - Elizabeth Vuono
- USDA Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA; (E.R.-M.); (E.V.); (D.P.G.); (M.V.B.)
| | - Maria Jesus Navas
- IRTA, Centre de Recerca en Sanitat Animal (IRTA-CReSA), Campus de la Universitat Autonoma de Barcelona, 08193 Bellaterra, Spain; (E.L.); (L.B.-C.); (M.J.N.); (M.M.); (F.A.); (J.Z.); (U.A.); (J.A.)
| | - Marta Muñoz
- IRTA, Centre de Recerca en Sanitat Animal (IRTA-CReSA), Campus de la Universitat Autonoma de Barcelona, 08193 Bellaterra, Spain; (E.L.); (L.B.-C.); (M.J.N.); (M.M.); (F.A.); (J.Z.); (U.A.); (J.A.)
| | - Francesc Accensi
- IRTA, Centre de Recerca en Sanitat Animal (IRTA-CReSA), Campus de la Universitat Autonoma de Barcelona, 08193 Bellaterra, Spain; (E.L.); (L.B.-C.); (M.J.N.); (M.M.); (F.A.); (J.Z.); (U.A.); (J.A.)
- Departament de Sanitat i d’Anatomia Animals, Facultat de Veterinària, UAB, 08193 Bellaterra, Spain
| | - Jinya Zhang
- IRTA, Centre de Recerca en Sanitat Animal (IRTA-CReSA), Campus de la Universitat Autonoma de Barcelona, 08193 Bellaterra, Spain; (E.L.); (L.B.-C.); (M.J.N.); (M.M.); (F.A.); (J.Z.); (U.A.); (J.A.)
| | - Uxia Alonso
- IRTA, Centre de Recerca en Sanitat Animal (IRTA-CReSA), Campus de la Universitat Autonoma de Barcelona, 08193 Bellaterra, Spain; (E.L.); (L.B.-C.); (M.J.N.); (M.M.); (F.A.); (J.Z.); (U.A.); (J.A.)
| | - Jordi Argilaguet
- IRTA, Centre de Recerca en Sanitat Animal (IRTA-CReSA), Campus de la Universitat Autonoma de Barcelona, 08193 Bellaterra, Spain; (E.L.); (L.B.-C.); (M.J.N.); (M.M.); (F.A.); (J.Z.); (U.A.); (J.A.)
| | - Maria Luisa Salas
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas, Campus de la Universidad Autònoma de Madrid, 28049 Madrid, Spain;
| | - Nikolay Anachkov
- Biologics Development, Huvepharma, 3A Nikolay Haytov Street, 1113 Sofia, Bulgaria;
| | - Douglas P. Gladue
- USDA Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA; (E.R.-M.); (E.V.); (D.P.G.); (M.V.B.)
| | - Manuel V. Borca
- USDA Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA; (E.R.-M.); (E.V.); (D.P.G.); (M.V.B.)
| | - Sonia Pina-Pedrero
- IRTA, Centre de Recerca en Sanitat Animal (IRTA-CReSA), Campus de la Universitat Autonoma de Barcelona, 08193 Bellaterra, Spain; (E.L.); (L.B.-C.); (M.J.N.); (M.M.); (F.A.); (J.Z.); (U.A.); (J.A.)
- Correspondence: (S.P.-P.); (F.R.)
| | - Fernando Rodriguez
- IRTA, Centre de Recerca en Sanitat Animal (IRTA-CReSA), Campus de la Universitat Autonoma de Barcelona, 08193 Bellaterra, Spain; (E.L.); (L.B.-C.); (M.J.N.); (M.M.); (F.A.); (J.Z.); (U.A.); (J.A.)
- Correspondence: (S.P.-P.); (F.R.)
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Rathakrishnan A, Reis AL, Goatley LC, Moffat K, Dixon LK. Deletion of the K145R and DP148R Genes from the Virulent ASFV Georgia 2007/1 Isolate Delays the Onset, but Does Not Reduce Severity, of Clinical Signs in Infected Pigs. Viruses 2021; 13:v13081473. [PMID: 34452339 PMCID: PMC8402900 DOI: 10.3390/v13081473] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 07/23/2021] [Accepted: 07/25/2021] [Indexed: 01/01/2023] Open
Abstract
African swine fever virus causes a frequently fatal disease of domestic pigs and wild boar that has a high economic impact across 3 continents. The large double-stranded DNA genome codes for approximately 160 proteins. Many of these have unknown functions and this hinders our understanding of the virus and host interactions. The purpose of the study was to evaluate the role of two virus proteins, K145R and DP148R, in virus replication in macrophages and virulence in pigs. To do this, the DP148R gene, alone or in combination with the K145R gene, was deleted from the virulent genotype II Georgia 2007/1 isolate. Neither of these deletions reduced the ability of the viruses to replicate in porcine macrophages compared to the parental wild-type virus. Pigs infected with GeorgiaΔDP148R developed clinical and post-mortem signs and high viremia, typical of acute African swine fever, and were culled on day 6 post-infection. The additional deletion of the K145R gene delayed the onset of clinical signs and viremia in pigs by 3 days, but pigs showed signs of acute African swine fever and were culled on days 10 or 13 post-infection. The results show that the deletion of DP148R did not attenuate the genotype II Georgia 2007/1 isolate, contrary to the results obtained with the genotype I Benin97/1 isolate. Additional deletion of the K145R gene delayed clinical signs, but infected pigs reached the humane endpoint. The deletion of additional genes would be required to attenuate the virus.
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Vuono EA, Ramirez-Medina E, Pruitt S, Rai A, Espinoza N, Velazquez-Salinas L, Gladue DP, Borca MV. Evaluation of the Function of the ASFV KP177R Gene, Encoding for Structural Protein p22, in the Process of Virus Replication and in Swine Virulence. Viruses 2021; 13:986. [PMID: 34073222 PMCID: PMC8227490 DOI: 10.3390/v13060986] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 05/18/2021] [Accepted: 05/19/2021] [Indexed: 12/11/2022] Open
Abstract
African swine fever virus (ASFV) causes a devastating disease of swine that has caused outbreaks in Central Europe since 2007, spreading into Asia in 2018. ASFV is a large, structurally complex virus with a large dsDNA genome encoding for more than 160 genes, most of them still uncharacterized. p22, encoded by the ASFV gene KP177R, is an early transcribed, structural virus protein located in the ASFV particle. Although its exact function is unknown, p22 has recently been identified as an interacting partner of several host proteins. Here, we describe the development of a recombinant ASFV (ASFV-G-∆KP177R) lacking the KP177R gene as a tool to evaluate the role of p22 in virus replication and virulence in swine. The recombinant ASFV-G-∆KP177R demonstrated that the KP177R gene is non-essential for ASFV replication in primary swine macrophages, with virus yields similar to those of the parental, highly virulent field isolate Georgia2010 (ASFV-G). In addition, experimental infection of domestic pigs with ASFV-G-∆KP177R produced a clinical disease similar to that caused by the parental ASFV-G. Therefore, and surprisingly, p22 does not seem to be involved in virus replication or virulence in swine.
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Affiliation(s)
- Elizabeth A. Vuono
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture Greenport, Greenport, NY 11944, USA; (E.A.V.); (E.R.-M.); (S.P.); (A.R.); (N.E.); (L.V.-S.)
- Department of Pathobiology and Population Medicine, Mississippi State University, Starkville, MS 39762, USA
| | - Elizabeth Ramirez-Medina
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture Greenport, Greenport, NY 11944, USA; (E.A.V.); (E.R.-M.); (S.P.); (A.R.); (N.E.); (L.V.-S.)
| | - Sarah Pruitt
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture Greenport, Greenport, NY 11944, USA; (E.A.V.); (E.R.-M.); (S.P.); (A.R.); (N.E.); (L.V.-S.)
| | - Ayushi Rai
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture Greenport, Greenport, NY 11944, USA; (E.A.V.); (E.R.-M.); (S.P.); (A.R.); (N.E.); (L.V.-S.)
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN 37830, USA
| | - Nallely Espinoza
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture Greenport, Greenport, NY 11944, USA; (E.A.V.); (E.R.-M.); (S.P.); (A.R.); (N.E.); (L.V.-S.)
| | - Lauro Velazquez-Salinas
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture Greenport, Greenport, NY 11944, USA; (E.A.V.); (E.R.-M.); (S.P.); (A.R.); (N.E.); (L.V.-S.)
- Department of Anatomy and Physiology, Kansas State University, Manhattan, KS 66506, USA
| | - Douglas P. Gladue
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture Greenport, Greenport, NY 11944, USA; (E.A.V.); (E.R.-M.); (S.P.); (A.R.); (N.E.); (L.V.-S.)
| | - Manuel V. Borca
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture Greenport, Greenport, NY 11944, USA; (E.A.V.); (E.R.-M.); (S.P.); (A.R.); (N.E.); (L.V.-S.)
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Ramirez-Medina E, Vuono E, Pruitt S, Rai A, Silva E, Espinoza N, Zhu J, Velazquez-Salinas L, Borca MV, Gladue DP. Development and In Vivo Evaluation of a MGF110-1L Deletion Mutant in African Swine Fever Strain Georgia. Viruses 2021; 13:286. [PMID: 33673255 PMCID: PMC7918709 DOI: 10.3390/v13020286] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/02/2021] [Accepted: 02/08/2021] [Indexed: 01/04/2023] Open
Abstract
African swine fever (ASF) is currently causing an epizootic, affecting pigs throughout Eurasia, and causing significant economic losses in the swine industry. ASF is caused by African swine fever virus (ASFV) that consists of a large dsDNA genome that encodes for more than 160 genes; few of these genes have been studied in detail. ASFV contains four multi-gene family (MGF) groups of genes that have been implicated in regulating the immune response and host specificity; however, the individual roles of most of these genes have not been well studied. Here, we describe the evaluation of the previously uncharacterized ASFV MGF110-1L open reading frame (ORF) using a deletion mutant of the ASFV currently circulating throughout Eurasia. The recombinant ASFV lacking the MGF110-1L gene (ASFV-G-ΔMGF110-1L) demonstrated in vitro that the MGF110-1L gene is non-essential, since ASFV-G-ΔMGF110-1L had similar replication kinetics in primary swine macrophage cell cultures when compared to parental highly virulent field isolate Georgia2007 (ASFV-G). Experimental infection of domestic pigs with ASFV-G-ΔMGF110-1L produced a clinical disease similar to that caused by the parental ASFV-G, confirming that deletion of the MGF110-1L gene from the ASFV genome does not affect viral virulence.
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Affiliation(s)
- Elizabeth Ramirez-Medina
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA; (E.R.-M.); (E.V.); (S.P.); (A.R.); (E.S.); (N.E.); (J.Z.); (L.V.-S.)
- Department of Pathobiology and Veterinary Science, University of Connecticut, Storrs, CT 06269, USA
| | - Elizabeth Vuono
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA; (E.R.-M.); (E.V.); (S.P.); (A.R.); (E.S.); (N.E.); (J.Z.); (L.V.-S.)
- Department of Pathobiology and Population Medicine, Mississippi State University, P.O. Box 6100, Starkville, MS 39762, USA
| | - Sarah Pruitt
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA; (E.R.-M.); (E.V.); (S.P.); (A.R.); (E.S.); (N.E.); (J.Z.); (L.V.-S.)
| | - Ayushi Rai
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA; (E.R.-M.); (E.V.); (S.P.); (A.R.); (E.S.); (N.E.); (J.Z.); (L.V.-S.)
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN 37830, USA
| | - Ediane Silva
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA; (E.R.-M.); (E.V.); (S.P.); (A.R.); (E.S.); (N.E.); (J.Z.); (L.V.-S.)
- Department of Anatomy and Physiology, Kansas State University, Manhattan, KS 66506, USA
| | - Nallely Espinoza
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA; (E.R.-M.); (E.V.); (S.P.); (A.R.); (E.S.); (N.E.); (J.Z.); (L.V.-S.)
| | - James Zhu
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA; (E.R.-M.); (E.V.); (S.P.); (A.R.); (E.S.); (N.E.); (J.Z.); (L.V.-S.)
| | - Lauro Velazquez-Salinas
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA; (E.R.-M.); (E.V.); (S.P.); (A.R.); (E.S.); (N.E.); (J.Z.); (L.V.-S.)
- Department of Anatomy and Physiology, Kansas State University, Manhattan, KS 66506, USA
| | - Manuel V. Borca
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA; (E.R.-M.); (E.V.); (S.P.); (A.R.); (E.S.); (N.E.); (J.Z.); (L.V.-S.)
| | - Douglas P. Gladue
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, NY 11944, USA; (E.R.-M.); (E.V.); (S.P.); (A.R.); (E.S.); (N.E.); (J.Z.); (L.V.-S.)
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Evaluation in Swine of a Recombinant Georgia 2010 African Swine Fever Virus Lacking the I8L Gene. Viruses 2020; 13:v13010039. [PMID: 33383814 PMCID: PMC7823879 DOI: 10.3390/v13010039] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 12/20/2020] [Accepted: 12/20/2020] [Indexed: 12/19/2022] Open
Abstract
African swine fever virus (ASFV) is the causative agent of African swine fever, a disease currently causing significant economic losses in Europe and Asia. Specifically, the highly virulent ASFV strain Georgia 2010 (ASFV-G) is producing disease outbreaks in this large geographical region. The ASFV genome encodes for over 150 genes, most of which are still not experimentally characterized. I8L is a highly conserved gene that has not been studied beyond its initial description as a virus ORF. Transcriptional analysis of swine macrophages infected with ASFV-G demonstrated that the I8L gene is transcribed early during the virus replication cycle. To assess the importance of I8L during ASFV-G replication in vitro and in vivo, as well as its role in virus virulence in domestic swine, we developed a recombinant virus lacking the I8L gene (ASFV-G-ΔI8L). Replication of ASFV-G-ΔI8L was similar to parental ASFV-G replication in primary swine macrophage cultures, suggesting that the I8L gene is not essential for ASFV-G replication in vitro. Similarly, replication of ASFV-G-ΔI8L in swine intramuscularly inoculated with 102 HAD50 displayed replication kinetics similar to ASFV-G. In addition, animals inoculated with ASFV-G-ΔI8L presented with a clinical disease indistinguishable from that induced by the same dose of the virulent parental ASFV-G isolate. We conclude that deletion of the I8L gene from ASFV-G does not affect virus replication in vitro or in vivo, nor changes the disease outcome in swine.
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Teklue T, Wang T, Luo Y, Hu R, Sun Y, Qiu HJ. Generation and Evaluation of an African Swine Fever Virus Mutant with Deletion of the CD2v and UK Genes. Vaccines (Basel) 2020; 8:E763. [PMID: 33327488 PMCID: PMC7768475 DOI: 10.3390/vaccines8040763] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 12/05/2020] [Accepted: 12/07/2020] [Indexed: 12/29/2022] Open
Abstract
African swine fever (ASF) is a highly contagious and often lethal disease caused by African swine fever virus (ASFV). ASF emerged in China in August 2018 and has since rapidly spread into many areas of the country. The disease has caused a significant impact on China's pig and related industries. A safe and effective vaccine is needed to prevent and control the disease. Several gene-deleted ASFVs have been reported; however, none of them is safe enough and commercially available. In this study, we report the generation of a double gene-deleted ASFV mutant, ASFV-SY18-∆CD2v/UK, from a highly virulent field strain ASFV-SY18 isolated in China. The results showed that ASFV-SY18-∆CD2v/UK lost hemadsorption properties, and the simultaneous deletion of the two genes did not significantly affect the in vitro replication of the virus in primary porcine alveolar macrophages. Furthermore, ASFV-SY18-∆CD2v/UK was attenuated in pigs. All the ASFV-SY18-∆CD2v/UK-inoculated pigs remained healthy, and none of them developed ASF-associated clinical signs. Additionally, the ASFV-SY18-∆CD2v/UK-infected pigs developed ASFV-specific antibodies, and no virus genome was detected in blood and nasal discharges at 21 and 28 days post-inoculation. More importantly, we found that all the pigs inoculated with 104 TCID50 of ASFV-SY18-∆CD2v/UK were protected against the challenge with the parental ASFV-SY18. However, low-level ASFV DNA was detected in blood, nasal swabs, and lymphoid tissue after the challenge. The results demonstrate that ASFV-SY18-∆CD2v/UK is safe and able to elicit protective immune response in pigs and can be a potential vaccine candidate to control ASF.
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Affiliation(s)
- Teshale Teklue
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China; (T.T.); (T.W.); (Y.L.)
| | - Tao Wang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China; (T.T.); (T.W.); (Y.L.)
| | - Yuzi Luo
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China; (T.T.); (T.W.); (Y.L.)
| | - Rongliang Hu
- Institute of Military Veterinary Medicine, Academy of Military Medical Sciences, Changchun 130000, China;
| | - Yuan Sun
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China; (T.T.); (T.W.); (Y.L.)
| | - Hua-Ji Qiu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China; (T.T.); (T.W.); (Y.L.)
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Gladue DP, O’Donnell V, Ramirez-Medina E, Rai A, Pruitt S, Vuono EA, Silva E, Velazquez-Salinas L, Borca MV. Deletion of CD2-Like (CD2v) and C-Type Lectin-Like (EP153R) Genes from African Swine Fever Virus Georgia-∆9GL Abrogates Its Effectiveness as an Experimental Vaccine. Viruses 2020; 12:E1185. [PMID: 33092057 PMCID: PMC7590024 DOI: 10.3390/v12101185] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Revised: 10/14/2020] [Accepted: 10/16/2020] [Indexed: 01/31/2023] Open
Abstract
African swine fever virus (ASFV) is currently the most dreaded infectious disease affecting the global swine production industry. There is no commercial vaccine available, making the culling of infected animals the current solution to control outbreaks. Effective experimental vaccines have been developed by deleting virus genes associated with virulence. Deletion of the ASFV 9GL gene (∆9GL) has resulted in the attenuation of different ASFV strains, although the degree of attenuation varies across isolates. Here, we investigated the possibility of the increased safety of the experimental vaccine strain ASFV-G-Δ9GL by deleting two additional virus genes involved in pathogenesis, CD2v, a CD2 like viral encoded gene from the EP402R open reading frame (ORF), and C-type lectin-like viral gene, encoded from the EP153R ORF. Two new recombinant viruses were developed, ASFV-G-Δ9GL/ΔCD2v and ASFV-G-Δ9GL/ΔCD2v/ΔEP153R, harboring two and three gene deletions, respectively. ASFV-G-Δ9GL/ΔCD2v/ΔEP153R, but not ASFV-G-Δ9GL/ΔCD2v, had a decreased ability to replicate in vitro in swine macrophage cultures when compared with parental ASFV-G-Δ9GL. Importantly, ASFV-G-Δ9GL/ΔCD2v and ASFV-G-Δ9GL/ΔCD2v/ΔEP153R induced almost undetectable viremia levels when inoculated into domestic pigs and failed to protect them against challenge with parental virulent ASFV-Georgia, while ASFV-G-Δ9GL offered robust protection during challenge. Therefore, the deletion of CD2-like and C-type lectin-like genes significantly decreased the protective potential of ASFV-G-Δ9GL as a vaccine candidate. This study constitutes an example of the unpredictability of genetic manipulation involving the simultaneous deletion of multiple genes from the ASFV genome.
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Affiliation(s)
- Douglas P. Gladue
- Plum Island Animal Disease Center, ARS, USDA, Greenport, NY 11944, USA; (V.O.); (E.R.-M.); (A.R.); (S.P.); (E.A.V.); (E.S.); (L.V.-S.)
| | - Vivian O’Donnell
- Plum Island Animal Disease Center, ARS, USDA, Greenport, NY 11944, USA; (V.O.); (E.R.-M.); (A.R.); (S.P.); (E.A.V.); (E.S.); (L.V.-S.)
- Plum Island Animal Disease Center, APHIS, USDA, Greenport, NY 11944, USA
| | - Elizabeth Ramirez-Medina
- Plum Island Animal Disease Center, ARS, USDA, Greenport, NY 11944, USA; (V.O.); (E.R.-M.); (A.R.); (S.P.); (E.A.V.); (E.S.); (L.V.-S.)
- Department of Anatomy and Physiology, Kansas State University, Manhattan, KS 66506, USA
| | - Ayushi Rai
- Plum Island Animal Disease Center, ARS, USDA, Greenport, NY 11944, USA; (V.O.); (E.R.-M.); (A.R.); (S.P.); (E.A.V.); (E.S.); (L.V.-S.)
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN 37830, USA
| | - Sarah Pruitt
- Plum Island Animal Disease Center, ARS, USDA, Greenport, NY 11944, USA; (V.O.); (E.R.-M.); (A.R.); (S.P.); (E.A.V.); (E.S.); (L.V.-S.)
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN 37830, USA
| | - Elizabeth A. Vuono
- Plum Island Animal Disease Center, ARS, USDA, Greenport, NY 11944, USA; (V.O.); (E.R.-M.); (A.R.); (S.P.); (E.A.V.); (E.S.); (L.V.-S.)
- Department of Pathobiology and Population Medicine, Mississippi State University, Mississippi State, MS 39762, USA
| | - Ediane Silva
- Plum Island Animal Disease Center, ARS, USDA, Greenport, NY 11944, USA; (V.O.); (E.R.-M.); (A.R.); (S.P.); (E.A.V.); (E.S.); (L.V.-S.)
- Department of Anatomy and Physiology, Kansas State University, Manhattan, KS 66506, USA
| | - Lauro Velazquez-Salinas
- Plum Island Animal Disease Center, ARS, USDA, Greenport, NY 11944, USA; (V.O.); (E.R.-M.); (A.R.); (S.P.); (E.A.V.); (E.S.); (L.V.-S.)
- Department of Anatomy and Physiology, Kansas State University, Manhattan, KS 66506, USA
| | - Manuel V. Borca
- Plum Island Animal Disease Center, ARS, USDA, Greenport, NY 11944, USA; (V.O.); (E.R.-M.); (A.R.); (S.P.); (E.A.V.); (E.S.); (L.V.-S.)
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X69R Is a Non-Essential Gene That, When Deleted from African Swine Fever, Does Not Affect Virulence in Swine. Viruses 2020; 12:v12090918. [PMID: 32825617 PMCID: PMC7551905 DOI: 10.3390/v12090918] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 08/17/2020] [Indexed: 12/21/2022] Open
Abstract
African swine fever virus (ASFV) is currently causing devastating outbreaks in Asia and Europe, and the ASFV strain Georgia (ASFV-G) is responsible for these outbreaks. ASFV-G is highly virulent and continues to be maintained in these outbreak areas, apparently without suffering significant genomic or phenotypic changes. When comparing the genome of ASFV-G to other isolates, a thus-far uncharacterized gene, X69R, is highly conserved and, interestingly, is similar to another ASFV uncharacterized gene, J64R. All sequenced ASFV isolates have one or both of these genes, X69R or J64R, suggesting that the presence of at least one of these genes may be necessary for ASFV replication and or virulence. The X69R gene is present in the ASFV-G genome while J64R is absent. To assess the importance of X69R in ASFV-G functionality, we developed a recombinant virus by deleting the X69R gene from the ASFV-G genome (ASFV-G-ΔX69R). ASFV-G-ΔX69R had the same replication kinetics in primary swine macrophage cultures as the parental ASFV-G, indicating that the X69R gene is not essential for ASFV-G viability or efficient replication in the main target cell during in vivo infection. In addition, swine intramuscularly inoculated with a low dose (102 HAD50) of ASFV-G-ΔX69R developed a clinical disease indistinguishable from that induced by the same dose of the virulent parental ASFV-G isolate. Viremia values of ASFV-G-ΔX69R did not significantly differ from those detected in animals infected with parental virus. Therefore, deletion of the X69R gene from ASFV-G does not affect virus replication or virulence in swine.
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Ramirez-Medina E, Vuono EA, Rai A, Pruitt S, Silva E, Velazquez-Salinas L, Zhu J, Borca MV, Gladue DP. The C962R ORF of African Swine Fever Strain Georgia Is Non-Essential and Not Required for Virulence in Swine. Viruses 2020; 12:E676. [PMID: 32585808 PMCID: PMC7354530 DOI: 10.3390/v12060676] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 06/16/2020] [Accepted: 06/18/2020] [Indexed: 12/22/2022] Open
Abstract
African swine fever virus (ASFV) is the causative agent of the African swine fever (ASF) epizootic currently affecting pigs throughout Eurasia, causing significant economic losses in the swine industry. The virus genome encodes for more than 160 genes, of which only a few have been studied in detail. Here we describe the previously uncharacterized ASFV open reading frame (ORF) C962R, a gene encoding for a putative NTPase. RNA transcription studies using infected swine macrophages demonstrate that the C962R gene is translated as a late virus protein. A recombinant ASFV lacking the C962R gene (ASFV-G-ΔC962R) demonstrates in vivo that the C962R gene is non-essential, since ASFV-G-ΔC962R has similar replication kinetics in primary swine macrophage cell cultures when compared to parental highly virulent field isolate Georgia2007 (ASFV-G). Experimental infection of domestic pigs with ASFV-G-ΔC962R produced a clinical disease similar to that caused by the parental ASFV-G, confirming that deletion of the C962R gene from the ASFV genome does not impact virulence.
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Affiliation(s)
- Elizabeth. Ramirez-Medina
- Plum Island Animal Disease Center, Agricultural Research Service (ARS), United States Department of Agriculture (USDA), Greenport, NY 11944, USA; (E.R.-M.); (A.R.); (S.P.); (E.S.); (L.V.-S.); (J.Z.)
- Department of Pathobiology and Veterinary Science, University of Connecticut, Storrs, CT 06269, USA
| | - Elizabeth. A. Vuono
- Department of Pathobiology and Population Medicine, Mississippi State University, P.O. Box 6100, Starkville, MS 39762, USA;
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN 37830, USA
| | - Ayushi. Rai
- Plum Island Animal Disease Center, Agricultural Research Service (ARS), United States Department of Agriculture (USDA), Greenport, NY 11944, USA; (E.R.-M.); (A.R.); (S.P.); (E.S.); (L.V.-S.); (J.Z.)
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN 37830, USA
| | - Sarah. Pruitt
- Plum Island Animal Disease Center, Agricultural Research Service (ARS), United States Department of Agriculture (USDA), Greenport, NY 11944, USA; (E.R.-M.); (A.R.); (S.P.); (E.S.); (L.V.-S.); (J.Z.)
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN 37830, USA
| | - Ediane. Silva
- Plum Island Animal Disease Center, Agricultural Research Service (ARS), United States Department of Agriculture (USDA), Greenport, NY 11944, USA; (E.R.-M.); (A.R.); (S.P.); (E.S.); (L.V.-S.); (J.Z.)
- Department of Anatomy and Physiology, Kansas State University, Manhattan, KS 66506, USA
| | - Lauro. Velazquez-Salinas
- Plum Island Animal Disease Center, Agricultural Research Service (ARS), United States Department of Agriculture (USDA), Greenport, NY 11944, USA; (E.R.-M.); (A.R.); (S.P.); (E.S.); (L.V.-S.); (J.Z.)
- Department of Anatomy and Physiology, Kansas State University, Manhattan, KS 66506, USA
| | - James. Zhu
- Plum Island Animal Disease Center, Agricultural Research Service (ARS), United States Department of Agriculture (USDA), Greenport, NY 11944, USA; (E.R.-M.); (A.R.); (S.P.); (E.S.); (L.V.-S.); (J.Z.)
| | - Manuel. V. Borca
- Plum Island Animal Disease Center, Agricultural Research Service (ARS), United States Department of Agriculture (USDA), Greenport, NY 11944, USA; (E.R.-M.); (A.R.); (S.P.); (E.S.); (L.V.-S.); (J.Z.)
| | - Douglas. P. Gladue
- Plum Island Animal Disease Center, Agricultural Research Service (ARS), United States Department of Agriculture (USDA), Greenport, NY 11944, USA; (E.R.-M.); (A.R.); (S.P.); (E.S.); (L.V.-S.); (J.Z.)
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40
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Rathakrishnan A, Moffat K, Reis AL, Dixon LK. Production of Recombinant African Swine Fever Viruses: Speeding Up the Process. Viruses 2020; 12:E615. [PMID: 32516890 PMCID: PMC7354605 DOI: 10.3390/v12060615] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 06/02/2020] [Accepted: 06/03/2020] [Indexed: 12/31/2022] Open
Abstract
African swine fever (ASF) is a devastating disease in pigs, with no vaccines for control. The genetic manipulation of African swine fever virus (ASFV) is often tedious and time consuming. Here, we describe a method to manipulate the virus genome to produce gene deletion viruses in a much-reduced time. This method combines the conventional homologous recombination with fluorescent-activated cells sorting (FACS), to isolate and purify viruses expressing fluorescent reporter genes. With three rounds of single cell isolation via FACS and two rounds of limiting dilution, we deleted two additional genes, EP153R and EP402R, from Benin 97/1 ASFV lacking the DP148R gene. By combining different fluorescent markers, this method has the potential to greatly facilitate studies on understanding ASFV gene functions and develop candidate live-attenuated vaccines.
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Affiliation(s)
| | | | | | - Linda K. Dixon
- The Pirbright Institute, Ash Road, Pirbright, Surrey GU24 0NF, UK; (A.R.); (K.M.); (A.L.R.)
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41
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Borca MV, O'Donnell V, Holinka LG, Risatti GR, Ramirez-Medina E, Vuono EA, Shi J, Pruitt S, Rai A, Silva E, Velazquez-Salinas L, Gladue DP. Deletion of CD2-like gene from the genome of African swine fever virus strain Georgia does not attenuate virulence in swine. Sci Rep 2020; 10:494. [PMID: 31949276 PMCID: PMC6965178 DOI: 10.1038/s41598-020-57455-3] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 12/23/2019] [Indexed: 11/09/2022] Open
Abstract
The CD2-like African swine fever virus (ASFV) gene 8DR, (also known as EP402R) encodes for a structural transmembrane glycoprotein that has been shown to mediate hemadsorption and be involved in host immunomodulation as well as the induction of protective immune response. In addition, several natural ASFV isolates showing decreased virulence in swine has been shown to be non-hemadsorbing suggesting an association between altered or deleted forms of 8DR and virus attenuation. Here we demonstrate that deletion of 8DR gene from the genome of ASFV Georgia2010 isolate (ASFV-G-Δ8DR) does not significantly alter the virulence of the virus. ASFV-G-Δ8DR inoculated intramuscularly or intranasally (in a range of 102 to 104 TCID50) produced a clinical disease in domestic pigs indistinguishable from that induced by the same doses of the virulent parental ASFV Georgia2010 isolate. In addition, viremia values in ASFV-G-Δ8DR do not differ from those detected in animals infected with parental virus. Therefore, deletion of 8DR gene is not associated with a noticeable decrease in virulence of the ASFV Georgia isolate.
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Affiliation(s)
- Manuel V Borca
- Agricultural Research Service (ARS), Plum Island Animal Disease Center, Greenport, NY, 11944, USA.
| | - Vivian O'Donnell
- Agricultural Research Service (ARS), Plum Island Animal Disease Center, Greenport, NY, 11944, USA.,Animal and Plant Health Inspection Service (APHIS), Plum Island Animal Disease Center, Greenport, NY, 11944, USA
| | - Lauren G Holinka
- Agricultural Research Service (ARS), Plum Island Animal Disease Center, Greenport, NY, 11944, USA
| | - Guillermo R Risatti
- Agricultural Research Service (ARS), Plum Island Animal Disease Center, Greenport, NY, 11944, USA.,Department of Pathobiology and Veterinary Science, University of Connecticut, Storrs, CT, 06269, USA
| | - Elizabeth Ramirez-Medina
- Agricultural Research Service (ARS), Plum Island Animal Disease Center, Greenport, NY, 11944, USA.,Department of Pathobiology and Veterinary Science, University of Connecticut, Storrs, CT, 06269, USA
| | - Elizabeth A Vuono
- Department of Pathology and Population Medicine, Mississippi State University, P.O. Box: 6100, Mississippi State, MS, 39762, USA
| | - Jishu Shi
- Department of Anatomy and Physiology, Kansas State University, Manhattan, KS, 66506, USA
| | - Sarah Pruitt
- Agricultural Research Service (ARS), Plum Island Animal Disease Center, Greenport, NY, 11944, USA.,Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN, 37830, USA
| | - Ayushi Rai
- Agricultural Research Service (ARS), Plum Island Animal Disease Center, Greenport, NY, 11944, USA.,Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN, 37830, USA
| | - Ediane Silva
- Agricultural Research Service (ARS), Plum Island Animal Disease Center, Greenport, NY, 11944, USA.,Department of Anatomy and Physiology, Kansas State University, Manhattan, KS, 66506, USA
| | - Lauro Velazquez-Salinas
- Agricultural Research Service (ARS), Plum Island Animal Disease Center, Greenport, NY, 11944, USA.,Department of Anatomy and Physiology, Kansas State University, Manhattan, KS, 66506, USA
| | - Douglas P Gladue
- Agricultural Research Service (ARS), Plum Island Animal Disease Center, Greenport, NY, 11944, USA.
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42
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Ramírez-Medina E, Vuono EA, Velazquez-Salinas L, Silva E, Rai A, Pruitt S, Berggren KA, Zhu J, Borca MV, Gladue DP. The MGF360-16R ORF of African Swine Fever Virus Strain Georgia Encodes for a Nonessential Gene That Interacts with Host Proteins SERTAD3 and SDCBP. Viruses 2020; 12:E60. [PMID: 31947814 PMCID: PMC7020080 DOI: 10.3390/v12010060] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Revised: 12/23/2019] [Accepted: 12/27/2019] [Indexed: 12/15/2022] Open
Abstract
African swine fever virus (ASFV) causes a contagious and frequently lethal disease of pigs with significant economic consequences to the swine industry. The ASFV genome encodes for more than 160 genes, but only a few of them have been studied in detail. Here we report the characterization of open reading frame (ORF) MGF360-16R. Kinetic studies of virus RNA transcription demonstrated that the MGF360-16R gene is transcribed as a late virus protein. Analysis of host-protein interactions for the MGF360-16R gene using a yeast two-hybrid screen identified SERTA domain containing 3 (SERTAD3) and syndecan-binding protein (SDCBP) as host protein binding partners. SERTAD3 and SDCBP are both involved in nuclear transcription and SDCBP has been shown to be involved in virus traffic inside the host cell. Interaction between MGF360-16R and SERTAD3 and SDCBP host proteins was confirmed in eukaryotic cells transfected with plasmids expressing MGF360-16R and SERTAD3 or SDCBP fused to fluorescent tags. A recombinant ASFV lacking the MGF360-16R gene (ASFV-G-ΔMGF360-16R) was developed from the highly virulent field isolate Georgia2007 (ASFV-G) and was used to show that MGF360-16R is a nonessential gene. ASFV-G-ΔMGF360-16R had a similar replication ability in primary swine macrophage cell cultures when compared to its parental virus ASFV-G. Experimental infection of domestic pigs showed that ASFV-G-ΔMGF360-16R is as virulent as the parental virus ASFV-G.
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Affiliation(s)
- Elizabeth Ramírez-Medina
- Agricultural Research Service, Plum Island Animal Disease Center, Greenport, NY 11944, USA; (E.R.-M.); (E.A.V.); (L.V.-S.); (E.S.); (A.R.); (S.P.); (K.A.B.); (J.Z.)
- Department of Pathobiology, University of Connecticut, Storrs, CT 06268, USA
| | - Elizabeth A. Vuono
- Agricultural Research Service, Plum Island Animal Disease Center, Greenport, NY 11944, USA; (E.R.-M.); (E.A.V.); (L.V.-S.); (E.S.); (A.R.); (S.P.); (K.A.B.); (J.Z.)
- Department of Pathobiology and Population Medicine, Mississippi State University, P.O. Box 6100, Starkville, MS 39762, USA
| | - Lauro Velazquez-Salinas
- Agricultural Research Service, Plum Island Animal Disease Center, Greenport, NY 11944, USA; (E.R.-M.); (E.A.V.); (L.V.-S.); (E.S.); (A.R.); (S.P.); (K.A.B.); (J.Z.)
- College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA
| | - Ediane Silva
- Agricultural Research Service, Plum Island Animal Disease Center, Greenport, NY 11944, USA; (E.R.-M.); (E.A.V.); (L.V.-S.); (E.S.); (A.R.); (S.P.); (K.A.B.); (J.Z.)
- Department of Pathobiology and Population Medicine, Mississippi State University, P.O. Box 6100, Starkville, MS 39762, USA
| | - Ayushi Rai
- Agricultural Research Service, Plum Island Animal Disease Center, Greenport, NY 11944, USA; (E.R.-M.); (E.A.V.); (L.V.-S.); (E.S.); (A.R.); (S.P.); (K.A.B.); (J.Z.)
- Oak Ridge Institute for Science and Education, Oak Ridge, TN 37830, USA
| | - Sarah Pruitt
- Agricultural Research Service, Plum Island Animal Disease Center, Greenport, NY 11944, USA; (E.R.-M.); (E.A.V.); (L.V.-S.); (E.S.); (A.R.); (S.P.); (K.A.B.); (J.Z.)
- Oak Ridge Institute for Science and Education, Oak Ridge, TN 37830, USA
| | - Keith A. Berggren
- Agricultural Research Service, Plum Island Animal Disease Center, Greenport, NY 11944, USA; (E.R.-M.); (E.A.V.); (L.V.-S.); (E.S.); (A.R.); (S.P.); (K.A.B.); (J.Z.)
| | - James Zhu
- Agricultural Research Service, Plum Island Animal Disease Center, Greenport, NY 11944, USA; (E.R.-M.); (E.A.V.); (L.V.-S.); (E.S.); (A.R.); (S.P.); (K.A.B.); (J.Z.)
| | - Manuel V. Borca
- Agricultural Research Service, Plum Island Animal Disease Center, Greenport, NY 11944, USA; (E.R.-M.); (E.A.V.); (L.V.-S.); (E.S.); (A.R.); (S.P.); (K.A.B.); (J.Z.)
| | - Douglas P. Gladue
- Agricultural Research Service, Plum Island Animal Disease Center, Greenport, NY 11944, USA; (E.R.-M.); (E.A.V.); (L.V.-S.); (E.S.); (A.R.); (S.P.); (K.A.B.); (J.Z.)
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Forth JH, Forth LF, King J, Groza O, Hübner A, Olesen AS, Höper D, Dixon LK, Netherton CL, Rasmussen TB, Blome S, Pohlmann A, Beer M. A Deep-Sequencing Workflow for the Fast and Efficient Generation of High-Quality African Swine Fever Virus Whole-Genome Sequences. Viruses 2019; 11:v11090846. [PMID: 31514438 PMCID: PMC6783980 DOI: 10.3390/v11090846] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 09/05/2019] [Accepted: 09/09/2019] [Indexed: 12/14/2022] Open
Abstract
African swine fever (ASF) is a severe disease of suids caused by African swine fever virus (ASFV). Its dsDNA genome (170-194 kbp) is scattered with homopolymers and repeats as well as inverted-terminal-repeats (ITR), which hamper whole-genome sequencing. To date, only a few genome sequences have been published and only for some are data on sequence quality available enabling in-depth investigations. Especially in Europe and Asia, where ASFV has continuously spread since its introduction into Georgia in 2007, a very low genetic variability of the circulating ASFV-strains was reported. Therefore, only whole-genome sequences can serve as a basis for detailed virus comparisons. Here, we report an effective workflow, combining target enrichment, Illumina and Nanopore sequencing for ASFV whole-genome sequencing. Following this approach, we generated an improved high-quality ASFV Georgia 2007/1 whole-genome sequence leading to the correction of 71 sequencing errors and the addition of 956 and 231 bp at the respective ITRs. This genome, derived from the primary outbreak in 2007, can now serve as a reference for future whole-genome analyses of related ASFV strains and molecular approaches. Using both workflow and the reference genome, we generated the first ASFV-whole-genome sequence from Moldova, expanding the sequence knowledge from Eastern Europe.
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Affiliation(s)
- Jan H Forth
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, 17493 Greifswald - Insel Riems, Germany.
| | - Leonie F Forth
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, 17493 Greifswald - Insel Riems, Germany.
| | - Jacqueline King
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, 17493 Greifswald - Insel Riems, Germany.
| | - Oxana Groza
- Animal Health Diagnostic Laboratory, Republican Center for Veterinary Diagnostic, str. Murelor, 3, MD-2051, mun. Chișinău, Moldova.
| | - Alexandra Hübner
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, 17493 Greifswald - Insel Riems, Germany.
| | - Ann Sofie Olesen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, DK-1870 Frederiksberg C, Denmark.
| | - Dirk Höper
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, 17493 Greifswald - Insel Riems, Germany.
| | - Linda K Dixon
- The Pirbright Institute, Ash Road, Pirbright, Woking, GU24 0NF, UK.
| | | | - Thomas Bruun Rasmussen
- DTU National Veterinary Institute, Technical University of Denmark, Lindholm, DK-4771 Kalvehave, Denmark.
- Department of Virus & Microbiological Special Diagnostics, Statens Serum Institut, DK-2300 Copenhagen S, Denmark.
| | - Sandra Blome
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, 17493 Greifswald - Insel Riems, Germany.
| | - Anne Pohlmann
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, 17493 Greifswald - Insel Riems, Germany.
| | - Martin Beer
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, 17493 Greifswald - Insel Riems, Germany.
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C G, I N, A S, V D, A S, E M, C P, R N, M A. Evolution in Europe of African swine fever genotype II viruses from highly to moderately virulent. Vet Microbiol 2018; 219:70-79. [PMID: 29778207 DOI: 10.1016/j.vetmic.2018.04.001] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 04/01/2018] [Accepted: 04/02/2018] [Indexed: 10/17/2022]
Abstract
Since its arrival in the Caucasus and Russia in 2007, African swine fever virus (ASFV) has spread widely and has now affected the EU countries of Estonia, Latvia, Lithuania, Poland and, more recently, the Czech Republic and Romania. The ever-increasing evidence of seropositive wild boar in certain areas suggests that some animals may be surviving for some time or could even be recovering from the disease. This could be due to acquired immunity after the primary infection and/or the presence of related viruses of reduced virulence. To assess these hypotheses, two ASFV field strains from Estonia were studied in vivo in two groups of domestic pigs. After an incubation period of 4 ± 1.6 days, the pigs inoculated intramuscularly with Es15/WB-Tartu 14 ASFV (group 2) developed clinical signs associated with acute disease and succumbed 7 and 11 days post infection (dpi). Pigs inoculated with Es15/WB-Valga-14 ASFV (group 1) had longer incubation times (8 days) than those in group 2 and developed variable clinical signs and lesions compatible with subacute and chronic forms of ASF; they succumbed at 11 and 25 dpi. The in-contact pigs in both groups became infected 7-14 days after exposure and exhibited variable clinical manifestations and pathological findings ranging from acute to chronic disease. Two animals per group recovered completely after infection and were protected against a subsequent homologous virus challenge-exposure performed at 78 dpi. Under experimental conditions, no transmission occurred from the survivors to susceptible sentinel pigs housed together with the survivors 137 days after the primary infection.
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Affiliation(s)
- Gallardo C
- European Union Reference Laboratory for African Swine Fever (EURL), Centro de Investigación en Sanidad Animal, INIA-CISA, Valdeolmos, 28130, Madrid, Spain.
| | - Nurmoja I
- Estonian NRL: Estonian Veterinary and Food Laboratory, Kreutzwaldi 30, Tartu, 51006, Estonia
| | - Soler A
- European Union Reference Laboratory for African Swine Fever (EURL), Centro de Investigación en Sanidad Animal, INIA-CISA, Valdeolmos, 28130, Madrid, Spain
| | - Delicado V
- European Union Reference Laboratory for African Swine Fever (EURL), Centro de Investigación en Sanidad Animal, INIA-CISA, Valdeolmos, 28130, Madrid, Spain
| | - Simón A
- European Union Reference Laboratory for African Swine Fever (EURL), Centro de Investigación en Sanidad Animal, INIA-CISA, Valdeolmos, 28130, Madrid, Spain
| | - Martin E
- European Union Reference Laboratory for African Swine Fever (EURL), Centro de Investigación en Sanidad Animal, INIA-CISA, Valdeolmos, 28130, Madrid, Spain
| | - Perez C
- European Union Reference Laboratory for African Swine Fever (EURL), Centro de Investigación en Sanidad Animal, INIA-CISA, Valdeolmos, 28130, Madrid, Spain
| | - Nieto R
- European Union Reference Laboratory for African Swine Fever (EURL), Centro de Investigación en Sanidad Animal, INIA-CISA, Valdeolmos, 28130, Madrid, Spain
| | - Arias M
- European Union Reference Laboratory for African Swine Fever (EURL), Centro de Investigación en Sanidad Animal, INIA-CISA, Valdeolmos, 28130, Madrid, Spain
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45
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The L83L ORF of African swine fever virus strain Georgia encodes for a non-essential gene that interacts with the host protein IL-1β. Virus Res 2018; 249:116-123. [PMID: 29605728 DOI: 10.1016/j.virusres.2018.03.017] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 03/26/2018] [Accepted: 03/27/2018] [Indexed: 01/01/2023]
Abstract
African swine fever virus (ASFV) causes a contagious and frequently lethal disease of pigs causing significant economic consequences to the swine industry. The ASFV genome encodes for more than 150 genes, but only a few of them have been studied in detail. Here we report the characterization of open reading frame L83L which encodes a highly conserved protein across all ASFV isolates. A recombinant ASFV harboring a HA tagged L83L protein was developed (ASFV-G-L83L-HA) and used to demonstrate that L83L is a transiently expressed early virus protein. A recombinant ASFV lacking the L83L gene (ASFV-G-ΔL83L) was developed from the highly virulent field isolate Georgia2007 (ASFV-G) and was used to show that L83L is a non-essential gene. ASFV-G-ΔL83L had similar replication in primary swine macrophage cells when compared to its parental virus ASFV-G. Analysis of host-protein interactions for L83L identified IL-1β as its host ligand. Experimental infection of domestic pigs showed that ASFV-G-ΔL83L is as virulent as the parental virus ASFV-G.
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46
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Borca MV, Holinka LG, Berggren KA, Gladue DP. CRISPR-Cas9, a tool to efficiently increase the development of recombinant African swine fever viruses. Sci Rep 2018; 8:3154. [PMID: 29453406 PMCID: PMC5816594 DOI: 10.1038/s41598-018-21575-8] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 02/07/2018] [Indexed: 01/26/2023] Open
Abstract
African swine fever virus (ASFV) causes a highly contagious disease called African swine fever. This disease is often lethal for domestic pigs, causing extensive losses for the swine industry. ASFV is a large and complex double stranded DNA virus. Currently there is no commercially available treatment or vaccine to prevent this devastating disease. Development of recombinant ASFV for producing live-attenuated vaccines or studying the involvement of specific genes in virus virulence has relied on the relatively rare event of homologous recombination in primary swine macrophages, causing difficulty to purify the recombinant virus from the wild-type parental ASFV. Here we present the use of the CRISPR-Cas9 gene editing system as a more robust and efficient system to produce recombinant ASFVs. Using CRISPR-Cas9 a recombinant virus was efficiently developed by deleting the non-essential gene 8-DR from the genome of the highly virulent field strain Georgia07 using swine macrophages as cell substrate.
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Affiliation(s)
- Manuel V Borca
- Agricultural Research Service (ARS), Plum Island Animal Disease Center, Greenport, NY, 11944, USA
| | - Lauren G Holinka
- Agricultural Research Service (ARS), Plum Island Animal Disease Center, Greenport, NY, 11944, USA
| | - Keith A Berggren
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN, 37831, USA
| | - Douglas P Gladue
- Agricultural Research Service (ARS), Plum Island Animal Disease Center, Greenport, NY, 11944, USA.
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