1
|
Chen Q, Liu L, Guo S, Li L, Yu Y, Liu Z, Tan C, Chen H, Wang X. Characterization of the monoclonal antibody and the immunodominant B-cell epitope of African swine fever virus pA104R by using mouse model. Microbiol Spectr 2024; 12:e0140123. [PMID: 38305163 PMCID: PMC10913377 DOI: 10.1128/spectrum.01401-23] [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: 04/05/2023] [Accepted: 12/20/2023] [Indexed: 02/03/2024] Open
Abstract
The African swine fever virus (ASFV) structural protein pA104R is the only histone-like protein encoded by eukaryotic viruses. pA104R is an essential DNA-binding protein required for DNA replication and genome packaging of ASFV, which are vital for pathogen survival and proliferation. pA104R is an important target molecule for diagnosing, treating, and immune prevention of ASFV. This study characterized monoclonal antibodies (mAbs) against pA104R and found them to recognize natural pA104R in ASFV strains with different genotypes, showing high conservation. Confirmation analyses of pA104R epitopes using mAbs indicated the presence of immunodominant B-cell epitopes, and further characterization showed the high antigenic index and surface accessibility coefficients of the identified epitope. Furthermore, the pA104R protein functions through the polar interactions between the binding amino acid sites; however, these interactions may be blocked by the recognition of generated mAbs. Characterizing the immunodominant B-cell epitope of the ASFV critical proteins, such as pA104R, may contribute to developing sensitive diagnostic tools and vaccine candidate targets.IMPORTANCEAfrican swine fever (ASF) is a highly pathogenic, lethal, and contagious viral disease affecting domestic pigs and wild boars. As no effective vaccine or other treatments have been developed, the control of African swine fever virus (ASFV) relies heavily on virus detection and diagnosis. A potential serological target is the structural protein pA104R. However, the molecular basis of pA104R antigenicity remains unclear, and a specific monoclonal antibody (mAb) against this protein is still unavailable. In this study, mAbs against pA104R were characterized and found to recognize natural pA104R in ASFV strains with different genotypes. In addition, confirmation analyses of pA104R epitopes using mAbs indicated the presence of immunodominant B-cell epitopes, and further characterization showed the high antigenic index and surface accessibility coefficients of the identified epitope. Characteristics of the immunodominant B-cell epitope of ASFV proteins, such as pA104R, may contribute to developing sensitive diagnostic tools and identifying vaccine candidate targets.
Collapse
Affiliation(s)
- Qichao Chen
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Lixinjie Liu
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Shibang Guo
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Liang Li
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Yifeng Yu
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Zhankui Liu
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Chen Tan
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
- Key Laboratory of Prevention & Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, Wuhan, China
- International Research Center for Animal Disease, Ministry of Science and Technology of the People’s Republic of China, Wuhan, China
| | - Huanchun Chen
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
- Key Laboratory of Prevention & Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, Wuhan, China
- International Research Center for Animal Disease, Ministry of Science and Technology of the People’s Republic of China, Wuhan, China
| | - Xiangru Wang
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
- Key Laboratory of Prevention & Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, Wuhan, China
- International Research Center for Animal Disease, Ministry of Science and Technology of the People’s Republic of China, Wuhan, China
| |
Collapse
|
2
|
Li DY, Cui XY, Huang XY, Hu Y, Tian XX, Wang T, Yang YB, Wang Q, Tian ZJ, Cai XH, An TQ. Characterization of Two Immunodominant Antigenic Peptides in NSP2 of PRRSV-2 and Generation of a Marker PRRSV Strain Based on the Peptides. Front Vet Sci 2022; 9:902822. [PMID: 35706603 PMCID: PMC9189411 DOI: 10.3389/fvets.2022.902822] [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: 03/23/2022] [Accepted: 04/28/2022] [Indexed: 11/13/2022] Open
Abstract
Porcine reproductive and respiratory syndrome (PRRS) is a widespread disease with great economic importance in the pig industry. Although vaccines against the PRRS virus (PRRSV) have been employed for more than 20 years, differentiating infected from vaccinated animals remains challenging. In this study, all 907 non-structural protein 2 (NSP2) full-length sequences of PRRSV-2 available from GenBank were aligned. Two peptides, at positions 562–627 (m1B) and 749–813 (m2B) of NSP2, were selected, and their potential for use in differential diagnosis was assessed. Both m1B and m2B were recognized by PRRSV-positive pig serum in peptide-coated enzyme-linked immunosorbent assays. Further epitope identification yielded five overlapping short peptides for the immunodominant regions of m1B and m2B. Using the infectious clone of PRRSV HuN4-F112 as a template, the deletion mutants, rHuN4-F112-m1B, rHuN4-F112-m2B, and rHuN4-F112-C5-m1B-m2B, were generated and successfully rescued in Marc-145 cells. Growth kinetics revealed that the deletion of m1B and m2B did not significantly affect virus replication. Hence, m1B and m2B show potential as molecular markers for developing a PRRSV vaccine.
Collapse
|
3
|
Identification of a B-Cell Epitope in the VP3 Protein of Senecavirus A. Viruses 2021; 13:v13112300. [PMID: 34835106 PMCID: PMC8621820 DOI: 10.3390/v13112300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 11/11/2021] [Accepted: 11/16/2021] [Indexed: 12/03/2022] Open
Abstract
Senecavirus A (SVA) is a member of the genus Senecavirus of the family Picornaviridae. SVA-associated vesicular disease (SAVD) outbreaks have been extensively reported since 2014–2015. Characteristic symptoms include vesicular lesions on the snout and feet as well as lameness in adult pigs and even death in piglets. The capsid protein VP3, a structural protein of SVA, is involved in viral replication and genome packaging. Here, we developed and characterized a mouse monoclonal antibody (mAb) 3E9 against VP3. A motif 192GWFSLHKLTK201 was identified as the linear B-cell epitope recognized by mAb 3E9 by using a panel of GFP-tagged epitope polypeptides. Sequence alignments show that 192GWFSLHKLTK201 was highly conserved in all SVA strains. Subsequently, alanine (A)-scanning mutagenesis indicated that W193, F194, L196, and H197 were the critical residues recognized by mAb 3E9. Further investigation with indirect immunofluorescence assay indicated that the VP3 protein was present in the cytoplasm during SVA replication. In addition, the mAb 3E9 specifically immunoprecipitated the VP3 protein from SVA-infected cells. Taken together, our results indicate that mAb 3E9 could be a powerful tool to work on the function of the VP3 protein during virus infection.
Collapse
|
4
|
Kong N, Meng Q, Jiao Y, Wu Y, Zuo Y, Wang H, Sun D, Dong S, Zhai H, Tong W, Zheng H, Yu H, Tong G, Xu Y, Shan T. Identification of a novel B-cell epitope in the spike protein of porcine epidemic diarrhea virus. Virol J 2020; 17:46. [PMID: 32245493 PMCID: PMC7119268 DOI: 10.1186/s12985-020-01305-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Accepted: 02/26/2020] [Indexed: 01/02/2023] Open
Abstract
Background Porcine epidemic diarrhea virus (PEDV) infection causes an acute enteric tract infectious disease characterized by vomiting, anorexia, dehydration, weight loss and high mortality in neonatal piglets. During PEDV infection, the spike protein (S) is a major virion structural protein interacting with receptors and inducing neutralizing antibodies. However, the neutralizing B-cell epitopes within PEDV S protein have not been well studied. Methods To accurately identify the important immunodominant region of S1, the purified truncated S1 proteins (SA, SB, SC, SD and SE) were used to immunize BALB/c mice to prepare polyclonal antibodies. The antisera titers were determined by indirect ELISA, western blot and IFA after four immunizations to find the important immunodominant region of S1, and then purified the immunodominant region of S1 protein and immunized mice to generate the special antibodies, and then used recombinant peptides to determine the B-cell epitopes of monoclonal antibodies. Results Five antisera of recombinant proteins of the spike protein region of PEDV were generated and we found that only the polyclonal antibody against part of the S1 region (signed as SE protein, residues 666–789) could recognize the native PEDV. Purified SE protein was used to immunize BALB/c mice and generate mAb 2E10. Pepscan of the SE protein demonstrated that SE16 (722SSTFNSTREL731) is the minimal linear epitope required for reactivity with the mAb 2E10. Further investigation indicated that the epitope SE16 was localized on the surface of PEDV S protein in the 3D structure. Conclusions A mAb 2E10 that is specifically bound to PEDV was generated and identified a specific linear B-cell epitope (SE16, 722SSTFNSTREL731) of the mAb. The epitope region of PEDV S1 localized in the different regions in comparison with the earlier identified epitopes. These findings enhance the understanding of the PEDV spike protein structure for vaccine design and provide a potential use for developing diagnostic methods to detect PEDV.
Collapse
Affiliation(s)
- Ning Kong
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China.,Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonosis, Yangzhou University, Yangzhou, People's Republic of China
| | - Qiong Meng
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China.,College of Life Science, Xinyang Normal University, Xinyang, China
| | - Yajuan Jiao
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China
| | - Yongguang Wu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China
| | - Yewen Zuo
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China
| | - Hua Wang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China
| | - Dage Sun
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China
| | - Sujie Dong
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China
| | - Huanjie Zhai
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China
| | - Wu Tong
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China.,Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonosis, Yangzhou University, Yangzhou, People's Republic of China
| | - Hao Zheng
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China.,Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonosis, Yangzhou University, Yangzhou, People's Republic of China
| | - Hai Yu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China.,Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonosis, Yangzhou University, Yangzhou, People's Republic of China
| | - Guangzhi Tong
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China.,Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonosis, Yangzhou University, Yangzhou, People's Republic of China
| | - Yongjie Xu
- College of Life Science, Xinyang Normal University, Xinyang, China.
| | - Tongling Shan
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China. .,Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonosis, Yangzhou University, Yangzhou, People's Republic of China.
| |
Collapse
|
5
|
Liu W, Shao J, Chen D, Chang Y, Chang H, Zhang Y. Identification of three linear B cell epitopes against non-structural protein 3ABC of FMDV using monoclonal antibodies. Appl Microbiol Biotechnol 2019; 103:8075-8086. [PMID: 31463546 DOI: 10.1007/s00253-019-10081-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 07/24/2019] [Accepted: 07/31/2019] [Indexed: 01/09/2023]
Abstract
Foot-and-mouth disease virus (FMDV) has led to serious losses in the farming industry worldwide, particularly in cattle and swine. In developing countries, the control and eradication of FMD rely upon vaccination, in which the inactivated vaccine is predominant. In the preparation of inactivated vaccine, a series of purification methods were used to remove non-structural proteins (NSPs). It is necessary to develop a quantitative detection method of residual NSP and confirm a threshold value for the evaluation of the vaccine. Meanwhile, it is also important to develop a sensitive and rapid diagnostic method to distinguish infected animals from vaccinated animals (DIVA). In this study, three monoclonal antibodies (MAbs) against NSP 3ABC, designated 2G5, 9E2, and 1E10, were used. Subsequently, a series of overlapping peptides were expressed using a prokaryotic expression system to determine the minimal epitopes identified by the MAbs. Three linear B cell epitopes (BCEs), "92EYIEKA97" "23EGPYAGPLE31" and "209EPHH212", were identified by MAbs 2G5, 9E2, and 1E10, respectively. Alanine-scanning mutagenesis analysis confirmed the critical amino acid in these epitopes. The epitope "92EYIEKA97" is located in 3A, which is deleted in some natural deletion mutants that result in a change in virus tropism. MAb 9E2 that identified the epitope "23EGPYAGPLE31" reacted with 3B1 and 3B2, but did not react with 3B3. In combination with sequence alignment analysis, the epitope "23EGPYAGPLE31" is highly conserved among different FMDV isolates. Preliminary screening using the known positive and negative sera indicated the MAb 9E2 has the potential for the development of a diagnostic method for DIVA. The residual NSP in inactivated vaccines can be detected using 9E2-HRP, which indicated the MAb 9E2 is able to evaluate inactivated vaccines. The four-amino acid epitope is the first reported to date that is recognized by 1E10. These results provide valuable insight into the diagnosis of DIVA and the NSP residual evaluation in inactivated vaccines.
Collapse
Affiliation(s)
- Wei Liu
- State Key Laboratory of Veterinary Etiological Biology, National Foot-and-Mouth Diseases Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China
| | - Junjun Shao
- State Key Laboratory of Veterinary Etiological Biology, National Foot-and-Mouth Diseases Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China
| | - Danian Chen
- State Key Laboratory of Veterinary Etiological Biology, National Foot-and-Mouth Diseases Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, China
| | - Yanyan Chang
- State Key Laboratory of Veterinary Etiological Biology, National Foot-and-Mouth Diseases Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China
| | - Huiyun Chang
- State Key Laboratory of Veterinary Etiological Biology, National Foot-and-Mouth Diseases Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, China.
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China.
| | - Yongguang Zhang
- State Key Laboratory of Veterinary Etiological Biology, National Foot-and-Mouth Diseases Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, China.
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China.
| |
Collapse
|