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Yang B, Meng R, Feng C, Huang J, Li Q, Wang X, Zhang D. An Antibody Neutralization Determinant on Domain III and the First α-Helical Domain in the Stem-Anchor Region of Tembusu Virus Envelope Protein. THE JOURNAL OF IMMUNOLOGY 2022; 209:684-695. [DOI: 10.4049/jimmunol.2200226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 06/06/2022] [Indexed: 01/04/2023]
Abstract
Abstract
Previous studies identified three neutralizing epitopes on domains I, II, and III of the Tembusu virus (TMUV) envelope (E). More evidence is needed to understand the molecular basis of Ab-mediated neutralization and protection against TMUV. In this study, we observed a neutralizing mAb, 6C8, that neutralized TMUV infection primarily by inhibiting cell attachment. In immunofluorescence assays, 6C8 recognized the premembrane and E proteins coexpressed in HEK-293T cells, but failed to react with premembrane or E expressed individually. Epitope mapping identified nine E protein residues positioned on BC/EF loops and F/G strands in domain III and the first α-helical domain in the stem region. Further investigation with mutant viruses showed that 6C8 pressure resulted in mutations at residues 330 of BC loop and 409 of the first α-helical domain, although 6C8 only exhibited a moderate neutralizing activity in BHK-21 cells and a weak protective activity in BALB/c mice and Shaoxing duck models. Mutations A330S and T409M conferred high- and low-level 6C8 resistance, respectively, whereas the combination of A330S and T409M mutations conferred moderate-level 6C8 resistance. As a result, a quasispecies comprising three groups of antigenic variants appeared in BHK-21 cell–derived viral stocks after repeated passages of TMUV strain Y in the presence of 6C8 treatment. Taken together, these findings have raised a concern about Ab-induced antigenic variations in vivo, and they have revealed information concerning the conformational structure of the 6C8 epitope and its role in constraint on antigenic variations. The present work contributes to a better understanding of the complexity of the TMUV immunogen.
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Affiliation(s)
- Baolin Yang
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Runze Meng
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Chonglun Feng
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Jingjing Huang
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Qiong Li
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xiaoyan Wang
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Dabing Zhang
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
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Meng R, Yang B, Feng C, Huang J, Wang X, Zhang D. The difference in CD4+ T cell immunity between high- and low-virulence Tembusu viruses is mainly related to residues 151 and 304 in the envelope protein. Front Immunol 2022; 13:890263. [PMID: 36016955 PMCID: PMC9395619 DOI: 10.3389/fimmu.2022.890263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Accepted: 07/20/2022] [Indexed: 11/22/2022] Open
Abstract
Tembusu virus (TMUV) can result in a severe disease affecting domestic ducks. The role of T cells in protection from TMUV infection and the molecular basis of T cell-mediated protection against TMUV remain largely uncharacterized. Here, we used the high-virulence TMUV strain Y and the low-virulence TMUV strain PS to investigate the protective role for TMUV-specific CD4+ and CD8+ T cells. When tested in a 5-day-old Pekin duck model, Y and PS induced comparable levels of neutralizing antibody, whereas Y elicited significantly stronger cellular immune response relative to PS. Using a duck adoptive transfer model, we showed that both CD4+ and CD8+ T cells provided significant protection from TMUV-related disease, with CD8+ T cell conferring more robust protection to recipient ducklings. For TMUV, CD4+ T cells mainly provided help for neutralizing antibody response, whereas CD8+ T cells mainly mediated viral clearance from infected tissues. The difference in T cell immunity between Y and PS was primarily attributed to CD4+ T cells; adoptive transfer of Y-specific CD4+ T cells resulted in significantly enhanced protective ability, neutralizing antibody response, and viral clearance from the brain relative to PS-specific CD4+ T cells. Further investigations with chimeric viruses, mutant viruses, and their parental viruses identified two mutations (T151A and R304M) in the envelope (E) protein that contributed significantly to TMUV-specific CD4+ T cell-mediated protective ability and neutralizing antibody response, with more beneficial effects being conferred by R304M. These data indicate T cell-mediated immunity is important for protection from disease, for viral clearance from tissues, and for the production of neutralizing antibodies, and that the difference in CD4+T cell immunity between high- and low-virulence TMUV strains is primarily related to residues 151 and 304 in the E protein.
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Zhang L, Li Z, Tang Z, Han L, Wei X, Xie X, Ren S, Meng K, Liu Y, Xu M, Qi L, Chen H, Wu J, Zhang N. Efficient Identification of Tembusu Virus CTL Epitopes in Inbred HBW/B4 Ducks Using a Novel MHC Class I-Restricted Epitope Screening Scheme. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2022; 209:145-156. [PMID: 35623661 DOI: 10.4049/jimmunol.2100382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 04/28/2022] [Indexed: 06/15/2023]
Abstract
The identification of MHC class I-restricted CTL epitopes in certain species, particularly nonmammals, remains a challenge. In this study, we developed a four-step identification scheme and confirmed its efficiency by identifying the Anpl-UAA*76-restricted CTL epitopes of Tembusu virus (TMUV) in inbred haplotype ducks HBW/B4. First, the peptide binding motif of Anpl-UAA*76 was determined by random peptide library in de novo liquid chromatography-tandem mass spectrometry, a novel nonbiased, data-independent acquisition method that we previously established. Second, a total of 38 TMUV peptides matching the motif were screened from the viral proteome, among which 11 peptides were conserved across the different TMUV strains. Third, the conserved TMUV peptides were refolded in vitro with Anpl-UAA*76 and Anpl-β2-microglobulin to verify the results from the previous two steps. To clarify the structural basis of the obtained motif, we resolved the crystal structure of Anpl-UAA*76 with the TMUV NS3 peptide LRKRQLTVL and found that Asp34 is critical for the preferential binding of the B pocket to bind the second residue to arginine as an anchor residue. Fourth, the immunogenicity of the conserved TMUV peptides was tested in vivo using specific pathogen-free HBW/B4 ducks immunized with the attenuated TMUV vaccine. All 11 conserved TMUV epitopes could bind stably to Anpl-UAA*76 in vitro and stimulate the secretion of IFN-γ and lymphocyte proliferation, and three conserved and one nonconserved peptides were selected to evaluate the CTL responses in vivo by flow cytometry and their tetramers. We believe that this new scheme could improve the identification of MHC class I-restricted CTL epitopes, and our data provide a foundation for further study on duck anti-TMUV CTL immunity.
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Affiliation(s)
- Lin Zhang
- Shandong Key Laboratory of Disease Control and Breeding, Institute of Animal Science and Veterinary Medicine, Shandong Academy of Agricultural Sciences, Jinan, China
| | - Zhuolin Li
- Department of Microbiology and Immunology, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Ziche Tang
- Department of Microbiology and Immunology, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Lingxia Han
- Division of Laboratory Animal and Comparative Medicine, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, Heilongjiang, China
| | - Xiaohui Wei
- Department of Microbiology and Immunology, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xiaoli Xie
- Department of Microbiology and Immunology, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Shuaimeng Ren
- Shandong Key Laboratory of Disease Control and Breeding, Institute of Animal Science and Veterinary Medicine, Shandong Academy of Agricultural Sciences, Jinan, China
- College of Life Sciences and Food Engineering, Hebei University of Engineering, Handan, Hebei, China
| | - Kai Meng
- Shandong Key Laboratory of Poultry Diseases Diagnosis and Immunology, Institute of Poultry, Shandong Academy of Agricultural Sciences, Jinan, China
| | - Yueyue Liu
- Shandong Key Laboratory of Poultry Diseases Diagnosis and Immunology, Institute of Poultry, Shandong Academy of Agricultural Sciences, Jinan, China
| | - Minli Xu
- Shandong Key Laboratory of Disease Control and Breeding, Institute of Animal Science and Veterinary Medicine, Shandong Academy of Agricultural Sciences, Jinan, China
| | - Lihong Qi
- Shandong Key Laboratory of Poultry Diseases Diagnosis and Immunology, Institute of Poultry, Shandong Academy of Agricultural Sciences, Jinan, China
| | - Hongyan Chen
- Division of Laboratory Animal and Comparative Medicine, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, Heilongjiang, China
| | - Jiaqiang Wu
- Shandong Key Laboratory of Disease Control and Breeding, Institute of Animal Science and Veterinary Medicine, Shandong Academy of Agricultural Sciences, Jinan, China;
- Shandong Key Laboratory of Poultry Diseases Diagnosis and Immunology, Institute of Poultry, Shandong Academy of Agricultural Sciences, Jinan, China
- Key Laboratory of Animal Resistant Biology of Shandong, College of Life Sciences, Shandong Normal University, Jinan, China; and
| | - Nianzhi Zhang
- Department of Microbiology and Immunology, College of Veterinary Medicine, China Agricultural University, Beijing, China;
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, China Agricultural University, Beijing, China
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Li Q, Feng C, Yang B, Meng R, Wang X, Zhang D. Antibody prophylaxis against Tembusu virus-associated disease. Arch Virol 2022; 167:1687-1691. [PMID: 35639191 DOI: 10.1007/s00705-022-05460-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 03/24/2022] [Indexed: 11/27/2022]
Abstract
Earlier studies have shown that Tembusu virus (TMUV) can elicit high levels of neutralizing antibodies, but the ability of antibodies to protect against TMUV-associated disease and to inhibit replication of TMUV in vivo remains to be investigated. Here, we tested the prophylactic efficacy of TMUV immune serum directly using a 2-day-old Pekin duck model. Passive administration of the immune serum prior to challenge protected ducklings against morbidity and mortality, substantially reduced TMUV-caused tissue injury, and significantly decreased TMUV levels in the periphery and central nervous system. These findings demonstrate that antibodies play a dominant protective role in controlling TMUV-associated disease.
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Affiliation(s)
- Qiong Li
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, People's Republic of China
| | - Chonglun Feng
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, People's Republic of China
| | - Baolin Yang
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, People's Republic of China
| | - Runze Meng
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, People's Republic of China
| | - Xiaoyan Wang
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, People's Republic of China
| | - Dabing Zhang
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, People's Republic of China.
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Yu Z, Ren H, Sun M, Xie W, Sun S, Liang N, Wang H, Ying X, Sun Y, Wang Y, Zheng Y, Hu X, Su J. Tembusu virus infection in laying chickens: Evidence for a distinct genetic cluster with significant antigenic variation. Transbound Emerg Dis 2021; 69:e1130-e1141. [PMID: 34821052 DOI: 10.1111/tbed.14402] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 10/28/2021] [Accepted: 11/10/2021] [Indexed: 11/27/2022]
Abstract
Tembusu virus (TMUV) associated disease is a growing cause of egg production decrease and encephalitis in domestic waterfowl, with expanding distribution. In previous studies, TMUV isolates were phylogenetically classified into two genetic lineages and different clusters with varied pathogenicity. However, little is known about the phenotypic and virulence characteristics of cluster 3 isolates within the duck TMUV lineage. In this study, the etiological agent causing egg drop in a laying chicken farm in southern China was investigated and a TMUV was isolated from pooled tissue samples. Genome sequencing and phylogenetic analysis grouped the isolate into TMUV cluster 3 with closest relation to the mosquito-origin TMUV YN12193. Cross-neutralization testing using convalescent sera revealed significant antigenic variation between the isolate and a representative strain of cluster 2.2. The experimental infection of SPF hens confirmed the ability of the isolate to replicate in multiple tissues and led to ovary damage. Additionally, high seroconversion rates (95.83%-100%) were detected in the three flocks following retrospective investigation. Our study demonstrates the occurrence of cluster 3 TMUV infection in laying chickens and that the virus exhibits significant antigenic variation compared with cluster 2 TMUV.
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Affiliation(s)
- Ziding Yu
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Hang Ren
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Mengxu Sun
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Wanying Xie
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Songsong Sun
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Ning Liang
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Haijian Wang
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xiaoqiang Ying
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Yuxi Sun
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Yuling Wang
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Yunping Zheng
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xueying Hu
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Jingliang Su
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
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Hu T, Wu Z, Wu S, Chen S, Cheng A. The key amino acids of E protein involved in early flavivirus infection: viral entry. Virol J 2021; 18:136. [PMID: 34217298 PMCID: PMC8254458 DOI: 10.1186/s12985-021-01611-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 06/29/2021] [Indexed: 02/11/2023] Open
Abstract
Flaviviruses are enveloped viruses that infect multiple hosts. Envelope proteins are the outermost proteins in the structure of flaviviruses and mediate viral infection. Studies indicate that flaviviruses mainly use envelope proteins to bind to cell attachment receptors and endocytic receptors for the entry step. Here, we present current findings regarding key envelope protein amino acids that participate in the flavivirus early infection process. Among these sites, most are located in special positions of the protein structure, such as the α-helix in the stem region and the hinge region between domains I and II, motifs that potentially affect the interaction between different domains. Some of these sites are located in positions involved in conformational changes in envelope proteins. In summary, we summarize and discuss the key envelope protein residues that affect the entry process of flaviviruses, including the process of their discovery and the mechanisms that affect early infection.
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Affiliation(s)
- Tao Hu
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang District, Chengdu, 611130, Sichuan, China
| | - Zhen Wu
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang District, Chengdu, 611130, Sichuan, China
| | - Shaoxiong Wu
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang District, Chengdu, 611130, Sichuan, China
| | - Shun Chen
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang District, Chengdu, 611130, Sichuan, China. .,Institute of Preventive Veterinary Medicine, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang District, Chengdu, 611130, Sichuan, China. .,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Wenjiang District, Chengdu, 611130, Sichuan, China.
| | - Anchun Cheng
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang District, Chengdu, 611130, Sichuan, China. .,Institute of Preventive Veterinary Medicine, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang District, Chengdu, 611130, Sichuan, China. .,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Wenjiang District, Chengdu, 611130, Sichuan, China.
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Sun X, Sun M, Zhang L, Yu Z, Li J, Xie W, Su J. Amino Acid Substitutions in NS5 Contribute Differentially to Tembusu Virus Attenuation in Ducklings and Cell Cultures. Viruses 2021; 13:v13050921. [PMID: 34065634 PMCID: PMC8156267 DOI: 10.3390/v13050921] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Revised: 05/07/2021] [Accepted: 05/11/2021] [Indexed: 01/04/2023] Open
Abstract
Tembusu virus (TMUV), a highly infectious pathogenic flavivirus, causes severe egg-drop and encephalitis in domestic waterfowl, while the determinants responsible for viral pathogenicity are largely unknown. In our previous studies, virulent strain JXSP2-4 had been completely attenuated by successive passages in BHK-21 cells and the avirulent strain was designated as JXSP-310. Based on the backbone of JXSP2-4, a series of chimeric viruses were generated according to the amino acid substitutions in NS5 and their infectivities were also analyzed in cell cultures and ducklings. The results showed that the viral titers of RNA-dependent RNA polymerase (RdRp) domain-swapped cheimeric mutant (JXSP-310RdRp) in cells and ducklings were both markedly decreased compared with JXSP2-4, indicating that mutations in the RdRp domain affected viral replication. There are R543K and V711A two amino acid substitutions in the RdRp domain. Further site-directed mutagenesis showed that single-point R543K mutant (JXSP-R543K) exhibited similar replication efficacy compared with JXSP2-4 in cells, but the viral loads in JXSP-R543K-infected ducklings were significantly lower than that of JXSP2-4 and higher than JXSP-310RdRp. Surprisingly, the single-point V711A mutation we introduced rapidly reverted. In addition, qRT-PCR and Western blot confirmed that the mutations in the RdRp domain significantly affected the replication of the virus. Taken together, these results show that R543K substitution in the RdRp domain impairs the in vivo growth of TMUV, but sustaining its attenuated infectivity requires the concurrent presence of the V711A mutation.
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Affiliation(s)
- Xue Sun
- Key Laboratory of Animal Epidemiology and Zoonosis, The Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China; (X.S.); (M.S.); (Z.Y.); (J.L.); (W.X.)
| | - Mengxu Sun
- Key Laboratory of Animal Epidemiology and Zoonosis, The Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China; (X.S.); (M.S.); (Z.Y.); (J.L.); (W.X.)
| | - Lijiao Zhang
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China;
| | - Ziding Yu
- Key Laboratory of Animal Epidemiology and Zoonosis, The Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China; (X.S.); (M.S.); (Z.Y.); (J.L.); (W.X.)
| | - Jinxin Li
- Key Laboratory of Animal Epidemiology and Zoonosis, The Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China; (X.S.); (M.S.); (Z.Y.); (J.L.); (W.X.)
| | - Wanying Xie
- Key Laboratory of Animal Epidemiology and Zoonosis, The Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China; (X.S.); (M.S.); (Z.Y.); (J.L.); (W.X.)
| | - Jingliang Su
- Key Laboratory of Animal Epidemiology and Zoonosis, The Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China; (X.S.); (M.S.); (Z.Y.); (J.L.); (W.X.)
- Correspondence: ; Tel.: +86-10-62732312
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