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Sun J, Zhu R, Wang M, Song J, Zhou L, Sun Z, Li Y, Jiao L, Xia L, He H, Zhang G, Wu Y. Development of a two-probe competitive enzyme-linked immunosorbent assay for porcine epidemic diarrhea virus based on magnetic nanoparticles. Int J Biol Macromol 2025; 305:141036. [PMID: 39971032 DOI: 10.1016/j.ijbiomac.2025.141036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2024] [Revised: 02/12/2025] [Accepted: 02/12/2025] [Indexed: 02/21/2025]
Abstract
Porcine epidemic diarrhea (PED) causes significant economic losses to the pig farming industry worldwide and currently lacks an effective vaccine. Multiple detection assays and protein purification methods use magnetic nanoparticles due to their biocompatibility, high specific surface area, and solution suspension properties. In this study, a two-probe competitive ELISA based on magnetic nanoparticles for detecting PEDV N protein was developed. MNPs-N and McAb-HRP probes were prepared and the procedure was optimized to identify the ideal reaction conditions. Compared to other methods, the developed method shortens the detection time to 50 min. The coefficient of variation (CV) for intra- and inter-lot replicates was less than 10 %, with reproducibility. The coincidence rate with commercial kits is 93.07 %, making this method reliable and suitable for PED immune monitoring and diagnostics.
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Affiliation(s)
- Junru Sun
- International Joint Research Center of National Animal Immunology, College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China; Ministry of Education Key Laboratory for Animal Pathogens and Biosafety, College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China
| | - Ruiqin Zhu
- International Joint Research Center of National Animal Immunology, College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China; Ministry of Education Key Laboratory for Animal Pathogens and Biosafety, College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China
| | - Mengxiang Wang
- International Joint Research Center of National Animal Immunology, College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China; Ministry of Education Key Laboratory for Animal Pathogens and Biosafety, College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China
| | - Jinxing Song
- College of Veterinary Medicine, Henan University of Animal Husbandry and Economy, Zhengzhou 450046, China
| | - Lei Zhou
- International Joint Research Center of National Animal Immunology, College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China; Ministry of Education Key Laboratory for Animal Pathogens and Biosafety, College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China
| | - Zhuoya Sun
- International Joint Research Center of National Animal Immunology, College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China; Ministry of Education Key Laboratory for Animal Pathogens and Biosafety, College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China
| | - Yanze Li
- International Joint Research Center of National Animal Immunology, College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China; Ministry of Education Key Laboratory for Animal Pathogens and Biosafety, College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China
| | - Liuyang Jiao
- International Joint Research Center of National Animal Immunology, College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China; Ministry of Education Key Laboratory for Animal Pathogens and Biosafety, College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China
| | - Lu Xia
- International Joint Research Center of National Animal Immunology, College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China; Ministry of Education Key Laboratory for Animal Pathogens and Biosafety, College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China
| | - Hua He
- International Joint Research Center of National Animal Immunology, College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China; Ministry of Education Key Laboratory for Animal Pathogens and Biosafety, College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China
| | - Gaiping Zhang
- International Joint Research Center of National Animal Immunology, College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China; Ministry of Education Key Laboratory for Animal Pathogens and Biosafety, College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China; Longhu Laboratory, Zhengzhou 450046, China.
| | - Yanan Wu
- International Joint Research Center of National Animal Immunology, College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China; Ministry of Education Key Laboratory for Animal Pathogens and Biosafety, College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China.
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Liu Z, Li L, Fang M, Wei X, Li J, Wu Q, Yang X, Ye Y, Wan G, Huang D, Song D. Distinguished Loop-Mediated Isothermal Amplification Assay to Detect Porcine Epidemic Diarrhea Virus Genotypes I and II. Vet Sci 2025; 12:399. [PMID: 40431492 PMCID: PMC12115415 DOI: 10.3390/vetsci12050399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2025] [Revised: 04/13/2025] [Accepted: 04/21/2025] [Indexed: 05/29/2025] Open
Abstract
Porcine epidemic diarrhea virus (PEDV), a primary pathogen causing diarrhea in pigs, particularly in piglets, has a mortality rate of up to 100%. Field PEDV strains circulating in pig production can be phylogenetically divided into two genotypes, GI and GII. Differential diagnosis of clinical strains with different genotypes is helpful for understanding disease epidemiology, vaccine selection, and prevention and control measures. The loop-mediated isothermal amplification method (LAMP), a novel nucleic acid amplification technique, has been utilized to detect a variety of pathogens in practice. In this study, we developed a distinguished RT-LAMP method to identify genotypes GI and GII strains of PEDV. Two pairs of primers, PEDV-LM and PEDV-LS, were designed based on the membrane and spike genes of PEDV, respectively. PEDV-LM primers exhibited specificity for all PEDV strains, while PEDV-LS primers specifically targeted the PEDV genotype GI. The diagnostic sensitivity of both primers was 1 × 102 copies/reaction, which is 100 times more sensitive than RT-PCR. The RT-LAMP reaction process was completed at 65 °C for 40 min just in a water bath or metal bath. A cross-reactivity assay confirmed that this method is specific for PEDV GI and GII, with no cross-amplification observed with other swine-origin viruses such as PDCoV, PoRV, PRV, and PRRSV. Therefore, this refined LAMP technique offers a rapid, sensitive, and reliable method with which to detect and differentiate between PEDV GI and GII, making it a superior tool for the large-scale clinical surveillance of PEDV infections.
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Affiliation(s)
- Zhong Liu
- Department of Preventive Veterinary Medicine, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China; (Z.L.); (L.L.); (M.F.); (X.W.); (J.L.); (Q.W.); (X.Y.); (Y.Y.); (G.W.); (D.H.)
| | - Lanlan Li
- Department of Preventive Veterinary Medicine, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China; (Z.L.); (L.L.); (M.F.); (X.W.); (J.L.); (Q.W.); (X.Y.); (Y.Y.); (G.W.); (D.H.)
| | - Mengtao Fang
- Department of Preventive Veterinary Medicine, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China; (Z.L.); (L.L.); (M.F.); (X.W.); (J.L.); (Q.W.); (X.Y.); (Y.Y.); (G.W.); (D.H.)
| | - Xiaoqing Wei
- Department of Preventive Veterinary Medicine, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China; (Z.L.); (L.L.); (M.F.); (X.W.); (J.L.); (Q.W.); (X.Y.); (Y.Y.); (G.W.); (D.H.)
| | - Jieqiong Li
- Department of Preventive Veterinary Medicine, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China; (Z.L.); (L.L.); (M.F.); (X.W.); (J.L.); (Q.W.); (X.Y.); (Y.Y.); (G.W.); (D.H.)
| | - Qi Wu
- Department of Preventive Veterinary Medicine, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China; (Z.L.); (L.L.); (M.F.); (X.W.); (J.L.); (Q.W.); (X.Y.); (Y.Y.); (G.W.); (D.H.)
| | - Xiaoxue Yang
- Department of Preventive Veterinary Medicine, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China; (Z.L.); (L.L.); (M.F.); (X.W.); (J.L.); (Q.W.); (X.Y.); (Y.Y.); (G.W.); (D.H.)
| | - Yu Ye
- Department of Preventive Veterinary Medicine, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China; (Z.L.); (L.L.); (M.F.); (X.W.); (J.L.); (Q.W.); (X.Y.); (Y.Y.); (G.W.); (D.H.)
- Jiangxi Engineering Research Center for Animal Health Products, Jiangxi Agricultural University, Nanchang 330045, China
| | - Gen Wan
- Department of Preventive Veterinary Medicine, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China; (Z.L.); (L.L.); (M.F.); (X.W.); (J.L.); (Q.W.); (X.Y.); (Y.Y.); (G.W.); (D.H.)
- Jiangxi Engineering Research Center for Animal Health Products, Jiangxi Agricultural University, Nanchang 330045, China
| | - Dongyan Huang
- Department of Preventive Veterinary Medicine, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China; (Z.L.); (L.L.); (M.F.); (X.W.); (J.L.); (Q.W.); (X.Y.); (Y.Y.); (G.W.); (D.H.)
- Jiangxi Engineering Research Center for Animal Health Products, Jiangxi Agricultural University, Nanchang 330045, China
| | - Deping Song
- Department of Preventive Veterinary Medicine, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China; (Z.L.); (L.L.); (M.F.); (X.W.); (J.L.); (Q.W.); (X.Y.); (Y.Y.); (G.W.); (D.H.)
- Jiangxi Engineering Research Center for Animal Health Products, Jiangxi Agricultural University, Nanchang 330045, China
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Zeng L, Bai J, Huang J, Huang S, Qin Y, Yin Y, Chen Y, Wei Z, Huang W, Ouyang K. Construction and preliminary immunological evaluation of EV-G replicon expressing PEDV-COE-N region. Virology 2025; 604:110436. [PMID: 39889482 DOI: 10.1016/j.virol.2025.110436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2024] [Revised: 01/14/2025] [Accepted: 01/23/2025] [Indexed: 02/03/2025]
Abstract
Porcine epidemic diarrhea virus (PEDV) is a highly contagious virus that causes acute infectious disease in swine, with mortality rates in piglets reaching up to 100%. In recent years, PEDV has led to significant economic losses in China's pig industry. As there is no specific treatment for PEDV, vaccination remains a key strategy for its prevention and control. This study utilized the EV-G replicon system to develop a nucleic acid vaccine expressing the PEDV core neutralizing epitope (COE) region, which was evaluated through immunization of Kunming mice. The results demonstrated that the vaccine successfully induced high levels of specific IgG and neutralizing antibodies in the mice, while also significantly enhanced splenic lymphocyte proliferation, and increased the expression of IL-4 and IFN-γ cytokines. These findings indicate that the constructed pBluescript-EV-G-COE-N plasmid is an effective DNA replicon vaccine. Notably, immunized with pBluescript-EV-G-COE-N replicons with chitosan resulted in higher neutralizing antibodies and IFN-γ, suggesting the enhanced immune efficacy. The successful construction and preliminary immunological evaluation of the pBluescript-EV-G-COE-N replicon highlights its potential in PEDV vaccine development and offers valuable data for future research in new PEDV vaccine formulations.
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Affiliation(s)
- Lingyou Zeng
- Laboratory of Animal Infectious Diseases and Molecular Immunology, College of Animal Science and Technology, Guangxi University, Nanning, 30005, China.
| | - Jiaguo Bai
- Laboratory of Animal Infectious Diseases and Molecular Immunology, College of Animal Science and Technology, Guangxi University, Nanning, 30005, China.
| | - Jiabao Huang
- Laboratory of Animal Infectious Diseases and Molecular Immunology, College of Animal Science and Technology, Guangxi University, Nanning, 30005, China.
| | - Shiting Huang
- Laboratory of Animal Infectious Diseases and Molecular Immunology, College of Animal Science and Technology, Guangxi University, Nanning, 30005, China.
| | - Yifeng Qin
- Laboratory of Animal Infectious Diseases and Molecular Immunology, College of Animal Science and Technology, Guangxi University, Nanning, 30005, China; Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning, 530005, China; Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, Nanning, 530005, China.
| | - Yeshi Yin
- Laboratory of Animal Infectious Diseases and Molecular Immunology, College of Animal Science and Technology, Guangxi University, Nanning, 30005, China; Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning, 530005, China; Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, Nanning, 530005, China.
| | - Ying Chen
- Laboratory of Animal Infectious Diseases and Molecular Immunology, College of Animal Science and Technology, Guangxi University, Nanning, 30005, China; Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning, 530005, China; Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, Nanning, 530005, China.
| | - Zuzhang Wei
- Laboratory of Animal Infectious Diseases and Molecular Immunology, College of Animal Science and Technology, Guangxi University, Nanning, 30005, China; Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning, 530005, China; Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, Nanning, 530005, China.
| | - Weijian Huang
- Laboratory of Animal Infectious Diseases and Molecular Immunology, College of Animal Science and Technology, Guangxi University, Nanning, 30005, China; Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning, 530005, China; Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, Nanning, 530005, China.
| | - Kang Ouyang
- Laboratory of Animal Infectious Diseases and Molecular Immunology, College of Animal Science and Technology, Guangxi University, Nanning, 30005, China; Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning, 530005, China; Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, Nanning, 530005, China.
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Sun J, Cheng J, Shi D, Xu X, Liu Y, Ying J, Zhao Y, Zheng H, Yan J, Sun D, Song H, Su M. Genetic Epidemiology of Porcine Epidemic Diarrhea Virus Circulating in China From 2010 to 2024: Characterization of Phylogenetic and Genetic Diversity of S1-Based Genes. J Med Virol 2025; 97:e70198. [PMID: 39891595 DOI: 10.1002/jmv.70198] [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: 09/02/2024] [Revised: 01/10/2025] [Accepted: 01/21/2025] [Indexed: 02/03/2025]
Abstract
As a porcine alphacoronavirus, porcine epidemic diarrhea virus (PEDV) frequently undergoes mutations that significantly reduce the effectiveness of current prevention and control strategies, leading to recurrent outbreaks in China. This study investigates the genetic evolution and mutation patterns of the S1 protein to characterize PEDV variation in China. Genetic evolutionary analysis of 804 PEDV S1 genes, including 620 Chinese PEDV strains, revealed that 78.06% of the Chinese PEDV strains belong to the G2a-subgroup, further divided into seven branches (G2a-Clade 1-7), with the predominant strains from 2020 to 2024 being in G2a-Clade 4 (68.00%). From 2021 to 2024, 32 novel substitutions, 25 deletions, and 8 insertions were identified in the S1 protein of Chinese strains compared to those from 2010 to 2011. Notably, complete mutations were observed at amino acid sites N139D, H189Y, L229P, I287M, F345L, A361T, T499I, and A520S. Moreover, protein homology modeling analysis displayed that these deletion-insertion mutations significantly altered the surface structure of the S protein, particularly in the N-terminal domain (NTD) and receptor-binding domain (RBD) regions of S1 protein. The predictive analysis using AlphaFold3 indicated that deletion-insertion mutations in the S1-RBD region notably affected the binding affinity of the S protein to porcine DC-SIGN. These findings enhance our understanding of the genetic evolution of PEDV in China.
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Affiliation(s)
- Jing Sun
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Zhejiang Provincial Engineering Research Center for Animal Health Diagnostics & Advanced Technology, Zhejiang International Science and Technology Cooperation Base for Veterinary Medicine and Health Management, China-Australia Joint Laboratory for Animal Health Big Data Analytics, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, China
| | - Jiongze Cheng
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Zhejiang Provincial Engineering Research Center for Animal Health Diagnostics & Advanced Technology, Zhejiang International Science and Technology Cooperation Base for Veterinary Medicine and Health Management, China-Australia Joint Laboratory for Animal Health Big Data Analytics, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, China
| | - Da Shi
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Xiangwen Xu
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Zhejiang Provincial Engineering Research Center for Animal Health Diagnostics & Advanced Technology, Zhejiang International Science and Technology Cooperation Base for Veterinary Medicine and Health Management, China-Australia Joint Laboratory for Animal Health Big Data Analytics, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, China
| | - Yijia Liu
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Zhejiang Provincial Engineering Research Center for Animal Health Diagnostics & Advanced Technology, Zhejiang International Science and Technology Cooperation Base for Veterinary Medicine and Health Management, China-Australia Joint Laboratory for Animal Health Big Data Analytics, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, China
| | - Jiale Ying
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Zhejiang Provincial Engineering Research Center for Animal Health Diagnostics & Advanced Technology, Zhejiang International Science and Technology Cooperation Base for Veterinary Medicine and Health Management, China-Australia Joint Laboratory for Animal Health Big Data Analytics, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, China
| | - Yulin Zhao
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Zhejiang Provincial Engineering Research Center for Animal Health Diagnostics & Advanced Technology, Zhejiang International Science and Technology Cooperation Base for Veterinary Medicine and Health Management, China-Australia Joint Laboratory for Animal Health Big Data Analytics, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, China
| | - Huihua Zheng
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Zhejiang Provincial Engineering Research Center for Animal Health Diagnostics & Advanced Technology, Zhejiang International Science and Technology Cooperation Base for Veterinary Medicine and Health Management, China-Australia Joint Laboratory for Animal Health Big Data Analytics, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, China
| | - Junfang Yan
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Zhejiang Provincial Engineering Research Center for Animal Health Diagnostics & Advanced Technology, Zhejiang International Science and Technology Cooperation Base for Veterinary Medicine and Health Management, China-Australia Joint Laboratory for Animal Health Big Data Analytics, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, China
| | - Dongbo Sun
- Laboratory for the Prevention and Control of Swine Infectious Diseases, College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, China
| | - Houhui Song
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Zhejiang Provincial Engineering Research Center for Animal Health Diagnostics & Advanced Technology, Zhejiang International Science and Technology Cooperation Base for Veterinary Medicine and Health Management, China-Australia Joint Laboratory for Animal Health Big Data Analytics, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, China
| | - Mingjun Su
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Zhejiang Provincial Engineering Research Center for Animal Health Diagnostics & Advanced Technology, Zhejiang International Science and Technology Cooperation Base for Veterinary Medicine and Health Management, China-Australia Joint Laboratory for Animal Health Big Data Analytics, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, China
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Zhang D, Xie Y, Liao Q, Jiao Z, Liang R, Zhang J, Zhang Y, Tan Y, Wang H, Zhang W, Xiao S, Peng G, Shi Y. Development of a safe and broad-spectrum attenuated PEDV vaccine candidate by S2 subunit replacement. J Virol 2024; 98:e0042924. [PMID: 39404450 PMCID: PMC11575183 DOI: 10.1128/jvi.00429-24] [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: 04/12/2024] [Accepted: 09/09/2024] [Indexed: 11/20/2024] Open
Abstract
Porcine epidemic diarrhea (PED) has caused serious economic losses to the swine livestock industry. Due to the rapid variation in the PEDV) genome, especially the spike (S) protein, the cross-protection ability of antibodies between different vaccine strains is weakened. Hence, the rapid development of safe, broad-spectrum and highly effective attenuated PEDV vaccine still needs further research. Here, we found that the replacement of the S2 subunit had little effect on S protein immunogenicity. Moreover, the chimeric virus (YN-S2DR13), the S protein of the YN strain was replaced by the DR13 S2 subunit, which lost its trypsin tropism and increased its propagation ability (approximately 1 titer) in Vero cells. Then, the pathogenesis of YN-S2DR13 was evaluated in neonatal piglets. Importantly, quantitative real-time PCR, histopathology, and immunohistochemistry confirmed that the virulence of YN-S2DR13 was significantly reduced compared with that of YN. Immunization with YN-S2DR13 induced neutralizing antibodies against both YN and DR13 in weaned piglets. In vitro passaging data also showed that YN-S2DR13 had good genetic stability. Collectively, these results suggest that YN-S2DR13 has significant advantages as a novel vaccine candidate, including a capacity for viral propagation to high titers with no trypsin requirement and the potential to provide protection against both PEDV G1 and G2 strains infections. Our results also suggests that S2 subunit replacement using reverse genetics can be a rapid strategy for the rational design of live attenuated vaccines for PEDV. IMPORTANCE Emerging highly virulent porcine epidemic diarrhea virus (PEDV) G2 strains has caused substantial economic losses worldwide. Vaccination with a live attenuated vaccine is a promising method to prevent and control PED because it can induce a strong immune response (including T- and B-cell immunity). Previous studies have demonstrated that the S2 subunit of the PEDV spike (S) protein is the determinant of PEDV trypsin independence. Here, we evaluated the pathogenicity, tissue tropism, and immunogenicity of the chimeric virus (YN-S2DR13) via animal experiments. We demonstrated that YN-S2DR13 strain, as a trypsin independent strain, increased intracellular proliferation capacity, significantly reduced virulence, and induced broad-spectrum neutralization protection against PEDV G1 and G2 strains. In vitro passaging data also validated the stability of YN-S2DR13. Our results showed that generating a chimeric PEDV strain that is trypsin-independent by replacing the S2 subunit is a promising approach for designing a live attenuated vaccine for PEDV in the future.
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Affiliation(s)
- Ding Zhang
- State 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
| | - Yunfei Xie
- State 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
| | - Qi Liao
- State 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
| | - Zhe Jiao
- State 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
| | - Rui Liang
- State 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
| | - Jintao Zhang
- State 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
| | - Yu Zhang
- State 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
| | - Yubei Tan
- State 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
| | - Huanbin Wang
- Department of Animal Nutrition and Feed Science College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Wanpo Zhang
- Veterinary Pathology Laboratory, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Shaobo Xiao
- State 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
| | - Guiqing Peng
- State 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
| | - Yuejun Shi
- State 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
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Shi K, Li B, Shi Y, Feng S, Yin Y, Long F, Pan Y, Wei Y. Phylogenetic and Evolutionary Analysis of Porcine Epidemic Diarrhea Virus in Guangxi Province, China, during 2020 and 2024. Viruses 2024; 16:1126. [PMID: 39066288 PMCID: PMC11281377 DOI: 10.3390/v16071126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2024] [Revised: 06/28/2024] [Accepted: 07/12/2024] [Indexed: 07/28/2024] Open
Abstract
The variant porcine epidemic diarrhea virus (PEDV) has caused considerable economic losses to the global pig industry since 2010. In this study, a total of 5859 diarrhea samples were collected from different pig farms in China's Guangxi province during January 2020 and March 2024 and tested for PEDV using RT-qPCR. The positivity rate of PEDV was 11.90% (697/5859). Ninety-two PEDV-positive samples were selected based on sampling time, and the sampling region for amplification, sequencing, and analysis of the S1, M, and N genes. Phylogenetic analysis of the S1 gene revealed that all strains from Guangxi province were distributed in three subgroups, i.e., 81.5% (75/92) in the G2a subgroup, 4.3% (4/92) in the G2b subgroup, and 14.1% (13/92) in the G2c subgroup. The sequence analysis revealed that the S1 gene sequences from Guangxi province had higher homology with the variant strains than with the classical strains, showing as high as 99.2% with the variant strain AJ1102 and only 94.3% with the classical strain CV777. Recombination analysis revealed that the GX-BS08-2023 strain (G2c) from Guangxi province originated from inter-lineage recombination between the GX-BS09-2023 (G2a) and CH-JN547228-2011 (G1a) strains. In addition, the S1 gene of the G2a and G2b subgroup strains shared many mutations and insertions. There were common mutations of N143D and P235L in the G2a subgroup. Evolutionary analysis revealed that all Guangxi strains belonged to the G2 genotype. These strains have spread rapidly since the PEDV variant strains that emerged in 2010, weakened until 2021, and then remained stable. In conclusion, the results revealed the latest genetic evolution of circulating PEDV strains in Guangxi province in recent years, providing important information for preventing and controlling PEDV infection. Currently, the G2a subgroup strains are the predominant strains circulating in pig herds in Guangxi province, southern China.
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Affiliation(s)
- Kaichuang Shi
- School of Basic Medical Sciences, Youjiang Medical University for Nationalities, Baise 533000, China
- College of Animal Science and Technology, Guangxi University, Nanning 530005, China
- Guangxi Center for Animal Disease Control and Prevention, Nanning 530001, China
| | - Biao Li
- College of Animal Science and Technology, Guangxi University, Nanning 530005, China
| | - Yuwen Shi
- College of Animal Science and Technology, Guangxi University, Nanning 530005, China
| | - Shuping Feng
- Guangxi Center for Animal Disease Control and Prevention, Nanning 530001, China
| | - Yanwen Yin
- Guangxi Center for Animal Disease Control and Prevention, Nanning 530001, China
| | - Feng Long
- Guangxi Center for Animal Disease Control and Prevention, Nanning 530001, China
| | - Yi Pan
- School of Basic Medical Sciences, Youjiang Medical University for Nationalities, Baise 533000, China
| | - Yingyi Wei
- College of Animal Science and Technology, Guangxi University, Nanning 530005, China
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7
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Zhang F, Luo Y, Lin C, Tan M, Wan P, Xie B, Xiong L, Ji H. Epidemiological monitoring and genetic variation analysis of pathogens associated with porcine viral diarrhea in southern China from 2021 to 2023. Front Microbiol 2024; 15:1303915. [PMID: 38572229 PMCID: PMC10987963 DOI: 10.3389/fmicb.2024.1303915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 03/04/2024] [Indexed: 04/05/2024] Open
Abstract
Large-scale outbreaks of virus-associated severe diarrhea have occurred in pig populations since 2010. To investigate the prevalence and genetic evolution of the diarrhea-associated viruses responsible for the outbreaks, we tested 1,791 diarrhea samples collected from 213 pig farms in five provinces in southern China between 2021 and 2023. The test results showed that porcine epidemic diarrhea virus (PEDV) was the most frequently detected virus. The prevalence rates ranged from 47.40 to 52.22% in samples and 76.06% (162/213) in pig farms. Porcine rotavirus (PoRV) was the second common virus, with prevalence rates ranging from 25.81 to 50.81% in samples and 72.77%(155/213) in pig farms. Porcine delta coronavirus (PDCoV) was the third common virus, with prevalence rates ranging from 16.33 to 17.48% in samples and 38.50% (82/213) in pig farms. The detection rates of both transmissible gastroenteritis virus (TGEV) and porcine acute diarrheal syndrome coronavirus (SADS-CoV) were very low, less than 1.01% in samples and less than 3.76% in pig farms. In this study, we found SADS-CoV only in piglet diarrhea samples from Jiangxi, Guangdong, and Guangxi provinces in China, with a prevalence rate of 5.16% (11/213) in pig farms. Co-infection with these diarrhea-associated viruses is a common occurrence. The most common co-infections were PEDV and PoRV, with a prevalence rate of 6.64% (119/1,791), followed by PDCoV and PoRV, with a prevalence rate of 4.19% (75/1,791). Phylogenetic analyses showed that PEDV and PEDV variants prevalent in southern China during the past three years clustered into genotype GIIb and recombinant PEDV subtypes. Among the currently endemic PEDV, the most common mutations occurred in the collagenase equivalent (COE) and epitope regions of the spike gene. PoRV strains were mainly dominated by the G9 subtype, followed by the G5, G3 and G4 subtypes. Our results suggest that variant PEDV, PDCoV and PoRV are the main pathogens of swine diarrhea, and singular- or co-infection with pathogenic enteric CoV is common in pig herds in southern China. Therefore, prevention and control of porcine viral diarrhea should be given high attention.
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Affiliation(s)
- Fanfan Zhang
- Institute of Animal Husbandry and Veterinary Medicine, Jiangxi Academy of Agricultural Sciences, Nanchang, Jiangxi, China
| | - Yangyang Luo
- Wen’s Foodstuff Group Co., Ltd., Wen’s Group Research Institute, Yunfu, Guangdong, China
| | - Cui Lin
- Institute of Animal Husbandry and Veterinary Medicine, Jiangxi Academy of Agricultural Sciences, Nanchang, Jiangxi, China
| | - Meifang Tan
- Institute of Animal Husbandry and Veterinary Medicine, Jiangxi Academy of Agricultural Sciences, Nanchang, Jiangxi, China
| | - Peiwei Wan
- Jiangxi Biological Vocational College, Nanchang, Jiangxi, China
| | - Baobao Xie
- Dabeinong Technology Co., Ltd. of Jiangxi, Nanchang, Jiangxi, China
| | - Ligen Xiong
- Institute of Animal Husbandry and Veterinary Medicine, Jiangxi Academy of Agricultural Sciences, Nanchang, Jiangxi, China
| | - Huayuan Ji
- Institute of Animal Husbandry and Veterinary Medicine, Jiangxi Academy of Agricultural Sciences, Nanchang, Jiangxi, China
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Li L, Li B, Wang J, Liu L, Li Y, Sun S, Yin S, Zhang L, Liu X, Xu X, Guo H. A novel recombination porcine epidemic diarrhea virus isolated from Gansu, China: Genetic characterization and pathogenicity. Vet Microbiol 2024; 290:109975. [PMID: 38183838 DOI: 10.1016/j.vetmic.2023.109975] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 12/21/2023] [Accepted: 12/28/2023] [Indexed: 01/08/2024]
Abstract
Porcine epidemic diarrhea virus (PEDV) is an acute and highly contagious porcine enteric coronavirus. It has caused serious economic losses of pig industry in China. Here we insolated a current PEDV field strain named GS2022, analyzed the characters of genetic variation and pathogenicity. The results demonstrated that the GS2022 strain was belong to a newly defined subgroup G2 d, forming an independent branch which mainly contains strains isolated in China from 2017 to 2023. Notably, there are multiple mutations and extensive N-glycosylation compared to CV777 strain and PT-P5 strain, therefore the structure of GS2022 strain is different from 6U7K and 7W6M. Animal pathogenicity test showed that GS2022 strain could cause severe clinical signs and the high level of virus shedding in 7-day-old piglets. But recovery of diarrhea after 5 days, and no pathological damage to important organs. Further study on 3-day-old piglets also indicated GS2022 strain have pathogenicity. In this study no piglets died, which make it possible for that GS2022 strain become a candidate vaccine. These results are helpful to understand the epidemiology, molecular characteristics, evolution, and antigenicity of PEDV circulating in China. It also provides reference for designing effective vaccines against PEDV.
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Affiliation(s)
- Linjie Li
- College of Veterinary Medicine, Northwest A&F University, Yangling, China; State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Bingqing Li
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Jin Wang
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Lei Liu
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China; College of Veterinary Medicine, Gansu Agricultural University, Lanzhou, China
| | - Yi Li
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Shiqi Sun
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Shuanghui Yin
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Liping Zhang
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Xinsheng Liu
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Xingang Xu
- College of Veterinary Medicine, Northwest A&F University, Yangling, China.
| | - Huichen Guo
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China; College of Veterinary Medicine, Gansu Agricultural University, Lanzhou, China.
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Li C, Wu Q, Song H, Lu H, Yang K, Liu Z, Liu W, Gao T, Yuan F, Zhu J, Guo R, Tian Y, Zhou D. Elucidating the biological characteristics and pathogenicity of the highly virulent G2a porcine epidemic diarrhea virus. J Gen Virol 2024; 105. [PMID: 38270573 DOI: 10.1099/jgv.0.001953] [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: 01/26/2024] Open
Abstract
Since the large-scale outbreak of porcine epidemic diarrhoea (PED) in 2010, caused by the genotype 2 (G2) variant of the porcine epidemic diarrhoea virus (PEDV), pig farms in China, even those vaccinated with the G2b vaccine, have experienced infections from the G2a variant, leading to significant economic losses. This study successfully isolated the G2a strain DY2020 from positive small intestine contents (SICs) by blind passage on Vero cells for four generations. The SICs were taken from Daye, Hubei Province, China. The biological characteristics were identified by indirect immunofluorescence assay (IFA) and transmission electron microscopy (TEM). The growth kinetics of the strain on Vero cells were detected by TCID50, and the virus titre could reach 107.35 TCID50 ml-1 (SD: 5.07×106). The pathogenicity towards colostrum-deprived piglets was conducted by assessing faecal viral shedding, morphometric analysis of intestinal lesions, and immunohistochemical staining. The results showed that DY2020 was highly virulent to colostrum-deprived piglets, with severe watery diarrhoea and other clinical symptoms appeared at 6 h post-infection (h p.i.), and all died within 30 h. Pathological tissue examination results showed that the lesions mainly occurred in the intestines of piglets, causing pathological changes such as shortening of intestinal villi. In summary, the discovery of the G2a strain DY2020 in this study is of great significance for understanding Hubei PEDV and provides an important theoretical basis for the development of new efficient PEDV vaccines.
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Affiliation(s)
- Chang Li
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Hubei Provincial Key Laboratory of Animal Pathogenic Microbiology, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, 430064, PR China
| | - Qiong Wu
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Hubei Provincial Key Laboratory of Animal Pathogenic Microbiology, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, 430064, PR China
| | - Haofei Song
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Hubei Provincial Key Laboratory of Animal Pathogenic Microbiology, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, 430064, PR China
| | - Hongyu Lu
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Hubei Provincial Key Laboratory of Animal Pathogenic Microbiology, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, 430064, PR China
| | - Keli Yang
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Hubei Provincial Key Laboratory of Animal Pathogenic Microbiology, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, 430064, PR China
| | - Zewen Liu
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Hubei Provincial Key Laboratory of Animal Pathogenic Microbiology, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, 430064, PR China
| | - Wei Liu
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Hubei Provincial Key Laboratory of Animal Pathogenic Microbiology, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, 430064, PR China
| | - Ting Gao
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Hubei Provincial Key Laboratory of Animal Pathogenic Microbiology, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, 430064, PR China
| | - Fangyan Yuan
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Hubei Provincial Key Laboratory of Animal Pathogenic Microbiology, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, 430064, PR China
| | - Jiajia Zhu
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Hubei Provincial Key Laboratory of Animal Pathogenic Microbiology, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, 430064, PR China
| | - Rui Guo
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Hubei Provincial Key Laboratory of Animal Pathogenic Microbiology, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, 430064, PR China
| | - Yongxiang Tian
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Hubei Provincial Key Laboratory of Animal Pathogenic Microbiology, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, 430064, PR China
| | - Danna Zhou
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Hubei Provincial Key Laboratory of Animal Pathogenic Microbiology, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, 430064, PR China
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10
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Li Z, Ma Z, Han W, Chang C, Li Y, Guo X, Zheng Z, Feng Y, Xu L, Zheng H, Wang X, Xiao S. Deletion of a 7-amino-acid region in the porcine epidemic diarrhea virus envelope protein induces higher type I and III interferon responses and results in attenuation in vivo. J Virol 2023; 97:e0084723. [PMID: 37681956 PMCID: PMC10537754 DOI: 10.1128/jvi.00847-23] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 06/16/2023] [Indexed: 09/09/2023] Open
Abstract
Porcine epidemic diarrhea virus (PEDV) leads to enormous economic losses for the pork industry. However, the commercial vaccines failed to fully protect against the epidemic strains. Previously, the rCH/SX/2016-SHNXP strain with the entire E protein and the rCH/SX/2015 strain with the deletion of 7-amino-acid (7-aa) at positions 23-29 in E protein were constructed and rescued. The pathogenicity assay indicated that rCH/SX/2015 is an attenuated strain, but rCH/SX/2016-SHNXP belongs to the virulent strains. Then, the recombination PEDV (rPEDV-EΔaa23-aa29)strain with a 7-aa deletion in the E protein was generated, using the highly virulent rCH/SX/2016-SHNXP strain (rPEDV-Ewt) as the backbone. Compared with the rPEDV-Ewt strain, the release and infectivity of the rPEDV-EΔaa23-aa29 strain were significantly reduced in vitro, but stronger interferon (IFN) responses were triggered both in vitro and in vivo. The pathogenicity assay showed that the parental strain resulted in severe diarrhea (100%) and death (100%) in all piglets. Compared with the parental strain group, rPEDV-EΔaa23-aa29 caused lower mortality (33%) and diminished fecal PEDV RNA shedding. At 21 days, all surviving pigs were challenged orally with rPEDV-Ewt. No pigs died in the two groups. Compared with the mock group, significantly delayed and milder diarrhea and reduced fecal PEDV RNA shedding were detected in the rPEDV-EΔaa23-aa29 group. In conclusion, the deletion of a 7-aa fragment in the E protein (EΔaa23-aa29) attenuated PEDV but retained its immunogenicity, which can offer new ideas for the design of live attenuated vaccines and provide new insights into the attenuated mechanism of PEDV. IMPORTANCE Porcine epidemic diarrhea virus (PEDV) causes high mortality in neonatal piglets and remains a large challenge to the pork industry. Unfortunately, no safe and effective vaccines are available yet. The pathogenesis and molecular basis of the attenuation of PEDV remain unclear, which seriously hinders the development of PEDV vaccines. This study found that the rPEDV carrying EΔaa23-aa29 mutation in the E protein induced significantly higher IFN responses than the parental virus, partially attenuated, and remained immunogenic in piglets. For the first time, PEDV E was verified as an IFN antagonist in the infection context and identified as a virulence factor of PEDV. Our data also suggested that EΔaa23-aa29 mutation can be a good target for the development of live attenuated vaccines for PEDV and also provide new perspectives for the attenuated mechanism of PEDV.
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Affiliation(s)
- Zhiwei Li
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
- State Key Laboratory for Animal Disease Control and Prevention, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, College of Veterinary Medicine, Lanzhou University, Lanzhou, Gansu, China
| | - Zhiqian Ma
- State Key Laboratory for Animal Disease Control and Prevention, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, College of Veterinary Medicine, Lanzhou University, Lanzhou, Gansu, China
| | - Weiguo Han
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Chuanzhe Chang
- State Key Laboratory for Animal Disease Control and Prevention, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, College of Veterinary Medicine, Lanzhou University, Lanzhou, Gansu, China
| | - Yang Li
- State Key Laboratory for Animal Disease Control and Prevention, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, College of Veterinary Medicine, Lanzhou University, Lanzhou, Gansu, China
| | - Xuyang Guo
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Zifang Zheng
- State Key Laboratory for Animal Disease Control and Prevention, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, College of Veterinary Medicine, Lanzhou University, Lanzhou, Gansu, China
| | - Yingtong Feng
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Lele Xu
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Haixue Zheng
- State Key Laboratory for Animal Disease Control and Prevention, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, College of Veterinary Medicine, Lanzhou University, Lanzhou, Gansu, China
| | - Xinglong Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Shuqi Xiao
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
- State Key Laboratory for Animal Disease Control and Prevention, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, College of Veterinary Medicine, Lanzhou University, Lanzhou, Gansu, China
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