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Liu C, Liu Y, Feng H, Zhao B, Chen Y, Huang H, Wang P, Deng R, Zhang G. PCV cap proteins fused with calreticulin expressed into polymers in Escherichia coli with high immunogenicity in mice. BMC Vet Res 2020; 16:313. [PMID: 32854700 PMCID: PMC7450944 DOI: 10.1186/s12917-020-02527-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 08/18/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Porcine circovirus type 2 (PCV2) is the main causative agent of porcine circovirus diseases (PCVDs) which causes huge yearly economic losses in the swine industry. Capsid protein (Cap) is the major structural protein of PCV2 that can induce a protective immune response. Therefore, developing a novel and safe subunit vaccine against PCV2 infection is needed. RESULTS In this study, the Cap gene was bound to the truncated calreticulin (CRT) (120-250 aa/120-308 aa) at the N/C terminal, and then the CRT-Cap fusion genes were expressed in Escherichia coli (E.coli). The size-exclusion chromatography and dynamic light scattering (DLS) data showed that the purified recombinant CRT-Cap fusion protein (rP5F) existed in the form of polymers. Immunization with rP5F stimulated high levels of PCV2 specific antibody and neutralization antibody in mice, which were almost identical to those induced by the commercial subunit and inactivated vaccines. The lymphocyte proliferation and cytokine secretion were also detected in rP5F immunized mice. According to the results of PCV2-challenge experiment, the virus loads significantly decreased in mice immunized with rP5F. The data obtained in the current study revealed that rP5F had the potential to be a subunit vaccine candidate against PCV2 in the future. CONCLUSIONS We have successfully expressed Cap-CRT fusion proteins in E.coli and optimized rP5F could form into immunogenic polymers. Mice immunized with rP5F efficiently induced humoral and part of cellular immune responses and decreased the virus content against PCV2-challenge, which suggested that rF5P could be a potential subunit vaccine candidate.
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Affiliation(s)
- Chang Liu
- Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, 450002, Henan, China
| | - Yunchao Liu
- Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, 450002, Henan, China
| | - Hua Feng
- Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, 450002, Henan, China
| | - Baolei Zhao
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450002, Henan, China
| | - Yumei Chen
- School of Life Sciences, Zhengzhou University, Zhengzhou, 450001, China
| | - Huimin Huang
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450002, Henan, China
| | - Pan Wang
- Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, 450002, Henan, China
| | - Ruiguang Deng
- Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, 450002, Henan, China
| | - Gaiping Zhang
- Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, 450002, Henan, China. .,College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450002, Henan, China. .,School of Life Sciences, Zhengzhou University, Zhengzhou, 450001, China.
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Zhu X, Wen L, Wang W, Xiao Q, Li B, He K. PCV2 inhibits the Wnt signalling pathway in vivo and in vitro. Vet Microbiol 2020; 247:108787. [PMID: 32768231 DOI: 10.1016/j.vetmic.2020.108787] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 07/01/2020] [Accepted: 07/05/2020] [Indexed: 11/16/2022]
Abstract
Porcine circovirus type 2 (PCV2) is an important pathogen of the current pig industry. The Wnt signalling pathway plays an important role in the growth of young animals. In this study, we mainly elucidated the relationship between PCV2 and the Wnt signalling pathway. In an in vivo experiment in mice, we demonstrated the downregulatory effects of PCV2 infection on expression levels of downstream components of the Wnt signalling pathway. Weight loss in mice was reversed by activating the Wnt signalling pathway, and the body weight was still significantly higher than that in mice infected with PCV2. We detected levels of growth hormone (GH) in the liver and sera, which showed that GH was also downregulated in mice challenged with PCV2. Lithium chloride, the activator of Wnt signalling, upregulated GH, albeit to a significantly lesser degree than that in corresponding non-stimulated mock mice. In vitro studies showed that PCV2 infection downregulated protein expression of β-catenin and mRNA expression of matrix metallopeptidase-2 (Mmp2), downregulated protein expression of β-catenin in the cytoplasm and nucleus, and reduced the activity of the TCF/LEF promoter, demonstrating that PCV2 inhibited activation of the Wnt signalling pathway in vitro. Finally, we found that Rep protein of PCV2 might be responsible for the inhibitory effect.
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Affiliation(s)
- Xuejiao Zhu
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, Nanjing 210014, Jiangsu Province, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China; Jiangsu Key Laboratory for Food Quality and Safety - State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, China
| | - Libin Wen
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, Nanjing 210014, Jiangsu Province, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China; Jiangsu Key Laboratory for Food Quality and Safety - State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, China
| | - Wei Wang
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, Nanjing 210014, Jiangsu Province, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China; Jiangsu Key Laboratory for Food Quality and Safety - State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, China
| | - Qi Xiao
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, Nanjing 210014, Jiangsu Province, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China; Jiangsu Key Laboratory for Food Quality and Safety - State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, China
| | - Bin Li
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, Nanjing 210014, Jiangsu Province, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China; Jiangsu Key Laboratory for Food Quality and Safety - State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, China
| | - Kongwang He
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, Nanjing 210014, Jiangsu Province, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China; Jiangsu Key Laboratory for Food Quality and Safety - State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, China.
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Guo Z, Ruan H, Qiao S, Deng R, Zhang G. Co-infection status of porcine circoviruses (PCV2 and PCV3) and porcine epidemic diarrhea virus (PEDV) in pigs with watery diarrhea in Henan province, central China. Microb Pathog 2020; 142:104047. [PMID: 32036077 DOI: 10.1016/j.micpath.2020.104047] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Revised: 02/04/2020] [Accepted: 02/05/2020] [Indexed: 12/30/2022]
Abstract
Porcine circoviruses (PCV2 and PCV3) and porcine epidemic diarrhea virus (PEDV) are important swine viruses that threaten the swine industry worldwide. Here, we evaluated the co-infection status of PCV2, PCV3 and PEDV in 76 enteric samples from piglets with severe diarrhea disease in Henan, China. All samples were tested by PCR/RT-PCR. Our results showed that the infection rate of PCV2, PCV3 and PEDV was 82.89%, 76.32% and 68.42%, respectively. Interestingly, most of these samples exhibited mixed infections. The co-infection rates of PCV2 and PCV3, PCV2 and PEDV, PCV3 and PEDV were 69.74%, 57.89% and 53.95%, respectively. And the triple infection rate was 48.68%. Furthermore, the genetic characteristics of PCV2 and PCV3 were analyzed based on the cap genes. Two PCV2 genotypes, PCV2b and PCV2d, were circulating in the fields. The cap gene of PCV2b and PCV2d isolates only shared 94.6%-95.0% nucleotide identities. The PCV3 isolates together with the reference strains could be divided into four clades (clade1-4), and the cap genes of these isolates have 98.6%-100% nucleotide identities to each other. Distinctive amino acid substitutions were also characterized on the cap protein of PCV2 and PCV3 isolates. Our studies provide the new knowledge on the co-infectious status of PCV2, PCV3 and PEDV in China. The results also provide insight into the genetic diversity and molecular epidemiology of PCV2 and PCV3.
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Affiliation(s)
- Zhenhua Guo
- Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, PR China
| | - Haiyu Ruan
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, PR China
| | - Songlin Qiao
- Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, PR China
| | - Ruiguang Deng
- Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, PR China
| | - Gaiping Zhang
- Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, PR China; College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, PR China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, PR China.
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Hu Y, Cai X, Zhan Y, Yuan X, Liu T, Tan L, Li Y, Zhang L, Yang L, Liu W, Deng Z, Wang N, Yang Y, Guo S, Wang A. Truncated Rep protein of porcine circovirus 2 (PCV2) caused by a naturally occurring mutation reduced virus replication in PK15 cells. BMC Vet Res 2019; 15:248. [PMID: 31307486 PMCID: PMC6632220 DOI: 10.1186/s12917-019-1984-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 06/27/2019] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Porcine circovirus 2 (PCV2) is the causative agent of porcine circovirus-associated diseases (PCVADs). The infection of PCV2 is widespread and has serious consequence, thereby causing significant economic losses in the swine industry worldwide. Previously, we found that a strain named YiY-3-2-3 has a naturally occurring point mutation (G710 to A710) in ORF1 region, which leads to a shorten product of the rep gene (945 to 660 base pair). Importantly, the Rep protein is responsible for genome replication of PCV2. To explore the effects of this mutation on the PCV2 replication, in the current study we constructed infectious clone of this IF-YiY-3-2-3, as well as those of its two parental strains of IF-YiY-3-2-1 and IF-YiY-3-2-10. Subsequently, these infectious clones which have 1.1 copy of PCV2 genome of their corresponding strains were transfected into PK15 cells to obtain rescued viruses, respectively. RESULTS Though all of the three infectious clones could be rescued, the copy number and infectivity of these rescued viruses were significantly different, as analyzed by fluorescence quantitative PCR, Tissue culture infectious dose 50 (TCID50), and indirect immunofluorescence assay (IFA). Notably, whether the PCV2 copy number, viral titer or the infectivity of rescued viruses from infectious clone IF-YiY-3-2-3 was significantly less than those of its parental clones. Meanwhile, the spatial structure of the Rep protein from the IF-YiY-3-2-3 displayed an apparent truncation at the C-terminal. CONCLUSIONS These findings therefore suggest that the Rep protein with truncated C-terminal would reduce virus replication and infectivity, and there might also exist both favorable and unfavorable mutations in the ORF1 of PCV2 in the process of its evolution.
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Affiliation(s)
- Yi Hu
- Lab of Animal Models and Functional Genomics (LAMFG), The Key Laboratory of Animal Vaccine & Protein Engineering, College of Veterinary Medicine, Hunan Agricultural University (HUNAU), Changsha, 410128, Hunan, China
| | - Xiong Cai
- Institute of Innovation and Applied Research in Chinese Medicine, Hunan University of Chinese Medicine, Changsha, 410208, China
| | - Yang Zhan
- Lab of Functional Proteomics (LFP), The Key Laboratory of Animal Vaccine & Protein Engineering, College of Veterinary Medicine, HUNAU, Changsha, 410128, Hunan, China
| | - Xiaomin Yuan
- Lab of Animal Models and Functional Genomics (LAMFG), The Key Laboratory of Animal Vaccine & Protein Engineering, College of Veterinary Medicine, Hunan Agricultural University (HUNAU), Changsha, 410128, Hunan, China
| | - Tanbin Liu
- Lab of Animal Models and Functional Genomics (LAMFG), The Key Laboratory of Animal Vaccine & Protein Engineering, College of Veterinary Medicine, Hunan Agricultural University (HUNAU), Changsha, 410128, Hunan, China
| | - Lei Tan
- Lab of Animal Models and Functional Genomics (LAMFG), The Key Laboratory of Animal Vaccine & Protein Engineering, College of Veterinary Medicine, Hunan Agricultural University (HUNAU), Changsha, 410128, Hunan, China
| | - Yalan Li
- Lab of Animal Models and Functional Genomics (LAMFG), The Key Laboratory of Animal Vaccine & Protein Engineering, College of Veterinary Medicine, Hunan Agricultural University (HUNAU), Changsha, 410128, Hunan, China
| | - Lijie Zhang
- State Key Laboratory of Medicinal Chemical Biology and College of Pharmacy, Nankai University, Tianjin, 300071, China
| | - Lingchen Yang
- Lab of Animal Models and Functional Genomics (LAMFG), The Key Laboratory of Animal Vaccine & Protein Engineering, College of Veterinary Medicine, Hunan Agricultural University (HUNAU), Changsha, 410128, Hunan, China
| | - Wei Liu
- Lab of Animal Models and Functional Genomics (LAMFG), The Key Laboratory of Animal Vaccine & Protein Engineering, College of Veterinary Medicine, Hunan Agricultural University (HUNAU), Changsha, 410128, Hunan, China
| | - Zhibang Deng
- Lab of Functional Proteomics (LFP), The Key Laboratory of Animal Vaccine & Protein Engineering, College of Veterinary Medicine, HUNAU, Changsha, 410128, Hunan, China
| | - Naidong Wang
- Lab of Functional Proteomics (LFP), The Key Laboratory of Animal Vaccine & Protein Engineering, College of Veterinary Medicine, HUNAU, Changsha, 410128, Hunan, China
| | - Yi Yang
- Lab of Functional Proteomics (LFP), The Key Laboratory of Animal Vaccine & Protein Engineering, College of Veterinary Medicine, HUNAU, Changsha, 410128, Hunan, China
| | - Shiyin Guo
- College of Food Science and Technology, HUNAU, Changsha, 410128, Hunan, China.
| | - Aibing Wang
- Lab of Animal Models and Functional Genomics (LAMFG), The Key Laboratory of Animal Vaccine & Protein Engineering, College of Veterinary Medicine, Hunan Agricultural University (HUNAU), Changsha, 410128, Hunan, China.
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Analysis of genetic variation of porcine circovirus type 2 within pig populations in central China. Arch Virol 2019; 164:1445-1451. [PMID: 30888560 DOI: 10.1007/s00705-019-04205-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 02/11/2019] [Indexed: 02/07/2023]
Abstract
In order to investigate the genetic diversity of porcine circovirus type 2 (PCV2), 284 clinical tissue samples were collected from different pig farms in central China from 2015 to 2017. A total of 162 tissue samples (162/284, 57.04%) were positive for PCV2 by PCR, and subsequently, the complete genome of 36 of these PCV2 samples was cloned and sequenced. The sequencing results showed that 37 complete PCV2 sequences were obtained from 36 PCV2-positive clinical samples. These PCV2 strains were relatively conserved and extremely homologous to the representative classical PCV2 strains. Of these, 20 PCV2 strains belonged to genotype PCV2d, 14 belonged to PCV2b, and three others belonged to PCV2a. Coinfection with PCV2b and PCV2d was identified in one sample (DF-2). These results show that PCV2d may be gradually replacing PCV2b as the predominant PCV2 genotype in central China, and that other genotypes also exist in individual regions. The results of this study will aid in our understanding of the molecular epidemiology of PCV2.
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Pan Y, Li P, Jia R, Wang M, Yin Z, Cheng A. Regulation of Apoptosis During Porcine Circovirus Type 2 Infection. Front Microbiol 2018; 9:2086. [PMID: 30233552 PMCID: PMC6131304 DOI: 10.3389/fmicb.2018.02086] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2018] [Accepted: 08/15/2018] [Indexed: 12/19/2022] Open
Abstract
Apoptosis, an indispensable innate immune mechanism, regulates cellular homeostasis by removing unnecessary or damaged cells. It contains three signaling pathways: the mitochondria-mediated pathway, the death receptor pathway and the endoplasmic reticulum pathway. The importance of apoptosis in host defenses is stressed by the observation that multiple viruses have evolved various strategies to inhibit apoptosis, thereby blunting the host immune responses and promoting viral propagation. Porcine Circovirus type 2 (PCV2) utilizes various strategies to induce or inhibit programmed cell death. In this article, we review the latest research progress of the apoptosis mechanisms during infection with PCV2, including several proteins of PCV2 regulate apoptosis via interacting with host proteins and multiple signaling pathways involved in PCV2-induced apoptosis, which provides scientific basis for the pathogenesis and prevention of PCV2.
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Affiliation(s)
- Yuhong Pan
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Pengfei Li
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Renyong Jia
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Mingshu Wang
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Zhongqiong Yin
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Anchun Cheng
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
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