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Wang Y, Xu F, Yuan C, Zhang Y, Ren J, Yue H, Ma T, Song Q. Comparison of immune effects of porcine circovirus type 2d (PCV2d) capsid protein expressed by Escherichia coli and baculovirus-insect cells. Vaccine 2024; 42:2848-2857. [PMID: 38514351 DOI: 10.1016/j.vaccine.2024.03.048] [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: 10/15/2023] [Revised: 03/15/2024] [Accepted: 03/18/2024] [Indexed: 03/23/2024]
Abstract
Porcine circovirus type 2 (PCV2) is an important pathogen harmful to global pig production, which causes immunosuppression and serious economic losses. PCV2 capsid (Cap) protein expressed by E. coli or baculovirus-insect cells are often used in preparation of PCV2 subunit vaccines, but the latter is expensive to produce. It is therefore crucial to comparison of the immune effects of Cap protein expressed by the above two expression systems for reducing the production cost and guaranteeing PCV2 vaccine quality. In this study, the PCV2d-Cap protein lacking nuclear localization signal (NLS), designated as E. coli-Cap and Bac-Cap, was expressed by E. coli and baculovirus-Spodoptera frugiperda Sf9 (Bac-Sf9) cells, respectively. The expressed Cap proteins could self-assemble into virus-like particles (VLPs), but the Bac-Cap-assembled VLPs were more regular. The two system-expressed Cap proteins induced similar specific IgG responses in mice, but the neutralizing antibody levels of Bac-Cap-immunized mice was higher than those of E. coli-Cap. After PCV2 challenge, IL-10 in Bac-Cap immunized mice decreased significantly than that in E. coli-Cap. The lesions and PCV2 antigen positive cells in tissues of mice immunized with E. coli-Cap and Bac-Cap were significantly reduced, and Bac-Cap appeared mild lesions and fewer PCV2 antigen-positive cells compared with E. coli-Cap immunized mice. The study indicated that Cap proteins expressed by E. coli and Bac-Sf9 cells could induce specific protective immunity, but the latter induced more effective immunity, which provides valuable information for the research and development of PCV2 vaccine.
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Affiliation(s)
- Yawen Wang
- College of Veterinary Medicine & Hebei Veterinary Biotechnology Innovation Center, Hebei Agricultural University, Baoding 071001, China
| | - Fan Xu
- College of Veterinary Medicine & Hebei Veterinary Biotechnology Innovation Center, Hebei Agricultural University, Baoding 071001, China
| | - Chen Yuan
- College of Veterinary Medicine & Hebei Veterinary Biotechnology Innovation Center, Hebei Agricultural University, Baoding 071001, China
| | - Yanan Zhang
- College of Veterinary Medicine & Hebei Veterinary Biotechnology Innovation Center, Hebei Agricultural University, Baoding 071001, China
| | - Jing Ren
- College of Veterinary Medicine & Hebei Veterinary Biotechnology Innovation Center, Hebei Agricultural University, Baoding 071001, China
| | - Huaining Yue
- College of Veterinary Medicine & Hebei Veterinary Biotechnology Innovation Center, Hebei Agricultural University, Baoding 071001, China
| | - Tiantian Ma
- College of Veterinary Medicine & Hebei Veterinary Biotechnology Innovation Center, Hebei Agricultural University, Baoding 071001, China
| | - Qinye Song
- College of Veterinary Medicine & Hebei Veterinary Biotechnology Innovation Center, Hebei Agricultural University, Baoding 071001, China.
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Zheng J, Li N, Li X, Han Y, Lv X, Zhang H, Ren L. The Nuclear Localization Signal of Porcine Circovirus Type 4 Affects the Subcellular Localization of the Virus Capsid and the Production of Virus-like Particles. Int J Mol Sci 2024; 25:2459. [PMID: 38473709 DOI: 10.3390/ijms25052459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 01/29/2024] [Accepted: 02/18/2024] [Indexed: 03/14/2024] Open
Abstract
Porcine circovirus 4 (PCV4) is a newly identified virus belonging to PCV of the Circoviridae family, the Circovirus genus. We previously found that PCV4 is pathogenic in vitro, while the virus's replication in cells is still unknown. In this study, we evaluated the N-terminal of the PCV4 capsid (Cap) and identified an NLS at amino acid residues 4-37 of the N-terminus of the PCV4 Cap, 4RSRYSRRRRNRRNQRRRGLWPRASRRRYRWRRKN37. The NLS was further divided into two fragments (NLS-A and NLS-B) based on the predicted structure, including two α-helixes, which were located at 4RSRYSRRRRNRRNQRR19 and 24PRASRRRYRWRRK36, respectively. Further studies showed that the NLS, especially the first α-helixes formed by the NLS-A fragment, determined the nuclear localization of the Cap protein, and the amino acid 4RSRY7 in the NLS of the PCV4 Cap was the critical motif affecting the VLP packaging. These results will provide a theoretical basis for elucidating the infection mechanism of PCV4 and developing subunit vaccines based on VLPs.
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Affiliation(s)
- Jiawei Zheng
- College of Animal Sciences, Key Lab for Zoonoses Research, Ministry of Education, Jilin University, 5333 Xi'an Road, Changchun 130062, China
| | - Nan Li
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 666 Liuying West Road, Changchun 130122, China
| | - Xue Li
- College of Animal Sciences, Key Lab for Zoonoses Research, Ministry of Education, Jilin University, 5333 Xi'an Road, Changchun 130062, China
| | - Yaqi Han
- College of Animal Sciences, Key Lab for Zoonoses Research, Ministry of Education, Jilin University, 5333 Xi'an Road, Changchun 130062, China
| | - Xinru Lv
- College of Animal Sciences, Key Lab for Zoonoses Research, Ministry of Education, Jilin University, 5333 Xi'an Road, Changchun 130062, China
| | - Huimin Zhang
- College of Animal Sciences, Key Lab for Zoonoses Research, Ministry of Education, Jilin University, 5333 Xi'an Road, Changchun 130062, China
| | - Linzhu Ren
- College of Animal Sciences, Key Lab for Zoonoses Research, Ministry of Education, Jilin University, 5333 Xi'an Road, Changchun 130062, China
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming 650201, China
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Du Q, Shi T, Wang H, Zhu C, Yang N, Tong D, Huang Y. The ultrasonically treated nanoliposomes containing PCV2 DNA vaccine expressing gC1qR binding site mutant Cap is efficient in mice. Front Microbiol 2023; 13:1077026. [PMID: 36713188 PMCID: PMC9874303 DOI: 10.3389/fmicb.2022.1077026] [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: 10/22/2022] [Accepted: 12/28/2022] [Indexed: 01/12/2023] Open
Abstract
Nowadays, vaccines are broadly used to prevent porcine circovirus type 2 (PCV2) infection-induced expenditures, but the virus is still spreading among pigs. The current PCV2 vaccines all rely on the immunogenicity of Cap, yet our previous studies found that Cap is also the major component mediating the PCV2 infection-induced immune suppression through its interaction with host gC1qR. Thereby, new vaccines are still necessary for PCV2 prevention and control. In this study, we constructed a new PCV2 DNA vaccine expressing the gC1qR binding site mutant Cap. We introduced the Intron A and WPRE elements into the vector to improve the Cap expression level, and fused the IL-2 secretory signal peptides to the N-terminal of Cap to mediate the secretion of Cap. We also screened and selected chemokines CXCL12, CCL22, and CCL25 to migrate dendritic cells. In addition, we contained the vectors with PEI and then ultrasonic them into nano size to enhance the entrance of the vectors. Finally, the animal experiments showed that the new PCV2 DNA vaccine expressing the gC1qR binding site mutant Cap could induce stronger humoral and cellular immune responses than the PCV2 DNA vaccine expressing the wild-type Cap and the non-ultrasonic treated PCV2 DNA vaccine in mice, and protect the mice from PCV2 infection and lung lesions. The results indicate the new PCV2 DNA vaccine expressing the gC1qR binding site mutant Cap has a certain development value, and provide new insight into the development of novel PCV2 vaccines.
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Affiliation(s)
- Qian Du
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China,Engineering Research Center of Efficient New Vaccines for Animals, Ministry of Education, Xianyang, China
| | - Tengfei Shi
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China,Engineering Research Center of Efficient New Vaccines for Animals, Ministry of Education, Xianyang, China
| | - Huaxin Wang
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China,Engineering Research Center of Efficient New Vaccines for Animals, Ministry of Education, Xianyang, China
| | - Changlei Zhu
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China,Engineering Research Center of Efficient New Vaccines for Animals, Ministry of Education, Xianyang, China
| | - Nan Yang
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China,Engineering Research Center of Efficient New Vaccines for Animals, Ministry of Education, Xianyang, China
| | - Dewen Tong
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China,Engineering Research Center of Efficient New Vaccines for Animals, Ministry of Education, Xianyang, China,*Correspondence: Dewen Tong,
| | - Yong Huang
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China,Engineering Research Center of Efficient New Vaccines for Animals, Ministry of Education, Xianyang, China,Yong Huang,
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