文献类型： 外文期刊

作者： Zhang, Chengxin ¹ ; He, Fang ¹ ; Li, Nianfeng ¹ ; Du, Wei ³ ; Wen, Jianxin ¹ ; Wu, Xiaoyan ² ; Shi, Jianli ² ; Li, Chen ² ; Liu, Chang ² ; Xu, Shaojian ² ; Han, Hong ² ; Hrabchenko, Nataliia ² ; Han, Xianjie ¹ ; Li, Jun ¹ ;

作者机构： 1.Qingdao Agr Univ, Qingdao 266109, Peoples R China

2.Shandong Acad Agr Sci, Div Swine Dis, Shandong Prov Key Lab Anim Dis Control & Breeding, Inst Anim Sci & Vet Med, Jinan 250100, Peoples R China

3.Shandong Normal Univ, Coll Life Sci, Jinan, Peoples R China

4.Shandong Acad Agr Sci, Jinan 250100, Peoples R China

关键词： PCV2d; Cap protein; Virus -like particles (VLPs); Escherichia coli expression system; Vaccine development; Immunogenicity

期刊名称：MICROBIAL PATHOGENESIS （ 影响因子：3.8； 五年影响因子：4.0 ）

ISSN： 0882-4010

年卷期： 2024 年 190 卷

页码：

收录情况： SCI

摘要： Porcine circovirus type 2 (PCV2) is a globally prevalent infectious pathogen affecting swine, with its capsid protein (Cap) being the sole structural protein critical for vaccine development. Prior research has demonstrated that PCV2 Cap proteins produced in Escherichia coli ( E. coli ) can form virus -like particles (VLPs) in vitro, and nuclear localization signal peptides (NLS) play a pivotal role in stabilizing PCV2 VLPs. Recently, PCV2d has emerged as an important strain within the PCV2 epidemic. In this study, we systematically optimized the PCV2d Cap protein and successfully produced intact PCV2d VLPs containing NLS using E. coli . The recombinant PCV2d Cap protein was purified through affinity chromatography, yielding 7.5 mg of recombinant protein per 100 ml of bacterial culture. We augmented the conventional buffer system with various substances such as arginine, beta-mercaptoethanol, glycerol, polyethylene glycol, and glutathione to promote VLP assembly. The recombinant PCV2d Cap self -assembled into VLPs approximately 20 nm in diameter, featuring uniform distribution and exceptional stability in the optimized buffer. We developed the vaccine and immunized pigs and mice, evaluating the immunogenicity of the PCV2d VLPs vaccine by measuring PCV2-IgG, IL -4, TNF- alpha, and IFN- gamma levels, comparing them to commercial vaccines utilizing truncated PCV2 Cap antigens. The HE staining and immunohistochemical tests confirmed that the PCV2 VLPs vaccine offered robust protection. The results revealed that animals vaccinated with the PCV2d VLPs vaccine exhibited high levels of PCV2 antibodies, with TNF- alpha and IFN- gamma levels rapidly increasing at 14 days post -immunization, which were higher than those observed in commercially available vaccines, particularly in the mouse trial. This could be due to the fact that full-length Cap proteins can assemble into more stable PCV2d VLPs in the assembling buffer. In conclusion, our produced PCV2d VLPs vaccine elicited stronger immune responses in pigs and mice compared to commercial vaccines. The PCV2d VLPs from this study serve as an excellent candidate vaccine antigen, providing insights for PCV2d vaccine research.