Yang Shu-Qing, Yang Ke, Li Xin-Ran, Zheng Yi, Cao San-Jie, Yan Qi-Gui, Huang Xiao-Bo, Wen Yi-Ping, Zhao Qin, Du Sen-Yan, Lang Yi-Fei, Zhao Shan, Li Chun, Wu Rui
Research Center for Swine Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
Sichuan Animal Disease Prevention and Control Center, Chengdu 610047, China.
J Virol Methods. 2025 Apr;333:115080. doi: 10.1016/j.jviromet.2024.115080. Epub 2024 Dec 5.
Porcine circovirus type 3 (PCV3) is endemic in swine worldwide and causes reproductive disorders, dermatitis and nephrotic syndrome, and multi-organ inflammation. PCV3 capsid protein (Cap) can self-assemble into virus-like particles (VLPs), and is an ideal candidate for vaccines and diagnostic reagents.In this study, the recombinant PCV3 Cap protein was successfully expressed in E. coli by deleting the nuclear localization sequence (NLS). The PCV3 VLPs were observed by transmission electron microscopy, and its immunogenicity was evaluated in six-week-old female BALB/c mice. A monoclonal antibody was named mAb 2D6, and demonstrated strong reactivity and specificity to PCV3 Cap. The purified mAb 2D6 was further used for bio-panning to select phage expressing specific epitopes from phage-displayed 7 mer-peptide library. A novel linear B-cell epitope, recognized by mAb 2D6, was identified at the amino acid region 47-53 of Cap. The phage peptide sequences were analyzed using multiple sequence alignment and evaluated by peptide ELISA. These results provide insights for developing diagnostic tools and potential vaccines for PCV3.
猪圆环病毒3型（PCV3）在全球猪群中呈地方性流行，可引起繁殖障碍、皮炎和肾病综合征以及多器官炎症。PCV3衣壳蛋白（Cap）能自组装成病毒样颗粒（VLPs），是疫苗和诊断试剂的理想候选物。在本研究中，通过删除核定位序列（NLS），重组PCV3 Cap蛋白在大肠杆菌中成功表达。通过透射电子显微镜观察到PCV3 VLPs，并在六周龄雌性BALB/c小鼠中评估其免疫原性。一种单克隆抗体被命名为mAb 2D6，对PCV3 Cap表现出强反应性和特异性。纯化的mAb 2D6进一步用于生物淘选，以从噬菌体展示的7肽文库中筛选表达特异性表位的噬菌体。在Cap的氨基酸区域47-53处鉴定出一个被mAb 2D6识别的新型线性B细胞表位。使用多序列比对分析噬菌体肽序列，并通过肽ELISA进行评估。这些结果为开发PCV3诊断工具和潜在疫苗提供了思路。
