Acta Veterinaria et Zootechnica Sinica ›› 2025, Vol. 56 ›› Issue (9): 4626-4637.doi: 10.11843/j.issn.0366-6964.2025.09.040

• Preventive Veterinary Medicine • Previous Articles     Next Articles

Preparation of Clostridium perfringens α Toxin-ferritin Nanoparticle Antigens and Evaluation of Its Immunogenicity in Mice

ZHAO Huiyu1,2(), LEI Yinuo2,3(), XING Qianru2, ZHANG Shan2, ZHANG Guangzhi2, JIANG Hui2, SHEN Qingchun2, DING Jiabo2, JIANG Shijin1,*(), FAN Xuezheng2,*()   

  1. 1. Shandong Agricultural University, Tai'an 271000, China
    2. Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
    3. Guangxi University, Nanning 530004, China
  • Received:2024-12-18 Online:2025-09-23 Published:2025-09-30
  • Contact: JIANG Shijin, FAN Xuezheng E-mail:1765137226@qq.com;1229042392@qq.com;jshijin@163.com;fanxuezheng@caas.cn

Abstract:

This study aimed to prepare Clostridium perfringens α-ferritin nanoparticle antigens and evaluate its immunogenicity in mice. The full-length α gene containing D56G and H68G point mutations and the Spytag sequence, as well as the gene fragment ferritin containing the ferritin gene and SpyCatcher sequence were cloned into the prokaryotic expression vector pET 28a vector respectively. Recombinant proteins were expressed followed by identification and purification. The cytotoxicity, lecithinase activity and haemolytic activity of purified αm2ST were analysed. The purified αm2ST and FeSC were docked in vitro. The docking product of α-ferritin (αm2-Fe) and αm2ST were mixed with adjuvant, respectively, and used for mice immunization. Mice serum was collected every week post immunization to measure IgG, IgG subtype antibody levels and the serum neutralization titers; on day 28 post the second immunization, splenocytes were isolated to analyze T-cell subsets and IFN-γ secretion levels. The results showed that at 28 ℃, αm2ST and FeSC were predominantly expressed in a soluble manner. The αm2ST was free of cytotoxicity, lecithinase activity, or hemolytic activity after detection, indicating that the αm2ST is non-toxic. After in vitro docking of αm2ST and FeSC, it was confirmed that the αm2-Fe formed nanoparticles with a diameter of 32.7-50.7 nm, with a main peak at 37.8 nm, after analyses with SDS-PAGE, TEM, and DLS. Following immunization in mice, the αm2-Fe group exhibited high levels of IgG2a antibodies (P < 0.001). On day 21 after the second immunization, the serum neutralization titer in the αm2-Fe group was 64-fold, significantly surpassing the 32-fold titer in the αm2ST group (P < 0.05). By day 28 after the second immunization, the IFN-γ levels in the supernatant of stimulated splenocytes were also higher in the αm2-Fe group compared to the αm2ST group (P < 0.05). Flow cytometry analysis revealed that the αm2-Fe group produced a higher proportion of effector CD8+ T cells (P < 0.000 1). Mice experiments confirmed that the αm2-Fe nanoparticle antigens effectively induce both humoral and cellular immunity in mice.

Key words: Clostridium perfringens, alpha toxin, ferritin, nanoparticles, immunogenicity

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