Abstract: Infectious bursal disease virus (IBDV) is the pathogen of infectious bursal disease (IBD). The high mortality of IBD causes severe economic losses to the global poultry industry. In recent years, the genetically engineered vaccines and DNA vaccines developed rapidly, bringing hope for more effective prevention and control of IBD. Ferritin can be assembled into stable multimers, which has been used as a candidate immunogen carrier for many diseases. In this study, the IBDV-VP2 and ferritin sequences were optimized according to the preference of Escherichia coli codons, and the fusion expression was carried out through the E. coli expression system, and the expression of the target protein was detected by mass spectrometry, Western blotting, SDS-PAGE, and transmission electron microscope. The fusion protein had been successfully expressed in the form of inclusion bodies in E. coli, and nano-sized particles of uniform size can be observed by transmission electron microscopy. This research can be used to explore the effect of ferritin self-assembly on improving the broad-spectrum and immunogenicity of IBDV vaccines, and lay the foundation for further research on its application mechanism as a drug and antigen carrier.

Key words: IBDV, nano ferritin protein, VP2, prokaryotic expression

摘要： 传染性法氏囊病毒（infectious bursal disease virus，IBDV）是传染性法氏囊病（infectious bursal disease，IBD）的病原，其导致的高死亡率使全球的家禽养殖业受到了严重的经济损失。近年来，基因工程疫苗和DNA疫苗的迅速发展为IBD更有效的防控带来了希望。基于自然合成的铁蛋白大多可以组装成较稳定的多聚体这一特点，其可以作为很多疾病的免疫原载体。根据大肠杆菌密码子的偏好性，对IBDV-VP2、铁蛋白序列进行了优化，并通过大肠杆菌表达系统进行了融合表达，通过质谱、Western blotting、SDS-PAGE检测，该融合蛋白已成功在大肠杆菌中以包涵体的形式表达，且通过透射电镜可观察到大小均一的纳米级颗粒，研究结果为后期探究铁蛋白自组装对提高IBDV疫苗的广谱性、免疫原性的作用提供了参考，也为进一步研究其作为药物和抗原载体的应用机制奠定了基础。

关键词: 传染性法氏囊病毒（IBDV）, 纳米铁蛋白, VP2, 原核表达