Biopharmaceutical Lab, College of Life Science, Northeast Agricultural University, Harbin, China.
Key Laboratory of Agricultural Biological Functional Gene, Northeast Agricultural University, Harbin, China.
Transbound Emerg Dis. 2021 Nov;68(6):3658-3675. doi: 10.1111/tbed.13974. Epub 2021 Jan 29.
Infectious bursal disease (IBD) is one of the most economically important infectious diseases. Currently, vaccination is the most effective method to prevent IBD. Medium-virulence vaccines can damage the bursa of Fabricius and result in immunosuppression. Therefore, it is essential to develop a safe and effective vaccine against infectious bursal disease virus (IBDV). In this study, the five neutralizing epitopes of the IBDV VP2 protein were confirmed by neutralizing single chain variable fragment antibodies. Then, the neutralizing epitopes antigen (NEA) protein was constructed with five neutralizing epitopes and expressed by pET-27b. Furthermore, the immune effect and protective immunity of the NEA protein with the following adjuvants were evaluated in specific-pathogen-free chickens: oil emulsion adjuvant (OEA), double emulsion adjuvant (DEA), granulocyte-macrophage colony-stimulating factor (GM-CSF) adjuvant and complete Freund's adjuvant (CFA). The experimental results demonstrated that chickens immunized with NEA vaccines elicited stronger humoral and/or cellular immune responses and inflammatory responses than those in the NEA protein group. Chickens were protected in OEA, CFA and GM-CSF adjuvant groups, which were challenged with virulent IBDV BC6/85. Furthermore, IBDV RNA was not measured, and there appeared to be little apoptosis in the bursa of Fabricius based on TUNEL histology and the expression of Bax and Bcl-2 in the OEA, CFA and GM-CSF adjuvant groups. Based on the experimental results, the advantages and disadvantages of adjuvants and industrial production methods, GM-CSF was found to be the optimal adjuvant. Therefore, NEA with GM-CSF adjuvant is a promising vaccine candidate against IBDV, and it provides a framework for developing other vaccines against infectious viral diseases.
传染性法氏囊病（IBD）是最具经济重要性的传染病之一。目前，疫苗接种是预防 IBD 的最有效方法。中等毒力疫苗会损害法氏囊并导致免疫抑制。因此，开发针对传染性法氏囊病病毒（IBDV）的安全有效的疫苗至关重要。在这项研究中，通过中和单链可变片段抗体确定了 IBDV VP2 蛋白的五个中和表位。然后，用五个中和表位构建了中和表位抗原（NEA）蛋白，并通过 pET-27b 进行表达。此外，用油乳剂佐剂（OEA）、双乳化佐剂（DEA）、粒细胞-巨噬细胞集落刺激因子（GM-CSF）佐剂和完全弗氏佐剂（CFA）评估了 NEA 蛋白的免疫效果和保护免疫在无特定病原体鸡中：油乳剂佐剂（OEA）、双乳化佐剂（DEA）、粒细胞-巨噬细胞集落刺激因子（GM-CSF）佐剂和完全弗氏佐剂（CFA）。实验结果表明，用 NEA 疫苗免疫的鸡产生了更强的体液和/或细胞免疫反应和炎症反应，比 NEA 蛋白组更强。在 OEA、CFA 和 GM-CSF 佐剂组中，用强毒 IBDV BC6/85 攻毒的鸡得到了保护。此外，在 OEA、CFA 和 GM-CSF 佐剂组中，未检测到 IBDV RNA，法氏囊的细胞凋亡似乎很少，基于 TUNEL 组织化学和 Bax 和 Bcl-2 的表达。根据实验结果，佐剂和工业生产方法的优缺点，发现 GM-CSF 是最佳佐剂。因此，用 GM-CSF 佐剂的 NEA 是一种有前途的针对 IBDV 的疫苗候选物，为开发针对其他传染性病毒病的疫苗提供了框架。
