Grasslands Research Centre, AgResearch, Hopkirk Research Institute, Private Bag 11008, Palmerston North, 4442, New Zealand.
Bioinformatics and Statistics, AgResearch, Palmerston North, New Zealand.
Sci Rep. 2020 Dec 18;10(1):22289. doi: 10.1038/s41598-020-79407-7.
Mycobacterium avium subspecies paratuberculosis (MAP) causes chronic progressive granulomatous enteritis leading to diarrhoea, weight loss, and eventual death in ruminants. Commercially available vaccines provide only partial protection against MAP infection and can compromise the use of bovine tuberculosis diagnostic tests. Here, we report the development of a protein-particle-based vaccine containing MAP antigens Ag85A-SOD-Ag85B-74F as a fusion ('MAP fusion protein particle'). The fusion antigen displayed on protein particles was identified using mass spectrometry. Surface exposure and accessibility of the fusion antigen was confirmed by flow cytometry and ELISA. The MAP fusion protein particle vaccine induced strong antigen-specific T-cell immune responses in mice, as indicated by increased cytokine (IFN-γ and IL-17A) and costimulatory signals (CD40 and CD86) in these animals. Following MAP-challenge, a significant reduction in bacterial burden was observed in multiple organs of the mice vaccinated with the MAP fusion protein particle vaccine compared with the PBS group. The reduction in severity of MAP infection conferred by the MAP fusion protein particle vaccine was similar to that of Silirum and recombinant protein vaccines. Overall, the results provide evidence that MAP antigens can be engineered as a protein particulate vaccine capable of inducing immunity against MAP infection. This utility offers an attractive platform for production of low-cost particulate vaccines against other intracellular pathogens.
分支杆菌亚种副结核分枝杆菌 (MAP) 引起慢性进行性肉芽肿性肠炎，导致反刍动物腹泻、体重减轻，最终死亡。市售疫苗仅对 MAP 感染提供部分保护作用，并可能影响牛结核病诊断测试的使用。在这里，我们报告了一种基于蛋白质颗粒的疫苗的开发，该疫苗含有 MAP 抗原 Ag85A-SOD-Ag85B-74F 作为融合体（“MAP 融合蛋白颗粒”）。使用质谱法鉴定了在蛋白质颗粒上显示的融合抗原。通过流式细胞术和 ELISA 证实了融合抗原的表面暴露和可及性。MAP 融合蛋白颗粒疫苗在小鼠中诱导了强烈的抗原特异性 T 细胞免疫反应，这些动物的细胞因子（IFN-γ 和 IL-17A）和共刺激信号（CD40 和 CD86）增加。与 PBS 组相比，接种 MAP 融合蛋白颗粒疫苗的小鼠在多个器官中 MAP 的细菌负荷显著降低。MAP 融合蛋白颗粒疫苗赋予的 MAP 感染严重程度降低与 Silirum 和重组蛋白疫苗相似。总体而言，结果提供了证据表明 MAP 抗原可以作为一种能够诱导针对 MAP 感染的免疫的蛋白质颗粒疫苗进行工程改造。这种用途为生产针对其他细胞内病原体的低成本颗粒疫苗提供了有吸引力的平台。
