猪德尔塔冠状病毒S蛋白纳米颗粒的构建及免疫原性评价

Construction and Immunogenicity Evaluation of Porcine deltacoronavirus Spike Protein Nanoparticles

为评价猪德尔塔冠状病毒(PDCoV)纤突(S)蛋白纳米颗粒的免疫原性,首先利用pcDNA3.1(+)-S1-CTD-Spa-His、pET28a-SpyCatcher-mi3分别表达了重组蛋白S1-CTD-Spy-His和SpyCatcher-mi3,纯化后,经SDS-PAGE鉴定表明在55 ku和37 ku处有目的条带。通过SpyTag-SpyCatcher蛋白连接酶系统,获得了S1-CTD-SpyCatcher-mi3纳米颗粒,在电镜下能够观察到直径35~40 nm的颗粒。血清抗体检测结果表明,S1-CTD-SpyCatcher-mi3纳米颗粒可诱导小鼠产生较强的体液免疫反应,S1-CTD-SpyCatcher-mi3组的特异性IgG抗体水平显著高于S1-CTD组(P<0.05),S1-CTD-SpyCatcher-mi3组和S1-CTD组与PBS对照组相比差异均极显著(P<0.01)。该研究表明,S1-CTD-SpyCatcher-mi3纳米颗粒具有良好的免疫原性,可诱导小鼠产生免疫保护力,为新型猪德尔塔冠状病毒感染疫苗的研制奠定了基础。

To evaluate the immunogenicity of Porcine deltacoronaviurs(PDCoV)spike(S)proteinnanoparticles,the recombinant proteins S1-CTD-Spy-His and SpyCatcher-mi3 were firstly expressed by using pcDNA3.1(+)-S1-CTD-Spa-His and pET28a-SpyCatcher-mi3,After purification,SDS-PAGE identification showed that there were target bands at 55 ku and 37 ku.Utilizing the SpyTag-SpyCatcher protein ligase system,S1-CTD-Spycatcher-mi3 nanoparticles were obtained,and the diameter of 35~40 nm nanoparticles were observed under electron microscopy.The results of serum antibody assay showed that S1-CTD-SpyCatcher-mi3 nanoparticles induced a strong humoral immune response in mice,and the specific IgG antibody levels of the S1-CTD-SpyCatcher-mi3 group were significantly higher than those of the S1-CTD group(P<0.05),and the differences between the S1-CTD-SpyCatcher-mi3 group and the S1-CTD group compared with the PBS control group were both highly significant(P<0.01).This study shows S1-CTD-SpyCatcher-mi3 nanoparticles have good immunogenicity and can induce immune protection in mice,which lays a foundation for the development of novel Porcine deltacoronavirus infection vaccine.