基于免疫信息学技术的结核分枝杆菌多表位疫苗构建  

Designing a multi-epitope vaccine against Mycobacterium tuberculosis by immunoinformatics approach

作　　者：曹钰婷 吴雪晗 宁钰 孟祥英[1] 乔晋娟 CAO Yu-ting;WU Xue-han;NING Yu;MENG Xiang-ying;QIAO Jin-juan(Department of Medical Laboratory Science,Weifang Medical University,Weifang 261053,Shandong,China)

机构地区：[1]潍坊医学院医学检验学院,山东潍坊261053

出　　处：《中国病原生物学杂志》2022年第9期999-1004,共6页Journal of Pathogen Biology

基　　金：山东省自然科学基金项目(No.ZR2020MH305);山东省医药卫生科技发展计划项目(No.2019WS593);国家级大学生创新创业训练计划项目(No.202110438065)。

摘　　要：目的筛选具有抗原表位可能性的结核分枝杆菌高活性结合肽(HABPs),构建基于HABPs的多表位疫苗。方法通过免疫信息学方法预测HABPs的保护性抗原可能性、细胞毒性、致敏性及潜在B细胞和T细胞表位;将筛选出的HABPs与佐剂霍乱毒素B亚单位连接,构建多表位疫苗,并对其二级结构和理化性质进行分析;采用I-TASSER服务器进行多表位疫苗三级结构同源建模,优化的模型质量通过PROCHECK、ERRAT及ProSA-web软件进行验证;使用PatchDock软件进行多表位疫苗与TLR-4的分子对接;对疫苗进行密码子优化、在线克隆和免疫模拟。结果共筛选出32条HABPs序列,构建的多表位疫苗包含881个氨基酸残基,二级结构由43.93%的α螺旋、13.62%的β折叠和42.45%的无规则卷曲组成,不稳定性指数(Ⅱ)、脂肪族指数和亲水性平均值分别为45.34、84.09和-0.009,表明该疫苗具有灵活、稳定的球形构象和亲水结构。Ramachandran图中位于核心区域和允许区的氨基酸比例大于90%,ERRAT评估整体质量因子值为74.39,Z值为-5.94,表明3D模型的质量整体较好。分子对接结果表明疫苗可与TLR-4稳定相互作用。经过密码子优化的疫苗可在大肠埃希菌中高效表达。免疫模拟显示,当反复暴露于多表位疫苗抗原时,机体的B细胞和T细胞免疫反应均得到增强。此外,多表位疫苗还可诱导高水平细胞因子的分泌。结论利用免疫信息学工具构建的基于HABPs的多表位疫苗含有B、T细胞表位,有望同时激发机体体液免疫和细胞免疫,具有良好应用前景,但其实际免疫效果还需进一步证实。Objective To screen potential epitopes from the highly active binding peptides(HABPs)of Mycobacterium tuberculosis(Mtb)and construct a multi-epitope vaccine based on HABPs.Methods The immunogenicity,toxicity,allergenicity and potential B-and T-cell epitopes of HABPs were predicted by immunoinformatics approach.A multiepitope vaccine was constructed by connecting the selected HABPs with the adjuvant,cholera toxin B subunit.Then the secondary structure and physicochemical properties of the construct were analyzed.The tertiary structure of vaccine protein was predicted using an online I-TASSER server,and the structural quality of the refined model was verified by PROCHECK,ERRAT and ProSA-web software.The designed multi-epitope vaccine protein was submitted to PatchDock server for molecular docking with TLR4.Finally,codon optimization,in silico cloning and immune simulation of the vaccine were carried out.Results In this study,32 HABPs were selected to construct the multi-epitope vaccine,which contained 881 amino acid residues.The secondary structure was composed of 43.93%helix,13.62%beta-strand,and 42.45%coil.The average values of instability index(Ⅱ),aliphatic index and grand average of hydropathicity were 45.34,84.09 and-0.009,respectively,indicating that the vaccine has a flexible and stable spherical conformation and a hydrophilic structure.Ramachandran plot showed that more than 90%residues of the multi-epitope vaccine lay in the favoured and additional allowed region,the overall quality factor evaluated by ERRAT is 74.39,and the Z score is-5.94,indicating that the model of the vaccine construct was reliable.A stable interaction of the vaccine with TLR-4 was confirmed by molecular docking.The codon-optimized vaccine could be efficiently expressed in Escherichia coli.The immune simulation showed that the second and third immunization stimulated a stronger immune response than the primary immunization.In addition,the multi-epitope vaccine could induce the secretion of high-level cytokines.Conclusion In this stu

关 键 词：结核分枝杆菌 免疫信息学 疫苗 表位 

分 类 号：R373.911[医药卫生—病原生物学]