在淋病奈瑟菌(Neisseria gonorrhoeae,NG)6种保守外膜蛋白中筛选优势表位,设计淋病奈瑟菌多表位亚单位疫苗并模拟其免疫效果.首先,通过C-ImmSim在线服务器对6种外膜蛋白进行计算机免疫模拟,并分别从细胞毒性T细胞(cytotoxic T lymphocyte,CTL)、辅助性T细胞(helper T cell,Th cell)及B细胞免疫反应强的外膜蛋白中筛选用于构建多表位亚单位疫苗的优势CTL表位、Th细胞表位和B细胞表位.其次,在对各优势表位进行抗原性、致敏性和毒性分析后,将不同排列组合的优势表位与抗菌肽及PADRE序列连接起来,设计出多表位亚单位疫苗.再次,对所设计的各种多表位亚单位疫苗进行计算机免疫模拟,以评价其体液免疫和细胞免疫的效果.最后,对筛选出的免疫效果较好的候选亚单位疫苗进行抗原性、致敏性、理化性质、溶解性评估以及二级结构分析,以确保候选亚单位疫苗符合疫苗设计标准.结果显示,筛选出符合要求的优势候选CTL表位8个、Th细胞表位10个和B细胞表位14个;共设计出64种多表位亚单位疫苗,其中3种亚单位疫苗的免疫模拟结果最佳,均满足抗原性强、对人体无致敏性及无细胞毒性的要求,且均为亲水性、耐热性较好的稳定蛋白质,同时能在大肠杆菌中实现可溶性的过表达,与抗体的亲和性也较强,符合疫苗设计的标准.研究结果表明,以C-ImmSim为主的生物信息学预测方法在多表位亚单位疫苗的反向设计及其免疫效果的高通量初步筛选方面具有良好的应用前景.本研究为淋病奈瑟菌疫苗研发提供了一种新的有效途径.
Immunoinformatics Design of Epitope-based Subunit Vaccines Against Neisseria gonorrhoeae
The dominant epitopes from six conserved outer membrane proteins of Neisseria gonorrhoeae(NG)were screeed,multi-epitope subunit vaccines were designed,and the immune responses against them were simulated.Firstly,computer simulation of six outer membrane proteins was performed through the C-ImmSim online server,and the dominant cytotoxic T lymphocyte(CTL)epitopes,helper T(Th)cell epitopes and B cell epitopes were screened from outer membrane proteins with strong CTL,Th cell and B cell immune responses,respectively.Secondly,after the antigenicity,allergenicity,and toxicity analysis of each candidate epitope,candidate epitopes with different arrangement and combinations were connected with antimicrobial peptide and PADRE sequences to construct multi-epitope subunit vaccines.Thirdly,the designed multi-epitope sub-unit vaccines were simulated by computer to evaluate their abilities to induce humoral and cellular immunity.Finally,the candidate subunit vaccines with good immune effect were screened and further evaluated for antigenicity,allergenicity,physicochemical properties,solubility,and secondary structure to ensure that the candidate subunit vaccines meet the vaccine design standards.Through these processes,eight candidate CTL epitopes,10 Th cell epitopes,and 14 B cell epitopes were selected out,and a total of 64 multi-epitope sub-unit vaccines were designed.Among them,three subunit vaccines had satisfactory immune simulation results,with strong antigenicity,no allergenicity to human body,and no cytotoxicity,were all stable proteins with good hydropathicity and heat resistance,achieved soluble overexpression in E.coli,and had strong affinity with antibodies,all of which met the standards for vaccine design.The results indicated that the bioinfor-matics prediction based mainly on C-ImmSim had a good application prospect in the reverse design of multi-epitope subunit vaccines and high-throughput preliminary screening of their immune effects.This study pro-vided a new and effective approach for the development of N.gonorrhoeae vaccines.
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维普
