新型冠状病毒ORF 1ab/S/M蛋白遗传进化分析及mRNA疫苗抗原表位序列筛选

Genetic evolution analysis of SARS-CoV-2 ORF 1ab/S/M protein and screening of epitopes of mRNA vaccine

目的分析新型冠状病毒(SARS-CoV-2)ORF 1ab/S/M蛋白的遗传进化特性并筛选mRNA疫苗的抗原表位序列。方法收集全球SARS-CoV-2的全基因组序列,比较ORF 1ab/S/M蛋白及核酸遗传差异并构建进化树,绘制遗传差异全球分布图。基于严重急性呼吸综合征冠状病毒(SARS-CoV)的研究基础,结合SARS-CoV-2的遗传差异,预测并筛选mRNA疫苗抗原表位候选序列。结果全球新型冠状病毒肺炎(COVID-19)暴发地区SARS-CoV-2的ORF 1ab核酸序列相似性为100.0%,同源性为99.3%;S蛋白核酸序列相似性为100.0%,同源性为97.5%;M蛋白核酸序列相似性为100.0%,同源性为99.9%。三种蛋白遗传变异的全球分布显示,美洲地区与亚欧地区暴发的SARS-CoV-2存在明显差异。SARS-CoV-2 ORF 1ab蛋白区段筛选出11条B细胞和13条T细胞mRNA疫苗候选目标序列,S蛋白区段筛选出6条B细胞和4条T细胞mRNA疫苗候选目标序列,M蛋白区段筛选出3条B细胞和7条T细胞mRNA疫苗候选目标序列。结论在美洲地区与亚欧地区暴发的SARS-CoV-2存在明显的遗传差异,通过构建新的线性抗原表位mRNA筛选策略,筛选出ORF 1ab/S/M编码区中多条引起免疫细胞响应的抗原表位序列,可为mRNA疫苗(串联抗原表位序列)研发、抗体制备及免疫机制研究提供参考。

Objective To analyze the genetic and evolutionary properties of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)ORF 1ab/S/M proteins and select antigen epitope sequences of mRNA vaccines.Methods We analyzed the worldwide SARS-CoV-2 genome sequences in this study and have focused on the protein and nucleic acid sequences of the ORF 1ab/S/M.The neighbor-joining tree was employed to map the global distribution of genetic differences.Based on current research on SARS-CoV-2 and SARS-CoV-2 genetic differences,we predicted candidate mRNA vaccines for SARS-CoV-2.Results The SARS-CoV-2 ORF 1ab nucleic acid sequence similarity is 100.0%,while the homology is 99.3%in the global hot region;the S-protein nucleic acid sequence similarity is 100.0%,while the homology is 97.5%;the M-protein nucleic acid sequence similarity is 100.0%,while the homology is 99.9%.Global distribution of ORF 1ab/S/M proteins indicates that there is a significant genetic difference between the Americas and Eurasia.Potential vaccine antigen epitope mRNA sequences(11 B cell responses and 13 T cell responses)were selected for SARS-CoV-2 ORF 1ab protein;6 B cell responses and 4 T cell responses antigen epitope mRNA sequences were selected for the Spike protein;3 B cell responses and 7 T cell responses antigen epitope mRNA sequences were selected for the membrane protein.Conclusion There are significant genetic differences in the global hot spot of SARS-CoV-2 in the Americas and Eurasia.Through our new antigen design strategy to screen linear epitopes,we predicted many sequences in ORF 1ab/S/M coding region that potentially raising an immune response.Our study will benefit the discovery of the mRNA vaccine(tandem antigen epitope sequence),antibody discovery,and potentially understanding related immune mechanisms.