Almofti Yassir A, Abd-Elrahman Khoubieb Ali, Eltilib Elsideeq E M
Department of Molecular Biology and Bioinformatics, College of Veterinary Medicine, University of Bahri, Khartoum, Sudan.
Department of Pharmaceutical Technology, College of Pharmacy, University of Medical Science and Technology (MUST), Khartoum, Sudan.
BMC Immunol. 2021 Mar 25;22(1):22. doi: 10.1186/s12865-021-00412-0.
The spread of a novel coronavirus termed severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in China and other countries is of great concern worldwide with no effective vaccine. This study aimed to design a novel vaccine construct against SARS-CoV-2 from the spike S protein and orf1ab polyprotein using immunoinformatics tools. The vaccine was designed from conserved epitopes interacted against B and T lymphocytes by the combination of highly immunogenic epitopes with suitable adjuvant and linkers.
The proposed vaccine composed of 526 amino acids and was shown to be antigenic in Vaxigen server (0.6194) and nonallergenic in Allertop server. The physiochemical properties of the vaccine showed isoelectric point of 10.19. The instability index (II) was 31.25 classifying the vaccine as stable. Aliphatic index was 84.39 and the grand average of hydropathicity (GRAVY) was - 0.049 classifying the vaccine as hydrophilic. Vaccine tertiary structure was predicted, refined and validated to assess the stability of the vaccine via Ramachandran plot and ProSA-web servers. Moreover, solubility of the vaccine construct was greater than the average solubility provided by protein sol and SOLpro servers indicating the solubility of the vaccine construct. Disulfide engineering was performed to reduce the high mobile regions in the vaccine to enhance stability. Docking of the vaccine construct with TLR4 demonstrated efficient binding energy with attractive binding energy of - 338.68 kcal/mol and - 346.89 kcal/mol for TLR4 chain A and chain B respectively. Immune simulation significantly provided high levels of immunoglobulins, T-helper cells, T-cytotoxic cells and INF-γ. Upon cloning, the vaccine protein was reverse transcribed into DNA sequence and cloned into pET28a(+) vector to ensure translational potency and microbial expression.
A unique vaccine construct from spike S protein and orf1ab polyprotein against B and T lymphocytes was generated with potential protection against the pandemic. The present study might assist in developing a suitable therapeutics protocol to combat SARSCoV-2 infection.
一种名为严重急性呼吸综合征冠状病毒2（SARS-CoV-2）的新型冠状病毒在中国和其他国家传播，在全球引起高度关注，且尚无有效疫苗。本研究旨在利用免疫信息学工具，从刺突S蛋白和orf1ab多聚蛋白设计一种针对SARS-CoV-2的新型疫苗构建体。该疫苗由高度免疫原性表位与合适的佐剂和连接子组合而成，设计自与B淋巴细胞和T淋巴细胞相互作用的保守表位。
所提出的疫苗由526个氨基酸组成，在Vaxigen服务器中显示具有抗原性（0.6194），在Allertop服务器中显示无致敏性。疫苗的理化性质显示其等电点为10.19。不稳定指数（II）为31.25，将该疫苗归类为稳定型。脂肪族指数为84.39，亲水性总平均值（GRAVY）为-0.049，将该疫苗归类为亲水性。通过Ramachandran图和ProSA-web服务器预测、优化和验证了疫苗的三级结构，以评估疫苗的稳定性。此外，疫苗构建体的溶解度大于蛋白质sol和SOLpro服务器提供的平均溶解度，表明疫苗构建体的溶解度。进行二硫键工程以减少疫苗中高移动性区域，从而提高稳定性。疫苗构建体与TLR4的对接显示出有效的结合能，TLR4链A和链B的吸引结合能分别为-338.68 kcal/mol和-346.89 kcal/mol。免疫模拟显著产生了高水平的免疫球蛋白、辅助性T细胞、细胞毒性T细胞和INF-γ。克隆后，将疫苗蛋白逆转录为DNA序列，并克隆到pET28a(+)载体中，以确保翻译效力和微生物表达。
构建了一种独特的针对B淋巴细胞和T淋巴细胞的刺突S蛋白和orf1ab多聚蛋白疫苗构建体，具有针对该大流行疾病的潜在保护作用。本研究可能有助于制定合适的治疗方案来对抗SARS-CoV-2感染。
