Kolla Harish Babu, Tirumalasetty Chakradhar, Sreerama Krupanidhi, Ayyagari Vijaya Sai
Department of Biotechnology, Vignan's Foundation for Science, Technology and Research (Deemed to be University), Vadlamudi, Guntur - District, Andhra Pradesh, 522 213, India.
J Genet Eng Biotechnol. 2021 May 11;19(1):69. doi: 10.1186/s43141-021-00160-z.
TSST-1 is a secretory and pyrogenic superantigen that is being responsible for staphylococcal mediated food poisoning and associated clinical manifestations. It is one of the main targets for the construction of vaccine candidates against Staphylococcus aureus. Most of the vaccines have met failure due to adverse reactions and toxicity reported during late clinical studies. To overcome this, an immunoinformatics approach is being used in the present study for the design of a multi-epitope vaccine to circumvent the problems related to toxicity and allergenicity.
In this study, a multi-epitope vaccine against Staphylococcus aureus targeting TSST-1 was designed through an immunoinformatics approach. B cell and T cell epitopes were predicted in silico and mapped with linkers to avoid junctional immunogenicity and to ensure the efficient presentation of exposed epitopes through HLA. β-defensin and PADRE were adjusted at the N-terminal end of the final vaccine as adjuvants. Physiochemical parameters, antigenicity, and allergenicity of the vaccine construct were determined with the help of online servers. The three-dimensional structure of the vaccine protein was predicted and validated with various tools. The affinity of the vaccine with TLR-3 was studied through molecular docking studies and the interactions of two proteins were visualized using LigPlot. The vaccine was successfully cloned in silico into pET-28a (+) for efficient expression in E. coli K12 system. Population coverage analysis had shown that the vaccine construct can cover 83.15% of the global population. Immune simulation studies showed an increase in the antibody levels, IL-2, IFN-γ, TGF-β, B cell, and T cell populations and induced primary, secondary, and tertiary immune responses.
Multi-epitope vaccine designed through a computational approach is a non-allergic and non-toxic antigen. Preliminary in silico reports have shown that this vaccine could elicit both B cell and T cell responses in the host as desired.
中毒性休克综合征毒素-1（TSST-1）是一种分泌性致热超抗原，可导致葡萄球菌介导的食物中毒及相关临床表现。它是构建抗金黄色葡萄球菌候选疫苗的主要靶点之一。大多数疫苗因在后期临床研究中报告的不良反应和毒性而失败。为克服这一问题，本研究采用免疫信息学方法设计多表位疫苗，以规避与毒性和致敏性相关的问题。
在本研究中，通过免疫信息学方法设计了一种针对金黄色葡萄球菌靶向TSST-1的多表位疫苗。在计算机上预测B细胞和T细胞表位，并用接头进行映射，以避免连接免疫原性，并确保通过HLA有效呈递暴露的表位。在最终疫苗的N端调整β-防御素和PADRE作为佐剂。借助在线服务器确定疫苗构建体的理化参数、抗原性和致敏性。使用各种工具预测并验证疫苗蛋白的三维结构。通过分子对接研究研究疫苗与TLR-3的亲和力，并使用LigPlot可视化两种蛋白质的相互作用。该疫苗在计算机上成功克隆到pET-28a(+)中，以便在大肠杆菌K12系统中高效表达。群体覆盖率分析表明，该疫苗构建体可覆盖全球83.15%的人群。免疫模拟研究表明抗体水平、IL-2、IFN-γ、TGF-β、B细胞和T细胞群体增加，并诱导了初次、二次和三次免疫反应。
通过计算方法设计的多表位疫苗是一种无过敏和无毒的抗原。初步的计算机报告表明，这种疫苗可以在宿主体内引发所需的B细胞和T细胞反应。
