Department of Biochemistry, Central University of Rajasthan, Ajmer, India.
Microbiol Immunol. 2021 Aug;65(8):302-316. doi: 10.1111/1348-0421.12870. Epub 2021 Jul 12.
Staphylococcus aureus is a versatile Gram's positive bacterium that can reside as an asymptomatic colonizer, which can cause a wide range of skin, soft-tissue, and nosocomial infections. A vaccine against multi-drug resistant S. aureus, therefore, is urgently needed. Subtractive proteomics and reverse vaccinology are newly emerging techniques to design multiepitope-based vaccines. The analysis of 7290 proteomes (sensitive and resistant strains), five potent nonhuman homologous vaccine targets [(UNIPORT ID Q2FZL3 (Staphopain B), Q2G2R8 (Staphopain A), Q2FWP0 (uncharacterized leukocidin-like protein 1), Q2G1S6 (uncharacterized protein), and Q2FWV3 (Staphylokinase, putative)] were selected. These proteins were absent in the gut microbiome, which further enhances the significance of these proteins in vaccine design. These five virulence-associated proteins mainly have a role in the invasion mechanism in the host phagocyte cells. MHC I, MHC II, and B cell epitopes were identified in these five proteins. Finalized epitopes were examined by different online servers to screen suitable epitopes for multi-epitope based vaccine design. Shortlisted antigenic and nonallergenic associated epitopes were joined with linkers to design 30 variants (VSA1-VSA30) of multi-epitope vaccine conjugates. The antigenicity and allergenicity of all the 30 vaccine constructs were identified, and VSA30 was found to have the highest antigenicity and lowest allergenicity, and hence was selected for further study. Accordingly, VSA30 was docked with different HLA allelic variants, and the best-docked complex (VSA30-1SYS) was further analyzed by molecular dynamics simulation (MDS). The MDS result confirms the interaction of VSA30 with MHC (HLA-allelic variant). Thus, the final vaccine construct was in silico cloned in the pET28a vector for suitable expression in a heterologous system. Therefore, the designed vaccine construct VSA-30 can be developed as an appropriate vaccine to target S. aureus infection. VSA-30 still needs experimental validation to assure the antigenic and immunogenic properties.
金黄色葡萄球菌是一种多功能的革兰氏阳性菌，可以作为无症状的定植菌存在，可引起广泛的皮肤、软组织和医院感染。因此，急需一种针对多药耐药金黄色葡萄球菌的疫苗。消减蛋白质组学和反向疫苗学是设计多表位疫苗的新兴技术。分析了 7290 个蛋白质组（敏感和耐药株）、5 种有效的非人类同源疫苗靶标[UNIPORT ID Q2FZL3（葡萄球菌蛋白酶 B）、Q2G2R8（葡萄球菌蛋白酶 A）、Q2FWP0（未鉴定的白细胞毒素样蛋白 1）、Q2G1S6（未鉴定蛋白）和 Q2FWV3（链激酶，推测）]。这些蛋白质不存在于肠道微生物组中，这进一步增强了这些蛋白质在疫苗设计中的意义。这 5 种毒力相关蛋白主要在宿主吞噬细胞的入侵机制中发挥作用。在这 5 种蛋白中鉴定出 MHC I、MHC II 和 B 细胞表位。通过不同的在线服务器对最终确定的表位进行了检查，以筛选适合多表位疫苗设计的合适表位。将选定的抗原性和非变应原性相关表位与接头连接起来，设计了 30 种多表位疫苗缀合物（VSA1-VSA30）。对所有 30 种疫苗构建体的抗原性和变应原性进行了鉴定，发现 VSA30 具有最高的抗原性和最低的变应原性，因此被选为进一步研究。相应地，将 VSA30 与不同的 HLA 等位变体对接，对接复合物（VSA30-1SYS）进一步通过分子动力学模拟（MDS）进行分析。MDS 结果证实了 VSA30 与 MHC（HLA 等位变体）的相互作用。因此，最终的疫苗构建体在计算机上被克隆到 pET28a 载体中，以便在异源系统中进行合适的表达。因此，设计的疫苗构建体 VSA-30 可以作为一种针对金黄色葡萄球菌感染的合适疫苗。VSA-30 仍需要实验验证以确保其抗原性和免疫原性。
