Abstract：
Francisella tularensis can cause severe disease in humans via the respiratory or cutaneous routes and a case fatality ratio of up to 10 % is reported due to lack of proper antibiotic treatment, while F. novicida causes disease in severely immunocompromised individuals. Efforts are needed to develop effective vaccine candidates against Francisella species. Thus, in this study, a systematic computational work frame was used to deeply investigate the whole proteome of Francisella novicida containing 1728 proteins to develop vaccine against F. tularensis and related species. Whole-proteome analysis revealed that four proteins including (A0Q492) (A0Q7Y4), (A0Q4N4), and (A0Q5D9) are the suitable vaccine targets after the removal of homologous, paralogous and prediction of subcellular localization. These proteins were used to predict the T cell, B cell, and HTL epitopes which were joined together through suitable linkers to construct a multi-epitopes vaccine (MEVC). The MEVC was found to be highly immunogenic and non-allergenic while the physiochemical properties revealed the feasible expression and purification. Moreover, the molecular interaction of MEVC with TLR2, molecular simulation, and binding free energy analyses further validated the immune potential of the construct. According to Jcat analysis, the refined sequence demonstrates GC contents of 41.48 % and a CAI value of 1. The in-silico cloning and optimization process ensured compatibility with host codon usage, thereby facilitating efficient expression. Computational immune simulation studies underscored the capacity of MEVC to induce both primary and secondary immune responses. The conservation analysis further revealed that the selected epitopes exhibit 100 % conservation across different species and thus provides wider protection against Francisella.
摘要：
由于缺乏适当的抗生素治疗，可以通过呼吸道或皮肤途径在人类中引起严重疾病，据报道病死率高达10％。而诺西达在严重免疫受损的个体中引起疾病。需要努力开发针对Francisella物种的有效疫苗候选物。因此，在这项研究中，使用系统的计算工作框架深入研究了含有1,728种蛋白质的新Francisella的整个蛋白质组，以开发针对F.tularensis和相关物种的疫苗。全蛋白质组分析显示，包括（A0Q492）（A0Q7Y4）在内的四种蛋白质，（A0Q4N4），(A0Q5D9)是去除同源后的合适疫苗靶标,亚细胞定位的旁系和预测。这些蛋白质被用来预测T细胞，B细胞,和HTL表位通过合适的接头连接在一起以构建多表位疫苗(MEVC)。发现MEVC具有高度免疫原性和非过敏性，而理化性质揭示了可行的表达和纯化。此外，MEVC与TLR2的分子相互作用,分子模拟,和结合自由能分析进一步验证了构建体的免疫潜力。根据Jcat分析,精制序列的GC含量为41.48%，CAI值为1。计算机克隆和优化过程确保了与宿主密码子使用的兼容性，从而促进高效表达。计算免疫模拟研究强调了MEVC诱导初级和次级免疫反应的能力。保守性分析进一步揭示了所选择的表位在不同物种中表现出100%保守性,因此提供了针对Francisella的更广泛的保护。
