细菌种类中抗生素抗性的出现是对公共健康的主要威胁,并且已经导致高死亡率以及高医疗保健成本。伯克霍尔德菌是卫生保健相关感染的病原体之一。由于本文中没有针对病原体的许可疫苗可用,使用反向疫苗学,生物信息学,和免疫信息学方法,设计了一种基于多表位的针对马氏芽孢杆菌的疫苗。在完全测序的B.mallei蛋白质组中,18,405核心,3671非冗余,并预测了14734个冗余蛋白。在3671种非冗余蛋白中,3蛋白质在细胞外基质中预测,11被预测为外膜蛋白,并在周质膜中预测了11种蛋白质。只有两种蛋白质,VI型分泌系统管蛋白(Hcp)和IV型菌毛分泌素蛋白,选择用于表位预测。六个表位,EAMPERMPAA,RSSPPAAGA,DNRPISINL,RQRFDAHAR,AERERQRFDA,和HARAAQLEPL,入围多表位疫苗设计。预测的表位通过特异性GPGPG接头彼此连接,然后表位肽通过EAAAK接头与佐剂分子连接,以使设计的疫苗在免疫学上更有效。还发现所设计的疫苗具有良好的物理化学性质,具有低分子量和较少的跨膜螺旋。分子对接研究显示疫苗构建体与MHC-I稳定结合,MHC-II,和TLR-4,能量评分为-944.1kcal/mol,-975.5千卡/摩尔,和-1067.3千卡/摩尔,分别。分子动力学模拟测定注意到对接的疫苗-受体复合物的稳定动力学,并且没有观察到剧烈变化。结合自由能估计显示,疫苗-MHC-I复合物的净值为-283.74kcal/mol,-296.88kcal/mol对于疫苗-MHC-II复合物,和-586.38kcal/mol的疫苗-TLR-4复合物。这些发现证实了所设计的疫苗构建体在与免疫受体结合方面显示了有希望的能力,并且一旦施用给宿主,可能能够引发强烈的免疫应答。需要来自小鼠模型中的实验的进一步证据来验证所设计的疫苗构建体针对马氏芽孢杆菌的真正免疫保护。
The emergence of antibiotic resistance in bacterial species is a major threat to public health and has resulted in high mortality as well as high health care costs. Burkholderia mallei is one of the etiological agents of health care-associated infections. As no licensed vaccine is available against the pathogen herein, using reverse vaccinology, bioinformatics, and immunoinformatics approaches, a multi-epitope-based vaccine against B. mallei was designed. In completely sequenced proteomes of B. mallei, 18,405 core, 3671 non-redundant, and 14,734 redundant proteins were predicted. Among the 3671 non-redundant proteins, 3 proteins were predicted in the extracellular matrix, 11 were predicted as outer membrane proteins, and 11 proteins were predicted in the periplasmic membrane. Only two proteins, type VI secretion system tube protein (Hcp) and type IV pilus secretin proteins, were selected for epitope prediction. Six epitopes, EAMPERMPAA, RSSPPAAGA, DNRPISINL, RQRFDAHAR, AERERQRFDA, and HARAAQLEPL, were shortlisted for multi-epitopes vaccine design. The predicted epitopes were linked to each other via a specific GPGPG linker and the epitopes peptide was then linked to an adjuvant molecule through an EAAAK linker to make the designed vaccine more immunologically potent. The designed vaccine was also found to have favorable physicochemical properties with a low molecular weight and fewer transmembrane helices. Molecular docking studies revealed vaccine construct stable binding with MHC-I, MHC-II, and TLR-4 with energy scores of -944.1 kcal/mol, -975.5 kcal/mol, and -1067.3 kcal/mol, respectively. Molecular dynamic simulation assay noticed stable dynamics of the docked vaccine-receptors complexes and no drastic changes were observed. Binding free energies estimation revealed a net value of -283.74 kcal/mol for the vaccine-MHC-I complex, -296.88 kcal/mol for the vaccine-MHC-II complex, and -586.38 kcal/mol for the vaccine-TLR-4 complex. These findings validate that the designed vaccine construct showed promising ability in terms of binding to immune receptors and may be capable of eliciting strong immune responses once administered to the host. Further evidence from experimentations in mice models is required to validate real immune protection of the designed vaccine construct against B. mallei.