College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.
Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China.
Microbiol Spectr. 2022 Aug 31;10(4):e0114822. doi: 10.1128/spectrum.01148-22. Epub 2022 Jul 12.
Klebsiella pneumoniae is an opportunistic Gram-negative bacterium that has become a leading causative agent of nosocomial infections, mainly infecting patients with immunosuppressive diseases. Capsular (K) serotypes K1, K2, K47, and K64 are commonly associated with higher virulence (hypervirulent Klebsiella pneumoniae), and more threateningly, isolates belonging to the last two K serotypes are also frequently associated with resistance to carbapenem (hypervirulent carbapenem-resistant Klebsiella pneumoniae). The prevalence of these isolates has posed significant threats to human health, and there are no appropriate therapies available against them. Therefore, in this study, a method combining immunoinformatics and pangenome analysis was applied for contriving a multiepitope subunit vaccine against these four threatening serotypes. To obtain cross-protection, 12 predicted conserved antigens were screened from the core genome of 274 complete Klebsiella pneumoniae genomes (KL1, KL2, KL47, and KL64), from which the epitopes of T and B cells were extracted for vaccine construction. In addition, the immunological properties, the interaction with Toll-like receptors, and the stability in a simulative humoral environment were evaluated by immunoinformatics methods, molecular docking, and molecular dynamics simulation. All of these evaluations indicated the potency of this constructed vaccine to be an effective therapeutic agent. Lastly, the cDNA of the designed vaccine was optimized and ligated to pET-28a(+) for expression vector construction. Overall, our research provides a newly cross-protective control strategy against these troublesome pathogens and paves the way for the development of a safe and effective vaccine. Klebsiella pneumoniae is an opportunistic Gram-negative bacterium that has become a leading causative agent of nosocomial infections. Among the numerous capsular serotypes, K1, K2, K47, and K64 are commonly associated with higher virulence (hypervirulent K. pneumoniae). More threateningly, the last two serotypes are frequently associated with resistance to carbapenem (hypervirulent carbapenem-resistant K. pneumoniae). However, there is currently no therapeutic agent or vaccine specifically against these isolates. Therefore, development of a vaccine against these pathogens is very essential. In this study, for the first time, a method combining pangenome analysis, reverse vaccinology, and immunoinformatics was applied for contriving a multiepitope subunit vaccine against K. pneumoniae isolates of K1, K2, K47, and K64. Also, the immunological properties of the constructed vaccine were evaluated and its high potency was revealed. Overall, our research will pave the way for the vaccine development against these four threatening capsular serotypes of K. pneumoniae.
肺炎克雷伯菌是一种机会性革兰氏阴性菌，已成为医院感染的主要病原体，主要感染患有免疫抑制性疾病的患者。荚膜（K）血清型 K1、K2、K47 和 K64 通常与更高的毒力（高毒力肺炎克雷伯菌）相关，更具威胁性的是，属于后两种 K 血清型的分离株也经常与碳青霉烯类药物耐药（高毒力耐碳青霉烯肺炎克雷伯菌）相关。这些分离株的流行对人类健康构成了重大威胁，并且没有针对它们的适当治疗方法。因此，在这项研究中，应用了一种结合免疫信息学和泛基因组分析的方法，用于设计针对这四种威胁性血清型的多表位亚单位疫苗。为了获得交叉保护，从 274 株完整肺炎克雷伯菌基因组（KL1、KL2、KL47 和 KL64）的核心基因组中筛选了 12 个预测的保守抗原，从这些基因组中提取了 T 细胞和 B 细胞的表位用于疫苗构建。此外，通过免疫信息学方法、分子对接和分子动力学模拟评估了免疫原性、与 Toll 样受体的相互作用以及在模拟体液环境中的稳定性。所有这些评估都表明，这种构建的疫苗具有成为有效治疗剂的潜力。最后，对设计的疫苗的 cDNA 进行了优化，并连接到 pET-28a(+) 用于表达载体构建。总的来说，我们的研究为这些棘手的病原体提供了一种新的交叉保护控制策略，并为开发安全有效的疫苗铺平了道路。
