Computer-based Design of Dengue Virus Vaccine Antigens

摘要 登革热病毒(DENV)感染在过去30年里一直在上升，约有3.9亿人 每年都会被感染。其中许多感染会导致严重的临床表现，包括登革热。 出血热、登革热休克综合征和死亡。这些统计数据包括#年报告的感染 在美国，例如2013年佛罗里达州的疫情，以及2016年夏威夷最近的疫情。DENV 由于四种DENV血清型的流行和潜在的 增强疾病的免疫力。登革热是DENV唯一获得许可的疫苗，一种减毒活疫苗 包含所有四种DENV血清型的疫苗，由于它只提供部分保护作用，因此取得的成功有限 在DENV血清型之间，已被证明在使用时增加严重登革热疾病的风险 未感染登革热的人。这些事实表明，迫切需要探索替代疫苗策略。 能够提供针对所有DENV血清型的广泛保护。我们和其他团体有 研究表明，感染了DENV的人会产生识别四级结构的抗体 横跨病毒被膜(E)蛋白二聚体的表位，该二聚体自然地呈现在组装的病毒上 浮出水面。一类识别该四元E蛋白二聚体表位的分离的人类抗体 (EDE)最近被证明可以广泛中和每一种DENV血清型。我们的建议是有根据的 关于最近发现的这些EDE广谱中和抗体的结构生物学，它提供了 这些抗体所针对的保守表位的原子分辨率。这些EDE抗体还识别可溶的 重组的DENV E蛋白(SRecE)，一种很有前途的亚单位疫苗抗原。然而，在 在生理条件下，DENV sRecE抗原在溶液中主要是单体，容易发生 由于低单体热稳定性导致的聚集，限制了蛋白质对EDE表位的呈递，以及它的 用作亚单位疫苗。我们的建议是利用这些人的现有结构信息 EDE广泛中和抗体，以及计算蛋白质设计，以设计和生产 稳定的EDE表位聚焦的DENV sRecE蛋白二聚体作为疫苗抗原。在未来的研究中，这些 稳定的DENV sRecE二聚体抗原将被用作疫苗候选，以评估它们广泛诱导的能力 中和EDE抗体，防止DENV感染。

ABSTRACT Dengue virus (DENV) infections have been on the rise over the past three decades, with ~390 million people infected each year. Many of these infections result in severe clinical manifestations, including dengue hemorrhagic fever, dengue shock syndrome and death. Included in these statistics are infections reported in the US, such as the outbreak in Florida in 2013, and the more recent outbreak in Hawaii in 2016. DENV vaccine development has been challenging due to the prevalence of four DENV serotypes and the potential for immune enhancement of disease. The only licensed vaccine for DENV, Dengvaxia, a live-attenuated vaccine containing all four DENV serotypes, has been met with limited success as it only provides partial protection between DENV serotypes, and has been shown to increase the risk of severe dengue disease when used in dengue uninfected people. These facts display the urgent need to explore alternative vaccine strategies that are capable of providing broad protection against all DENV serotypes. We and other groups have shown that people who have been infected by DENV, develop antibodies that recognize a quaternary structural epitope which spans the viral envelope (E) protein dimer that is presented naturally on the assembled viral surface. A class of these isolated human antibodies which recognize this quaternary E protein dimer epitope (EDE) have recently been shown to broadly neutralize each of the DENV serotypes. Our proposal is grounded on the recently discovered structural biology of these EDE broadly neutralizing antibodies (Abs) which provides atomic resolution of the conserved epitope targeted by these Abs. These EDE Abs also recognize the soluble recombinant version of the DENV E protein (sRecE), a promising subunit vaccine antigen. However, under physiological conditions, the DENV sRecE antigen is predominantly monomeric in solution, and is prone to aggregation due to low monomer thermostability, limiting the protein’s presentation of EDE epitopes, and its use as a subunit vaccine. Our proposal is to leverage the existing structural information of these human EDE broadly neutralizing antibodies, and computational protein design, to engineer and produce stable EDE-epitope focused DENV sRecE protein dimers as vaccine antigens. In future studies, these stable DENV sRecE dimer antigens will be used as vaccine candidates to assess their ability to elicit broadly neutralizing EDE Abs and provide protection against DENV infection.