Dengue virus mRNA lipid nanoparticle vaccine

每年有近4亿人因被感染的蚊子叮咬而感染登革病毒(DENV) 集中在世界的热带和亚热带地区。症状可从发烧疾病到 严重登革热，表现为血浆渗漏、血压骤降、器官衰竭和休克 最终会导致死亡。严重的登革热并发症通常与继发性异型有关。 四种循环血清型中的一种感染。在这种情况下，针对交叉免疫的体液免疫反应 反应性、中和性差的表位通过抗体依赖导致易感细胞感染性增加 增强(ADE)。此外，DENV免疫与寨卡病毒易感性增加有关 通过ADE。目前还没有可用的疗法来对抗DENV疾病。登华夏，唯一的 有执照的DENV疫苗，被发现在幼稚人群中增加住院率，因此不是 推荐给大部分高危人群。迫切需要一种安全有效的疫苗 这引起了对所有四种DENV血清型的强大、平衡、中和的反应。我们打算写一部小说 利用紧急平台的DENV疫苗：编码脂质中病毒蛋白的mRNAs 纳米颗粒(LNP)。MRNA-LNP疫苗在一种安全的， 非传染性平台。此外，我们还可以通过以下方式引导宿主免疫反应针对中和表位 使病毒蛋白的编码基因发生突变。我们假设一个序列工程的四价体 MRNA-LNP疫苗将诱导针对所有四种血清型的平衡、保护性免疫反应 登革热，没有引起免疫增强和ADE的潜力。在本研究的目标1中，我们将 为ALL产生和优化编码前膜和包膜病毒糖蛋白的mRNA结构 DENV的四个血清型。我们将突变驱动ADE的中和能力差、交叉反应的表位。在AIM 2我们将在小鼠模型中表征对疫苗的免疫反应。除了量化幽默之外 和细胞免疫反应，我们还将衡量所有疫苗的免疫增强能力。在AIM 3，我们将在易感小鼠模型中通过挑战接种疫苗的小鼠来评估疫苗的有效性和安全性 用不同的DENV血清型监测保护和ADE。我们还将确定保护机制 通过采用迁移实验。通过这项研究，我们将确定具有广泛应用前景的DENV疫苗。 作为候选人类疫苗的进一步评估的保护性和缺乏免疫增强。

Nearly 400 million people are infected with dengue virus (DENV) each year through the bite of infected mosquitos concentrated in the tropical and subtropical regions of the world. Symptoms can range from febrile illness to severe dengue that manifests as plasma leakage, sudden loss of blood pressure, organ failure, and shock that can ultimately lead to death. Severe dengue complications are often associated with a secondary heterotypic infection of one of the four circulating serotypes. In this scenario, humoral immune responses targeting cross- reactive, poorly-neutralizing epitopes lead to increased infectivity of susceptible cells via antibody-dependent enhancement (ADE). Additionally, DENV immunity has been implicated in increased susceptibility to Zika virus through ADE. Currently there are no available therapeutics to combat DENV disease. Dengvaxia, the only licensed DENV vaccine, was found to increase hospitalization rates in naïve populations, and thus is not recommended for a large portion of at-risk individuals. There is an urgent need for a safe and efficacious vaccine that elicits a robust, balanced, neutralizing response to all four DENV serotypes. We propose to develop a novel DENV vaccine utilizing an emergent platform: mRNA encoding for viral proteins encapsidated in a lipid nanoparticle (LNP). mRNA-LNP vaccines elicit robust humoral and cell-mediated immune responses in a safe, non-infectious platform. Additionally, we can direct the host immune response towards neutralizing epitopes by mutating the mRNA encoding for the viral protein. We hypothesize that a sequence-engineered tetravalent mRNA-LNP vaccine will induce a balanced, protective immune response against all four serotypes of dengue without the potential of causing immune enhancement and ADE. In Aim 1 of this study we will generate and optimize mRNA constructs encoding for the pre-membrane and envelope viral glycoproteins for all four serotypes of DENV. We will mutate the poorly-neutralizing, cross-reactive epitopes that drive ADE. In Aim 2 we will characterize the immune response to the vaccines in a mouse model. In addition to quantifying humoral and cellular immune responses, we will also measure the immune enhancement capacity of all vaccines. In Aim 3, we will evaluate vaccine efficacy and safety in susceptible mouse models, by challenging vaccinated mice with different DENV serotypes to monitor protection and ADE. We will also determine mechanism of protection via adoptive transfer experiments. Through this study, we will identify DENV vaccines that demonstrate broad protection and lack of immune enhancement for further evaluation as candidate human vaccines.