Revolutionary Eilat-based Chikungunya Vaccine Vector

摘要 传统上，病毒疫苗涉及安全性和免疫原性之间的权衡，尤其是 对控制爆炸性新兴疾病所需疫苗的挑战，在这些疾病中，快速保护和持久 豁免权至关重要。为了克服这些挑战，我们开发了一种蚊子特有的甲型病毒，埃拉特病毒 (EILV)，作为一种革命性的新疫苗载体。埃拉特在蚊子细胞中复制到异常高的滴度，但 由于进入和RNA的基本限制，在脊椎动物细胞中的复制完全有缺陷 复制。我们用基孔肯雅病毒包膜蛋白构建了EILV嵌合基因 (CHIKV)，这是导致衰弱的慢性关节痛重新爆发的主要原因 数以百万计的人，最近几乎影响到美洲所有国家。最近，一种寨卡病毒疫苗 排在全球疫苗需求的第二位。在初步研究中，EILV/CHIKV嵌合疫苗 候选人提供快速和持久的保护后，单一剂量的小鼠和挑战 非人灵长类动物。我们将进一步发展这一嵌合体，并测试基于EILV的嵌合体的假设 病毒可用作“假灭活”甲型病毒疫苗，有三个目的： 1.优化EILV/CHIKV嵌合疫苗的复制和免疫原性，证实其安全性 (包括明确证明脊椎动物细胞中缺乏RNA复制)，验证是否有效 在无血清介质中生产，并开发廉价的纯化方法。 2.研究优化的EILV/CHIKV疫苗对小鼠的保护作用，了解其免疫学特性 宿主保护机制，包括先天和获得性免疫反应的特征 接种和挑战小鼠，并确定宿主保护的免疫相关因素。 3.优化EILV/CHIKV疫苗的剂量，并确认其快速、长寿的免疫原性和 食蟹猴的保护。这些结果将与灭活和活体衰减进行比较 寨卡病毒疫苗。 其结果将是一种安全、有效、廉价的单剂CHIKV疫苗，提供快速、持久的 保护，以及可应用于所有其他致病甲型病毒的平台技术，如 委内瑞拉和东部马脑炎病毒，以及最近出现的马亚罗病毒。这些疫苗 将非常适合于控制通常影响资源匮乏的热带国家的爆炸性疫情。 了解这种疫苗显著免疫原性的机理研究也将影响其他 通过解剖诱导所需的病毒疫苗的基本成分来设计疫苗平台 各种手臂的保护性免疫反应。

ABSTRACT Traditionally, viral vaccines have involved trade-offs between safety and immunogenicity, which is especially challenging for vaccines needed to control explosive emerging diseases where rapid protection and durable immunity are crucial. To overcome these challenges, we developed a mosquito-specific alphavirus, Eilat virus (EILV), as a revolutionary new vaccine vector. Eilat replicates to exceptionally high titers in mosquito cells but is completely defective for replication in vertebrate cells due to fundamental restrictions in entry and RNA replication. We generated a chimeric EILV cDNA with envelope proteins derived from chikungunya virus (CHIKV), which is responsible for major reemerging outbreaks of debilitating, chronic arthralgia involving millions of persons and recently affecting nearly all countries in the Americas. A CHIKV vaccine was recently ranked the #2 priority for global vaccine needs. In preliminary studies, the chimeric EILV/CHIKV vaccine candidate provided rapid and durable protection following a single dose against challenge of mice and nonhuman primates. We will further develop this chimera and test the hypothesis that EILV-based chimeric viruses can serve as “pseudoinactivated” alphavirus vaccines, using three Aims: 1. Optimize the replication and immunogenicity of the chimeric EILV/CHIKV vaccine, confirm its safety (including unambiguously demonstrating a lack of RNA replication in vertebrate cells), verify efficient production in serum-free media, and develop inexpensive purification methods. 2. Study the protective efficacy of the optimized EILV/CHIKV vaccine in mice and understand the immune mechanisms of host protection, including characterization of innate and adaptive immune responses in vaccinated and challenged mice, and determination of the immune correlates of host protection. 3. Optimize the dosage of the EILV/CHIKV vaccine and confirm its rapid and long-lived immunogenicity and protection in cynomolgus macaques. These outcomes will be compared to inactivated and live-attenuated CHIKV vaccines. The result will be a safe, efficacious, inexpensive single-dose CHIKV vaccine that provides rapid and long-lived protection, as well as a platform technology that can be applied to all other pathogenic alphaviruses such as Venezuelan and Eastern equine encephalitis viruses, and the recently emerging Mayaro virus. These vaccines will be ideally suited for controlling explosive outbreaks that typically affect resource-poor tropical countries. The mechanistic studies to understand the remarkable immunogenicity of this vaccine will also impact other vaccine design platforms by dissecting the fundamental components of a viral vaccine required to induce various arms of the protective immune response.