A novel vaccine against mosquito-borne Zika virus based on mosquito salivary gland protein AgBR1

摘要 虫媒病毒对世界范围内的人类和动物健康构成持续威胁。它们通过以下方式传输 食血节肢动物，主要是蚊子。其中一种是埃及伊蚊，是几种蚊子的主要媒介 广泛传播的虫媒病毒，如寨卡病毒、登革热和西尼罗河病毒，其中大多数都是人类许可的 疫苗不存在或不是最理想的。这些病原体与唾液一起传播到宿主皮肤。 在进食过程中。这种唾液含有一百多种独特的蛋白质，可以调节许多生理上的 功能，促进血液喂养。 已有研究表明，许多唾液蛋白通过调节虫媒病毒的侵染性和致病性来增强虫媒病毒的感染性和致病能力。 咬伤部位的免疫反应。针对它们的阻断疗法的发展可能是一个好消息。 减少病毒在受感染宿主中传播的方法。这种方法还可以克服与以下方面相关的问题 使用病毒抗原作为疫苗靶标，由于其高度变异性或诱导抗体的可能性-- 依赖性增强发作。 在第一阶段，已经建立了针对一个唾液的新的预防策略的原则证明 埃及伊蚊唾液中分泌的蛋白质AgBR1，被动免疫和主动免疫均可使其免疫受损 小鼠模型对通过蚊子叮咬传播的寨卡病毒有部分保护。的程度 保护力与免疫动物中达到的抗体效价相关。然而，使用 免疫受损模型有一些局限性，例如抗体反应的薄弱，这是一个事实 限制可实现的最大保护。在此第二阶段应用程序中，我们将定义、优化和 验证疫苗接种方案。 我们将绕过免疫低下动物模型的限制，在 具有免疫能力的小鼠宿主。我们将测试通过转移抗体和/或 免疫细胞给免疫低下的小鼠，也研究免疫反应的细胞分支的作用 抗ZIKV感染，因为对蚊子唾液抗原的细胞免疫反应知之甚少。 此外，我们将在豚鼠和仓鼠身上进行这些疫苗接种研究，以证明一种强大的 对AgBR1的免疫应答可以在小鼠以外的物种中激发。我们将培育出一只豚鼠， 埃及伊蚊叮咬传播寨卡病毒的仓鼠模型，我们将进行免疫试验 我们的候选疫苗的有效性。最后，我们将分析我们的疫苗对其他寨卡病毒的潜在效力-- 相关的黄病毒，如DENV和WNV，目的是产生一种泛黄病毒候选疫苗，该候选疫苗 可以单独使用，也可以与病原体特异性疫苗结合使用。

SUMMARY Arboviruses present a constant threat to human and animal health worldwide. They are transmitted by hematophagous arthropods, primarily mosquitoes. One of them, Aedes aegypti, is the primary vector of several widely spread arboviruses such as Zika, dengue and West Nile viruses, and for most of them, human-licensed vaccines do not exist or are suboptimal. These pathogens are transmitted into the host skin together with saliva during feeding. This saliva contains over one hundred unique proteins which can modulate many physiological functions, facilitating blood feeding. It has been shown that many salivary proteins enhance infectivity and pathogenesis of arboviruses by modulating immune responses at the bite site. The development of blocking therapies against them could be a good approach to reduce viral spread in the infected host. This approach may also overcome issues associated with the use of viral antigens as a vaccine targets, due to their high variability or the possibility of induction of antibody- dependent enhancement episodes. In Phase I, a proof-of-principle has been established for a novel strategy of prophylaxis, targeting one salivary protein secreted in A. aegypti saliva, AgBR1, in which passively and actively immunized immunocompromised murine models were partially protected against Zika virus transmitted via mosquito bites. The degree of protection correlated with the antibody titer reached in the immunized animals. However, the use of immunocompromised models has some limitations, such as the weakness of the antibody response, a fact that limits the maximum protection that can be achieved. In this Phase II application, we will define, optimize, and validate a vaccination regimen. We will circumvent the limitations of the immunocompromised animal model by conducting immunizations in immunocompetent murine hosts. We will test the degree of protection achieved by transferring antibodies and/or immune cells to immunocompromised mice, also studying the role of the cellular branch of the immune response against ZIKV infection, as the cellular immune response against mosquito salivary antigens is poorly understood. In addition, we will perform these vaccination studies in guinea pigs and hamsters, to demonstrate that a strong immune response against AgBR1 can be elicited in species other than mice. We will develop a guinea pig and a hamster model of Zika infection transmitted by A. aegypti mosquito bites, and we will test the immunization efficacy of our vaccine candidates. Lastly, we will analyze the potential efficacy of our vaccine against other Zika- related flaviviruses, such as DENV and WNV, with the aim to generate a pan-flaviviral vaccine candidate which could be used alone or in conjunction with pathogen-specific vaccines.