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

总结 虫媒病毒对全球人类和动物健康构成持续威胁。它们是由 吸血的节肢动物，主要是蚊子。其中之一，埃及伊蚊，是几个主要的载体， 广泛传播的虫媒病毒，如寨卡病毒、登革热病毒和西尼罗河病毒，其中大多数是人类许可的， 疫苗不存在或不理想。这些病原体与唾液一起传播到宿主皮肤中 在喂食期间。这种唾液含有超过一百种独特的蛋白质，可以调节许多生理功能。 功能，促进血液供应。 研究表明，许多唾液蛋白可通过调节病毒的免疫反应增强虫媒病毒的感染性和致病性， 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很好的方法。 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相关的问题： 使用病毒抗原作为疫苗靶点，因为它们的高度可变性或诱导抗体的可能性， 依赖性增强发作 在第一阶段，已经建立了一种新的预防策略的原理验证，针对一种唾液 A.在被动和主动免疫的免疫低下的埃及人唾液中， 鼠模型部分地免受通过蚊子叮咬传播的寨卡病毒的侵害。程度 保护作用与免疫动物中达到的抗体滴度相关。但使用 免疫受损模型具有一些局限性，例如抗体应答的弱点， 限制了可以实现的最大保护。在第二阶段的应用程序中，我们将定义，优化， 验证疫苗接种方案。 我们将绕过免疫功能低下的动物模型的局限性， 免疫活性鼠宿主。我们将测试通过转移抗体和/或免疫原性抗体所实现的保护程度。 免疫细胞的免疫功能低下的小鼠，也研究细胞的免疫反应分支的作用 目前，针对ZIKV感染的细胞免疫应答还不清楚，因为针对蚊子唾液抗原的细胞免疫应答知之甚少。 此外，我们将在豚鼠和仓鼠中进行这些疫苗接种研究，以证明强免疫力 可以在小鼠以外的物种中引发针对AgBR 1的免疫应答。我们将培育一只豚鼠， 一个由A.埃及蚊子叮咬，我们将测试免疫 我们候选疫苗的有效性。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，目的是产生泛黄病毒疫苗候选物， 可以单独使用或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.