Develop and Assess mRNA Lipid Nanoparticle Vaccines Against Cryptococcosis

新生隐球菌和C. gattii引起危及生命的隐球菌脑膜脑炎， 是当今世界上常见的中枢神经系统真菌感染。12个月死亡率 隐球菌性脑膜脑炎患者中，即使采用目前的抗真菌治疗， 开发针对隐球菌病的疫苗以治疗高风险患者仍然是最紧迫和最重要的问题之一。 对抗这种毁灭性真菌感染的挑战性目标。到目前为止，灭活的全细胞疫苗和 重组蛋白亚单位疫苗正在临床前研究中进行研究。两种灭活的全细胞 疫苗或蛋白质亚单位疫苗具有问题（例如，安全性、技术、成本和有效性问题）和无 目前已进入临床试验阶段。 基于递送稳定的mRNA编码的新兴的和临床证明的疫苗技术 包装在脂质纳米颗粒（LNP）中的免疫原尚未开发用于任何细菌或真菌 感染.在这里，我们将研究这项技术，以开发针对隐球菌感染的疫苗。我们 研究小组有脂质体和核酸的经验，并一直与 dectin修饰的脂质体用于靶向抗真菌药物输送多年。靶向抗真菌药物递送， dectin修饰的脂质体在体外和动物模型中都显示出巨大的前景。我们还 使用灭活隐球菌突变体进行隐球菌感染疫苗接种的经验。 利用这些经验，我们的目标是生产高效的mRNA LNP疫苗， 隐球菌病我们已经将几种新策略纳入我们的新型mRNA疫苗设计中。为 例如，基于先前证实的重组免疫原的功效选择待测试的编码免疫原。 作为保护性免疫原的蛋白质、高的体内转录物丰度、细胞外定位以及它们的 在真菌发病机制中的作用。因为每种细胞外蛋白质都是由宿主体内的mRNA产生的 细胞中，它会被糖基化，因此与真菌C产生的蛋白质更相似。新形动物 与E.杆菌为达致这个目标，我们建议 以下两个具体目标：（i）构建携带编码不同候选C.新生 蛋白免疫原。(ii)测试每种mRNA提供的免疫原性和持久的宿主保护 纳米颗粒疫苗和组合疫苗在隐球菌病小鼠模型中的应用。完成本 该提案可能会为针对隐球菌病的mRNA疫苗提供一个成功的平台， 其他真菌病。拟议工作的探索性质及其可能产生的影响 我们对抗这种和其他致命真菌病原体的能力使这种应用非常适合R21 机制

Cryptococcus neoformans and C. gattii cause life threatening cryptococcal meningoencephalitis, the most common fungal infection of the central nervous system in the world today. The 12-month mortality rate for individuals with cryptococcal meningoencephalitis is 60% even with the current antifungal treatment. Developing vaccines against cryptococcosis to treat high risk patients remains one of the most urgent and challenging goals to combat this devastating fungal infection. So far, inactivated whole cell vaccines and recombinant protein subunit vaccines are being investigated in preclinical studies. Both inactivated whole cell vaccines or protein subunit vaccines have issues (e.g., safety, technical, cost, and efficacy concerns) and none have made it to clinical trials yet. The emerging and clinically proven vaccine technology based on delivering stabilized mRNAs encoding immunogens packaged in lipid nanoparticles (LNPs) has not been developed for any bacterial or fungal infections. Here we will investigate this technology to develop vaccines against cryptococcal infections. Our research group has experience with liposomes and nucleic acids, and have been working with together on dectin-decorated liposomes for targeted antifungal drug delivery for years. The targeted antifungal delivery with dectin-decorated liposomes has shown great promise in both in vitro and animal models. We have also experience with vaccination against Cryptococcus infection using inactivated cryptococcal mutants. Capitalizing on these experiences, our goal is to produce a highly effective mRNA LNP vaccine for cryptococcosis. We have incorporated several new strategies into our novel mRNA vaccine design. For example, encoded immunogens to be tested are selected based on prior demonstrated efficacy of recombinant proteins to be protective immunogens, high in vivo transcript abundance, extracellular localization, and their roles in fungal pathogenesis. Because each extracellular protein will be produced from an mRNA in the host cell, it will be glycated, and hence, more closely resemble proteins produced by the fungus C. neoformans as compared to recombinant proteins produced by E. coli. To meet our goal, we propose to accomplish the following two specific aims: (i) Construct LNPs carrying the mRNAs encoding distinct candidate C. neoformans protein immunogens. (ii) Test the immunogenicity and durable host protection provided by each mRNA nanoparticle vaccine and a combinatorial vaccine in mouse models of cryptococcosis. Completion of this proposal will likely provide a successful platform for mRNA vaccine against cryptococcosis and in the future other fungal diseases. The exploratory nature of the proposed work and the potential impact it could have on our ability to fight this and other deadly fungal pathogens make this application perfectly fit for the R21 mechanism.