Develop and Assess mRNA Lipid Nanoparticle Vaccines Against Cryptococcosis

新生隐球菌和加蒂氏菌引起的危及生命的隐球菌性脑膜脑炎最多 当今世界常见的中枢神经系统真菌感染。美国12个月的死亡率 即使在目前的抗真菌治疗下，患有隐球菌性脑膜脑炎的患者仍有60%。 开发针对隐球菌病的疫苗来治疗高危患者仍然是最紧迫的和 具有挑战性的目标，以抗击这种毁灭性的真菌感染。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进行临床前研究。两者都是灭活的整个细胞 疫苗或蛋白质亚单位疫苗有问题(例如，安全、技术、成本和疗效方面的问题)，而没有 已经进入了临床试验。 基于递送稳定的mRNAs编码的新兴和临床验证的疫苗技术 以脂质纳米粒(LNPs)包装的免疫原尚未针对任何细菌或真菌开发 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。我们的 研究小组在脂质体和核酸方面有经验，并一直在与 多年来用于靶向抗真菌药物的Dectin修饰脂质体。靶向抗真菌药物的应用 十字甲素修饰的脂质体在体外和动物模型中都显示出巨大的前景。我们还有 使用灭活隐球菌变异体接种隐球菌感染疫苗的经验。 利用这些经验，我们的目标是生产一种高效的mRNALNP疫苗 隐球菌病。我们在新的信使核糖核酸疫苗设计中加入了几种新的策略。为 例如，要测试的编码免疫原是基于先前证明的重组的有效性来选择的 作为保护性免疫原的蛋白质，体内高转录本丰度，细胞外定位，以及它们的 在真菌发病机制中的作用。因为每一种胞外蛋白都是由宿主中的一种信使核糖核酸产生的 细胞，它将被糖化，因此，更类似于真菌新生芽孢杆菌产生的蛋白质，如 与大肠杆菌产生的重组蛋白相比。为了实现我们的目标，我们建议实现 以下两个具体目标：(I)构建携带编码不同候选新生隐球菌mRNAs的LNPs 蛋白质免疫原。(Ii)测试每个基因提供的免疫原性和持久宿主保护 在隐球菌病小鼠模型中的纳米颗粒疫苗和组合疫苗。完成这项工作 这一提议可能会为未来针对隐球菌病的mRNA疫苗提供一个成功的平台 其他真菌疾病。拟议工作的探索性及其可能对 我们对抗这种和其他致命真菌病原体的能力使这款应用程序非常适合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.