Development of mRNA-platform vaccines

项目总结 百日咳是由人类特有病原体百日咳杆菌引起的一种呼吸道疾病。两代人 已开发和许可的百日咳疫苗有：全细胞百日咳(DTP)和无细胞百日咳 (DTaP/Tdap)。百日咳被认为是一种过去的疾病，但最近又重新出现。数量 2012年的百日咳病例是有记录以来最低的一年(1976年)的48倍，这也是50年来的最高水平。 虽然百日咳的增加有多种潜在原因，但流行病学研究清楚地表明， DTaP和TDAP的免疫持续时间在加强免疫后每年迅速下降，并回归到非 人体内的保护水平。每剂全细胞疫苗包含数百种抗原，其中许多 是免疫显性的。全细胞疫苗还可诱导辅助性T细胞1和17(Th1/Th17)细胞免疫反应。 另一方面，无细胞疫苗专注于Th2介导的体液反应，专门针对百日咳毒素， 丝状血凝素、Pertactin和菌毛。我们的目标是开发一种能够诱导Th1的疫苗 与无细胞疫苗相比，该疫苗包括更多的抗原。基因疫苗提供了一个平台 它们可以很容易地针对目标抗原/病原体进行修饰，并诱导Th1反应。核糖核酸疫苗 编码该抗原，一旦表达，就会导致由TFH反应介导的免疫。我们使用了一种 筛选百日咳杆菌抗原并鉴定保护性多价制剂(mRNA-DTP10；8)的平台 百日咳抗原与白喉和破伤风抗原)在小鼠攻击模型中。在这个项目中，我们将 进一步扩大我们的研究范围，探讨百日咳基因疫苗对小鼠的保护作用。 进行长寿研究的小鼠模型，并检测DTaP Prime/mRNA-Boost效应(SA1)。接下来，我们将利用 百日咳大鼠模型的全身体积描记比较mRNA、全细胞和 用于预防咳嗽的脱细胞免疫(SA2)。我们将研究信使百日咳疫苗。 百日咳狒狒模型的免疫原性和攻击性实验(SA3)。最后，我们将致力于 建立一套检测百日咳mRNA疫苗产生的表型抗体的方法，并在每种抗体之间架起桥梁 百日咳模型，这将促进临床发展。通过这些研究，我们的目标是描述 百日咳的mRNA免疫，并更清楚地了解如何使用该疫苗平台来 克服使用多种致病因子的“复杂或疑难”病原体。我们希望获得的数据 每一个目标都将导致对百日咳免疫的更深层次的理解，以及阐明mrna平台。 用于细菌疫苗。

PROJECT SUMMARY Pertussis is a respiratory disease caused by the obligate human pathogen Bordetella pertussis. Two generations of pertussis vaccines have been developed and licensed: whole cell pertussis (DTP) and acellular pertussis (DTaP/Tdap). Pertussis was thought to be a disease of the past but has recently re-emerged. The number of cases of pertussis in 2012 was 48-fold over the lowest year on record (1976), which was also a 50-year high. While the increase of pertussis has multiple potential reasons, epidemiological studies clearly suggest that the duration of immunity of both DTaP and Tdap wanes quickly each year after a booster, and regresses to non- protective levels in humans. Each dose of whole cell vaccine contains hundreds of antigens, of which numerous are immunodominant. Whole cell vaccines also induce T helper 1 and 17 (Th1/Th17) cellular immune responses. On the other hand, acellular vaccines focus Th2-mediated humoral responses exclusively to pertussis toxin, filamentous hemagglutinin, pertactin, and fimbriae. We aim to develop a vaccine that would induce Th1 responses and include a greater number of antigens than acellular vaccines. mRNA vaccines provide a platform that can be easily modified for the targeted antigen/pathogen and they induce Th1 responses. mRNA vaccines encode the antigen, which once expressed, results in immunity mediated by Tfh responses. We used an mRNA platform to screen antigens of B. pertussis and identified a protective multivalent formulation (mRNA-DTP10; 8 pertussis antigens with diphtheria and tetanus antigens) in a murine challenge model. In this project, we will further extend our studies and investigate the correlates of protection of the mRNA-pertussis vaccine in the murine model with longevity studies and examine DTaP prime / mRNA-boost effects (SA1). Next, we will utilize the coughing rat model of pertussis with whole body plethysmography to compare mRNA, whole cell, and acellular immunity for protection against cough (SA2). We will study the mRNA pertussis vaccine in immunogenicity and challenge experiments using the baboon model of pertussis (SA3). Lastly, we will aim to develop a suite of assays to phenotype antibodies produced by mRNA pertussis vaccines and bridge each of the pertussis models, which will facilitate clinical development. Through these studies, we aim to characterize the mRNA-pertussis immunity and develop a clearer understanding of how this vaccine platform can be used to overcome “complex or difficult” pathogens that employ numerous virulence factors. We expect the data acquired in each aim will result in a deeper understanding of pertussis immunity as well as illuminate the mRNA platform for bacterial vaccines.