Vaccine Development for Falciparum Malaria in Pregnant Women and Their Offspring

描述（由申请人提供）：疟疾影响着世界上近一半的人口，每年导致超过一百万人死亡。非洲疟疾流行地区的幼儿由于免疫系统不成熟，死亡率最高。全球控制该疾病的努力收效有限，尚未批准任何疫苗用于临床。因此，迫切需要使用新方法发现新的候选疫苗，特别是对于代表关键目标群体的母亲和婴儿。米歇洛博士拟议的指导职业发展奖的研究目标是为育龄妇女发现新的抗疟疾疫苗，以保护她们高度脆弱的后代在婴儿早期免受严重或致命的疟疾的侵害。在博士的指导下。布朗大学的柯蒂斯和弗里德曼以及博士。来自 NIH/NIAID 疟疾免疫学和疫苗学实验室的 Duffy 和 Fried 是国际知名的研究人员，他计划检验这样的假设：通过识别介导婴儿对严重或致命疟疾的抵抗力的经胎盘获得性疟疾抗体，可以发现新的疫苗靶标。该提案的目的是鉴定保守的恶性疟原虫抗原，这些抗原可以被从患有轻度或无临床疟疾的婴儿在出生后第一年幸存的母亲分娩时获得的静脉血中的 IgG 抗体识别，但不能被婴儿因疟疾而患有严重疾病或死亡的母亲的 IgG 抗体识别。 Michelow 博士的团队将利用他们从坦桑尼亚穆赫扎 (Muheza) 的大型纵向队列 (n=739) 收集的血浆样本和流行病学数据。为了实现这些目标，他们提出了三个具体目标，分别是 1) 发现、2) 验证和 3) 下调恶性疟原虫候选疫苗抗原。这种以患者为导向的转化策略的优势在于，他们将在疫苗表位发现的最早阶段使用具有自然获得的疟疾抗体的母亲和婴儿的血浆。基于 Kurtis 博士开创的成功方法，他们将对患有严重疟疾的婴儿的母亲与患有轻度或无疟疾的婴儿的母亲的精选血浆组进行差异化高通量全蛋白质组筛查。为此，他们将使用新生产的恶性疟原虫 (3D7) 疟疾基因组 DNA T7 噬菌体展示文库以及野生型血液阶段互补 DNA T7 噬菌体文库。然后，将通过测试来自同一人群的大量独立母亲和婴儿群体来验证候选疫苗抗原，以确定哪些特定疟疾抗体最可靠地预测更好的疟疾结果。他们将采用混合效应逻辑回归模型来解释重复测量和混杂变量，并采用 Cox 比例风险生存模型来比较与预定义终点的时间。然后，将使用生物信息学和表面定位研究以及功能评估，使用血液阶段候选物的侵袭和生长抑制测定来向下选择主要候选抗原。米歇尔博士之前在儿科传染病和热带医学方面的临床培训、他对肺炎或先天性梅毒儿童诊断测试的研究，以及他在生产针对糖基化病毒感染的新型免疫治疗药物方面的实验室工作，为他提出的研究项目奠定了坚实的基础。在导师的指导下，他将通过应用严格、机械和创造性的探究方法，将基础科学概念转化为相关的人类干预和疗法，弥合基础科学和以患者为导向的研究之间的差距。他计划通过获得以下三个关键领域的关键新技能来实现他的目标：1）疫苗免疫学，2）先进的分子方法，3）应用生物统计学、流行病学和人口研究。具体来说，他将接受以下方法的培训：实施基于噬菌体的创新分子筛选策略，选择和测试最佳疟疾疫苗表位，培养和基因操纵疟疾寄生虫，进行基于细胞的感染测定，询问疟疾基因组/蛋白质组数据库，使用复杂的细胞成像技术，使用先进的统计方法对复杂数据进行建模以解释混杂变量和重复测量，并强调生物伦理问题的重要性。拟议的研究经验将使米歇尔博士做好准备，实现他的长期职业目标，即成为疟疾疫苗发现领域假设驱动转化研究的熟练研究者。合理确定的一项或多项 当前提案中的主要候选疫苗表位将构成其 R01 申请的基础。他的目标是 1) 确认源自坦桑尼亚天然恶性疟原虫菌株的抗原的相关性，2) 进行动物研究以研究新疫苗的有效性和作用机制，以及 3) 建立 I 期健康人类志愿者疫苗研究。米歇洛博士和他的卓有成就的研究团队致力于利用创造性策略开发新的有效疟疾疫苗的使命。

DESCRIPTION (provided by applicant): Malaria affects almost one-half of the world's population and causes more than one million deaths annually. Young children in malaria endemic areas of Africa have the highest mortality because of their immature immune systems. Global efforts to control the disease have had limited success and no vaccine has yet been approved for clinical use. Therefore, there is an urgent unmet need to discover new vaccine candidates using novel approaches, especially for mothers and infants who represent key target groups. Dr. Michelow's research goal for the proposed Mentored Career Development Award is to discover new anti-malarial vaccines for women of childbearing age in order to protect their highly vulnerable offspring from severe or fatal malaria in early infancy. Under the mentorship of Drs. Kurtis and Friedman from Brown University, and Drs. Duffy and Fried from the NIH/NIAID Laboratory of Malaria Immunology and Vaccinology, who are internationally renowned investigators, he plans to test the hypothesis that novel vaccine targets can be discovered by identifying transplacentally acquired malarial antibodies that mediate infants' resistance to severe or fatal malaria. The objective of this proposal is to identify conserved Plasmodium falciparum antigens that are uniquely recognized by IgG antibodies in venous blood obtained at delivery from mothers whose infants survived their first year of life with mild or no clinical malaria, but that are not recognized by IgG antibodies from mothers whose infants suffered severe disease or death due to malaria. Dr. Michelow's team will capitalize on plasma samples and epidemiological data that they already collected from a large well-characterized longitudinal cohort in Muheza, Tanzania (n=739). In order to achieve these objectives, they propose three Specific Aims that are directed at 1) discovering, 2) validating and 3) downselecting P. falciparum candidate vaccine antigens. The strength of this patient-oriented translational strategy derives from the fact that they will use plasma of mothers and infants with naturally acquired malarial antibodies at the earliest stage of vaccine epitope discovery. Based on the successful approach pioneered by Dr. Kurtis, they will perform a differential high throughput whole proteome screen on select groups of pooled plasma from mothers of infants with severe malaria vs. mothers of infants with mild or no malaria. They will use a newly produced P. falciparum (3D7) malaria genomic DNA T7 phage display library as well as a wild type blood-stage complementary DNA T7 phage library for this purpose. Candidate vaccine antigens will then be validated by testing a large independent cohort of mothers and infants from the same population to determine which specific malarial antibodies most reliably predict better malaria outcomes. They will employ mixed effects logistic regression modeling to account for repeated measures and confounding variables as well as the Cox proportional hazards survival model to compare time to predefined endpoints. Lead candidate antigens will then be downselected using bioinformatics and surface localization studies, as well as functional evaluations, using invasion and growth inhibition assays for blood stage candidates. Dr. Michelow's previous clinical training in Pediatric Infectious Diseases and Tropical Medicine, his research on diagnostic tests for children with pneumonia or congenital syphilis, and his laboratory work on production of novel immunotherapeutics for glycosylated virus infections, have laid a solid foundation for his proposed research project. Under the guidance of his mentors, he will bridge the gap between basic science and patient-oriented research by applying rigorous, mechanistic and creative methods of enquiry to translate basic science concepts into relevant human interventions and therapies. He plans to accomplish his goals by acquiring critical new skills in the following three key areas: 1) vaccine immunology, 2) advanced molecular methods, and 3) applied biostatistics, epidemiology and human population research. Specifically, he will be trained in methods to implement innovative phage-based molecular screening strategies, select and test optimal malaria vaccine epitopes, cultivate and genetically manipulate malaria parasites, perform cell-based infection assays, interrogate the malaria genome/proteome databases, use sophisticated cell imaging technologies, model complex data using advanced statistical methods to account for confounding variables and repeated measures, and reinforce importance of bioethical issues. The proposed research experiences will prepare Dr. Michelow to achieve his long-term career goal of becoming a skilled investigator in hypothesis-driven translational research in the field of malaria vaccine discovery. One or more rationally identified lead candidate vaccine epitopes from the current proposal will form the basis of his R01 application. His objectives will be to 1) confirm the relevance of the antigen/s derived from native P. falciparum strains from Tanzania, 2) conduct animal studies to study effectiveness and mechanisms of action of new vaccines, and 3) establish a Phase I healthy human volunteer vaccine study. Dr. Michelow and his team of highly accomplished investigators are committed to the mission of developing new effective malaria vaccines using creative strategies.