Biologically informed design of CD8+ T cell-dependent pre-erythrocytic stage malaria vaccines

CD8 T 细胞依赖性红细胞前阶段疟疾疫苗的生物学知情设计

基本信息

批准号：
10558591
负责人：
Stefan HI Kappe
金额：
$ 124.22万
依托单位：
SEATTLE CHILDREN'S HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-02-04 至 2026-01-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10558591
关键词：
Acceleration Address Animal Model Antigen Presentation Antigen-Presenting Cells Antigens Attenuated Attenuated Vaccines Basic Science Behavior Biological Biological Assay Biology Biomass CD8-Positive T-Lymphocytes CRISPR/Cas technology Categories Cell Cycle Kinetics Cell Separation Cells Cellular biology Cessation of life Clinical Trials Cross Presentation Data Development Dominant-Negative Mutation Ensure Epitopes Erythrocytes Gene Deletion Generations Genetic Engineering Genome engineering Hepatocyte Human Immune Immune response Immunity Immunization Immunize Immunologics In Vitro Infection Knowledge Liver MHC Class I Genes Malaria Malaria Vaccines Mediating Modeling Molecular Mus Parasites Peptides Phase Plasmodium Plasmodium falciparum Plasmodium falciparum vaccine Plasmodium vaccine Plasmodium yoelii Predisposition Process Proteins Proteome Proteomics Radiation Rodent Sporozoites Subunit Vaccines Surface Surface Antigens T cell response T-Cell Activation T-Lymphocyte Epitopes Technology Testing Time Tissues Transgenes Translational Research Vaccination Vaccine Design Vaccines Viral Vector Work attenuation cell killing design genomic locus immunogenicity liver infection malaria infection next generation overexpression parasite genome promoter response tool transcriptome vaccine candidate vaccine efficacy vaccine immunogenicity vector vector vaccine

项目摘要

PROJECT SUMMARY/ABSTRACT Immunization with whole pre-erythrocytic (sporozoite and liver stage) Plasmodium falciparum (Pf) vaccines confers sterilizing immunity in human clinical trials. Replication-deficient vaccines, such as radiation- attenuated sporozoites infect the liver as sporozoites but do not develop into liver stage schizonts. Replication- competent vaccines, however, infect the liver and replicate as tissue schizonts. Multiple lines of evidence in animal models of malaria have shown that protection is dependent on antigen-specific CD8+ T cells that recognize liver stage-infected hepatocytes, leading to their elimination. Replication-competent parasite vaccination confers superior durable sterilizing immunity against infection, and this appears to be, in animal models, associated with broader and better CD8+ T cell responses. However, it remains largely unknown how the distinct molecular cell biological features of whole attenuated parasite vaccines drive differences in the priming of protective CD8+ T cells and of equal importance, which liver stage antigens are directly presented by wildtype liver stage-infected hepatocytes that are the targets of vaccine-elicited protective CD8+ T cells. We will address these critical knowledge gaps. In Aim 1, we will identify the distinct time points during which the demise of liver stage-infected hepatocytes results in optimal cross-presentation of liver stage antigens by antigen presenting cells to CD8+ T cells. For this, we will use the Plasmodium yoelii (Py) rodent malaria model to inform vaccine design of Pf, with which mechanistic host studies cannot be done. We will also determine at what time points of wildtype liver stage development infected hepatocytes are most vulnerable to effector CD8+ T cell- mediated elimination. In concert with this, we will determine dynamic liver stage transcriptomes and proteomes throughout development and down-select the subset of liver stage proteins most prone to intrahepatocytic processing and MHC class I-restricted peptide presentation. In Aim 2, we will directly determine the MHC class I peptidome of Py and Pf presented on infected hepatocytes, specifically at timepoints of highest vulnerability and test their reactivity with whole parasite-vaccine-elicited CD8+ T cells. We will then test reactive epitopes as well as nonreactive epitopes (covert epitopes) as vectored subunit vaccines in mice. As in Aim 1, mechanistic testing cannot be done in Pf and thus we will conduct studies of Py to guide our Pf work. In Aim 3, we will genetically engineer the ultimate Pf replication-competent parasite strain that is built with gene deletions and dominant negative transgenes of parasite origin and will also over-express protective CD8+ T cell epitopes that target liver stages at the point of their greatest vulnerability. Thus, in a multi-pronged approach our project will develop the next generation of pre-erythrocytic vaccines including both vectored subunit vaccine candidates and whole genetically attenuated parasite vaccine candidates, designed to generate optimal and durable protective CD8+ T cell responses against Pf infection.

项目摘要/摘要用全芽孢杆菌（Sporozoite和肝脏）疟原虫（PF）进行免疫接种疫苗赋予人类临床试验中的免疫力。复制缺陷疫苗，例如辐射 - 减毒的孢子虫将肝脏感染为子孢子，但不会发展为肝脏阶段。复制 - 然而，胜任的疫苗感染了肝脏，并复制为组织。多种证据疟疾的动物模型表明，保护取决于抗原特异性CD8+ T细胞识别感染肝阶段的肝细胞，从而消除它们。复制能力的寄生虫疫苗接种赋予了耐用的耐用抗性免疫，这似乎是在动物中模型，与更广泛和更好的CD8+ T细胞响应相关。但是，这在很大程度上是未知的整个减毒的寄生虫疫苗的不同分子细胞生物学特征驱动差异保护性CD8+ T细胞的启动和同等重要性，肝脏抗原直接通过野生型肝脏感染的肝细胞是疫苗吸收的保护性CD8+ T细胞的靶标。我们将解决这些关键的知识差距。在AIM 1中，我们将确定灭亡的不同时间点肝阶段感染的肝细胞可通过抗原对肝阶段抗原的最佳交叉呈现将细胞呈现给CD8+ T细胞。为此，我们将使用疟原虫yoelii（Py）啮齿动物疟疾模型告知 PF的疫苗设计，无法通过该疫苗进行机械宿主研究。我们还将在什么时候确定野生型肝脏阶段发育的点感染了肝细胞最容易受到效应子CD8+ T细胞的影响介导的消除。与此相关，我们将确定动态肝阶段转录组和蛋白质组织在整个发育和下调的肝脏阶段蛋白的子集最容易容易肝内细胞加工和MHC I类限制性肽表现。在AIM 2中，我们将直接确定MHC类我的PY和PF肽组在感染的肝细胞上呈现，特别是在最高脆弱性的时间点上并用整个寄生虫吸引的CD8+ T细胞测试其反应性。然后，我们将测试反应性表位为以及无反应性表位（掩盖表位）作为小鼠的矢量亚基疫苗。与AIM 1一样，机械不能在PF中进行测试，因此我们将对PY进行研究以指导我们的PF工作。在AIM 3中，我们将遗传学工程师用基因缺失和寄生虫起源的主要负转基因，还将过表达保护性CD8+ T细胞表位目标肝阶段在其最大脆弱性的位置。因此，在多管齐的方法中，我们的项目将开发下一代的预疫苗前疫苗，包括两个矢量亚基疫苗和全遗传衰减的寄生虫疫苗候选物，旨在产生最佳和耐用的保护性 CD8+ T细胞反应针对PF感染。