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.

项目概要/摘要使用完整的前红细胞（子孢子和肝脏阶段）恶性疟原虫（Pf）进行免疫疫苗在人体临床试验中赋予绝育免疫力。复制缺陷型疫苗，例如辐射疫苗减毒子孢子以子孢子的形式感染肝脏，但不会发育成肝期裂殖体。复制- 然而，有效的疫苗会感染肝脏并以组织裂殖体的形式复制。多方面的证据疟疾动物模型表明，保护作用依赖于抗原特异性 CD8+ T 细胞，识别肝阶段感染的肝细胞，从而消除它们。具有复制能力的寄生虫疫苗接种赋予了针对感染的卓越持久的灭菌免疫力，这似乎在动物身上模型，与更广泛和更好的 CD8+ T 细胞反应相关。然而，目前仍不清楚如何全减毒寄生虫疫苗独特的分子细胞生物学特征导致了差异保护性 CD8+ T 细胞的启动，同样重要的是，肝阶段抗原直接呈递野生型肝阶段感染的肝细胞是疫苗诱导的保护性 CD8+ T 细胞的目标。我们将解决这些关键的知识差距。在目标 1 中，我们将确定死亡的不同时间点肝阶段感染的肝细胞导致肝阶段抗原与抗原的最佳交叉呈递将细胞呈递给 CD8+ T 细胞。为此，我们将使用约氏疟原虫 (Py) 啮齿动物疟疾模型来告知 Pf 的疫苗设计，无法进行机制宿主研究。我们还将确定在什么时间野生型肝脏阶段发育点感染的肝细胞最容易受到效应 CD8+ T 细胞的影响 - 介导消除。与此相一致，我们将确定动态肝脏阶段转录组和蛋白质组在整个发育过程中，向下选择最容易发生肝细胞内的肝脏阶段蛋白的子集加工和 MHC I 类限制性肽呈递。在目标2中，我们将直接确定MHC类别 Py 和 Pf 的 I 肽组呈现在受感染的肝细胞上，特别是在脆弱性最高的时间点并测试它们与完整的寄生虫疫苗诱导的 CD8+ T 细胞的反应性。然后我们将测试反应性表位以及作为小鼠载体亚单位疫苗的非反应性表位（隐蔽表位）。如目标 1 所示，机械 Pf 中无法进行测试，因此我们将对 Py 进行研究来指导我们的 Pf 工作。在目标 3 中，我们将通过基因工程改造最终具有 Pf 复制能力的寄生虫菌株，该菌株是通过基因删除构建的寄生虫来源的显性失活转基因，也会过度表达保护性 CD8+ T 细胞表位目标是肝脏最脆弱的阶段。因此，我们的项目将通过多管齐下的方式开发下一代前红细胞疫苗，包括载体亚单位候选疫苗和全基因减毒候选寄生虫疫苗，旨在产生最佳且持久的保护作用 CD8+ T 细胞针对 Pf 感染的反应。