mRNA as a mediator of immunological information transfer in vivo

mRNA 作为体内免疫信息传递的介质

基本信息

批准号：
8735569
负责人：
J. Lindsay Whitton
金额：
$ 28.43万
依托单位：
SCRIPPS RESEARCH INSTITUTE, THE
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-06-01 至 2016-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8735569
关键词：
Acute Antibodies Antiviral Agents Bacteria Bacterial Infections Biological CD4 Positive T Lymphocytes CD8B1 gene Cancer Vaccines Cells Characteristics Clinical Code Complex Cross Presentation Cross-Priming Data Dendritic Cells Disease Enterovirus Epitopes Goals Grant Human Immune Immune response Immunity Immunology In Vitro Infection Injection of therapeutic agent MHC Class I Genes Mediator of activation protein Messenger RNA Microbe Mus Names Nature Organism Paper Pathway interactions Peptides Play Process Proteins RNA Reading Recombinants Regulatory Element Role Signal Transduction Study Section Surface T cell response T-Lymphocyte Testing Transfer RNA Translating Translations Uncertainty Vaccination Vaccines Viral Viral Proteins Virus Virus Diseases Work Yeasts cell type extracellular high reward high risk in vivo innovation microbial pathogen public health relevance research study tumor vector vaccine

项目摘要

In vivo injection of mRNA triggers immune responses to the encoded proteins, and confers protection against disease. For this and other reasons, outlined below, RNA vaccines have great clinical potential, so it is important that we understand how they induce immunity. I hypothesize that RNA vaccines may be exploiting a cell type, and biological pathway, that have evolved specifically to capture, internalize, and translate mRNA. I propose that this pathway facilitates the transfer of immunological information into uninfected dendritic cells (DCs), thereby playing a key part in regulating CD8+ T cell responses to many viral and bacterial infections. Almost all acute virus infections induce strong CD8+ T cell responses, which are initiated when na¿ve CD8+ T cells are activated by contact with an MHC class I / epitope peptide complex on the surface of DCs that express appropriate costimulatory molecules. However, many viruses do not infect DCs; and some viruses that infect DCs also encode proteins that quite effectively inhibit MHC class I presentation. These facts posed a puzzle: how could epitopes encoded by these viruses be effectively presented by DCs? The answer came with the identification of cross-presentation which, if it results in the triggering of naive CD8+ T cells, causes cross-priming. However, two in vivo observations show that cross-presentation/cross-priming (hereinafter, CP) is not always highly-efficient. First, enteroviruses replicate to very high titers and induce CD4+ T cells and antibodies, yet (unique among acute virus infections) they completely avoid triggering na¿ve CD8+ T cells. Second, extracellular bacterial infections, in which microbial protein is hugely abundant, do not induce strong CD8+ T cell responses. For reasons described below, I hypothesize that both observations can be explained by proposing that some transfer of immunological information into uninfected DCs may rely on mRNA (rather than protein). So, this proposal has two goals: First, to evaluate how naked RNA induces immunity. Second, to test the hypothesis that, during most microbial infections, mRNA is transferred to uninfected DCs; if it is translated therein, the encoded protein will reach the class I MHC pathway, inducing strong CD8+ T cell responses; I have named this mechanism TATOR (transfer and translation of RNA). Conversely, if the mRNA cannot be translated, the organism is undetectable by CD8+ T cells. Thus, the specific characteristics of their mRNAs renders enteroviruses and extracellular bacteria invisible to CD8+ T cells. Aim 1. To identify and characterize the DC subset that is involved in RNA-triggered immunity. Aim 2. To determine if mRNA regulatory sequences explain why extracellular bacteria fail to induce strong CD8+ T cell responses.

体内注射mRNA触发对编码蛋白的免疫回报，并传达保护反疾病。由于此和其他原因（以下概述），RNA疫苗具有巨大的临床潜力，因此，重要的是要了解它们如何影响免疫学。我假设RNA疫苗可能是利用细胞类型和生物途径，这些细胞类型已专门进化以捕获，内在化和翻译mRNA。我建议该途径有助于将免疫信息转移到未感染的树突状细胞（DC），从而在调节CD8+ T细胞反应中发挥关键作用病毒和细菌感染。几乎所有急性病毒感染都会影响强大的CD8+ T细胞反应，这通过与MHC I /表位肽接触而激活Na�VECD8+ T细胞时开始在表达适当的共刺激分子的DC表面上的复合物。但是，很多病毒不感染DC；一些感染DC的病毒还编码蛋白质，这些蛋白质非常有效抑制MHC I类介绍。这些事实提出了一个难题：这些事实如何被这些编码的表位 DC有效地提出病毒？答案是由交叉陈述的识别如果它导致启发幼稚的CD8+ T细胞，则会导致交叉播种。但是，两个体内观察结果表明，交叉呈递/交叉染色（以下简称CP）并不总是高效。首先，肠病毒复制至非常高的滴度并诱导CD4+ T细胞和抗体，但（唯一）在急性病毒感染中）它们完全避免触发VE CD8+ T细胞。其次，细胞外微生物蛋白极丰富的细菌感染不会诱导强烈的CD8+ T细胞回答。由于下面描述的原因，我假设这两个观察结果都可以通过提议将免疫信息转移到未感染的DC中可能依赖mRNA （而不是蛋白质）。因此，该提议有两个目标：首先，评估裸露的RNA如何诱导免疫。其次，为了检验以下假设：在大多数微生物感染中，mRNA被转移到未感染的DC；如果在其中翻译，则编码的蛋白质将到达I类MHC途径，诱导强的CD8+ T细胞反应；我命名了这种机制tator（转移和翻译的 RNA）。相反，如果无法翻译mRNA，则CD8+ T细胞无法检测到生物体。这是其mRNA的特定特征 CD8+ T细胞看不见。目的1。识别和表征与RNA触发的免疫共同体有关的DC子集。目标2。确定mRNA调节序列是否解释了为什么细胞外细菌无法诱导强烈的CD8+ T细胞反应。