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：
8854024
负责人：
J. Lindsay Whitton
金额：
$ 22.18万
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 2017-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8854024
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

DESCRIPTION (provided by applicant): 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.

描述（由申请人提供）：在体内注射mRNA触发对编码蛋白的免疫反应，并赋予对疾病的保护。出于此和其他原因（下面概述），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诱导免疫力。我假设RNA疫苗可能正在利用细胞类型和生物途径，这些途径已专门进化以捕获，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）中，从而在调节CD8+ T细胞对许多病毒和细菌感染的反应中起关键作用。几乎所有急性病毒感染都会诱导强烈的CD8+ T细胞反应，当Na？ve CD8+ T细胞通过与DC表面表达适当的共刺激分子表面的MHC I /表位肽复合物接触而激活时会启动。但是，许多病毒不感染DC。一些感染DC的病毒还编码了非常有效抑制M类表现的蛋白质。这些事实提出了一个难题：这些病毒对这些病毒编码的表位如何有效地提出？答案是由识别交叉呈现的，如果它导致触发幼稚的CD8+ T细胞会导致交叉染色。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（在急性病毒感染中是独一无二的）它们完全避免触发Na？ve cd8+ T细胞。其次，微生物蛋白非常丰富的细胞外细菌感染不会诱导强烈的CD8+ T细胞反应。由于下面描述的原因，我假设可以通过提出将免疫信息转移到未感染的DC中来解释这两种观察结果，这可能依赖于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如何诱导免疫力。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中。如果在其中翻译，则编码蛋白将达到I类MHC途径，引起强大的CD8+ T细胞反应；我命名了这种机制TATOR（RNA的转移和翻译）。相反，如果无法翻译mRNA，则CD8+ T细胞无法检测到生物体。因此，其mRNA的特定特征使肠病毒和CD8+ T细胞不可见的细胞外细菌。目标1。识别和表征与RNA触发免疫有关的DC子集。目的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。