Non-canonical epitope presentation and antigen processing by MHC-E

MHC-E 的非典型表位呈递和抗原加工

• 批准号: 10801509
• 负责人: Klaus J Fruh
• 金额: $ 71.95万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-25 至 2028-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10801509
• 关键词: AIDS vaccine development; Antibodies; Antigen Presentation; Antigen Presentation Pathway; Antigens; Bacteria; Binding; Biology; CD4 Positive T Lymphocytes; CD8-Positive T-Lymphocytes; CD94 Antigen; CRISPR screen; Cell Line; Cells; Clinical; Complex; Cytomegalovirus; Cytoprotection; Data; Endoplasmic Reticulum; Epitopes; Frequencies; GAG Gene; Gene Deletion; Gene Expression; Gene Targeting; Genes; Goals; HIV; HIV vaccine; Heterophile Antigens; Histocompatibility; Histocompatibility Antigens Class II; Human; Image; Immune response; Immunity; Immunologic Deficiency Syndromes; Immunologics; Immunology; Immunotherapeutic agent; In Vitro; Infection; Integration Host Factors; International; Lentivirus; Macaca mulatta; Mediating; MicroRNAs; Modeling; Molecular; Monitor; Mycobacterium tuberculosis; Myelogenous; Myeloid Cells; N-terminal; Natural Killer Cells; Outcome; Parasites; Pathogenicity; Pathway interactions; Peptides; Phase; Plasmodium knowlesi; Protein Sortings; Proteins; Reagent; Recombinants; Research; Research Personnel; Rhesus; Role; SIV; Signal Transduction; Site; Sorting; Structure; Surface; T cell differentiation; T cell response; T memory cell; T-Cell Receptor; T-Lymphocyte; Techniques; Translations; Vaccine Design; Vaccines; Vesicle; Viral; Viral Genes; Viral Proteins; Virulent; Virus; Work; antigen processing; cell type; cellular targeting; design; experience; genetic testing; in vivo; monocyte; novel; novel vaccines; posters; prophylactic; response; seropositive; small hairpin RNA; trafficking; transcriptomics; translational immunology; vaccine platform; vector; vector vaccine

Project Summary In the course of developing cytomegalovirus (CMV) as a new vaccine platform for eliciting effector differentiated T cell immunity, we observed that rhesus CMV (RhCMV) expressing simian immunodeficiency (SIV) antigens elicit immune responses that control and ultimately clear highly pathogenic SIV. Surprisingly however, protection was only observed with genetically modified vectors eliciting CD8+ T cells restricted by non-polymorphic, highly conserved MHC-E instead of classical MHC-I. Targeting HIV peptides presented by HLA-E thus represents a novel, unexpected and unconventional approach to AIDS vaccine development that has recently entered the clinical phase. However, we have only a very limited understanding of the molecular mechanisms that render CMV the only vaccine vector capable of eliciting these unconventional responses to any antigen and that render lentivirus-infected cells vulnerable to T cell control. Our findings that MHC-E presents a wide variety of antigens is unexpected because MHC-E predominantly binds the nonameric VMAPRTL(L,I,V,F)L (VL9) self-peptide contained in the cleavable leader sequence of MHC-I. Here, our goal is to elucidate how MHC-E is loaded with diverse non-canonical peptides in uninfected cells or in cells infected with HIV or CMV in vitro and to identify the RhCMV-infected cells and molecular mechanisms required for the priming of MHC-E restricted CD8+ T cells in vivo. These objectives will be accomplished by an international team of investigators with relevant experience. Aim 1 is to use a unique set of MHC-E/peptide specific reagents to monitor MHC-E peptide loading and presentation by myeloid and HIV-infected cells upon inhibiting specific cellular proteins and pathways. Cellular targets will be selected from hits of preliminary CRISPR/cas9 screens or based on their known function in vesicular traffic or peptide loading of classical MHC molecules. In aim 2, we will investigate how the extensive reorganization of intracellular vesicular structures observed in CMV-infected cells contributes to the loading of MHC-E with non-canonical peptides. A particular emphasis will be on the role of viral microRNAs which redirect vesicular traffic by targeting vesicular sorting proteins and which seem to be required for MHC-E restricted T cell stimulation by CMV-infected cells. The role of viral microRNAs as well as selected host pathways for the induction of these T cells in vivo will be examined in aim 3. This will be accomplished by generating recombinant RhCMV lacking microRNAs or expressing host gene-targeting small hairpin RNAs. Since recent results suggest that priming of MHC-E restricted T cells requires infection of myeloid cells expressing micro-RNA142, we will identify the infected cell type and characterize neighboring T cells by combining sophisticated imaging and spatial transcriptomic techniques. We expect that the results of this research will impact basic and translational immunology including the design of novel vaccines and immunotherapeutics.

项目概要 在开发巨细胞病毒（CMV）作为新疫苗平台以引发效应分化的过程中 T细胞免疫，我们观察到恒河猴巨细胞病毒（RhCMV）表达猿猴免疫缺陷（SIV）抗原 引发控制并最终清除高致病性 SIV 的免疫反应。但令人惊讶的是，保护 仅在转基因载体中观察到诱导 CD8+ T 细胞受到非多态性、高度 保守的 MHC-E 而不是经典的 MHC-I。因此，针对 HLA-E 呈递的 HIV 肽代表了一种 一种新颖的、意想不到的、非传统的艾滋病疫苗开发方法，最近已进入 临床阶段。然而，我们对导致这种现象的分子机制了解非常有限。 CMV 是唯一能够对任何抗原引发这些非常规反应的疫苗载体 慢病毒感染的细胞易受 T 细胞控制。我们发现 MHC-E 呈递多种抗原 出乎意料的是，MHC-E 主要结合非单体 VMAPRTL(L,I,V,F)L (VL9) 自肽 包含在 MHC-I 的可切割前导序列中。在这里，我们的目标是阐明 MHC-E 是如何加载的 体外未感染细胞或感染 HIV 或 CMV 的细胞中的多种非典型肽，并鉴定 RhCMV 感染的细胞和 MHC-E 限制性 CD8+ T 细胞启动所需的分子机制 体内。这些目标将由具有​​相关经验的国际研究团队来实现。 目标 1 是使用一套独特的 MHC-E/肽特异性试剂来监测 MHC-E 肽负载和 骨髓细胞和 HIV 感染细胞在抑制特定细胞蛋白和途径后呈现。蜂窝网络 靶标将从初步 CRISPR/cas9 筛选的命中中或根据其已知功能进行选择 经典 MHC 分子的囊泡运输或肽负载。在目标 2 中，我们将研究如何广泛 在 CMV 感染的细胞中观察到的细胞内囊泡结构的重组有助于负载 MHC-E 与非规范肽。特别强调的是病毒 microRNA 的作用，它可以重定向 通过靶向囊泡分选蛋白来实现囊泡运输，这似乎是 MHC-E 限制性 T 细胞所必需的 CMV 感染细胞的刺激。病毒 microRNA 的作用以及选定的宿主诱导途径 这些 T 细胞在体内的数量将在目标 3 中进行检查。这将通过生成重组 RhCMV 来实现 缺乏 microRNA 或表达靶向宿主基因的小发夹 RNA。由于最近的结果表明 MHC-E 限制性 T 细胞的启动需要感染表达 micro-RNA142 的骨髓细胞，我们将鉴定 通过结合复杂的成像和空间分析来识别受感染的细胞类型并表征邻近的 T 细胞 转录组技术。我们预计这项研究的结果将影响基础和转化 免疫学，包括新型疫苗和免疫疗法的设计。