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.

项目摘要 在开发巨细胞病毒（CMV）的过程中 T细胞免疫，我们观察到表达猿猴免疫缺陷（SIV）抗原的恒河猴CMV（RHCMV） 引起控制并最终清除高度致病性SIV的免疫反应。令人惊讶的是，保护 仅在引起非晶状体限制的CD8+ T细胞的转基因载体中观察到 保守的MHC-E而不是经典的MHC-I。因此，靶向HLA-E呈现的HIV肽代表A 新的，意外的和非常规的方法来艾滋病疫苗开发，最近进入了 临床阶段。但是，我们对渲染的分子机制只有非常有限的理解 CMV是唯一能够引起对任何抗原的非常规反应的疫苗向量 慢病毒感染的细胞容易受到T细胞控制。我们的发现MHC-E提出了多种抗原 之所以出乎意料，是因为MHC-E主要结合非陆战VMAPRTL（L，I，V，F）L（VL9）自肽 包含在MHC-I的可切合领导者序列中。在这里，我们的目标是阐明如何加载MHC-E 在未感染的细胞中或在体外感染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​​相关经验的国际调查员团队实现。 AIM 1是使用一组独特的MHC-E/肽特定试剂监测MHC-E肽加载和 在抑制特定的细胞蛋白和途径的情况下，由髓样和HIV感染的细胞呈现。细胞 目标将从初步CRISPR/CAS9屏幕的命中选择或基于其已知功能 经典MHC分子的囊泡流量或肽负载。在AIM 2中，我们将研究如何广泛 在CMV感染细胞中观察到的细胞内囊泡结构的重组有助于加载 MHC-E具有非典型肽。重定向的病毒microRNA的作用将特别强调 囊泡流量通过靶向囊泡分选蛋白，而MHC-E限制的T细胞似乎需要 CMV感染的细胞刺激。病毒microRNA和选定的宿主途径的作用 在AIM 3中将检查这些T细胞的体内。这将通过产生重组RHCMV来完成 缺少microRNA或表达宿主基因靶向小发夹RNA。由于最近的结果表明 MHC-E限制的T细胞的启动需要感染表达微RNA142的髓样细胞，我们将确定 感染的细胞类型并通过组合复杂的成像和空间来表征相邻的T细胞 转录组技术。我们预计这项研究的结果将影响基本和翻译 免疫学，包括新型疫苗和免疫疗法的设计。