Delineating the non-conventional MHC class I and class II peptidome of influenza

描述流感的非传统 MHC I 类和 II 类肽组

基本信息

批准号：
10041955
负责人：
Laurence Crane Eisenlohr
金额：
$ 26.67万
依托单位：
CHILDREN'S HOSP OF PHILADELPHIA
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-06-01 至 2022-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10041955
关键词：
Antigen-Presenting Cells Antigens Autoantigens Autoimmune Diseases Biological Assay CD4 Positive T Lymphocytes CD8-Positive T-Lymphocytes CD8B1 gene Cell physiology Cells Cellular biology Codon Nucleotides Collaborations Communicable Diseases Complex Coupled Data Databases Development Endoplasmic Reticulum Degradation Pathway Epitope Mapping Epitopes Extracellular Space Flow Cytometry Frequencies Future Gene Expression Genetic Transcription Genome Goals Histocompatibility Antigens Class II Host Defense Immune Immune system Immunity In Vitro Infection Infectious Agent Influenza Investigation Light Liquid Chromatography MHC Class I Genes Mainstreaming Major Histocompatibility Complex Malignant Neoplasms Mass Spectrum Analysis Mediating Methods Modeling Modification Mus Nature Oligonucleotides Outcome Peptides Peripheral Phosphorylation Post-Translational Protein Processing Prevalence Production Proteins Proteome Publications Publishing RNA RNA Processing RNA Splicing Reading Frames Research Ribosomal Frameshifting Site-Directed Mutagenesis Surface Antigens System T cell response T-Cell Activation T-Lymphocyte Techniques Terminator Codon Testing Therapeutic Tissues Translating Translation Initiation Translations Tumor Antigens Work adaptive immune response antigen processing cytokine flu glycosylation immunogenicity interest mouse model multicatalytic endopeptidase complex pathogen polypeptide prophylactic response synthetic peptide tandem mass spectrometry virtual

项目摘要

PROJECT SUMMARY A cornerstone of adaptive immune responses to infectious agents, cancers and self-tissues is the activation of CD4+ and CD8+ T cells by antigen-derived peptides (epitopes) complexed with Major Histocompatibility Complex class II and class I molecules (MHC-II and -I), respectively. Accordingly, identification of T cell-activating peptides is frequently a critical step in the development of rational prophylactic and therapeutic strategies. Most methods for identification are guided by the prevailing view that peptides are excerpted from the products of conventional transcription, RNA processing and translation. However, we and other labs have demonstrated that MHC-I- and -II-bound peptides can be derived from a wide array of non-canonical mechanisms, including initiation of translation in an alternative reading frame, initiation at a non-AUG codon, co-translational frameshifting, and proteasome-mediated post-translational peptide splicing. Currently, non-conventional epitopes are of peripheral interest, perhaps because many fundamental questions concerning their significance remain unanswered. We do not understand: 1) the fraction of all presented peptides that are non-conventional, 2) whether all the mechanisms underlying non-canonical peptide production have been described, 3) the relative frequencies with which different mechanisms produce non-conventional epitopes, 4) the extent to which non-conventional epitopes drive T cell responses to infectious agents, cancers and self-antigens, and, 5) the prevalence of MHC- II-presented non-canonical peptides, most examples thus far being MHC-I-restricted. With respect to question 4, a recent publication and our preliminary data indicate that non-canonical peptides can drive strong, immunodominant T cell responses. With respect to question 5, the Eisenlohr lab has developed a model of MHC- II-restricted peptide production that is far more complex than generally envisioned. Thus, many of the mechanisms that produce MHC-I-restricted non-conventional epitopes should apply to MHC-II. Through a highly complementary collaboration between the Eisenlohr and Ternette labs, via cutting-edge mass spectrometry, well-developed immune recognition assays, and an array of methods to identify mechanisms underlying non- conventional epitope expression, we will test the hypothesis that both MHC-I and MHC-II non-canonical epitopes, produced by a variety of mechanisms, drive a substantial portion of the TCD8+ and TCD4+ responses to influenza. In addition to potentially uncovering new fundamental cell biology, outcomes could substantially alter the view of host defenses against a high priority infectious disease, pointing to new prophylactic and therapeutic strategies. In addition, we envision the work launching several lines of future investigation, including: 1) assessing the protective capacities of non-conventional epitope-specific T cells, 2) elucidating the antigen processing machinery that produces non-conventional epitopes, 3) identifying the determinants of immunodominance and functionality with respect to conventional vs non-conventional epitopes, and 4) carrying out similar analyses with other infectious agents, cancers and autoimmune diseases.

项目概要对传染源、癌症和自身组织的适应性免疫反应的基石是激活 CD4+ 和 CD8+ T 细胞由抗原衍生肽（表位）与主要组织相容性复合物复合而成分别为 II 类和 I 类分子（MHC-II 和 -I）。因此，T细胞激活肽的鉴定通常是制定合理的预防和治疗策略的关键步骤。大多数方法鉴定以普遍观点为指导，即肽是从常规产品中提取的转录、RNA 加工和翻译。然而，我们和其他实验室已经证明 MHC-I- 和 -II 结合肽可以源自多种非规范机制，包括启动在替代阅读框架中翻译、在非 AUG 密码子处起始、共翻译移码，以及蛋白酶体介导的翻译后肽剪接。目前，非常规表位是外周表位兴趣，也许是因为有关其重要性的许多基本问题仍未得到解答。我们不明白：1）所有呈现的非常规肽的比例，2）是否所有已经描述了非规范肽产生的机制，3）与哪些不同的机制产生非常规表位，4）非常规表位的程度表位驱动 T 细胞对传染源、癌症和自身抗原的反应，以及 5) MHC- 的流行 II 呈递的非经典肽，迄今为止大多数例子都是 MHC-I 限制性的。关于问题 4、最近的出版物和我们的初步数据表明，非规范肽可以驱动强大的、免疫显性 T 细胞反应。关于问题5，艾森洛尔实验室开发了一个MHC模型—— II 限制性肽的生产比通常想象的要复杂得多。因此，许多产生 MHC-I 限制性非常规表位的机制应适用于 MHC-II。通过一个高度 Eisenlohr 和 Ternette 实验室之间通过尖端质谱技术进行互补合作，成熟的免疫识别测定，以及一系列方法来识别非免疫机制常规表位表达，我们将测试 MHC-I 和 MHC-II 非规范表位的假设，由多种机制产生，驱动 TCD8+ 和 TCD4+ 对流感的大部分反应。除了有可能发现新的基础细胞生物学之外，结果还可能大大改变人们的观点宿主对高度优先的传染病的防御，指出了新的预防和治疗策略。此外，我们预计这项工作将启动多方面的未来调查，包括：1）评估非传统表位特异性 T 细胞的保护能力，2) 阐明抗原加工产生非常规表位的机器，3）识别免疫优势的决定因素和传统与非常规表位的功能，以及 4) 进行类似的分析其他传染源、癌症和自身免疫性疾病。