Mechanistic investigation of differential T cell responses to distinct Mycobacterium tuberculosis antigens

T 细胞对不同结核分枝杆菌抗原的差异反应的机制研究

• 批准号: 10536054
• 负责人: Zachary Howard
• 金额: $ 4.26万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10536054
• 关键词: Adoptive Transfer; Animal Model; Antigen Targeting; Antigenic Variation; Antigens; BCG Live; Bacteria; CD4 Positive T Lymphocytes; Cessation of life; Clinical; Clinical Trials; DNA Vaccines; Data; Development; Disease; Drug resistance; Epidemiology; Exhibits; Flow Cytometry; Genes; Genome; Goals; Human; Immune; Immune Evasion; Immune response; Immunofluorescence Microscopy; Immunohistochemistry; Individual; Infection; Infection prevention; Inflammation; Inflammatory; Investigation; Laboratories; Lead; Lung; Lymphoid; Mediating; Mediator of activation protein; Mus; Mutation; Mycobacterium tuberculosis; Mycobacterium tuberculosis antigens; Myelogenous; Peptide/MHC Complex; Phenotype; Phylogenetic Analysis; Population; Pulmonary Inflammation; Pulmonary Tuberculosis; Role; T cell receptor repertoire sequencing; T cell response; T-Lymphocyte; T-Lymphocyte Epitopes; T-Lymphocyte Subsets; Testing; Tuberculosis; Tuberculosis Vaccines; Vaccinated; Vaccination; Vaccine Antigen; Vaccines; Variant; Work; antigen challenge; antigen-specific T cells; coronavirus disease; disorder prevention; effector T cell; genome analysis; global health; human model; immunopathology; immunoregulation; improved; novel; pathogen; pressure; prevent; response; single-cell RNA sequencing; transmission process; vaccine development; vaccine response

Abstract Tuberculosis (TB) is a major global health threat and the only licensed TB vaccine, Bacille Calmette-Guérin (BCG), is inadequate: despite widespread use of BCG, there were 9.9 million new TB cases globally in 2020. Thus, improved vaccines against Mtb are urgently needed. T cell responses remain the primary goal of TB vaccines, as CD4 T cells are necessary to control Mtb in humans and animal models. T cell vaccines have been thus far unsuccessful in preventing infection, but the recent clinical trial of M72-AS01E demonstrated ~50% efficacy as a Prevention of Disease (POD) vaccine. Since TB is transmitted by those with active disease, which is characterized by inflammation and immunopathology, a vaccine that reduces or prevents active disease and immunopathology can have a large impact on the global problem of TB. However, the most optimal antigen target(s) for TB vaccines are not defined, and the lack of evolutionary variation in the known antigens of Mtb suggests that T cell recognition of those antigens is not detrimental to the pathogen or beneficial to the host. Through a comprehensive analysis of genomes from 216 phylogenetically diverse Mtb, my advisor and his colleagues discovered a distinct subset of Mtb antigens that are sequence variable and exhibit evidence of evolutionary selection pressure. In a screen of DNA vaccines encoding these sequence variable antigens, I discovered one (encoding 4 sequence variable antigens) that alters immunopathology and inflammatory Th1 responses in mice subsequently challenged with Mtb, without reducing lung bacterial burdens. Additional studies in our laboratory have demonstrated distinct CD4 T cell effector responses to these same antigens in humans. From these and other results, we hypothesize that a functionally distinct T cell response to one or more of our vaccine antigens is responsible for altered immunopathology in vaccinated mice after challenge. The objective of this proposal is to characterize the cellular responses in vaccinated mice after challenge and identify the mechanism that accounts for altered immunopathology. I will characterize the cellular response using spectral flow cytometry and immunofluorescence microscopy. I will then characterize the vaccine-specific T cell response using peptide:MHC tetramers and single cell RNA sequencing to identify potential mechanisms mediating the altered immunopathology response. Finally, I will identify the underlying mechanism(s) by performing adoptive transfers of sorted T cells to identify the phenotype of the T cells that alter immunopathology during infection. This work will identify differential T cell responses to distinct Mtb antigens and demonstrate a role of immunoregulation in mediating a vaccine response to Mtb infection. The findings will provide an understanding of T cell responses to Mtb antigens that can modulate immunopathology. This will provide a framework of vaccine-induced immunoregulatory responses to inform development of POD vaccines for Mtb.

抽象的 结核病（TB）是主要的全球健康线索，也是唯一获得许可的结核病疫苗 （BCG），不足：尽管BCG广泛使用，但2020年全球有990万例新结核病病例。 因此，需要改善针对MTB的疫苗。 疫苗，因为CD4 T细胞是控制人类和动物模型中MTB的必要条件。 到目前为止，在积极感染中未能成功，但最近的M72-AS01E临床试验显示约50％ 作为疾病预防（POD）疫苗的功效。 以炎症和免疫病理学为特征 免疫病理学可能会对全球性结核病产生很大的影响。 未定义TB疫苗的靶标，并且MTB的已知抗原缺乏进化变化 表明TCELL告诉认知这些抗原并不有害于病原体或对宿主有益。 通过对216个系统疾病多样化MTB的基因组的全面分析，我的顾问及其他的顾问 同事们发现了一个不同的MTB抗原子集，这些抗原是可变的，并有证据表明 在编码序列可变的DNA疫苗屏幕中的进化选择压力 发现了一种（编码4个序列变量抗原），可以改变免疫病理学和炎症Th1 小鼠的反应随后对MTB提出了挑战，而无需减轻肺部的额外研究 在我们的实验室中，已经显示出对人类中相同相同抗原的不同CD4 T细胞效应子的反应。 从这些结果和其他结果中，我们假设功能性的独特的t对我们的ORMORE的反应 挑战后，疫苗抗原负责疫苗接种的免疫病理 该提议的表征是在挑战后表征接种小鼠的细胞反应，并确定您 解释免疫病理学改变的机制。 流式细胞仪和免疫荧光显微镜。 使用肽：MHC四聚体和单细胞RNA测序来识别介导您的潜在机制 改变了免疫病理学的反应。 在感染过程中分类对免疫病理学的转移。 这项工作将使T细胞对不同的MTB抗原的反应，并证明 介导对MTB感染的疫苗反应中的免疫调节。 T细胞对MTB抗原的反应可以模块化。 疫苗诱导的免疫调节反应为MTB的POD疫苗开发提供了信息。