Host proteins that interact with the BCG cell envelope

与 BCG 细胞包膜相互作用的宿主蛋白

• 批准号: 10408860
• 负责人: Catherine Leimkuhler Grimes
• 金额: $ 21.83万
• 依托单位: UNIVERSITY OF MASSACHUSETTS AMHERST
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-05-20 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10408860
• 关键词: Acetylmuramyl-Alanyl-Isoglutamine; Address; Adjuvant; Adult; Affinity Chromatography; Alkynes; Azides; BCG Live; BCG Vaccine; Bacille Calmette-Guerin vaccination; Bacteria; Binding; Binding Proteins; COVID-19; COVID-19 mortality; Carbohydrate Chemistry; Cell Wall; Cells; Chemicals; Child; Collaborations; Communities; Complex; Copper; Cord Factors; Crosslinker; Data; Diazomethane; Disease; Epigenetic Process; Etiology; Freund' s Adjuvant; Genus Mycobacterium; Immunity; Immunologic Receptors; Immunologist; Infection; Innate Immune Response; Innate Immune System; Knowledge; Label; Lipids; Malignant neoplasm of urinary bladder; Membrane; Microbe; Modification; Molecular; Muramic Acid; Mycobacterium bovis; Mycobacterium smegmatis; Mycobacterium tuberculosis; Natural Immunity; Pathology; Pattern; Peptidoglycan; Persons; Physiological; Physiology; Polysaccharides; Proteins; Publishing; Pulmonary Tuberculosis; Randomized Controlled Trials; Reagent; Shapes; Testing; Training; Trehalose; Tuberculosis; Vaccines; Work; cancer therapy; cell envelope; cross immunity; crosslink; cycloaddition; epidemiology study; experimental study; head-to-head comparison; host-microbe interactions; in vivo; insight; macrophage; monocyte; mycobacterial; pathogen; receptor; tool

Project Summary The Mycobacterium bovis BCG vaccine has variable efficacy against adult pulmonary tuberculosis (TB) but protects children against both TB and unrelated infections and is used in bladder cancer treatment. Recent epidemiological studies have associated BCG vaccination with lowered COVID-19 mortality. While multiple, randomized controlled trials are now underway to test causality, molecular studies are urgently needed to address the proposed `trained [innate] immunity' mechanism of BCG cross-protection. Trained immunity may also contribute to BCG's specific protection against TB, a disease that afflicts 10 million people each year. The innate immune response to live mycobacteria or inactivated components (e.g. complete Freund's adjuvant [CFA]) has long thought to originate with the mycobacterial cell envelope, specifically the muramic acid moiety of cell wall peptidoglycan and trehalose dimycolates (TDM) in the outer `myco' membrane. During trained immunity, for example, epigenetic reprograming of monocytes depends on the innate immune receptor Nod2. Nod2, in turn, is potently stimulated by the N-glycolyl muramic acid found in mycobacteria and their relatives. Determining how fragments of the BCG envelope interact with the innate immune system may enhance our understanding of both heterologous and TB-specific protection. The molecular identities of the fragments recognized in vivo are unknown and the list of mammalian binding partners is likely incomplete. We will address these long-standing questions by synthesizing, validating and deploying clickable photoaffinity probes that either mimic envelope fragments or that incorporate into the peptidoglycan or TDM of live BCG. In proof- of-concept experiments, we will identify host proteins that interact with BCG peptidoglycan and TDM. Probes that label the envelope of live bacteria will permit host delivery of microbe-associated molecular patterns (MAMPs) in a more physiologically-relevant context. In parallel, synthesis of functionalized peptidoglycan fragments and TDM will allow head-to-head comparison of host proteins that interact with synthesized or purified MAMPs and those that interact with MAMPs released by live bacteria during infection. These experiments will reveal the earliest host–BCG interactions that may shape protection against TB and unrelated pathologies like COVID-19. Further, they will provide enabling tools to the community for studying the innate immune response to non-protein adjuvants, vaccines, and pathogens. Our approach is extendable to other glycan- and lipid-containing MAMPs (e.g., LPS).

项目摘要 牛分枝杆菌BCG疫苗对成人肺结核（TB）具有可变的效率，但 保护儿童免受结核病和无关的感染，并用于膀胱癌治疗。最近的 流行病学研究已将BCG疫苗接种与降低的COVID死亡率相关联。而多个， 现在正在进行随机对照试验以测试因果关系，迫切需要分子研究 探讨拟议的“训练有素的[先天性]免疫力” BCG交叉保护机制。受过训练的免疫力可能 还为BCG针对结核病的特定保护做出了贡献，该疾病每年遭受1000万人的困扰。这 对活分枝杆菌或灭活成分的先天免疫反应 [CFA]）长期以来一直认为源自分枝杆菌细胞包膜，特别是穆拉米亚酸部分 外部“迈科”膜中的细胞壁胡椒糖和海藻糖二聚体（TDM）。在训练期间 免疫力，例如，单核细胞的表观遗传重编程取决于先天免疫受体NOD2。 反过来，NOD2可能会受到分枝杆菌及其亲戚中的N-糖基穆拉米酸的刺激。 确定BCG信封的碎片如何与先天免疫系统相互作用可以增强我们 了解异源和特异性保护。碎片的分子身份 公认的体内未知，哺乳动物结合伴侣的清单可能不完整。我们将 通过综合，验证和部署可点击的光性问题来解决这些长期存在的问题 该模仿包络片段，或将其包含在实时BCG的PepperyDoglycan或TDM中。在证明中 - 概念实验，我们将确定与BCG辣椒糖和TDM相互作用的宿主蛋白。探针 标记活细菌的信封将允许宿主递送微生物相关的分子模式 （MAMP）在更相关的环境中。同时，功能化的辣椒合成 片段和TDM将允许与合成或合成的宿主蛋白进行正面比较 纯化的MAMP和与感染过程中活细菌释放的哺乳动物相互作用的哺乳动物。这些 实验将揭示最早的主机-BCG相互作用，这些相互作用可能会影响针对结核病和无关的保护 诸如Covid-19的病理。此外，他们将为社区提供有利的工具来研究先天 对非蛋白质佐剂，疫苗和病原体的免疫反应。我们的方法扩展到其他 含脂质的哺乳动物（例如LPS）。