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).

项目概要 牛分枝杆菌 BCG 疫苗对成人肺结核 (TB) 具有不同的功效，但 保护儿童免受结核病和无关感染的侵害，并用于膀胱癌的治疗。最近的 流行病学研究表明，BCG 疫苗接种与降低 COVID-19 死亡率相关。虽然多个， 目前正在进行随机对照试验来测试因果关系，迫切需要进行分子研究 解决拟议的卡介苗交叉保护的“训练有素的[先天]免疫”机制。经过训练的免疫力可能 还有助于 BCG 对结核病（每年影响 1000 万人的疾病）提供特定保护。这 对活分枝杆菌或灭活成分（例如弗氏完全佐剂）的先天免疫反应 [CFA]）长期以来一直被认为起源于分枝杆菌细胞包膜，特别是胞壁酸部分 外“真菌”膜中的细胞壁肽聚糖和海藻糖二霉菌酸酯（TDM）。训练期间 例如，单核细胞的表观遗传重编程依赖于先天免疫受体Nod2。 反过来，Nod2 会受到分枝杆菌及其近亲中发现的 N-乙醇酰胞壁酸的强烈刺激。 确定 BCG 包膜片段如何与先天免疫系统相互作用可能会增强我们的免疫能力。 了解异源保护和结核病特异性保护。片段的分子身份 体内识别的未知，并且哺乳动物结合配偶体的列表可能不完整。我们将 通过合成、验证和部署可点击的光亲和探针来解决这些长期存在的问题 要么模仿包膜片段，要么融入活卡介苗的肽聚糖或 TDM 中。证明—— 在概念实验中，我们将鉴定与 BCG 肽聚糖和 TDM 相互作用的宿主蛋白。探头 标记活细菌的包膜将允许宿主传递微生物相关的分子模式 （MAMP）在更生理相关的背景下。同时，功能化肽聚糖的合成 片段和 TDM 将允许对与合成或相互作用的宿主蛋白进行头对头比较 纯化的 MAMP 以及与感染期间活细菌释放的 MAMP 相互作用的 MAMP。这些 实验将揭示最早的宿主与卡介苗的相互作用，这可能会形成针对结核病和不相关疾病的保护作用 像 COVID-19 这样的病症。此外，他们将为社区提供研究先天性的工具。 对非蛋白质佐剂、疫苗和病原体的免疫反应。我们的方法可以扩展到其他 含有聚糖和脂质的 MAMP（例如 LPS）。