Mechanistic characterization of vaginal microbiome-metabolome associations and metabolite-mediated host inflammation

项目总结/摘要 阴道微生物组与重要的健康结果相关，包括细菌性阴道病（BV）， 早产、艾滋病风险和宫颈癌，但这些关联的机制目前尚不清楚， 针对微生物组的治疗具有低功效。代谢组改变，包括高水平产生 胺如腐胺是BV的定义特征，也是症状的主要原因， 并且宿主对BV相关代谢物（包括胺）的反应的特征很差。初步数据显示 在南非BV高患病率队列中，阴道液中60%的可检测代谢物显著高于 在最佳乳酸杆菌优势细菌群落和非最佳非乳酸杆菌优势细菌群落之间存在差异， 占主导地位的（NLD）社区。强BV和NLD相关代谢物包括腐胺和咪唑 丙酸盐（ImP），已知这两种物质在非阴道疾病中具有不良宿主作用，但其 生殖道中的产生和影响在很大程度上仍不清楚。这些结果表明细菌 包括NLD群落的蛋白质表达产生这些代谢物的酶。本研究将（1）描述 代谢组和宏基因组组成，以验证发现并确定候选 用于腐胺和ImP生产的酶，（2）表征培养的阴道细菌中的酶， 评估已知药理学抑制剂的作用，和（3）评估腐胺和ImP对代谢的影响 和炎性宿主反应，并测试它们是否可以被已知的宿主途径抑制剂阻断。的 结果将阐明阴道代谢组相关的病理生理学，并可直接鉴定候选疗法。 PI是哈佛医学院的医学讲师， 马萨诸塞州总医院（MGH）;除了研究计划外，该提案还包括五年的职业生涯 发展规划他的职业目标是成为一名独立的医生科学家研究员， 阴道微生物组和代谢组介导的疾病的机制，通过细菌学，生物化学， 免疫学方法来鉴定新的疗法。该提案建立在PI先前的学习经验基础上 阴道微生物组动力学和研究微生物组内细菌物种的生理学。的 目前的提议通过研究阴道炎的微生物决定因素， 代谢物组组成，鉴定这些代谢物影响的宿主途径，并测试途径抑制剂。他 将在他的主要导师道格·权博士的指导下进行这项研究，道格·权博士在拉根研究所工作， 麻省理工学院、麻省理工学院和哈佛大学以及他的共同导师，哈佛大学化学系的艾米丽Balskus博士 和化学生物学。他将追求教学课程，并接受培训，指导和合作，从 多元化的专家团队。建议的培训为PI提供了独特的技能和丰富的初始数据 帮助他过渡到独立研究

Project Summary/Abstract The vaginal microbiome is associated with important health outcomes, including bacterial vaginosis (BV), preterm birth, HIV risk, and cervical cancer, but mechanisms for these associations are unclear and current microbiome-directed therapies have low efficacy. Metabolome alterations including high-level production of amines like putrescine are a defining feature of BV and a major cause of symptoms, but underlying mechanisms and host responses to BV-associated metabolites including amines are poorly characterized. In preliminary data from a South African cohort with high BV prevalence, 60% of detectable metabolites in vaginal fluid significantly differ between optimal Lactobacillus-dominant bacterial communities and non-optimal non-Lactobacillus- dominant (NLD) communities. Strongly BV- and NLD-associated metabolites included putrescine and imidazole propionate (ImP), both of which are known to have adverse host effects in non-vaginal diseases but whose production and effects remain largely uncharacterized in the genital tract. These results suggest bacteria comprising NLD communities express enzymes that produce these metabolites. The study will (1) characterize metabolome and metagenome composition in additional cohorts to validate findings and identify candidate enzymes for putrescine and ImP production, (2) characterize the enzymes in cultured vaginal bacteria and assess effects of known pharmacologic inhibitors, and (3) assess effects of putrescine and ImP on metabolic and inflammatory host responses and test whether they can be blocked by known host pathway inhibitors. The results will elucidate vaginal metabolome-related pathophysiology and may directly identify candidate therapies. The PI is an Instructor in Medicine at Harvard Medical School and the Division of Infectious Diseases at Massachusetts General Hospital (MGH); in addition to the research plan this proposal includes a five-year career development plan. His career goal is to become an independent physician-scientist investigator studying mechanisms of vaginal microbiome- and metabolome-mediated disease through bacteriologic, biochemical, and immunologic approaches to identify novel therapies. The proposal builds on the PI’s prior experience studying vaginal microbiome dynamics and investigating the physiology of bacterial species within the microbiome. The current proposal significantly expands his scientific scope by investigating microbial determinants of vaginal metabolome composition, identifying host pathways those metabolites affect, and testing pathway inhibitors. He will pursue this research under the guidance of his primary mentor, Dr. Doug Kwon, at the Ragon Institute of MGH, MIT and Harvard and his co-mentor, Dr. Emily Balskus, at the Harvard University Department of Chemistry and Chemical Biology. He will pursue didactic coursework and receive training, guidance, and collaboration from a diverse team of experts. The proposed training provides the PI with a unique skillset and wealth of initial data to facilitate his transition to research independence.