Discovery of Potential Therapeutic Agents from Insect-Associated Symbiotic Bacter

描述(由申请人提供)：许多疾病缺乏有效的治疗方法，这突显了发现新药的必要性。天然产品是由有机体产生的化合物，作为药物使用的历史悠久。然而，来自传统来源的新天然产品，即放线菌细菌的回报递减，再加上重新发现的问题，必须在其他地方找到它们。这一建议涉及到从非传统来源--与昆虫共生的细菌--中寻找天然产物，并利用这些已发现的天然产物的分布和进化史数据在 其他系统。这项拟议的项目将在哈佛医学院生物化学和分子药理学系乔恩·克拉迪教授的实验室进行。就总体战略而言，该项目可分为三个目标。第一个是识别和优先考虑从昆虫农业系统中产生新的天然产品的细菌共生体。合作伙伴卡梅隆·柯里教授的实验室中不断扩大的昆虫相关放线杆菌收集将受到下一代测序的影响，以形成基因组草稿。利用生物合成基因簇查询这些基因簇，寻找具有已知活性的天然产物以找到类似物，并使用合作者Michael Fischbach教授的实验室开发的生物信息学软件进行彻底扫描，以发现许多其他生物合成簇，包括那些神秘的和/或非常新颖的簇。第二个具体目标涉及从优先的一组细菌共生体中分离和表征新的天然产物。这涉及到在各种条件下培养细菌，以诱导结构性表达和隐蔽的天然产物的表达，并使用差异代谢组学或生物测定指导的分级来鉴定它们的产物。分离的天然产物的结构将得到解决，治疗潜力将通过Clardy实验室的分析并与哈佛医学院朗伍德化学和细胞生物学研究所合作进行表征。第三个目标是确定新的生物活性天然产物的进化史和分布。生物信息学方法将被用来将天然产物与生物合成基因簇联系起来。这些簇将与放线菌范围内的其他簇进行比较，从而深入了解与昆虫相关的放线菌生态位内和之外的分布。这些集群的进化研究将通过遗传共性和系统发育分析来进行。分布和进化数据将有助于从其他放线杆菌和其他细菌门中识别类似物。进化数据将特别有助于追踪明显不同的相似之处。

DESCRIPTION (provided by applicant): The lack of effective treatments for many diseases underscores the need to discover new drugs. Natural products, which are chemical compounds produced by organisms, have had a rich history of being used as pharmaceutical drugs. However, diminishing returns of new natural products from traditional sources, namely actinomycete bacteria, compounded with the problem of rediscovery necessitates finding them elsewhere. This proposal involves prospecting for natural products from an unconventional source - bacteria in symbiosis with insects in eusocial agricultural systems, and using the distribution and evolutionary history data for these discovered natural products to find analogs in other systems. The proposed project will be carried out in Prof. Jon Clardy's laboratory in the Department of Biological Chemistry and Molecular Pharmacology at Harvard Medical School. In regards to the overall strategy, the project can be split into three objectives. The first is to identify and prioritize bacterial symbionts from insect agricultural systems that produce novel natural products. The expanding insect-associated actinobacteria collection in collaborator Prof. Cameron Currie's lab will be subjected to next generation sequencing to form draft genomes. These will be queried with biosynthetic gene clusters for natural products with known activity to find analogs, and scanned thoroughly using bioinformatics software developed in collaborator Prof. Michael Fischbach's laboratory to unearth many other biosynthetic clusters, including those that are cryptic and/or very novel. The second specific aim involves the isolation and characterization of new natural products from the prioritized set of bacterial symbionts. This involves growing bacteria under various conditions to elicit expression of constitutively-expressed and cryptic natural products, and identifying their production using differential metabolomics or bioassay-guided fractionation. The structures of the isolated natural products will be solved, and therapeutic potential will be characterized through assays in the Clardy lab and in conjunction with the Institute of Chemistry and Cell Biology - Longwood at Harvard Medical School. The third aim is ascertaining the evolutionary history and distribution of the novel bioactive natural products. Bioinformatics methods will be used to link the natural products back to the biosynthetic gene cluster. These clusters will be compared to others in the span of actinobacteria, giving insight into distribution within the insect-associated actinobacteria niche and beyond. Evolutionary studies of the clusters will be performed through genetic synteny and phylogenetic analysis. The distribution and evolutionary data will allow for identification of analogs from other actinobacteria and other bacterial phyla. The evolutionary data will especially help in tracking down markedly different analogs.