Investigating the role of natural and engineered curli fibers in mediating interactions with the gut epithelium

研究天然卷曲纤维和工程卷曲纤维在调节与 肠道上皮 摘要 微生物群在维持肠道功能方面的重要性推动了对 共生菌和益生菌，试图鉴定具有治疗潜力的菌株。一个 开发可行疗法的常见策略是使用自然产生的微生物或 确定一种能产生预期效果的特定分子制剂，并将其制成药物。而当 这种方法已经取得了一些成功，但由于缺乏对生物学的了解而受到阻碍 机制，无法在肠道环境中合理地操纵组织的适应性，以及 交付机制不完善。我们提出了一种影响主持人的替代方法 生理过程集中在工程细菌产生的基质蛋白在 寄主殖民。具体地说，这项提案将确定自然发生和 工程化卷曲纤维在肠道内调节炎症过程。卷曲纤维，它 是大肠杆菌生物膜中的一种蛋白质成分，在 病原菌的背景，因为它们有能力调节与宿主组织的黏附和 刺激炎性细胞因子的产生。然而，最近的证据表明，这些纤维 也可能通过增加屏障功能起到保护作用。有趣的是，一种益生菌大肠杆菌 通常用于帮助炎症性肠病缓解的菌株(Nissle) (IBD)患者在体外也能产生丰富的卷曲纤维。我们将在基因上使用 尼斯勒的工程菌株，以确定卷曲纤维在多大程度上发挥中介作用 肠道内的炎症过程。同时，我们将创造尼斯勒菌株，这些菌株 在其卷曲纤维上展示抗炎细胞因子。这些药物的功效 各种基因改变的尼斯勒菌株将使用体外和体外相结合的方法进行测量。 活体模型系统。值得注意的是，我们将使用由我们的 合作者深入了解卷曲纤维与上皮细胞相互作用的分子机制。 该系统能够研究更高级的上皮功能，如屏障功能、绒毛 高度和粘附性，比传统的Transwell测试要好得多。我们建议的工作是 该系统还将有助于验证其作为益生菌快速筛选技术的有效性。结合在一起 随着慢性肠炎小鼠模型的建立，这些模型系统将促进 治疗慢性阻塞性肺疾病的有效微生物的鉴定与开发 肠道发炎。这也是我们实验室建立生物膜基质的更广泛努力的一部分 蛋白质可以成为治疗输送和益生菌靶向的多功能新平台。

Investigating the role of natural and engineered curli fibers in mediating interactions with the gut epithelium Abstract The importance of the microbiome in maintaining gut function has fueled the study of commensals and probiotics in an attempt to identify strains with therapeutic potential. A common strategy to develop viable therapeutics is then to use the naturally occurring microbe or identify a specific molecular agent that leads to the desired effect and make it into a drug. While this approach has seen some success, it is hindered by a lack of understanding of biological mechanisms, an inability to rationally manipulate organismal fitness in the gut environment, and inadequate delivery mechanisms. We propose an alternative approach to influencing host physiological processes focused on engineering the matrix proteins produced by bacteria during host colonization. Specifically, this proposal will determine the role of naturally occurring and engineered curli fibers in mediating inflammatory processes inside the gut. Curli fibers, which are a proteinaceous component of the E. coli biofilm, have been studied extensively in the context of pathogenic strains because of their ability to mediate adhesion to host tissues and stimulate inflammatory cytokine production. However, recent evidence suggests that the fibers may also play a protective role by increasing barrier function. Interestingly, a probiotic E. coli strain (Nissle) that is commonly used to help maintain remission in inflammatory bowel disease (IBD) patients, is also known to produce copious curli fibers in vitro. We will use genetically engineered strains of Nissle to determine to what extent curli fibers play a role in mediating inflammatory processes in the gut. Simultaneously, we will create Nissle strains that are engineered to display anti-inflammatory cytokines on their curli fibers. The efficacy of these various genetically altered Nissle strains will be measured using a combination of in vitro and in vivo model systems. Notably, we will make use of a Gut-on-a-Chip system developed by our collaborators to gain insight into the molecular mechanisms of curli fiber-epithelium interactions. This system enables the study of higher-order epithelial functions, like barrier function, villus height, and adhesion, much better than conventional transwell assays. Our proposed work with this system will also help validate it as a rapid screening technique for probiotics. In combination with established mouse models of chronic gut inflammation, these model systems will facilitate efficient identification and development of microbes with therapeutic potential against chronic gut inflammation. This is also part of a broader effort in our lab to establish that biofilm matrix proteins can be a versatile new platform for therapeutic delivery and probiotic targeting.