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

研究天然和工程卷曲纤维在介导与 肠上皮 摘要 微生物组在维持肠道功能方面的重要性推动了对微生物的研究。 抗生素和益生菌，试图确定具有治疗潜力的菌株。一 开发可行的治疗剂的常见策略是使用天然存在的微生物或 确定一种特定的分子试剂，导致所需的效果，并使其成为一种药物。而 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， 机制，无法合理地操纵肠道环境中的生物体适应性，以及 交付机制不足。我们提出了另一种方法来影响主机 生理过程集中在工程化的基质蛋白产生的细菌在 宿主殖民具体而言，该提案将确定自然发生的作用， 工程卷曲纤维介导肠道内的炎症过程。卷曲纤维， 是E.大肠杆菌生物膜，已经在 致病菌株的背景，因为它们能够介导对宿主组织的粘附， 刺激炎性细胞因子产生。然而，最近的证据表明， 还可以通过增加屏障功能来发挥保护作用。有趣的是，益生菌E.杆菌 菌株（Nissle），通常用于帮助维持炎症性肠病的缓解 (IBD)患者，也已知在体外产生大量卷曲纤维。我们将利用基因 尼氏工程菌株，以确定卷曲纤维在介导 肠道的炎症过程。与此同时，我们将创造出 在卷曲纤维上展示抗炎细胞因子。这些的功效 将使用体外和体内的组合来测量各种遗传改变的尼氏菌株。 体内模型系统。值得注意的是，我们将利用我们开发的肠道芯片系统， 合作者深入了解卷曲纤维上皮相互作用的分子机制。 该系统使得能够研究更高级的上皮功能，如屏障功能、绒毛功能和细胞功能。 高度和粘附性，比常规的transwell测定法好得多。我们建议的工作与 该系统还将有助于验证其作为益生菌的快速筛选技术。组合 通过建立慢性肠道炎症的小鼠模型，这些模型系统将促进 有效鉴定和开发具有治疗慢性 肠道炎症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 蛋白质可以是用于治疗递送和益生菌靶向的通用新平台。

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.