Human Gastrointestinal Biomimetics for Enteric Bacterial Infections

项目摘要-项目3 肠粘膜表面是一个复杂的机械生理环境，由病原体、 共生、共生、共主。因为这种复杂性可能会影响我们对疾病病因的理解，所以 对于开发准确捕捉其生理过程的模型系统至关重要。人类肠道有机化合物(HIO) 已被提议作为一种粘膜仿生剂来研究由肠道病原体引起的传染病。我们的 以前资助的项目(NIAID U19 NAMSED倡议的一部分)确立了HIO的使用，以了解 肠聚集性大肠杆菌(EAEC)是儿童持续性腹泻的常见原因，其发病机制 免疫功能受损，还有旅行者。目前还没有针对EAEC的疫苗，抗生素治疗也因 多药耐药，保护共生体的消融，以及报告的在减少腹泻方面的无效 持续时间。我们研究的一个开创性发现是意想不到的观察到对EAEC的易感性 感染在很大程度上取决于宿主捐赠者，特别是在新数据表明 EAEC的粘膜受体是硫酸乙酰肝素蛋白多糖(HSPG)。此次更新的工作建立在此基础上 通过现在的假设观察到EAEC特异性的黏附驱动了分泌物的局部递送 肠道上皮细胞病变的影响因素。在目标1中，一大批重债穷国的特点是 对EAEC感染的敏感性和与供体状态相关的分子发病标志 HSPG。在目标2中，关键的肠道机械生理特性，包括腔内血流，基底侧向僵硬， 评估免疫细胞的存在和节段连通性对HSPG依赖的EAEC的影响。 感染。最后，人类肠道微生物群(共生体和噬菌体)通过竞争来对抗EAEC 将确定以葡聚糖为基础的肠道生态位。这项工作将揭示支配EAEC的宿主因素 对感染的敏感性，驱动感染的机械生理线索，以及有针对性的基于生物群的方法 既有对抗性又有治疗作用。

Project Summary – Project 3 The intestinal mucosal surface is a complex mechano-physiologic environment comprised of pathogen, commensal, and host. Because this complexity may affect our understanding of the etiology of disease, it is critical to develop model systems that accurately capture their physiology. Human intestinal organoids (HIOs) have been proposed as a mucosal biomimetic to study infectious diseases caused by enteric pathogens. Our previously funded project (part of the NIAID U19 NAMSED initiative) established the use of HIOs to understand the pathogenesis of Enteroaggregative E. coli (EAEC), a common cause of persistent diarrhea in children, the immunocompromised, and travelers. There is no vaccine for EAEC and antibiotic treatment is complicated by multi-drug resistance, the ablation of protective commensals, and reported ineffectiveness at reducing diarrheal duration. A seminal finding from our study was the unexpected observation that the susceptibility to EAEC infection was substantially dependent on the host donor, especially in the context of new data that suggests the mucosal receptor for EAEC is heparan-sulfated proteoglycan (HSPG). The work in this renewal builds upon this observation by now hypothesizing that EAEC donor-specific adherence drives the local delivery of secreted cytopathic effectors to the intestinal epithelium. In Aim 1, a large collection of HIOs are characterized for their sensitivity to EAEC infection and hallmark signatures of molecular pathogenesis correlated to the status of donor HSPGs. In Aim 2, key intestinal mechano-physiologic properties, including luminal flow, basolateral stiffness, the presence of immune cells, and segmental connectivity, are assessed for their effect on HSPG-dependent EAEC infection. Finally, human intestinal microbiota (commensals and phage) that antagonize EAEC by competing for a glycan-based intestinal niche will be identified. This work will reveal the host factors that govern EAEC susceptibility to infection, the mechano-physiologic cues that drive them, and targeted biota-based approaches that are antagonistic and therapeutic.