Human Gastrointestinal Biomimetics for Enteric Bacterial Infections

项目概要-项目3 肠粘膜表面是一个复杂的机械生理环境， 主持人，主持人。因为这种复杂性可能会影响我们对疾病病因的理解， 对于开发准确捕捉其生理机能的模型系统至关重要。人类肠道类器官（HIO） 已经提出作为粘膜仿生物来研究由肠道病原体引起的感染性疾病。我们 以前资助的项目（NIAID U19 NAMSED倡议的一部分）建立了使用HIO来了解 肠聚集性大肠杆菌的发病机制。大肠杆菌（EAEC），一个常见的原因，持续腹泻的儿童， 免疫力低下者和旅行者目前还没有针对EAEC的疫苗，抗生素治疗也很复杂， 多药耐药性，保护性组织的消融，以及报告的减少结肠炎的无效性 持续时间我们研究的一个开创性发现是， 感染在很大程度上取决于宿主供体，特别是在新的数据表明， EAEC的粘膜受体是硫酸乙酰肝素蛋白聚糖（HSPG）。这次复兴的工作建立在这一基础上 通过现在假设EAEC供体特异性粘附驱动局部递送分泌的 对肠上皮细胞的致细胞病变效应物。在目标1中，大量HIO的特征在于其 对EAEC感染的敏感性和与供体状态相关的分子发病机制的标志性特征 HSPGs。在目标2中，关键的肠道机械生理特性，包括管腔流动、基底外侧刚度、 评估免疫细胞的存在和节段连接对HSPG依赖性EAEC的影响 感染最后，人类肠道微生物群（噬菌体和噬菌体）通过竞争EAEC而拮抗EAEC。 将鉴定基于聚糖的肠生态位。这项工作将揭示宿主因素，支配EAEC 对感染的易感性，驱动它们的机械生理学线索，以及基于生物群的靶向方法 既有对抗性又有治疗性。

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.