Harnessing Induced Human Intestinal Organoids (iHIOs) and Metagenomics to Unravel Host Immune-microbiota Interactions During Cancer Chemotherapy-associated Clostridium difficile Infections

癌症化疗相关的艰难梭菌感染（CDI）对 癌症患者的治疗结果。导致治疗中断和/或剂量强度降低， 对肿瘤消退的灾难性影响。不幸的是，降低癌症患者CDI发病率的努力 由于对CDI病理生理学的了解有限以及现有技术的表现不佳， 预测因子，特别是在细胞减少性癌症化疗（CCC）治疗的患者。直到更可靠 识别CCC患者中CDI的预测因子并理解CDI发展的基础科学， 减少发病率和改进治疗战略的努力仍然不够。本研究的目的是 建议的重点是预防CCC治疗患者的CDI，同时为Dr. Apewokin转变为一名独立的医生科学家，专注于癌症支持性护理。 正常宿主对胃肠道感染的保护作用是由许多过程介导的。 免疫球蛋白提供体液保护，而内源性肠道微生物群落结构有利于 对病原微生物定植的抗性。我们已经在初步研究中证明， 癌症化疗改变了这些因素，并导致CDI特异性免疫球蛋白和肠 微生物多样性我们提出了一个概念模型的CCC相关的CDI，捕捉这些过程， 因此，我假设CCC诱导的CD特异性体液保护和微生物多样性的丧失 将CD定植转化为感染。为了测试这个概念模型，我们将建立AIM #1， 发生CDI（例）的CCC患者具有较低的CD特异性体液保护。在AIM #2中，CCC患者 发生CDI的患者（病例）的肠道微生物多样性较低，而发生CDI的CCC患者（AIM#3） 在CCC期间经历现有CD生物的克隆扩增。我们将进行一项病例对照研究， CDI阳性病例和16例CDI阴性对照。我们将使用宏基因组学和诱导人类肠道 类器官模型（iHIO）作为模型系统来询问CCC患者中的CDI发展。iHIOs 概括人体生理学和疾病病理学，并纳入对疾病至关重要的成分， 人类宿主的反应我们还将采用鸟枪测序来评估微生物因素， CCC期间的CDI。将这些最先进的方法与协作协同研究相结合 方法将使我们能够描述CDI的病理生理学特征，并阐明不能被诊断的机制。 通过传统方法和模型进行。1）蛋白质毒素生物学和定量技术培训， 2)分子生物学和宏基因组学，3）生物统计学和免疫遗传学，以及4）临床试验设计将 作为Apewokin博士过渡到成为一名独立的医生科学家的工具， 外部R类奖项。一个由互补的知名专家组成的指导团队-A博士。 韦斯，P. Scaglioni，D. Haslam和T. Mersha -已经组装来实现这一目标。

Cancer-chemotherapy associated Clostridium difficile infection (CDI) has an adverse effect on treatment outcomes in cancer patients. It leads to treatment interruptions and/or dose intensity reduction with calamitous effects on tumor regression. Unfortunately, efforts at reducing CDI incidence in cancer patients have been hampered by limited understanding of CDI pathophysiology and poor performance of established predictors particularly in cytoreductive cancer chemotherapy (CCC) treated patients. Until more reliable predictors of CDI in CCC patients are identified and the basic science of CDI development is understood, efforts to curtail incidence and improve treatment strategies will remain inadequate. The research aims of this proposal are focused on preventing CDI in CCC-treated patients while providing the training scaffold for Dr. Apewokin's transition to becoming an independent physician-scientist with a focus on cancer supportive care. Protection against gastrointestinal infections in the normal host is mediated by many processes. Immunoglobulins provide humoral protection while the endogenous gut microbial community structure favors resistance to pathogenic organism colonization. We have demonstrated in pilot studies that cytoreductive cancer chemotherapy modifies these factors and leads to reduction of CDI-specific immunoglobulins and gut microbial diversity. We propose a conceptual model of CCC-associated CDI that captures these processes and accordingly hypothesize that CCC-induced loss of CD-specific humoral protection and microbial diversity transforms CD colonization to infection. To test this conceptual model we will establish that AIM #1, CCC patients who develop CDI (cases) have lower CD-specific humoral protection. In AIM #2, CCC patients who develop CDI (cases) have lower gut microbial diversity, and AIM#3, CCC patients who develop CDI undergo clonal expansion of existing CD organisms during CCC. We will conduct a case-control study of 16 CDI-positive cases and 16 CDI-negative controls. We will use metagenomics and induced human intestinal organoid models (iHIOs) as a model system to interrogate CDI development in CCC patients. iHIOs recapitulate human physiology and disease pathology, and incorporate components critical to disease and human host response. We will also employ shotgun sequencing to evaluate microbial factors contributing to CDI during CCC. Integrating these state-of-the-art methodologies with collaborative synergistic research approaches will allow us to characterize CDI pathophysiology and elucidate mechanisms that could not be performed by traditional methods and models.Training in 1) protein toxin biology and quantification techniques, 2) molecular biology and metagenomics, 3) biostatistics and immunogenetics, and 4) clinical trial design will serve as a vehicle for Dr.Apewokin to transition to become an independent physician-scientist competitive for external R type awards. A mentoring team consisting of complementary renowned experts -Drs. A. Weiss, P. Scaglioni, D. Haslam and T. Mersha - has been assembled to achieve this goal.