Human Gastrointestinal Biomimetics for Enteric Viral Infections

项目总结 胃肠炎(GE)是全球主要的死亡原因之一。我们的研究重点是人类轮状病毒 (HRV)和人类诺如病毒(HuNoV)是导致全球超过320,000人病毒性GE的两个主要原因 每年的死亡人数。目前还没有针对这两种病毒的抗病毒药物，也没有针对HuNov的疫苗。虽然疫苗 在高收入国家(84%-90%)，HRV是可用的并有效的，但疗效仍然不佳(45%-90%)。 57%)在疾病负担最大的低收入环境中。从经济上讲，感染HNOV会导致 每年超过40亿美元的直接医疗成本和超过600亿美元的社会成本。这些数据强调了 需要继续投资于克服粘膜肠道疾病的研究。 这两种人类胃肠道病毒都不会感染小鼠；此外，HRV在培养细胞中复制很差，而HuNov 近50年不能种植。使用组织干细胞来源的人类肠道器官(HIO)培养 作为这些人类胃肠道病原体的复制模型，我们取得了一些了不起的基础性发现。钥匙 研究结果包括：这两种人类病毒至少在两种不同的肠道细胞(肠细胞和肠上皮细胞)中复制 肠内分泌细胞)，心率变异性病毒也在结肠中复制。每种病毒在基因上都与 编码的组织血抗原(HBGA)，但这些多糖在感染中扮演不同的角色。HBGA表达可以 不限制感染，但与严重的HRV疾病相关，而感染HuNoV是必需的。 与HBGA的相互作用对两种病毒都是依赖于菌株的。每种病毒通过一种病毒感染极化的上皮细胞 HRV基底部感染和HuNov顶部感染的途径不同。受感染的HIO培养产生 新形式的HRV在囊泡中释放，表现出与标准细胞培养衍生病毒不同的特性。 这两种病毒都能诱导一种主要的上皮细胞固有的III型干扰素(干扰素)反应；令人惊讶的是，这会起作用 不限制病毒复制，提示III型干扰素可能具有抗病毒以外的其他功能。HIO允许 多株HuNov和胆汁的培养是复制的关键因素。 尽管这些仅使用上皮细胞的HIO研究提供了有关HRV和HuNoV的新知识 感染，我们仍然缺乏对导致感染的病理生理和宿主反应的全面了解 危及生命的疾病。需要继续开发“人体迷你肠道”模型才能充分理解 人-胃肠道病毒的相互作用与发病机制有关，并改善了对病毒感染的粘膜免疫反应。 利用复杂的仿生培养，我们建议回答基础和临床的两个生物学问题。 相关性：在感染HRV和HuNoV期间，什么机制介导了严重的胃肠道疾病(目标1)，以及 微生物-微生物相互作用在病毒GE病理生理学中的作用是什么(目标2)？通过互动 有了项目2和3以及我们的两个科学核心，我们预测我们的研究将进步并使人类 器官仿生学作为理解人类粘膜感染并充当桥梁的翻译模型 在临床前动物模型和首个人类临床试验之间。

PROJECT SUMMARY Gastroenteritis (GE) is among the leading causes of mortality globally. Our research focuses on human rotavirus (HRV) and human norovirus (HuNoV), the two leading causes of viral GE worldwide causing over 320,000 deaths annually. No antivirals are available for either virus and there is no vaccine for HuNoVs. While vaccines to HRV are available and are effective in high-income countries (84-90%), the efficacy remains suboptimal (45- 57%) in low-income settings where the burden of disease is greatest. Economically, HuNoV infections result in over $4 billion in direct healthcare costs and over $60 billion in societal costs each year. These data underscore the need for continued investment in studies to overcome mucosal enteric disease. Both these human GI viruses do not infect mice; further, HRV replicates poorly in cultured cells, and HuNoV was noncultivatable for over almost 50 years. Using tissue stem cell-derived human intestinal organoid (HIO) cultures as a replication model for these human GI pathogens, we made some remarkable fundamental discoveries. Key findings include: both human viruses replicate in at least two distinct intestinal cell types (enterocytes and enterendocrine cells) in the small intestine, and HRVs also replicate in the colon. Each virus binds to genetically encoded histo-blood antigens (HBGAs) but these glycans play different roles in infection. HBGA expression does not restrict infection but correlates with severe HRV disease while it is required for infection with HuNoV. Interactions with HBGA are strain-dependent for both viruses. Each virus infects the polarized epithelium by a different route with HRVs infecting basolaterally and HuNoVs infecting apically. Infected HIO cultures produce a new form of HRV released in vesicles that exhibit different properties from standard cell-culture derived virus. Both viruses induce a predominant epithelial innate response of type III interferon (IFN); surprisingly this does not restrict virus replication suggesting type III IFN may have other functions than being antiviral. HIOs allow cultivation of multiple HuNoV strains and bile is a critical factor for replication. Although these previous studies using epithelial-only HIOs provide new knowledge on HRV and HuNoV infections, we still lack a comprehensive understanding of the pathophysiology and host responses that lead to life-threatening disease. Continued development of “human mini-gut” models is required to fully understand human-GI virus interactions linked to pathogenesis and improve mucosal immune responses to viral infections. Using complex biomimetic cultures, we propose to answer two biological questions of fundamental and clinical relevance: What mechanisms mediate severe GI disease during infection with HRV and HuNoV (Aim 1), and what is the role of microbe-microbe interactions in the pathophysiology of viral GE (Aim 2)? Through interactions with Projects 2 and 3 and our two Scientific Cores, we predict our studies will advance and enable human organ biomimetics as translational models to understand human mucosal infections and to serve as a bridge between preclinical animal models and first-in-human clinical trials.