A Microphysiological Mimicry of Human Lung-Bone Marrow Organ-Organ Crosstalk On-a-Chip

项目摘要。 威胁全球卫生安全的几种具有流行潜力的新型病毒性呼吸道传染病 在过去的20年里出现了。甲型流感病毒（IAV）占新出现的呼吸道病毒的50%， 导致严重的发病率和死亡率。IAV可以感染多种鸟类和哺乳动物物种，包括 人类，并具有进化和适应新宿主的非凡能力。尽管取得了巨大进展， 病毒学和流行病学，哪种亚型或毒株的IAV将导致下一次爆发仍然是不可预测的。 重要的是，没有临床模拟，病理生理学相关，并在体外容易获得 多器官系统，用于预测新出现和重新出现的流感病毒在人类中的致病性。 最近令人信服的证据表明，两种主要类型的骨髓（BM）产生的先天性 免疫细胞在塑造IAV感染的结果，中性粒细胞提供保护和增加循环 单核细胞与病理学增加有关。因此，这两种不同细胞中任一种的选择性动员 对IAV肺部感染的反应类型可以间接揭示给定病毒的潜在致病性 株该项目的总体目标是开发一个高度创新，简化，但先进和复杂， 利用芯片上器官技术的人流感感染的生理学相关体外模型， 预测不同IAV毒株的毒力和感染性，通过复制临床和体内观察到的免疫学 与感染严重程度相关。更具体地说，我们将设计一种首创的流体集成多- 使用原代人源性细胞重建BM-肺轴的器官系统，用于实时分析 炎症和白细胞动员。我们的核心假设是， 动态活微系统可以概括不同的免疫细胞动员和组织病理学， 体外对高致病性与低致病性IAV感染的反应。为了解决这个假设，我们 提出了以下具体目标：（1）设计活的和造血活性的人芯片上BM， 将其与我们团队先前开发的人类肺小气道芯片连接起来， 表征稳态生理学和器官-器官串扰;以及（3）挑战BM-肺微系统， 在有节奏的呼吸下，空气中的IAV会产生不同的白细胞动员和组织损伤， 对明显致病的病毒株的反应。这种新颖的平台在仿真和预测方面具有巨大的潜力 IAV的致病性（例如，在暴发、流行期间或推测存在高毒力菌株时）， 利用从所需供体/患者群体分离的人细胞，而不需要使病毒适应宿主 (as一些动物研究需要）。此外，它还可以大大加快药物开发研究， 个性化药物功效测试和新治疗靶点的鉴定。

PROJECT SUMMARY. Several new viral respiratory tract infectious diseases with epidemic potential that threaten global health security have emerged in the past 20 years. Influenza A viruses (IAVs) comprise 50% of the emerging respiratory viruses and can cause substantial morbidity and mortality. IAVs can infect a diversity of avian and mammalian species, including humans, and have the remarkable capacity to evolve and adapt to new hosts. Despite the tremendous progress made in virology and epidemiology, which subtype or strain of IAV will cause the next outbreak remains unpredictable. Importantly, there is no clinically simulating, pathophysiologically relevant, and readily available in vitro multi-organ system for predicting the pathogenicity of emerging and re-emerging influenza viruses in humans. Recent compelling evidence have revealed opposing roles for two major classes of bone marrow (BM)-produced innate immune cells in shaping the outcome of IAV infection, with neutrophils offering protection and increase in circulating monocytes being associated with increased pathology. Thus, selective mobilization of either of these two distinct cell types in response to pulmonary infection with IAV can indirectly reveal potential pathogenicity of a given viral strain. The overarching goal of this project is to develop a highly innovative, reductionist, yet advanced and complex, physiologically relevant in vitro model of influenza infection in humans utilizing Organ-on-Chip technology in order to predict virulence and infectivity of different IAV strains, by reproducing clinically and in vivo-observed immunological correlates of infection severity. More specifically, we will engineer a first-in-kind fluidically integrated multi- organ system that recreates BM-lung axis, using primary human-derived cells, for real-time analysis of inflammation and leukocyte mobilization in response to influenza challenge. Our central hypothesis is that this dynamic living microsystem can recapitulate differential immune cell mobilization and tissue pathology in response to high-pathogenicity vs. low-pathogenicity IAV infections in vitro. To address the hypothesis, we propose the following specific aims: (1) to engineer a living and hematopoietically active human BM-on-a-Chip and microfluidically link it to a human Lung Small Airway-on-a-Chip that our team has previously developed and characterize homeostatic physiology and organ-organ crosstalk; and (3) to challenge the BM-Lung microsystem with airborne IAVs under rhythmic breathing and reproduce differential leukocyte mobilization and tissue damage in response to distinctly pathogenic viral strains. Such a novel platform holds great potential in emulating and predicting pathogenicity of IAVs (e.g., during outbreaks, pandemics or when presence of a highly virulent strain is speculated), utilizing human cells isolated from desired donor/patient populations, and without needing to adapt the virus for host (as required for some animal studies). In addition, it can considerably accelerate drug development studies by enabling personalized drug efficacy testing and identification of new therapeutic targets.