Institute of Medical Microbiology, Jena University Hospital, Am Klinikum 1, D-07747 Jena, Germany. Center for Sepsis Control and Care, Jena University Hospital, D-07747 Jena, Germany. Section of Experimental Virology, Institute of Medical Microbiology, Jena University Hospital, Hans-Knöll-Str. 2, D-07745, Jena, Germany.
Biofabrication. 2020 Feb 19;12(2):025012. doi: 10.1088/1758-5090/ab7073.
Pneumonia is one of the most common infectious diseases worldwide. The influenza virus can cause severe epidemics, which results in significant morbidity and mortality. Beyond the virulence of the virus itself, epidemiological data suggest that bacterial co-infections are the major cause of increased mortality. In this context, Staphylococcus aureus represents a frequent causative bacterial pathogen. Currently available models have several limitations in the analysis of the pathogenesis of infections, e.g. some bacterial toxins strongly act in a species-specific manner. Human 2D mono-cell culture models often fail to maintain the differentiation of alveolus-specific functions. A detailed investigation of the underlying pathogenesis mechanisms requires a physiological interaction of alveolus-specific cell types. The aim of the present work was to establish a human in vitro alveolus model system composed of vascular and epithelial cell structures with cocultured macrophages resembling the human alveolus architecture and functions. We demonstrate that high barrier integrity maintained for up to 14 d in our model containing functional tissue-resident macrophages. We show that flow conditions and the presence of macrophages increased the barrier function. The infection of epithelial cells induced a high inflammatory response that spread to the endothelium. Although the integrity of the epithelium was not compromised by a single infection or co-infection, we demonstrated significant endothelial cell damage associated with loss of barrier function. We established a novel immune-responsive model that reflects the complex crosstalk between pathogens and host. The in vitro model allows for the monitoring of spatiotemporal spreading of the pathogens and the characterization of morphological and functional alterations attributed to infection. The alveolus-on-a-chip represents a promising platform for mechanistic studies of host-pathogen interactions and the identification of molecular and cellular targets of novel treatment strategies in pneumonia.
肺炎是全球最常见的传染病之一。流感病毒可引发严重的流行疫情，导致发病率和死亡率显著升高。除了病毒本身的毒力之外，流行病学数据表明细菌合并感染是导致死亡率增加的主要原因。在这种情况下，金黄色葡萄球菌是一种常见的致病细菌病原体。目前可用的模型在感染发病机制的分析中存在多种局限性，例如，某些细菌毒素具有强烈的种属特异性作用。人类 2D 单层细胞培养模型通常无法维持肺泡特异性功能的分化。要深入研究潜在的发病机制，需要肺泡特异性细胞类型之间的生理相互作用。本研究的目的是建立一种由血管和上皮细胞结构组成的人肺泡体外模型系统，并共培养类似于人类肺泡结构和功能的巨噬细胞。我们证明，我们的模型中含有功能组织驻留巨噬细胞，其屏障完整性可维持长达 14 天。我们还证明，流动条件和巨噬细胞的存在可增强屏障功能。上皮细胞的感染会引发强烈的炎症反应，并扩散到内皮细胞。尽管单一感染或合并感染并未破坏上皮细胞的完整性，但我们发现与屏障功能丧失相关的内皮细胞损伤显著。我们建立了一种新型免疫反应模型，可反映病原体和宿主之间复杂的串扰。该体外模型可用于监测病原体的时空扩散，并对感染引起的形态和功能改变进行特征描述。肺泡芯片代表了研究宿主-病原体相互作用以及鉴定肺炎新型治疗策略的分子和细胞靶点的有前途的平台。
