A Porcine Ex Vivo Lung Perfusion Model To Investigate Bacterial Pathogenesis
A Porcine Ex Vivo Lung Perfusion Model To Investigate Bacterial Pathogenesis
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DOI：
10.1128/mbio.02802-19
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发表时间：
2019-11-01
期刊：
影响因子：
6.4
通讯作者：
Bengoechea, Jose A.
中科院分区：
文献类型：
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作者：
Dumigan, Amy;Fitzgerald, Marianne;Bengoechea, Jose A.
动物感染模型的使用对于了解微生物的发病机制以及开发和测试治疗方法至关重要。昆虫和二维(2D)和3D组织模型正越来越多地被用作哺乳动物模型的替代品。然而，人们担心这些模型是否概括了宿主-病原体相互作用的复杂性。在这项研究中，我们利用猪肺建立了体外肺灌流(EVLP)感染模型，以研究肺炎克雷伯菌引发的肺炎作为呼吸道感染的模型。猪EVLP模型概括了肺炎克雷伯菌肺炎肺损伤的特点。这个模型也有助于评估肺炎克雷伯菌的致病潜力，因为我们观察到，与野生型感染的肺相比，减毒的克雷伯菌被膜突变株引起的病理组织损害较小，细菌负荷也随之降低。猪EVLP模型可以评估感染后的炎症反应；与小鼠肺炎模型类似，我们观察到野生型感染的肺中IL-10增加，被膜突变体感染的肺中干扰素-γ增加。该模型还允许在单细胞水平上监测表型。野生型肺炎克雷伯菌使巨噬细胞偏向类M2状态。在探索猪骨髓来源的巨噬细胞的体外实验中，揭示了M2转录因子STAT6的作用，以及克雷伯菌诱导的IL-10表达受p38和细胞外信号调节激酶(ERK)控制。克雷伯菌诱导的巨噬细胞极化依赖于被膜。总之，这项研究的结果支持以猪肺为平台的EVLP模型用于研究呼吸道病原体的感染生物学。重要的是，实施接近人类疾病的感染模型对于了解感染和在进入临床阶段之前测试新的治疗方法是必不可少的。大多数临床前研究都使用啮齿动物，尽管小鼠和人类之间的差异助长了这样的结论，即小鼠研究不能可靠地预测人类的结果。在这项研究中，我们利用体外肺灌流(EVLP)系统建立了一种全肺猪感染模型，该系统是为修复人类肺移植而建立的。作为原理的证明，我们提供的证据表明，猪EVLP感染人类病原体肺炎克雷伯菌重现了克雷伯氏菌引发的肺炎的已知特征。此外，我们的数据显示，猪EVLP模型有助于揭示肺炎克雷伯菌毒力的特征，包括对免疫细胞的操纵。总之，这项研究的结果支持使用猪肺作为替代宿主的EVLP模型用于评估呼吸道感染。
The use of animal infection models is essential to understand microbial pathogenesis and to develop and test treatments. Insects and two-dimensional (2D) and 3D tissue models are increasingly being used as surrogates for mammalian models. However, there are concerns about whether these models recapitulate the complexity of host-pathogen interactions. In this study, we developed the ex vivo lung perfusion (EVLP) model of infection using porcine lungs to investigate Klebsiella pneumoniae-triggered pneumonia as a model of respiratory infections. The porcine EVLP model recapitulates features of K. pneumoniae-induced pneumonia lung injury. This model is also useful to assess the pathogenic potential of K. pneumoniae, as we observed that the attenuated Klebsiella capsule mutant strain caused less pathological tissue damage with a concomitant decrease in the bacterial burden compared to that in lungs infected with the wild type. The porcine EVLP model allows assessment of inflammatory responses following infection; similar to the case with the mouse pneumonia model, we observed an increase of il-10 in the lungs infected with the wild type and an increase of ifn-gamma in lungs infected with the capsule mutant. This model also allows monitoring of phenotypes at the single-cell level. Wild-type K. pneumoniae skews macrophages toward an M2-like state. In vitro experiments probing pig bone marrow-derived macrophages uncovered the role for the M2 transcriptional factor STAT6 and that Klebsiella-induced il-10 expression is controlled by p38 and extracellular signal-regulated kinase (ERK). Klebsiella-induced macrophage polarization is dependent on the capsule. Together, the findings of this study support the utility of the EVLP model using pig lungs as a platform to investigate the infection biology of respiratory pathogens.IMPORTANCE The implementation of infection models that approximate human disease is essential to understand infections and for testing new therapies before they enter into clinical stages. Rodents are used in most preclinical studies, although the differences between mice and humans have fueled the conclusion that murine studies are unreliable predictors of human outcomes. In this study, we have developed a whole-lung porcine model of infection using the ex vivo lung perfusion (EVLP) system established to recondition human lungs for transplant. As a proof of principle, we provide evidence demonstrating that infection of the porcine EVLP with the human pathogen Klebsiella pneumoniae recapitulates the known features of Klebsiella-triggered pneumonia. Moreover, our data revealed that the porcine EVLP model is useful to reveal features of the virulence of K. pneumoniae, including the manipulation of immune cells. Together, the findings of this study support the utility of the EVLP model using pig lungs as a surrogate host for assessing respiratory infections.