Ehrentraut Heidi, Weisheit Christina K, Frede Stilla, Hilbert Tobias
Department of Anesthesiology and Intensive Care Medicine, University Hospital Bonn.
Department of Anesthesiology and Intensive Care Medicine, University Hospital Bonn;
J Vis Exp. 2019 Jul 6(149). doi: 10.3791/59999.
Airway administration of lipopolysaccharide (LPS) is a common way to study pulmonary inflammation and acute lung injury (ALI) in small animal models. Various approaches have been described, such as the inhalation of aerosolized LPS as well as nasal or intratracheal instillation. The presented protocol describes a detailed step-by-step procedure to induce ALI in mice by direct intratracheal LPS instillation and perform FACS analysis of blood samples, bronchoalveolar lavage (BAL) fluid, and lung tissue. After intraperitoneal sedation, the trachea is exposed and LPS is administered via a 22 G venous catheter. A robust and reproducible inflammatory reaction with leukocyte invasion, upregulation of proinflammatory cytokines, and disruption of the alveolo-capillary barrier is induced within hours to days, depending on the LPS dosage used. Collection of blood samples, BAL fluid, and lung harvesting, as well as the processing for FACS analysis, are described in detail in the protocol. Although the use of the sterile LPS is not suitable to study pharmacologic interventions in infectious diseases, the described approach offers minimal invasiveness, simple handling, and good reproducibility to answer mechanistic immunological questions. Furthermore, dose titration as well as the use of alternative LPS preparations or mouse strains allow modulation of the clinical effects, which can exhibit different degrees of ALI severity or early vs. late onset of disease symptoms.
气道内给予脂多糖（LPS）是在小动物模型中研究肺部炎症和急性肺损伤（ALI）的常用方法。已经描述了各种方法，例如吸入雾化的LPS以及经鼻或气管内滴注。本文介绍的方案描述了通过直接气管内滴注LPS在小鼠中诱导ALI并对血液样本、支气管肺泡灌洗（BAL）液和肺组织进行流式细胞术分析的详细分步程序。腹腔内镇静后，暴露气管并通过22G静脉导管给予LPS。根据所用LPS的剂量，在数小时至数天内可诱导出强烈且可重复的炎症反应，包括白细胞浸润、促炎细胞因子上调以及肺泡-毛细血管屏障破坏。方案中详细描述了血液样本、BAL液的采集、肺组织的收获以及用于流式细胞术分析的处理过程。尽管使用无菌LPS不适合研究传染病中的药物干预，但所描述的方法具有微创性、操作简单且重复性好的特点，可用于回答免疫机制问题。此外，剂量滴定以及使用替代的LPS制剂或小鼠品系可调节临床效果，临床效果可能表现出不同程度的ALI严重程度或疾病症状的早发与晚发。
