Inflammation, Repair and Development Section, National Heart and Lung Institute, Imperial College, London, UK.
Department of Respiratory Medicine, Interstitial Lung Disease Unit, Royal Brompton Hospital, London, UK.
Immunology. 2020 Jun;160(2):171-182. doi: 10.1111/imm.13195. Epub 2020 Apr 14.
The airway epithelium represents a physical barrier to the external environment acting as the first line of defence against potentially harmful environmental stimuli including microbes and allergens. However, lung epithelial cells are increasingly recognized as active effectors of microbial defence, contributing to both innate and adaptive immune function in the lower respiratory tract. These cells express an ample repertoire of pattern recognition receptors with specificity for conserved microbial and host motifs. Modern molecular techniques have uncovered the complexity of the lower respiratory tract microbiome. The interaction between the microbiota and the airway epithelium is key to understanding how stable immune homeostasis is maintained. Loss of epithelial integrity following exposure to infection can result in the onset of inflammation in susceptible individuals and may culminate in lung disease. Here we discuss the current knowledge regarding the molecular and cellular mechanisms by which the pulmonary epithelium interacts with the lung microbiome in shaping immunity in the lung. Specifically, we focus on the interactions between the lung microbiome and the cells of the conducting airways in modulating immune cell regulation, and how defects in barrier structure and function may culminate in lung disease. Understanding these interactions is fundamental in the search for more effective therapies for respiratory diseases.
气道上皮细胞构成了对外界环境的物理屏障，作为抵御包括微生物和过敏原在内的潜在有害环境刺激的第一道防线。然而，肺上皮细胞越来越被认为是微生物防御的积极效应器，有助于下呼吸道的固有和适应性免疫功能。这些细胞表达了大量针对保守的微生物和宿主基序的模式识别受体，具有特异性。现代分子技术揭示了下呼吸道微生物组的复杂性。微生物群与气道上皮细胞之间的相互作用是理解如何维持稳定的免疫平衡的关键。暴露于感染后上皮完整性的丧失可能导致易感个体发生炎症，并可能导致肺部疾病。在这里，我们讨论了关于肺上皮细胞与肺部微生物组相互作用以塑造肺部免疫的分子和细胞机制的现有知识。具体而言，我们专注于肺微生物组与传导气道细胞之间的相互作用，调节免疫细胞调节，以及屏障结构和功能的缺陷如何导致肺部疾病。了解这些相互作用对于寻找更有效的呼吸道疾病治疗方法至关重要。
