Department of Pediatrics, Columbia University, New York, NY 10027, USA.
Am J Respir Cell Mol Biol. 2011 Aug;45(2):189-201. doi: 10.1165/rcmb.2011-0011RT. Epub 2011 Feb 17.
The airway epithelium represents the first point of contact for inhaled foreign organisms. The protective arsenal of the airway epithelium is provided in the form of physical barriers and a vast array of receptors and antimicrobial compounds that constitute the innate immune system. Many of the known innate immune receptors, including the Toll-like receptors and nucleotide oligomerization domain-like receptors, are expressed by the airway epithelium, which leads to the production of proinflammatory cytokines and chemokines that affect microorganisms directly and recruit immune cells, such as neutrophils and T cells, to the site of infection. The airway epithelium also produces a number of resident antimicrobial proteins, such as lysozyme, lactoferrin, and mucins, as well as a swathe of cationic proteins. Dysregulation of the airway epithelial innate immune system is associated with a number of medical conditions that can result in compromised immunity and chronic inflammation of the lung. This review focuses on the innate immune capabilities of the airway epithelium and its role in protecting the lung from infection as well as the outcomes when its function is compromised.
气道上皮是人体与吸入性外源生物的第一道接触防线。气道上皮的保护机制由物理屏障以及大量的受体和抗菌化合物组成，这些物质构成了先天免疫系统。许多已知的先天免疫受体，包括 Toll 样受体和核苷酸寡聚化结构域样受体，都在气道上皮细胞中表达，从而导致促炎细胞因子和趋化因子的产生，这些细胞因子和趋化因子直接影响微生物，并招募免疫细胞（如中性粒细胞和 T 细胞）到感染部位。气道上皮还产生许多常驻抗菌蛋白，如溶菌酶、乳铁蛋白和黏蛋白，以及一系列阳离子蛋白。气道上皮先天免疫系统的失调与许多医学病症有关，这些病症可能导致免疫功能受损和肺部慢性炎症。本文主要聚焦于气道上皮的先天免疫功能，以及它在保护肺部免受感染方面的作用，以及其功能受损时的后果。
