气道上皮细胞的抗原递呈作用

Antigen presenting action of airway epithelial cells

气道上皮细胞构成气道黏膜表面的保护屏障，长期以来一直认为气道上皮的功能仅限于通过纤毛摆动和黏液运输发挥防御作用。现已证实支气管上皮细胞可表达组织相容性复合体（MHC）分子、协同刺激分子和黏附分子，具备成为抗原递呈细胞的必要条件；免疫荧光示踪、电子显微镜、共定位（colocalized）研究均显示气道上皮细胞以MHCⅡ类途径加工递呈抗原。研究气道上皮细胞的抗原递呈功能及其控制规律，有助于拓宽对气道上皮细胞生理功能的认识、阐明气道炎症发生机制有重要意义。

Bronchial epithelium lines the mucosal surface of airways,forming a mechanical barrier that separates the external environment from the internal milieu. It has long been believed that the function of epithelial cells is limited to protecting against invading microorganisms and removing them by means of the mucociliary escalator. Now bronchial epithelial cells may have the capacity to act as antigen-presenting cell because they have been reported to express major histocompatibility complex （MHC） molecules, costimulatory molecules and adhesion molecules. Immunofluorescence, electron-microscopic, and colocalization studies showed that antigen followed a class Ⅱ endocytic pathway inside the airway epithelial cells. It is conducive to broadening the cognition of airway physiological function and expounding the occurrence mechanism of airway inflammation to study the antigen presenting action and its control mechanism,which is of great significance.