Interaction between mucosal epithelium and immune system in human nasal mucosa.

上呼吸道的粘膜屏障，包括鼻腔，是接触吸入性抗原的第一个部位，在天然免疫方面发挥着重要的宿主防御作用，在很大程度上是由上皮细胞的紧密连接调节的。紧密连接分子表达于M细胞、树突状细胞和上呼吸道上皮细胞。各种抗原通过鼻粘膜中的细胞被采样、运输和释放到淋巴细胞，同时维持屏障的完整性。正常人鼻上皮细胞紧密连接分子的表达和屏障功能受到多种刺激的影响，包括生长因子、TLR配体和细胞因子。此外，上皮来源的细胞因子在增加HNECs紧密连接分子的同时，增强了屏障功能。此外，RSV感染体外培养的HNECs可诱导屏障功能和促炎细胞因子的释放。

The mucosal barrier of the upper respiratory tract including the nasal cavity, which is the first site of exposure to inhaled antigens, plays an important role in host defense in terms of innate immunity and is regulated in large part by tight junctions of epithelial cells. Tight junction molecules are expressed in both M cells and dendritic cells as well as epithelial cells of upper airway. Various antigens are sampled, transported, and released to lymphocytes through the cells in nasal mucosa while they maintain the integrity of the barrier. Expression of tight junction molecules and the barrier function in normal human nasal epithelial cells are affected by various stimuli including growth factor, TLR ligand, and cytokine. In addition, epithelial-derived cytokines, enhances the barrier function together with an increase of tight junction molecules in HNECs. Furthermore, RSV infection in HNECs in vitro induces the barrier function together with proinflammatory cytokine release.