Imaizumi T, Kumagai M, Taima K, Fujita T, Yoshida H, Satoh K
Dept. of Vascular Biology, Institute of Brain Science, Hirosaki University School of Medicine, 5-Zaifu-cho, Hirosaki 036-8562, Japan.
Eur Respir J. 2005 Jun;25(6):1077-83. doi: 10.1183/09031936.05.00102104.
Bronchial epithelial cells play an important role in airway host defence, and interferon (IFN)-gamma controls immune reactions by regulating the expression of various genes in bronchial epithelial cells. Signal transducer and activator of transcription 1 (STAT1) is the key transcriptional factor in IFN-gamma signalling. Retinoic acid-inducible gene-I (RIG-I) is a member of the DExH box family of proteins and designated a putative RNA helicase. RNA helicases play diverse roles in regulation of gene expression and cellular functions, and RIG-I is implicated in antiviral responses. The aim of the present study was to investigate the effect of IFN-gamma on RIG-I expression in a cell line derived from human bronchial epithelial cells, BEAS-2B. Induction of RIG-I in response to IFN-gamma was found in BEAS-2B cells. Induction of RIG-I by IFN-gamma was also demonstrated in another pulmonary epithelial cell line, NCI-H292. Transfection of BEAS-2B cells with RIG-I complementary DNA resulted in the upregulation of STAT1. Induction of IFN-gamma-inducible protein 10 by IFN-gamma was enhanced in the cells overexpressing RIG-I. It is concluded that retinoic acid-inducible gene-I may play an important role in the regulation of immunological reactions in bronchial epithelial cells elicited by interferon-gamma.
支气管上皮细胞在气道宿主防御中发挥重要作用，而干扰素（IFN）-γ通过调节支气管上皮细胞中各种基因的表达来控制免疫反应。信号转导和转录激活因子1（STAT1）是IFN-γ信号传导中的关键转录因子。维甲酸诱导基因-I（RIG-I）是DExH盒蛋白家族的成员，被指定为一种假定的RNA解旋酶。RNA解旋酶在基因表达调控和细胞功能中发挥多种作用，并且RIG-I与抗病毒反应有关。本研究的目的是调查IFN-γ对源自人支气管上皮细胞BEAS-2B的细胞系中RIG-I表达的影响。在BEAS-2B细胞中发现了RIG-I对IFN-γ的应答诱导。在另一种肺上皮细胞系NCI-H292中也证实了IFN-γ对RIG-I的诱导。用RIG-I互补DNA转染BEAS-2B细胞导致STAT1上调。在过表达RIG-I的细胞中，IFN-γ对IFN-γ诱导蛋白10的诱导增强。结论是，维甲酸诱导基因-I可能在干扰素-γ引发的支气管上皮细胞免疫反应调节中发挥重要作用。
