Thomas L H, Friedland J S, Sharland M, Becker S
Department of Infectious Diseases, Imperial College School of Medicine (Hammersmith Campus), London, United Kingdom.
J Immunol. 1998 Jul 15;161(2):1007-16.
Respiratory syncytial virus (RSV) infection is an important cause of lower respiratory tract illness, the severity of which may be partly due to cellular recruitment. RSV infection activates chemokine secretion from airway epithelial cells by largely unknown mechanisms. We investigated the regulation of RSV-induced activation of the chemokine RANTES in the bronchial epithelial cell line BEAS-2B and primary normal human tracheobronchial epithelial cultures. RANTES protein and mRNA were detected at 24 h and up until 72 h from cultures of BEAS-2B infected with replicating virus, but not with UV-inactivated RSV. RSV infection of BEAS-2B or normal human tracheobronchial epithelial cells stimulated NF-kappa B translocation to the nucleus and binding to the RANTES-specific kappa B-binding sequences within 2 h, with levels peaking at 24 h. Supershift assays indicated that binding was due to p50/p65 heterodimers. BEAS-2B cells were transfected with a replication-deficient adenoviral vector, expressing a mutated, nondegradable form of I kappa B alpha. I kappa B alpha overexpression specifically blocked NF-kappa B translocation and inhibited mRNA accumulation and secretion of RANTES induced by RSV or TNF-alpha plus IFN-gamma. Adenoviral transfection did not interfere with RSV replication or significantly induce apoptosis. Further, a control adenovirus, expressing the beta-galactosidase gene, did not alter cellular functions. Thus, NF-kappa B nuclear translocation is a critical step in RSV induction of RANTES secretion. Elucidating the mechanisms of cellular activation by RSV and targeting specific areas may lead to novel therapeutic approaches in the treatment of RSV.
呼吸道合胞病毒(RSV)感染是下呼吸道疾病的重要病因,其严重程度可能部分归因于细胞募集。RSV感染通过 largely unknown mechanisms 激活气道上皮细胞分泌趋化因子。我们研究了RSV诱导支气管上皮细胞系BEAS-2B和原代正常人气管支气管上皮培养物中趋化因子RANTES激活的调控机制。在感染复制型病毒的BEAS-2B培养物中,在24小时直至72小时均可检测到RANTES蛋白和mRNA,但紫外线灭活的RSV感染则检测不到。RSV感染BEAS-2B或正常人气管支气管上皮细胞可在2小时内刺激NF-κB易位至细胞核并与RANTES特异性κB结合序列结合,水平在24小时达到峰值。超迁移分析表明结合是由于p50/p65异二聚体。用表达突变的、不可降解形式的IκBα的复制缺陷型腺病毒载体转染BEAS-2B细胞。IκBα过表达特异性阻断NF-κB易位,并抑制RSV或TNF-α加IFN-γ诱导的RANTES的mRNA积累和分泌。腺病毒转染不干扰RSV复制或显著诱导细胞凋亡。此外,表达β-半乳糖苷酶基因的对照腺病毒不改变细胞功能。因此,NF-κB核易位是RSV诱导RANTES分泌的关键步骤。阐明RSV激活细胞的机制并靶向特定区域可能会带来治疗RSV的新治疗方法。