Meakins-Christie Laboratories, McGill University, Montréal, Québec, Canada.
Clin Exp Allergy. 2012 Jan;42(1):85-94. doi: 10.1111/j.1365-2222.2011.03894.x. Epub 2011 Nov 9.
Structural cells are an important reservoir of chemokines that coordinate the influx of various immune cells to the lungs of asthmatics. Airway smooth muscle cells (ASMC) are an important source of these chemokines. CCL15 is a recently described chemo-attractant for neutrophils, eosinophils, monocytes and lymphocytes.
To determine the production and the regulation of CCL15 by ASMC and to investigate its production in asthmatic airways.
Human ASMC were obtained from main bronchial airway segments of patients with mild, moderate and severe asthma. To induce chemokine production, cells were incubated with IL-4, IL-13, TNF-α or IFN-γ in presence or absence of dexamethasone, mithramycin A (SP-1 inhibitor) or the IKK-2 inhibitor, AS602868. CCL15 mRNA expression was evaluated by real-time PCR. Immunoreactive CCL15 was detected by immuno-fluorescence and CCL15 protein concentration in the supernatant was measured using ELISA.
CCL15 is constitutively expressed in human ASMC and is strongly up-regulated by TNF-α. This up-regulation is inhibited by dexamethasone, mithramycin A and AS602868. TNF-α-induced CCL15 levels can be synergistically enhanced by the presence of IFN-γ, at both the transcriptional and translation level. This synergism is NF-κB-dependent. Asthmatic biopsies demonstrated higher expression of CCL15 compared with non-asthmatic controls.
Our results show that ASMC are a potent source of CCL15 in the airways and may directly participate in the recruitment of inflammatory cells to asthmatic airways. Targeting the production of CCL15 by ASMC might reduce the inflammatory response within the airways of asthmatic patients.
结构性细胞是协调各种免疫细胞流入哮喘患者肺部的趋化因子的重要储库。气道平滑肌细胞（ASMC）是这些趋化因子的重要来源。CCL15 是一种最近描述的中性粒细胞、嗜酸性粒细胞、单核细胞和淋巴细胞趋化因子。
确定 ASMC 产生和调节 CCL15，并研究其在哮喘气道中的产生。
从轻度、中度和重度哮喘患者的主支气管气道段中获得人 ASMC。为了诱导趋化因子产生，细胞在存在或不存在地塞米松、米托霉素 A（SP-1 抑制剂）或 IKK-2 抑制剂 AS602868 的情况下用 IL-4、IL-13、TNF-α 或 IFN-γ 孵育。通过实时 PCR 评估 CCL15 mRNA 表达。通过免疫荧光检测免疫反应性 CCL15，并用 ELISA 测量上清液中的 CCL15 蛋白浓度。
CCL15 在人 ASMC 中持续表达，并强烈上调 TNF-α。这种上调可被地塞米松、米托霉素 A 和 AS602868 抑制。IFN-γ 的存在可协同增强 TNF-α 诱导的 CCL15 水平，在转录和翻译水平上均如此。这种协同作用依赖于 NF-κB。与非哮喘对照相比，哮喘活检显示 CCL15 表达更高。
我们的结果表明，ASMC 是气道中 CCL15 的强大来源，可能直接参与招募炎症细胞进入哮喘气道。靶向 ASMC 产生 CCL15 可能会减少哮喘患者气道内的炎症反应。
