Leal Teresinha, Bergamini Gabriella, Huaux François, Panin Nadtha, Noel Sabrina, Dhooghe Barbara, Haaf Jeremy B, Mauri Pierluigi, Motta Sara, Di Silvestre Dario, Melotti Paola, Sorio Claudio
Louvain Centre for Toxicology and Applied Pharmacology, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain , Brussels , Belgium.
Cystic Fibrosis Translational Research Laboratory "D. Lissandrini", Department of Medicine, Division of General Pathology, University of Verona, Verona, Italy; Cystic Fibrosis Center, Azienda Ospedaliera Universitaria Integrata di Verona, Verona, Italy.
Front Immunol. 2016 Nov 15;7:499. doi: 10.3389/fimmu.2016.00499. eCollection 2016.
airway infections are a major cause of morbidity and mortality in patients with cystic fibrosis (CF). Azithromycin improves the related clinical outcomes, but its mechanisms of action remain poorly understood. We tested the hypothesis that azithromycin downregulates -induced pro-inflammatory responses by modifying release of bacterial proteins.
We monitored inflammatory markers in lungs of CF mutant mice and their littermate controls in response to conditioned media (CM) collected from the reference PAO1 strain cultured in the presence or in the absence of azithromycin. A mass spectrometry-based proteomic approach was applied to examine whether the macrolide elicits a differential release of bacterial proteins.
CM collected from azithromycin-untreated PAO1 cultures induced powerful pro-inflammatory neutrophil-dominated responses. Azithromycin attenuated the responses, mainly of macrophage chemoattractant protein-1, tumor necrosis factor-α, and interferon-γ, in CF but not in wild-type mice. Proteomic analysis showed that azithromycin upregulated an array of bacterial proteins including those associated with regulation of immune functions and with repair and resolution of inflammatory responses like the chaperone DnaK and the -adenosylmethionine synthase, while it downregulated the extracellular heme acquisition protein HasA and the catalytic enzyme lysylendopeptidase.
Supernatants collected from cultures of the bacterial strain PAO1 represent a novel experimental model to trigger lung inflammatory responses that should be closer to those obtained with live bacteria, but without bacterial infection. Combined with a bactericidal effect, complex regulation of bacterial innate immune and metabolic factors released in the cultured medium by the action of the macrolide can contribute to its anti-inflammatory effects.
气道感染是囊性纤维化（CF）患者发病和死亡的主要原因。阿奇霉素可改善相关临床结局，但其作用机制仍知之甚少。我们检验了阿奇霉素通过改变细菌蛋白释放来下调诱导的促炎反应这一假说。
我们监测了CF突变小鼠及其同窝对照小鼠肺部的炎症标志物，以响应从在有或无阿奇霉素存在的情况下培养的参考PAO1菌株收集的条件培养基（CM）。应用基于质谱的蛋白质组学方法来检查大环内酯类药物是否引发细菌蛋白的差异释放。
从未经阿奇霉素处理的PAO1培养物中收集的CM诱导了以中性粒细胞为主的强烈促炎反应。阿奇霉素减弱了CF小鼠而非野生型小鼠的反应，主要是巨噬细胞趋化蛋白-1、肿瘤坏死因子-α和干扰素-γ的反应。蛋白质组学分析表明，阿奇霉素上调了一系列细菌蛋白，包括那些与免疫功能调节以及与炎症反应的修复和消退相关的蛋白，如伴侣蛋白DnaK和S-腺苷甲硫氨酸合酶，同时下调了细胞外血红素获取蛋白HasA和催化酶赖氨酰内肽酶。
从PAO1菌株培养物中收集的上清液代表了一种新的实验模型，可引发肺部炎症反应，这种反应应更接近活细菌引发的反应，但无细菌感染。结合杀菌作用，大环内酯类药物作用于培养基中释放的细菌固有免疫和代谢因子的复杂调节可有助于其抗炎作用。
