Bronchoalveolar lavage fluid exosomes contribute to cytokine and leukotriene production in allergic asthma
Bronchoalveolar lavage fluid exosomes contribute to cytokine and leukotriene production in allergic asthma
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DOI：
10.1111/j.1398-9995.2012.02835.x
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发表时间：
2012-07-01
期刊：
影响因子：
12.4
通讯作者：
Gabrielsson, S.
中科院分区：
文献类型：
--
作者：
Paredes, P. Torregrosa;Esser, J.;Gabrielsson, S.
白三烯（LTs）是参与哮喘的有效促炎介质。外泌体是一种纳米大小的囊泡，从各种细胞中释放出来，可以刺激或下调免疫反应，这取决于原始细胞的状态和性质。我们最近发现结节病患者支气管肺泡灌洗液（BALF）外泌体谱发生改变，但它们在哮喘中的作用尚不清楚。我们的目的是研究来自BALF的外泌体是否具有LT生物合成能力，并探讨哮喘中BALF外泌体的表型和功能特征。方法采集健康个体（n = 13）和桦木花粉轻度过敏性哮喘患者（n = 12）在桦木过敏原激发前后的支气管肺泡灌洗液外泌体。外泌体采用流式细胞术和Western blot检测。用ELISA法和反相高效液相色谱法分别测定了它们诱导人支气管上皮细胞（BEC） 16HB14o-产生IL-8和LT的能力。结果与健康个体的BALF外泌体相比，哮喘患者的BALF外泌体显示出更高水平的外泌体相关标志物，如四跨蛋白CD63和CD81以及清道夫受体CD36。在过敏原激发前后的BALF外泌体之间没有观察到主要差异。此外，我们发现BALF外泌体含有用于LT生物合成的酶。哮喘患者的外泌体促进BEC中LTC4和IL-8释放的作用显著增加，CysLT1受体拮抗剂孟鲁司特降低了外泌体诱导的IL-8分泌。结论哮喘患者和健康人支气管肺泡灌洗液外泌体表现出不同的表型和功能。哮喘患者的BALF外泌体可能通过增加气道上皮细胞因子和LTC4的生成而参与亚临床炎症。
Background Leukotrienes (LTs) are potent pro-inflammatory mediators involved in asthma. Exosomes, nanosized vesicles released from various cells, can stimulate or down-regulate immune responses, depending on the state and nature of the originating cell. We have recently shown an altered exosome profile in bronchoalveolar lavage fluid (BALF) of patients with sarcoidosis, but their role in asthma is unknown. Our aims were to investigate whether exosomes from BALF have LT biosynthetic capacity and to explore phenotypic and functional characteristics of BALF exosomes in asthma. Methods Bronchoalveolar lavage fluid exosomes were collected from healthy individuals (n = 13) and patients with mild allergic asthma to birch pollen (n = 12) before and after birch allergen provocation. Exosomes were characterized by flow cytometry and Western blot. Their capacity to induce IL-8 and LT production in the human bronchial epithelial cell (BEC) line 16HB14o- was measured by ELISA and reverse-phase HPLC, respectively. Results Compared to BALF exosomes from healthy individuals, BALF exosomes from asthmatics displayed higher levels of exosome-associated markers, such as the tetraspanins CD63 and CD81 and the scavenger receptor CD36. No major differences were observed between BALF exosomes from before and after allergen provocation. Furthermore, we show that BALF exosomes contain enzymes for LT biosynthesis. The effect of exosomes to promote LTC4 and IL-8 release in BEC was significantly increased for exosomes from asthmatics, and the CysLT1 receptor antagonist Montelukast reduced exosome-induced IL-8 secretion. Conclusions Bronchoalveolar lavage fluid exosomes from asthmatic and healthy individuals exhibit distinct phenotypes and functions. BALF exosomes from asthmatics might contribute to subclinical inflammation by increasing cytokine and LTC4 generation in airway epithelium.