Calvén Jenny, Akbarshahi Hamid, Menzel Mandy, Ayata Cemil Korcan, Idzko Marco, Bjermer Leif, Uller Lena
Division of Respiratory Immunopharmacology, Department of Experimental Medical Science, BMC D12, Lund University, 221 84, Lund, Sweden.
Department of Pneumology, University Hospital Freiburg, Killianstrasse 5, 79106, Freiburg, Germany.
J Transl Med. 2015 Aug 29;13:281. doi: 10.1186/s12967-015-0645-3.
Bronchial smooth muscle cells (BSMCs) from severe asthmatics have been shown to overexpress the Th2-driving and asthma-associated cytokine IL-33. However, little is known regarding factors involved in BSMC production of IL-33. Rhinovirus (RV) infections cause asthma exacerbations, which exhibit features of Th2-type inflammation. Here, we investigated the effects of epithelial-derived media and viral stimuli on IL-33 expression in human BSMCs.
Primary human BSMCs from healthy (n = 3) and asthmatic (n = 3) subjects were stimulated with conditioned media from primary human bronchial epithelial cells (BECs), double-stranded (ds)RNA, dsRNA/LyoVec, or infected with RV. BSMCs were also pretreated with the purinergic receptor antagonist suramin. IL-33 expression was analysed by RT-qPCR and western blot and ATP levels were determined in cell supernatants.
RV infection and activation of TLR3 by dsRNA increased IL-33 mRNA and protein in healthy and asthmatic BSMCs. These effects were inhibited by dexamethasone. BSMC expression of IL-33 was also increased by stimulation of RIG-I-like receptors using dsRNA/LyoVec. Conditioned media from BECs induced BSMC expression of IL-33, which was further enhanced by dsRNA. BEC-derived medium and viral-stimulated BSMC supernatants exhibited elevated ATP levels. Blocking of purinergic signalling with suramin inhibited BSMC expression of IL-33 induced by dsRNA and BEC-derived medium.
RV infection of BSMCs and activation of TLR3 and RIG-I-like receptors cause expression and production of IL-33. Epithelial-released factor(s) increase BSMC expression of IL-33 and exhibit positive interaction with dsRNA. Increased BSMC IL-33 associates with ATP release and is antagonised by suramin. We suggest that epithelial-derived factors contribute to baseline BSMC IL-33 production, which is further augmented by RV infection of BSMCs and stimulation of their pathogen-recognising receptors.
重度哮喘患者的支气管平滑肌细胞（BSMCs）已被证明过度表达驱动Th2型和与哮喘相关的细胞因子白细胞介素-33（IL-33）。然而，关于参与BSMCs产生IL-33的因素知之甚少。鼻病毒（RV）感染会导致哮喘发作，表现出Th2型炎症的特征。在此，我们研究了上皮来源的培养基和病毒刺激对人BSMCs中IL-33表达的影响。
用来自原代人支气管上皮细胞（BECs）的条件培养基、双链（ds）RNA、dsRNA/LyoVec刺激来自健康（n = 3）和哮喘（n = 3）受试者的原代人BSMCs，或使其感染RV。BSMCs也用嘌呤能受体拮抗剂苏拉明进行预处理。通过逆转录定量聚合酶链反应（RT-qPCR）和蛋白质印迹分析IL-33表达，并测定细胞上清液中的三磷酸腺苷（ATP）水平。
RV感染和dsRNA激活Toll样受体3（TLR3）可增加健康和哮喘BSMCs中IL-33的信使核糖核酸（mRNA）和蛋白质水平。这些作用被地塞米松抑制。使用dsRNA/LyoVec刺激视黄酸诱导基因I样受体（RIG-I样受体）也可增加BSMCs中IL-33的表达。BECs的条件培养基可诱导BSMCs表达IL-33，dsRNA可进一步增强这种表达。BECs来源的培养基和病毒刺激的BSMCs上清液中ATP水平升高。用苏拉明阻断嘌呤能信号传导可抑制dsRNA和BECs来源的培养基诱导的BSMCs中IL-33的表达。
BSMCs感染RV以及激活TLR3和RIG-I样受体会导致IL-33的表达和产生。上皮释放的因子会增加BSMCs中IL-33的表达，并与dsRNA表现出正性相互作用。BSMCs中IL-33增加与ATP释放相关，且被苏拉明拮抗。我们认为上皮来源的因子有助于BSMCs产生基线IL-33，而BSMCs感染RV并刺激其病原体识别受体可进一步增强这种产生。
