Blomme Evy E, Provoost Sharen, Bazzan Erica, Van Eeckhoutte Hannelore P, Roffel Mirjam P, Pollaris Lore, Bontinck Annelies, Bonato Matteo, Vandenbroucke Louise, Verhamme Fien, Joos Guy F, Cosio Manuel G, Vanoirbeek Jeroen A J, Brusselle Guy G, Saetta Marina, Maes Tania
Dept of Respiratory Medicine, Laboratory for Translational Research in Obstructive Pulmonary Diseases, Ghent University Hospital, Ghent, Belgium.
Dept of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padova, Padova, Italy.
Eur Respir J. 2020 Sep 24;56(3). doi: 10.1183/13993003.01289-2019. Print 2020 Sep.
Occupational asthma, induced by workplace exposures to low molecular weight agents such as toluene 2,4-diisocyanate (TDI), causes a significant burden to patients and society. Little is known about innate lymphoid cells (ILCs) in TDI-induced asthma. A critical regulator of ILC function is microRNA-155, a microRNA associated with asthma.
To determine whether TDI exposure modifies the number of ILCs in the lung and whether microRNA-155 contributes to TDI-induced airway inflammation and hyperresponsiveness.
C57BL/6 wild-type and microRNA-155 knockout mice were sensitised and challenged with TDI or vehicle. Intracellular cytokine expression in ILCs and T-cells was evaluated in bronchoalveolar lavage (BAL) fluid using flow cytometry. Peribronchial eosinophilia and goblet cells were evaluated on lung tissue, and airway hyperresponsiveness was measured using the forced oscillation technique. Putative type 2 ILCs (ILC2) were identified in bronchial biopsies of subjects with TDI-induced occupational asthma using immunohistochemistry. Human bronchial epithelial cells were exposed to TDI or vehicle.
TDI-exposed mice had higher numbers of airway goblet cells, BAL eosinophils, CD4 T-cells and ILCs, with a predominant type 2 response, and tended to have airway hyperresponsiveness. In TDI-exposed microRNA-155 knockout mice, inflammation and airway hyperresponsiveness were attenuated. TDI exposure induced IL-33 expression in human bronchial epithelial cells and in murine lungs, which was microRNA-155 dependent in mice. GATA3CD3 cells, presumably ILC2, were present in bronchial biopsies.
TDI exposure is associated with increased numbers of ILCs. The proinflammatory microRNA-155 is crucial in a murine model of TDI asthma, suggesting its involvement in the pathogenesis of occupational asthma due to low molecular weight agents.
职业性哮喘由工作场所接触低分子量物质如甲苯2,4 -二异氰酸酯（TDI）诱发，给患者和社会带来了沉重负担。关于TDI诱发哮喘中固有淋巴细胞（ILC）的情况知之甚少。ILC功能的一个关键调节因子是微小RNA - 155，这是一种与哮喘相关的微小RNA。
确定TDI暴露是否会改变肺部ILC的数量，以及微小RNA - 155是否促成TDI诱发的气道炎症和高反应性。
将C57BL / 6野生型和微小RNA - 155基因敲除小鼠用TDI或赋形剂进行致敏和激发。使用流式细胞术评估支气管肺泡灌洗（BAL）液中ILC和T细胞内细胞因子的表达。对肺组织中的支气管周围嗜酸性粒细胞和杯状细胞进行评估，并使用强迫振荡技术测量气道高反应性。使用免疫组织化学在TDI诱发的职业性哮喘患者的支气管活检中鉴定假定的2型ILC（ILC2）。将人支气管上皮细胞暴露于TDI或赋形剂。
暴露于TDI的小鼠气道杯状细胞、BAL嗜酸性粒细胞、CD4 T细胞和ILC数量更多，呈现主要的2型反应，并且往往具有气道高反应性。在暴露于TDI的微小RNA - 155基因敲除小鼠中，炎症和气道高反应性减弱。TDI暴露诱导人支气管上皮细胞和小鼠肺中IL - 33表达，在小鼠中这依赖于微小RNA - 155。支气管活检中存在GATA3⁺CD3⁻细胞，推测为ILC2。
TDI暴露与ILC数量增加有关。促炎性微小RNA - 155在TDI哮喘小鼠模型中至关重要，表明其参与了由低分子量物质引起的职业性哮喘的发病机制。
