Wex Eva, Thaler Eva, Blum Sylvia, Lamb David
Respiratory Diseases Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany.
PLoS One. 2014 Dec 26;9(12):e116166. doi: 10.1371/journal.pone.0116166. eCollection 2014.
Mast cells are central effector cells in allergic asthma and are augmented in the airways of asthma patients. Attenuating mast cell degranulation and with it the early asthmatic response is an important intervention point to inhibit bronchoconstriction, plasma exudation and tissue oedema formation. To validate the efficacy of novel pharmacological interventions, appropriate and practicable in vivo models reflecting mast cell-dependent mechanisms in the lung, are missing. Thus, we developed a novel model of passive pulmonary anaphylaxis in rats. Rats were passively sensitized by concurrent intratracheal and intradermal (ear) application of an anti-DNP IgE antibody. Intravenous application of the antigen, DNP-BSA in combination with Evans blue dye, led to mast cell degranulation in both tissues. Quantification of mast cell degranulation in the lung was determined by (1) mediator release into bronchoalveolar lavage, (2) extravasation of Evans blue dye into tracheal and bronchial lung tissue and (3) invasive measurement of antigen-induced bronchoconstriction. Quantification of mast cell degranulation in the ear was determined by extravasation of Evans blue dye into ear tissue. We pharmacologically validated our model using the SYK inhibitor Fostamatinib, the H1-receptor antagonist Desloratadine, the mast cell stabilizer disodium cromoglycate (DSCG) and the β2-adrenergic receptor agonist Formoterol. Fostamatinib was equally efficacious in lung and ear. Desloratadine effectively inhibited bronchoconstriction and ear vascular leakage, but was less effective against pulmonary vascular leakage, perhaps reflecting the differing roles for histamine receptor sub-types. DSCG attenuated both vascular leakage in the lung and bronchoconstriction, but with a very short duration of action. As an inhaled approach, Formoterol was more effective in the lung than in the ear. This model of passive pulmonary anaphylaxis provides a tissue relevant readout of early mast cell activity and pharmacological benchmarking broadly reflects responses observed in patients with asthma.
肥大细胞是过敏性哮喘的关键效应细胞，在哮喘患者气道中数量增加。减轻肥大细胞脱颗粒以及随之而来的早期哮喘反应是抑制支气管收缩、血浆渗出和组织水肿形成的重要干预点。为了验证新型药物干预的疗效，目前缺少反映肺中肥大细胞依赖性机制的合适且可行的体内模型。因此，我们开发了一种新型大鼠被动性肺过敏模型。通过气管内和皮内（耳部）同时应用抗二硝基苯（DNP）IgE抗体使大鼠被动致敏。静脉注射抗原DNP-牛血清白蛋白（DNP-BSA）并结合伊文思蓝染料，导致两个组织中的肥大细胞脱颗粒。通过以下方法对肺中肥大细胞脱颗粒进行定量：（1）介质释放到支气管肺泡灌洗液中；（2）伊文思蓝染料渗入气管和支气管肺组织；（3）侵入性测量抗原诱导的支气管收缩。通过伊文思蓝染料渗入耳部组织对耳部肥大细胞脱颗粒进行定量。我们使用脾酪氨酸激酶（SYK）抑制剂福斯替尼、H1受体拮抗剂地氯雷他定、肥大细胞稳定剂色甘酸二钠（DSCG）和β2肾上腺素能受体激动剂福莫特罗对我们的模型进行了药理学验证。福斯替尼在肺和耳中同样有效。地氯雷他定有效抑制支气管收缩和耳部血管渗漏，但对肺血管渗漏的效果较差，这可能反映了组胺受体亚型的不同作用。DSCG减轻了肺中的血管渗漏和支气管收缩，但作用持续时间非常短。作为一种吸入方法，福莫特罗在肺中的效果比在耳中更有效。这种被动性肺过敏模型提供了早期肥大细胞活性与组织相关的读数，药理学基准大致反映了哮喘患者中观察到的反应。
