Chronic refractory cough (CRC) is characterised by cough hypersensitivity. Interferon-γ (IFN-γ) has been reported to induce calcium influx, action potentials of vagal neurons in vitro and cough response in guinea pigs. While the effect of IFN-γ in CRC patients remains unknown. Here, via flow-cytometry and inhalation cough challenge, we found CRC patients had significantly increased levels of sputum IFN-γ+CD4+ T cells, IFN-γ+CD8+ T cells as well as supernatant of IFN-γ. The average number of coughs in CRC patients increased as the concentration of inhaled IFN-γ went up in IFN-γ cough challenge. Two or more coughs and five or more coughs elicited by inhaled IFN-γ in CRC patients occurred in 7 of 10 and 2 of 10, respectively. Preinhaled IFN-γ (100 µg/mL) increased the capsaicin cough sensitivity in CRC patients but not healthy volunteers. Targeting IFN-γ may be a potential effective anti-tussive strategy in CRC patients.

中文翻译：

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干扰素-γ的表达及其对慢性难治性咳嗽患者咳嗽超敏反应的影响

慢性难治性咳嗽（CRC）的特点是咳嗽过敏。据报道，干扰素-γ (IFN-γ) 可诱导钙内流、体外迷走神经神经元的动作电位和豚鼠的咳嗽反应。虽然 IFN-γ 在 CRC 患者中的作用仍然未知。在这里，通过流式细胞术和吸入性咳嗽攻击，我们发现 CRC 患者的痰中 IFN-γ+CD4+ T 细胞、IFN-γ+CD8+ T 细胞以及 IFN-γ 上清液的水平显着增加。在 IFN-γ 咳嗽攻击中，随着吸入 IFN-γ 浓度的增加，CRC 患者的平均咳嗽次数增加。在 CRC 患者中，吸入 IFN-γ 引起的 2 次或更多咳嗽和 5 次或更多咳嗽分别发生在 10 名中的 7 名和 10 名中的 2 名中。预吸入 IFN-γ (100 µg/mL) 增加了 CRC 患者对辣椒素咳嗽的敏感性，但对健康志愿者没有影响。