Asthma is a complex and heterogeneous inflammatory response characterized by various immune cells, including myeloid-derived suppressor cells (MDSCs) and CD4+ T-cell subsets. However, few studies on MDSC subsets and the association between MDSCs and CD4+ T-cell subsets in asthma are reported. In the present study, we detected CD4+ T cells and MDSC subsets and evaluated the relationship of these cells in mice with ovalbumin-induced asthma. We found that asthmatic mice showed severe airway inflammatory response and inflammatory cell infiltration in the lungs and bronchoalveolar lavage fluid. We also noted increased numbers of Th2, Th17, and MDSCs; decreased proportion of Th1 and Treg cells in the splenocytes and lungs; and increased expression of pro-inflammatory cytokines in splenocytes and lungs. Granulocytic MDSCs (G-MDSCs) and Th17 cells were closely related. Gemcitabine treatment reduced the G-MDSC level and the iNOS expression, alleviated the inflammatory response, and decreased the proportion and number of Th2 and Th17 cells in asthmatic mice. Besides the increase in Th2 and Th17 cells, the findings indicate that G-MDSC elevation plays a crucial role in asthmatic mice.

中文翻译：

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粒细胞髓源性抑制细胞升高与实验性哮喘小鼠 Th17 细胞升高密切相关。

哮喘是一种复杂且异质的炎症反应，其特征在于各种免疫细胞，包括髓源性抑制细胞 (MDSC) 和 CD4+ T 细胞亚群。然而，很少有关于 MDSC 亚群和 MDSC 与哮喘中 CD4+ T 细胞亚群之间关联的研究报道。在本研究中，我们检测了 CD4+ T 细胞和 MDSC 亚群，并评估了这些细胞与卵清蛋白诱导的哮喘小鼠的关系。我们发现哮喘小鼠在肺部和支气管肺泡灌洗液中表现出严重的气道炎症反应和炎症细胞浸润。我们还注意到 Th2、Th17 和 MDSC 数量增加；脾细胞和肺中 Th1 和 Treg 细胞的比例降低；并增加脾细胞和肺中促炎细胞因子的表达。粒细胞 MDSCs (G-MDSCs) 和 Th17 细胞密切相关。吉西他滨治疗降低了哮喘小鼠的 G-MDSC 水平和 iNOS 表达，减轻了炎症反应，并降低了 Th2 和 Th17 细胞的比例和数量。除了 Th2 和 Th17 细胞的增加外，研究结果表明 G-MDSC 升高在哮喘小鼠中起着至关重要的作用。