嗜酸性鼻息肉ST2+CD4+记忆性T细胞通过p38-MAPK通路产生激素抵抗的机制研究

Glucocorticoid resistance within eosinophilic nasal polyps (ENP) is an important clinical issue attracting great attention in recent years and is eagerly needed to be addressed. Recent studies have revealed that ST2+CD4+ memory-type T cells (ST2+Tm) participate in the steroid resistant pathogenicity of airway type 2 inflammation, while the role of ST2+Tm in ENP steroid resistant remains unclear. We previously found that IL-33 and ST2 are highly expressed in NP. Further experiments showed the frequencies of ST2+Tm were significantly increased in ENP patients with GCR. Dexamethasone showed limited effects on the Th2 function of ST2+Tm derived from ENP as well as phosphorylation level of p38 kinase. Since p38-MAPK signaling is the main pathway that memory T helper 2 cells driving inflammatory pathogenicity, we hypothesize that ST2+Tm induce glucocorticoid resistance in ENP through activation of p38 kinase signaling. In the present study, we aim to isolate and in vitro culture the subset of ST2+Tm, investigate the phenotype and steroid resistant characteristic of these cells. Stepwise blockade of the p38 MAPK signaling, further exploring the intracellular signaling mechanism that contribute to steroid resistant of the ST2+Tm. The results of this study contribute to elucidate the mechanism of ST2+Tm cells mediating steroid resistant in ENP, and provide evidence for exploiting precise and effective drugs reversing steroid resistant ENP.

嗜酸性鼻息肉(ENP)存在糖皮质激素抵抗是近年引起重视且亟待解决的重要临床问题之一，文献报道ST2+CD4+记忆性T细胞(ST2+Tm)在气道Th2炎症激素抵抗的发病中具有突出效应，但其是否和ENP激素抵抗的发病有关仍不清。我们先前发现鼻息肉高表达ST2及其配体IL-33；进一步预实验发现激素抵抗ENP中ST2+Tm比例增高；激素在体外既不能抑制ENP来源ST2+Tm的促Th2功能，也不能影响其胞内p38-MAPK通路的磷酸化。据此我们假设：ST2+Tm可能通过p38-MAPK通路的活化参与了ENP激素抵抗的发病。本项目拟进一步分离组织ST2+Tm，采用流式技术、ELISA、qRT-PCR等分析细胞的激素抵抗特性；通过逐级阻断p38-MAPK通路，深入研究ST2+Tm激素抵抗的机制。本研究结果将明晰ST2+Tm在ENP激素抵抗中的作用和机制，为逆转ENP激素抵抗开发精准有效的药物提供依据。

嗜酸性鼻息肉(ENP)存在糖皮质激素抵抗是亟待解决的重要临床问题，ST2+CD4+记忆性T细胞(ST2+Tm)在气道Th2炎症激素抵抗的发病中具有突出效应，但其是否和ENP激素抵抗的发病有关仍不清。我们先前发现鼻息肉组织高表达ST2及其配体IL-33。在本项目的资助下，我们进一步验证及探讨ENP的ST2+Tm中IL-33/ST2信号通路产生激素抵抗的机制。实验结果发现：1）激素抵抗型ENP比激素敏感型ENP表达更高水平IL-33；且激素抵抗型ENP的CD4+T细胞表达更高水平ST2，提示激素抵抗型ENP中IL-33/ST2信号较激素敏感型ENP更强；2）通过分离ENP组织单个核细胞（NPMC）、外周血单个核细胞（PBMC）体外培养后进行干预，流式分析发现地塞米松（Dex）对PBMC中IL5+ST2+CD4+T细胞有抑制作用，而对NPMC中IL5+ST2+CD4+T细胞无影响，提示ENP组织，而非外周血中，ST2+Tm对激素抵抗。3）流式分析和Western Blot结果显示Dex对ST2+Tm中ST2、p38-MAPK、GR表达与phosho-p38磷酸化水平无显著作用，而抑制p38-MAPK磷酸化后ST2+NPMC对激素的抵抗作用被部分逆转。以上实验结果表明ENP中ST2+Tm中IL-33/ST2信号通过p38-MAPK磷酸化介导了其对激素抵抗作用，明确了ENP中ST2+Tm对激素抵抗的机制，为ENP激素抵抗的临床转化应用提供实验依据。