鼻黏膜微环境通过调控局部肥大细胞表达参与嗜酸粒细胞性CRSwNP发病的作用机制

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a heterogeneous disease, and eosinophilic and non-eosinophilic CRSwNP (Eos CRSwNP and Non-Eos CRSwNP) have different pathogenic mechanism. Our previous work found that local IgE production is a critical factor for the development of Eos CRSwNP. Increased accumulation and activation of mast cells have been reported for Eos CRSwNP. Crosslinking IgE / IgD bound to mast cells by corresponding antigens can lead to mast cell activation, release of B cell-stimulating factors such as B cell-activating factor, and then facilitated local IgE production and exaggerated eosinophilic inflammation in CRSwNP, which further highlighting a contribution of mast cell activation to the eosinophilic inflammation in CRSwNP. However, the initiation factors and upstream molecular events of upregulation of mast cell expression in Eos CRSwNP have not been revealed. It is the mast cell progenitors (MCp) which leaves the bone marrow and travels via the circulatory system to peripheral sites. At these sites, stimulated by the local microenvironment the MCp matures into a mature mast cell. This study compared the expression of mast cells and MCp in peripheral blood and nasal tissues of patients with Eos and Non-Eos CRSwNP. The expression levels of cytokines in the nasal microenvironment, which were able to influence the chemotaxis and maturation of MCp, were examined. Flow cytometry, utilizing magnetic activated cell sorting, cell culture and tissue culture were used to investigate the regulation of differential expression of mast cells by nasal microenvironment, which further affected the local IgE production of nasal polyps. This study attempts to reveal how the local microenvironment affects the development of Eos CRSwNP by regulating the expression of mast cells and then affecting the local IgE production in the nasal mucosa. This study helps to elucidate the mechanism by which mast cells participate in the pathogenesis of Eos CRSwNP, and provides a new approach to the treatment of Eos CRSwNP.

嗜酸粒细胞性鼻息肉（Eos CRSwNP）与非嗜酸粒细胞性鼻息肉（Non-Eos CRSwNP）存在不同的发病机制。我们前期研究显示肥大细胞参与Eos CRSwNP发病机制。在Eos CRSwNP中，肥大细胞表达增强，交联肥大细胞表面的 IgE / IgD引起细胞活化，释放B细胞刺激因子,从而促进局部IgE的产生及嗜酸性粒细胞炎症的形成。然而在Eos CRSwNP中，肥大细胞表达上调的启动因素和上游分子事件并未被揭示。外周血肥大前体细胞（MCp）迁移至局部组织并在其中转化为成熟的肥大细胞，暗示了局部微环境对肥大细胞的调控作用。本课题拟通过对比Eos和Non-Eos CRSwNP的外周血及局部组织中MCp的表达，影响MCp趋化、成熟的细胞因子的表达，并采用细胞培养等手段探讨局部微环境如何调控肥大细胞表达从而影响局部IgE产生参与鼻息肉发病机制；为Eos CRSwNP的治疗提供新途径。

伴鼻息肉的慢性鼻鼻窦炎根据是否伴有嗜酸性粒细胞浸润分为嗜酸粒细胞性鼻息肉（Eos CRSwNP）与非嗜酸粒细胞性鼻息肉（Non-Eos CRSwNP）。二者存在不同的发病机制。我们前期研究显示肥大细胞参与Eos CRSwNP的嗜酸粒细胞性炎症的形成。在Eos CRSwNP中，肥大细胞表达增强，交联肥大细胞表面的 IgE / IgD引起细胞活化，释放B细胞刺激因子,从而促进局部IgE的产生及嗜酸性粒细胞炎症的形成。然而在Eos CRSwNP中，肥大细胞表达上调的启动因素和上游分子事件并未被揭示。外周血肥大前体细胞（MCp）迁移至局部组织并在其中转化为成熟的肥大细胞，暗示了局部微环境对肥大细胞的调控作用。本课题通过流式细胞术分析了Eos和Non-Eos CRSwNP的外周血及局部组织中MCp的表达，结果显示，在外周血中，MCp细胞在三组患者中表达无显著性差异。与外周血结果相反，在鼻黏膜局部中，Eos和Non-Eos CRSwNP 患者中MCp细胞在鼻黏膜单个核细胞中的表达均显著升高，在Eos CRSwNP 患者中升高更明显。此外，我们还发现鼻黏膜MCp细胞表达水平与黏膜局部肥大细胞表达水平呈正相关，暗示了在鼻黏膜肥大细胞的差异性表达受局部环境因素如血管通透性、趋化因子、促进MCp细胞成熟细胞因子等的调控。通过RT-PCR、ELISA等技术我们分析了鼻黏膜组织中影响MCp趋化、成熟的细胞因子的表达。结果显示，在鼻黏膜局部中，VCAM-1、SCF、IL-3、IL-9等在Eos CRSwNP 患者中显著升高。暗示了较正常组，在Eos CRSwNP 患者中更多的MCp细胞由外周血迁移至鼻黏膜局部并在其中转化为成熟的肥大细胞。 通过细胞培养等技术，我们发现细菌提取物可刺激组织块表达SCF、IL-3、IL-9等影响MC成熟的细胞因子的表达。暗示了局部微环境对肥大细胞的差异性表达的调控影响。为Eos CRSwNP的治疗提供新途径。