NETs及其调控Dectin-1介导的免疫应答在宿主抗着色芽生菌病中的作用研究

Chromoblastomycosis has prolonged course with stubbornly intractable skin lesions, affecting the quality of life and even threatening patents’ lives. Previously studies indicated that neutrophil extracellular traps (NETs) may be participated in the killing of Fonsecaea pedrosoi muriform cell, and the muriform cell could escape from the Dectin-1 mediated Th17 immune response. The interactions between NETs and Dectin-1 mediated immune response can be seen in Candida albicans infections. In this study, we are planning to detect the release and the activity of NETs against muriform cell in vitro by co-culturing isolated human neutrophils with muriform cell. The changes of chitin and β-glucan of muriform cell after NETs attack were also detected, along with the function of immune cells which express Dectin-1, including phagocytosis, production of cytokines and the proportion of Th17 cells. Additionally, we will construct MPO-/- mice infected chromoblastomycosis model to observe the effects of NETs deficiency on the pathogenesis of chromoblastomycosis, confirm the release of NETs, and detect the immune response mediated by Dectin-1. Based on the above study, the role of NETs and its regulations on Dectin-1 mediated immune response in the pathogenesis of chromoblastomycosis will be evaluated, and a new research strategy would be supplied for the treatment of chromoblastomycosis.

着色芽生菌病（CBM）病程迁延、顽固难治，影响患者生活质量甚至威胁生命。研究证明：中性粒细胞胞外诱捕网（NETs）可能参与杀伤裴氏着色霉的硬壳细胞；硬壳细胞可逃避Dectin-1介导的Th17细胞免疫应答；白念珠菌感染时NETs与Dectin-1介导的免疫应答存在相互调控关系。因此，本项目拟通过硬壳细胞与中性粒细胞体外共培养，检测NETs的释放及对硬壳细胞的杀伤活性；检测NETs杀伤后硬壳细胞几丁质及β-葡聚糖的变化、表达Dectin-1的免疫细胞的吞噬、分泌细胞因子及诱导Naïve T分化为Th17细胞的功能。构建MPO-/-小鼠裴氏着色霉感染模型：观察NETs缺乏对CBM病程的影响；验证NETs的释放；检测Dectin-1介导的免疫应答的变化。本项目的完成，有助于揭示NETs及其调控Dectin-1介导的免疫应答在宿主抗CBM中的作用，为阐明CBM的发病机制和开发新的免疫治疗奠定基础。

着色芽生菌病（CBM）病程迁延、顽固难治，影响患者生活质量甚至威胁生命。本研究发现中性粒细胞（PMNs）可通过中性粒细胞胞外诱捕网（NETs）杀伤硬壳细胞；树突状细胞介导的Th17适应性免疫炎症通路在NETs杀伤硬壳细胞中起重要作用；阻断Th17通路发现机体抵抗CBM过程中PMNs释放NETs减弱。此外，我们还关注了NETs在诱发银屑病炎症反应中的作用，发现念珠菌可经NETs加剧银屑病炎症反应；以及系统糖皮质激素治疗可增加口腔念珠菌中非白念珠菌的比例，降低念珠菌对伊曲康唑和氟康唑的药物敏感性。以上研究结果不仅揭示NETs在宿主抗CBM中的作用，为控制慢性真菌感染寻找新的思路；更为进一步探索NETs在机体抗感染免疫和促炎反应中的双重作用奠定基础，有助于开发更多精准银屑病治疗药物。