间充质干细胞外泌体携带miR-150诱导耐受性DC抑制鼻过敏反应的作用及其机制的研究

Allergic rhinitis has been becoming the focus of research for its high incidence in general population worldwide. The pathogenesis of allergy remains unclear and lacks of ideal therapies. Recent studies found that mesenchymal stem cells could induce tolerogenic dendritic cells through the secretion of IL-10 and TGF-betato inhibit allergic reaction. Then, do exosomes derived from mesenchymal stem cells have the same functions in inducing immune tolerance by tolerogenic DCs? What is the mechanism? Our preliminary studies indicated that miR-150, a well‐known anti‐inflammatory miRNA, could inhibit DC differentiation and maturation and promote the secretion of IL-10, leading to T cell tolerance, which could be packaged into mesenchymal stem cell exosomes. We found that systemic administration of BMSC exosomes laden miR-150 ameliorated the symptoms of murine allergic rhinitis. Furthermore, miR-150 could negatively regulate of its target gene IRAK2 and promote the secretion of IL - 10, an anti‐inflammatory factor, and inhibit the allergic inflammatory responses. Thus, we hypothesize that: BMSC-derived miR-150—laden exosomes can regulate DC differentiation and functions though the TLR/IL-1R signaling pathways, in which IRAK2 is involved, to induce DC to differentinto the immature phenotype though inhibiting the expression of the surface costimulatory molecules and secreting IL–10. Based on our preliminary findings, the proposed project is designed to investigate the effects and mechanisms by which the BMSC-exosome derived miR-150 mediates inhibition of allergic inflammation using liposomes carrying miR-150 to induce tolerogenic dendritic cells in an allergic environment, to provide new insights and novel therapeutic strategies for the treatment of allergic diseases.

变应性鼻炎是鼻科的常见病，其发病机制十分复杂，且缺乏理想的治疗方法。最新研究发现，间充质干细胞能诱导耐受性树突状细胞通过分泌IL-10和TGF-β抑制过敏反应。那么，间充质干细胞外泌体是否也能诱导DC产生免疫耐受呢？机制是什么？我们前期研究发现间充质干细胞外泌体中含有大量的miR-150，能诱导DC耐受，分泌IL-10，缓解过敏性鼻炎小鼠的症状。因此我们假设：间充质干细胞外泌体通过携带miR-150诱导DC耐受抑制过敏反应的发生。本项目拟在前期研究基础上，通过向间充质干细胞脂质体转染miR-150，观察miR-150对其靶基因IRAK2的负向调控作用，能否阻断树突状细胞内TLR/IL-1R信号通路，抑制DC表面共刺激分子的表达，促进IL-10的分泌，阐明间充质干细胞外泌体通过携带miR-150诱导DC耐受产生抗过敏的作用及其关键调控机制，从而为过敏性疾病的研究和治疗寻求新的靶点。

变应性鼻炎是鼻科的常见病，其发病机制十分复杂，且缺乏理想的治疗方法，恢复和调节免疫平衡是抑制过敏反应的重要手段。树突状细胞不仅是免疫应答的启动者，也是免疫平衡的的维持者，诱导耐受性树突状细胞的产生是治疗过敏性疾病的新靶点。本课题旨在研究间充质干细胞外泌体通过携带miR-150诱导耐受型树突状细胞的产生，抑制变应性鼻炎的作用及机制。.本研究首先分离提取间充质干细胞外泌体，并对其形态表征进行鉴定；观察其对树突状细胞表面共刺激分子、T细胞增殖、分泌细胞因子的影响，探讨间充质干细胞外泌体对树突状细胞分化成熟和功能的影响；然后建立变应性鼻炎小鼠模型检测miR-150及其靶基因IRAK2的表达变化，观察间充质干细胞外泌体携带miR-150对变应性鼻炎的治疗效果，并探讨miR-150抑制其靶基因IRAK2的表达调控TLR/IL-1R信号通路诱导DC产生耐受表型，改善炎症及恢复Th1/Th2与Th17/Treg 免疫平衡抑制鼻过敏反应的作用。此外，本课题组还对树突状细胞外泌体、上皮细胞外泌体进行改装，使其携带特异性抗原表位肽或相关细胞因子，使其具有靶向性或抗原特异性能诱导产生免疫耐受，抑制过敏反应。.综上，间充质干细胞外泌体能够抑制树突状细胞分化成熟，并诱导免疫耐受抑制过敏反应；miR-150及其靶基因IRAK2与变应性鼻炎的发病有关，间充质干细胞外泌体作为理想的药物载体，不仅含有间充质干细胞的生物学功能，还能携带miR-150通过抑制其靶基因IRAK2的表达，调控TLR/IL-1R信号通路诱导DC 产生耐受表型。由于不同细胞来源的外泌体携带不同的活性物质，具有不同的免疫调控作用，本课题组通过对不同细胞来源的外泌体进行选择性组装，使其能够携带药物进行靶向性投递，调节机体免疫平衡；为进一步开发具有自主知识产权的用于治疗过敏性疾病的新型药物奠定了基础，具有广阔的应用开发前景。