TRAF1在雷帕霉素抑制过敏性哮喘炎症反应中的作用及其机制研究

In recent years, the effect on inflammatory reaction of immunosuppressive drugs attracts more and more close attention, and some researchers try to reveal the mechanism and regularity of anaphylaxis by point of autarcetic view by many pertinent data,and expected to find a new method or pathway of non-specifical molecule combining with specific drug to cure allergy. Owing to powerful immunosuppressing effect and little poisonous side effect, the macrocyclic lactone drug rapamycin is planed to be used to treat allergic asthma. Before this article, in order to indicate the mechanism of rapamycin in allergic disease, we have observed the effect of rapamycin on DC2.4 and p815 cells, then analysized the expression spectrum of their whole genome. Our preliminary experiments showed that rapamycin can upregulate the expression of TRAF1 obviously and the inflammation of lung from allergic asthma mouse was attenuated prominently by rapamycin. On the basis of these results, we prepare to study the effect of rapamycin and TRAF1 on regulating inflammation and activating mast cells and dendrtic cells, which contributes to indicating the mechanism actions of that. Subsequently, we plan to observe the role of TRAF1 more further, we hope to probe the possible related action mechanism between rapamycin and TRAF1..The meanings of this study mainly are , first, the mechanism of action of immunosuppressive drug, such as rapamycin, and its key role in inhibiting allergic asthma and activating dendritic cells will be confirmed.next, the relationship between immunosuppressive drug and suppressing factor for inflammation will be probed. The result will provide theoretical evidence for controlling allergic asthma by targeting TRAF1. Besides, this study will provide a mirror for other allergic responses related toTRAF1. In point of non-specific immunity view, and conduce to break through the limit of specific allergic antigen.

近年来，免疫抑制药物在临床炎症控制中的作用越来越受到关注，一些研究者开始从天然免疫角度寻求非特异免疫分子结合免疫抑制药物治疗过敏症的新途径。大环内酯药物rapamycin具有强免疫抑制效应，为了探讨它在过敏性疾病中的作用机制，课题组前期研究用rapamycin处理树突状细胞DC2.4和肥大细胞p815后，进行全基因组表达谱分析，发现rapamycin能抑制过敏性哮喘的炎症损伤，并能上调与炎症相关分子TRAF1表达。本项目拟在前期研究的基础上，阐明rapamycin和TRAF1对过敏性哮喘、肥大细胞及树突状细胞活化的作用，揭示其作用机理，进而探索rapamycin、TRAF1分子在过敏性哮喘中的协调作用及机制。.其意义在于：（1）揭示rapamycin影响过敏性哮喘及肥大细胞、树突状细胞的活化机理。（2）揭示免疫抑制药物与胞内炎症分子间的联系，为寻求药物靶向治疗和控制过敏症途径提供新思路。

近年来，免疫抑制药物在临床炎症控制中的作用越来越受到关注，一些研究者开始从天然免疫角度寻求非特异免疫分子结合免疫抑制药物治疗过敏症的新途径。大环内酯药物rapamycin具有强免疫抑制效应，为了探讨它在过敏性疾病中的作用机制，课题组前期研究用rapamycin处理树突状细胞DC2.4和肥大细胞p815后，进行全基因组表达谱分析，发现rapamycin能抑制过敏性哮喘的炎症损伤，并能上调与炎症相关分子TRAF1表达。本项目拟在前期研究的基础上，阐明rapamycin和TRAF1对过敏性哮喘、肥大细胞及树突状细胞活化的作用，揭示其作用机理，进而探索rapamycin、TRAF1分子在过敏性哮喘中的协调作用及机制。研究进展过程中，检测TRAF-1因子的基因芯片合成遇到问题被搁置，且自每批模型鼠骨髓中分离培养的树突状细胞和肥大细胞数量较少，难以达到实验分组的样本要求，改进实验方法的过程中，我们发现OVA诱导过敏性哮喘炎症的C57小鼠巨噬细胞Rheb1表达和mTORC1活性均增加。因此，我们接着利用巨噬细胞特异性敲除Rheb1小鼠模型来研究OVA诱导过敏性哮喘中Rheb1的作用及其细胞和分子机制，实验结果显示：1. OVA诱导的过敏性炎症促进小鼠肺泡炎症细胞mTORC1和Rheb1活化；2.巨噬细胞特异性敲除Rheb1加剧OVA诱导过敏性炎症的发生；3.巨噬细胞特异性敲除Rheb1在过敏性炎症中诱导Th2细胞因子而抑制Th1细胞因子表达；4.巨噬细胞特异性敲除Rheb1增加M2型巨噬细胞极化而抑制M1型巨噬细胞；5.巨噬细胞特异性敲除Rheb1在过敏性炎症中增加M2型巨噬细胞极化而抑制M1型巨噬细胞。.鉴于这些发现，我们推测Rheb1作为TSC1/2复合物的下游效应器，能够改变Th1/Th2细胞因子表达，直接参与调节巨噬细胞极性和影响OVA诱导过敏性哮喘，此过程可能依赖TSC-mTORC1信号通路发挥作用。总而言之，巨噬细胞特异性敲除Rheb1直接抑制Rheb1 GTP酶活性和mTORC1活性，阻断了M1型巨噬细胞极化而促进了M2型巨噬细胞极化，因此Rheb1在巨噬细胞中可能是哮喘的关键控制点之一。