TSLP诱导树突状细胞表达OX-40L的信号转导通路在变应性鼻炎中的机制研究

Allergic rhinitis（AR） is one of the global healthy problems. Quality of life is significantly decreased in patients with AR. The pathogenesis of AR is Type l hypersensitivity reaction which give priority to Th2 cells and caused mainly by environmental allergens coming into contact with nasal mucosa.The present treatment is aimed at the end stage of the cascade reaction.So AR can not be completely cured until now. It was found in our previous researches that thymic stromal lymphopoietin (TSLP) is highly expressed in nasal mucosa of patients with AR and AR mouse model. TSLP can strongly activate DCs, and can induce the high expression of OX40 ligand (OX40L).OX40L represents the original Th2 trigger from TSLP-DCs, by which TSLP activates DCs to create a Th2-permissive microenvironment.OX-40L is a critical key point of TSLP-mediated Th2 responses. They acts as a master switch to control allergic reaction on upstream. However, Inhibition TSLP and OX40L faced with many problems, including great changes of structure, easily be metabolised, playing a wider role during allergic reaction.It is necessary to find new key sites, which has clear and specific function.Base on previous researches, TSLP-induced DCs are applied as subjects to find the possible signal transduction pathway by signal transduction pathway finder gene chips, RT-PCR, phosphorylation analysis. By application of the key signal transduction pathway inhibitor to treat AR mouse model to identify the key signal transduction molecules during the TSLP induced OX-40L expression on DCs. and will be found. It is expected to find the function of TSLP induced OX-40L in AR,to put forward the new mechanism of the AR pharmacotherapy, to provide new possible molecular targets of drug action role and new treatment methods of AR.

变应性鼻炎（AR）是影响患者生活质量的全球性健康问题，发病机制为鼻黏膜接触过敏原所引发的以Th2细胞为主的I型超敏反应，目前治疗主要针对级联反应终末阶段，尚无治愈手段。我课题组前期实验发现，胸腺基质淋巴细胞生成素(TSLP)高表达于AR患者和小鼠模型的鼻黏膜，诱导树突状细胞（DCs)OX40L的高表达，形成了促进Th2细胞的微环境，在变态反应上游具有开关样调控因素。但抑制TSLP和OX40L存在变异大、易代谢、作用广泛等缺点，需进一步寻找新的功能明确、作用特异的关键靶位。故本课题拟在前期研究基础上以TSLP诱导的DCs为研究对象，通过信号转导通路发现者芯片筛选、磷酸化检测验证、信号转导通路抑制、AR动物模型实验，发现并鉴定DCs表达OX40L的关键信号转导分子，并初步阐明其在AR发生发展中的作用，为药物治疗AR机制提出新认识，并提供可能的药物作用靶位和新治疗策略。

TSLP分子目前被证实是DC细胞介导的过敏性鼻炎的关键分子，文献报道称TSLP可以诱导DC细胞超表达OX40L分子，进而引发Th2类分子的免疫应答；另有文献称STAT各类分子的磷酸化水平与TSLP分子紧密相连，因此我们推测CYT387（JAK/STAT信号通路抑制剂）影响TSLP-DCs诱导naive T细胞向Th2细胞分化且能够缓解过敏性鼻炎；Western blot结果显示TSLP处理后的DCs细胞中JAK1，JAk2，STAT1，STAT3及STAT5分子的磷酸化水平显著升高，而加入抑制剂CYT387后磷酸化水平回复正常；流式细胞术显示细胞表面抗原分子CD11c，CD80，CD86及MHC2类分子的表达水平经TSLP处理后显著上调，而抑制剂CYT387可以逆转此结果，且CYT387显著降低TSLP-DC诱导的naive T细胞向Th2细胞分化的能力。AR小鼠模型中，通过Western blot和qPCR检测OX40L的表达量显著上调，且CYT387可逆转此结果；ELISA结果显示，AR小鼠模型中IL-4和IL-5的表达水平降低，IFN-γ表达水平上调。我们的结论：阻断JAK/STAT信号通路后TSLP-DCs细胞诱导naive T细胞分化为Th2细胞的能力减弱。