特应性皮炎（AD）经皮致敏现象普遍存在，但其机制尚不清楚。作为表皮中的前哨细胞，朗格汉斯细胞（LCs）在此过程中发挥重要作用。Langerin是特异性表达于LCs上的C型凝集素受体。我们的前期研究显示，Langerin可与多种变应原(包括Mannan)特异性结合；Mannan多糖作用的体外皮片模型中，移出皮片的LCs数量和比率明显增加；与健康人比较，AD患者LCs上表达的Langerin水平增高。故推测Langerin在介导变应原经皮致敏过程中扮演重要角色。 本课题拟以LCs、皮片培养系统、Langerin-AD小鼠为研究对象，进行AD患者LCs表面Langerin表达、Langerin与多种变应原结合能力、Langerin介导变应原识别、递呈和诱导下游免疫反应和分子机制研究。试图证实Langerin在介导变应原免疫应答及在AD经皮致敏中的作用。检索已发表文献，未见AD此方面的研究报道。

Epicutaneous sensitization(ES) is very common in atopic dermatitis(AD). Until now, the exact mechanisms are still unknown. As the important sentinel cell, Langerhans cells(LCs) play an key role in this process. Langerin is a typical C type lectin receptors expressed on LCs. Our previous studies showed that Langerin could bind with many kinds of allergens specifically, and Mannan could promote immature LCs moving out the skin explants culture to become mature. Contrast to healthy controls, Langerin expression levels of LCs was higher in AD patients. In view of these preliminary data, we speculate that Langerin may be involved in EC directly. In our experimental design, we will use LCs, skin explants culture and K5-rtTA/tetO-TSLP mice as the research objects to study the following aspects: ①Langerin expression levels of LCs in AD patients;②Binding ability between Langerin and some kind of allergens; ③The mechanisms of allergen recognition、presentation and T cell responses mediated by Langerin. Through the above series studies, we try to verify the real function of Langerin on mediation allergen immune response and EC of AD. After retrieve the published papers, we could not find any relevant reported studies .