Analysis of the dynamic skin immune and physical barrier system by tight junctions and Langerhans cells

皮肤屏障由角质层屏障和紧密连接屏障构成。角质层屏障的不足使患者易患特应性皮炎，其机制是通过增强经皮变应原渗透和随后的过敏性致敏。我们发现，表皮朗格汉斯细胞从内向外穿透紧密连接屏障，并摄取穿透角质层的抗原，但仅限于通过紧密连接屏障穿透体内。在特应性皮炎患者中，郎格汉斯细胞紧密连接穿透的数量增加，这表明对外部变应原的经皮致敏作用增强。

Skin barrier is constituted by the stratum corneum barrier and tight junction barrier. Insufficiency of the stratum corneum barrier predispose patients to atopic dermatitis via enhanced percutaneous allergen penetration and subsequent allergic sensitization. We discovered that epidermal Langerhans cells penetrate through the tight junction barrier from inside to outside and take up antigens that penetrate through the stratum corneum but are limited to penetrate into the body by the tight junction barrier. In the atopic dermatitis patients, the tight junction penetration of Langerhans cells are increased in number, suggesting enhanced percutaneous sensitization against external allergens.