[The role of Langerhans cells in the skin immune system]

Langerhans cells (LC) are members of the dendritic cells family, residing in the basal and suprabasal layers of the epidermis and in the epithelia of the respiratory, digestive and urogenital tracts. They specialize in antigen presentation and belong to the skin immune system (SIS). LC acquire antigens in peripheral tissues, transport them to regional lymph nodes, present to naive T cells and initiate adaptive immune response. LC have strong immunogenic properties but they may also act as mediators of tolerance, for example to comensal bacteria. They are involved in antimicrobial immunity, skin immunosurveillance, induction phase of the contact hypersensitivity and in the pathogenesis of chronic inflammatory diseases of the skin or mucosa. We present the current knowledge of Langerhans cells' role in the skin immune system.