Epidermal Langerhans cells in the terrestrial turtle, Kinosternum integrum

In mammalian epidermis, Langerhans cells (LC) are the only antigen-presenting dendritic cells that possess the ectoenzyme adenosine triphosphase (ATPase) and constitutively express class II molecules encoded by the major histocompatibility complex. Recently, we demonstrated the presence of LC in chicken epidermis. The aim of the present study is to demonstrate the presence of LC-like cells in turtle Kinosternum integrum, epidermis by light and ultrastructural ATPase histochemistry. ATPase-positive dendritic cells were observed in epidermal sheets whose maximum mean number was 192 cells/mm2. Electron microscopy for ATPase stained sections showed an electrondense precipitate in the plasma membrane of dendritic clear cells located among basal and suprabasal keratinocytes, ultrastructurally similar to LC. In serial sections, some dendritic cells showed LC (Birbeck) granules. The present study demonstrates for the first time ATPase-positive dendritic cells, morphologically similar to LC, in reptilian epidermis.