EPIDERMAL LANGERHANS CELLS IN THE TERRESTRIAL TURTLE, KINOSTERNUM-INTEGRUM

In mammalian epidermis, Langerhans cells (LC) are the only antigen-pre senting dendritic cells that possess the ectoenzyme adenosine triphosp hase (ATPase) and constitutively express class II molecules encoded by the major histocompatibility complex. Recently, we demonstrated the p resence of LC in chicken epidermis. The aim of the present study is to demonstrate the presence of LC-like cells in turtle Kinosternum integ rum, epidermis by light and ultrastructural ATPase histochemistry. ATP ase-positive dendritic cells were observed in epidermal sheets whose m aximum mean number was 192 cells/mm(2). Electron microscopy for ATPase stained sections showed an electrondense precipitate in the plasma me mbrane of dendritic clear cells located among basal and suprabasal ker atinocytes, ultrastructurally similar to LC. In serial sections, some dendritic cells showed LC (Birbeck) granules. The present study demons trates for the first time ATPase-positive dendritic cells, morphologic ally similar to LC, in reptilian epidermis.