Ultrastructure of normal armadillo epidermis.

In view of the importance of the nine-banded armadillo (Dasypus novemcinctus) in leprosy research, we studied the ultrastructure of the normal epidermis of this species. The three basic cell types of human epidermis were identified in armadillo skin: keratinocytes, melanocytes, and Langerhans' cells. The role of Langerhans' cells in the human cell-mediated immune system and the description of changes in the number and structure of Langerhans' cells in human leprosy make detailed observations of these cells in the armadillo highly relevant. Clear cells with ultrastructural features typical of Langerhans' cells were observed in normal armadillo epidermis in all areas of skin sampled (abdomen, chin, ear, and thigh), but are fewer than in human skin. These baseline findings are valuable for further studies on Langerhans' cells and the cell-mediated immune function in armadillos with naturally acquired or experimental leprosy.