ATPase and MHC class II molecules co-expression in Rana pipiens dendritic cells

Mammalian Langerhans cells are antigen-presenting cells located in different epithelia. These cells have a characteristic ultrastructural pattern, present a plasmatic membrane ATPase activity and constitutively express class II molecules of the major histocompatibility complex. ATPase-positive dendritic cells that are morphologically similar to Langerhans cells have also been found in amphibian epidermis. In order to demonstrate that ATPase-positive dendritic cells of amphibian epidermis express class II molecules and are present in other stratified epithelia, histochemical and immunohistochemical as well as ultrastructural analysis were performed. ATPase-positive dendritic cells and class II-positive dendritic cells were observed in epidermis, nictitant membrane and cornea. In epidermis the number of ATPase-positive dendritic cells was 656 +/- 186/mm(2) while class II-positive dendritic cells was 119 +/- 45/mm(2). Some ATPase-positive dendritic cells showed co-expression of class II molecules. These results suggest the existence of dendritic cell subsets in amphibians as is clearly demonstrated in mammals. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.