Comparative ultrastructure of Langerhans-like cells in spleens of ray-finned fishes (Actinopterygii)

• Published in: Journal of morphology (1931) Vol. 271; no. 10; pp. 1229 - 1239
• Main Authors: Lovy, Jan, Wright, Glenda M., Speare, David J., Tyml, Tomas, Dykova, Iva
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.10.2010
• Subjects: Actinopterygii; Animals; Birbeck granules; cyprinidae; Cypriniformes; Cytoplasmic Granules - ultrastructure; dendritic cells; Esox lucius; fish; Fishes - anatomy & histology; Freshwater; halibut; Hippoglossus hippoglossus; Langerhans cell; Langerhans Cells - chemistry; Langerhans Cells - ultrastructure; Marine; Microscopy, Electron, Transmission; Multivesicular Bodies - ultrastructure; Perca fluviatilis; Pleuronectiformes; Salmonidae; Salmoniformes; Spleen - cytology; Spleen - ultrastructure; Trichogaster trichopterus; ultrastructure; A, Atlantic
• ISSN: 0362-2525; 1097-4687
• DOI: 10.1002/jmor.10866

We studied the morphology and occurrence of splenic Langerhans‐like (LL) cells in species representing 11 orders of ray‐finned fishes, Actinopterygii. LL cells were frequent in spleen tissue of species among Cypriniformes, Esociformes, Salmoniformes, and Pleuronectiformes. These cells contained granules which resembled Birbeck granules known to occur in mammalian Langerhans cells. The ultrastructure of LL cells in Northern pike, Esox lucius, and in Atlantic halibut, Hippoglossus hippoglossus were similar to those reported in salmonids. LL cells found in cyprinids shared some characteristics with the LL cells in other Actinopterygii species, although unique structures distinguished them from the latter. They contained dense bodies within the Birbeck‐like (BL) granules, a characteristic that was never observed in species outside the Cypriniformes. Two types of BL granules were characterized in cyprinid LL cells. The ultrastructure of BL granules across the species is discussed. LL cells in all Actinopterygii species demonstrated close contacts with nearby cells, characterized by adherens‐like junctions. Additionally, multivesicular bodies were present within the cytoplasm and large aggregates of exosomes were observed closely associated with the plasma membrane suggesting their release from the cells. These structures are discussed in relation to mammalian dendritic cells. Macrophages found in European perch, Perca fluviatilis, blue gourami, Trichogaster trichopterus, and Atlantic halibut, Hippoglossus hippoglossus contained lysosomes and residual bodies with structures resembling Birbeck granules. These granules and cells were clearly distinct from LL cells. J. Morphol. 2010. © 2010 Wiley‐Liss, Inc.