Langerin/CD207 positive dendritic-like cells in the haemopoietic tissues of salmonids

The presence of dendritic cells in fish is studied with immunohistochemistry using a commercially available antibody developed against Langerin/CD207 present in human Langerhans cells. Langerin/CD207, a protein known to be associated with the development of Birbeck granules in human and murine systems, was found to be expressed within the cytoplasm of spleen and head kidney cells of Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss). Reactivity was also observed within a few number of cells within the head kidney of Atlantic salmon, but not observed in any other tissues examined. Immunohistochemical results showed Langerin/CD207 reactivity in the cytoplasm of cells in Atlantic salmon and rainbow trout comparable to reactivity seen in human Langerhans cells. The results in this study further corroborate the presence of dendritic cells with remarkable similarities to human Langerhans cells in the spleens and to a lesser extent in head kidney of salmonids.