Morphological and immunohistochemical characterisation of thymus in juvenile turbot (Psetta maxima, L.).

VIGLIANO, F.A.; LOSADA, A.P.; CASTELO, M.; BERMÚDEZ, R.; QUIROGA, M.I.

CELL AND TISSUE RESEARCH

SPRINGER

Año: 2011 vol. 346 p. 407 - 416

0302-766X

We performed structural and immunohistochemical studies on thymus of juvenile turbot (Psetta maxima L.) in order to define its cellular composition. Thymic stroma was mainly composed by two subpopulations of reticulo-epithelial cells (RECs). RECs immunoreactive to anti-actin antibody were distributed through the organ, while RECs that were cytokeratin-immunopositive were located in the outer zone of the thymus. The parenchyma of the thymus was composed of several cell types such as lymphocytes/thymocytes, lymphoblasts, melano-macrophages, and to a lesser extent by nurse-like cells, immunoglobulin positive (Ig+) cells, mucous cells, rodlet cells, and neuroendocrine cells. CD3ɛ+ lymphocytes were mainly located in the outer zone. On the other hand, Ig+ cells were observed in the transitional region between inner and outer zone of the thymus. Neuroendocrine cells were large and exhibited immunoreactivity to neuropeptide Y and vasoactive intestinal polypeptide. They were located in the inner zone of the thymus in close association with lymphoblasts and lymphocytes/thymocytes. This work provides useful information on the structure and cellular composition of thymus of turbot, identifying several immunomarkers that allow the identification of different cell types, providing the basis for further studies on immune response of turbot against diseases.