INDUCED HYPER (T3) AND HYPO (PTU) THYROIDISM AFFECT TRANSCRIT PROFILE IMMUNE RESPONSES IN RAINBOW TROUT HEAD KIDNEY

In mammals, increasing data suggests that there exists a complex and bi-directional relationship between thyroid and immune systems. However the existence of such interactions in fish is unknown. Here, we administered the biologically active hormone 3.3′.5-triiodo-L-thyronine (T3) and the anti-thyroid drug, propilthiouracil (PTU) to juvenile rainbow trout and examined the head kidney expression profile with a custom-made microarray enriched in immune-related genes. A seven day-experiment was performed. Fish were divided in 3 groups. First group received 20 µg/g fish feed of T3; second group received 5000 µg/g fish feed of PTU; third group served as control. After 7 days orally administering T3 or PTU, differentially expressed transcript levels from selected immune-related rainbow trout genes were studied in head kidney. Three groups were studied (T3-treated, PTU treated and control), each group having 4 biological replicates (each replicate consisting of 2 pooled fish).