The concept of maintaining animal health through the best possible nutrition is well-accepted in modern animal farming. The new concept of functional amino acids (AA) is arising in the nutritional immunology field, and are defined as those AA that participate in and regulate key metabolic pathways to improve, for instance, health and survival in organisms. Tryptophan in particular have known roles in the improvement of the immune response to infection and recent evidence indicate that several immune mechanisms are influenced by its availability.

Still, the role of tryptophan on brain activation and cell-mediated immune mechanisms involved in the response and resolution of inflammation still needs further attention in fish. This is particularly true for the aquaculture industry, where few therapeutic possibilities are available against infectious episodes. The main goal of the present project is to provide a better understanding of the underpinning neuro-endocrine and immune machinery of fish fed tryptophan supplements and to deliver a deeper understanding of the basic mechanisms involved during inflammation using the European seabass (Dicentrarchus labrax) as a model. The INFLAMAA project also aims to gather information on the transcriptome of fish undergoing acute and chronic inflammatory events and to propose biomarkers for applications in fish health management. The INFLAMAA team will use an innovative multidisciplinary approach that aims to explore the links between tryptophan nutrition, immune function and endocrine-immune plasticity. Underlying mechanisms will be addressed by localising key elements of the opioid system, autophagy-lysosomal signalling pathway and inflammation in the headkidney and leucocytes, and expression of genes controlling aspects of neuro-endocrine and immune systems in the brain, head-kidney and peripheral cells and tissues. Additionally, peripheral metabolic changes in European seabass submitted to acute and chronic inflammatory insults will be studied in the liver. An innovative approach will assess tryptophan digestibility and utilisation during the onset of inflammation while high-throughput sequencing will assess the European seabass transcriptome during acute and chronic inflammation. The INFLAMAA project assembled an innovative research strategy to include tryptophan supplements in functional feeds in order to improve welfare and survival in farmed European seabass. Through a practical point of view, the outcome of this project is to design dietary therapeutic interventions in order to increase disease resistance in fish. The expected impact of the INFLAMAA project is to deepen our knowledge on the interactions of tryptophan nutrition and inflammation. Nowadays, few studies have demonstrated clear links between AA nutrition and endocine/immune functioning or other key welfare aspects in fish. Ultimately, transcriptome analyses will be suited for the identification of new biomarkers for fish health assessment.