Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR), Universidade do Porto, Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos s/n, 4450-208, Matosinhos, Portugal.
Departamento de Biologia, Faculdade de Ciências da Universidade do Porto (FCUP), Rua do Campo Alegre s/n, Ed. FC4, 4169-007, Porto, Portugal.
Sci Rep. 2017 Dec 21;7(1):18009. doi: 10.1038/s41598-017-18345-3.
Teleost innate immune system is a most developed and powerful system in which fish highly rely throughout their lives. Conditions in aquaculture farms are particularly prone to disease, thus, health and welfare ensuring strategies are an urgent call to which nutrition is gradually becoming a most regarded achievement tool. This study intended to evaluate different amino acids' effect on immune-related mechanisms as well as their potential as enhancers of European seabass, Dicentrarchus labrax, leucocyte functioning. To achieve these goals, primary cultures of head-kidney leucocytes were established and kept in amino acid (glutamine, arginine, tryptophan or methionine) supplemented culture media in two doses. The effects of amino acids treatments were then evaluated after stimulation with either Vibrio anguillarum or Vibrio anguillarum lipopolysaccharides by measuring nitric oxide production, extracellular respiratory burst, ATP and arginase activities, and expression of immune-related genes. Glutamine, arginine and tryptophan showed to be particularly relevant regarding cell energy dynamics; arginine and tryptophan supplementation also resulted in down-regulation of important immune-related genes. Immune responses in cells treated with methionine were generally enhanced but further studies, particularly those of enzymes activity, are essential to complement gene expression results and to better understand this nutrient's immune role in fish.
硬骨鱼先天免疫系统是鱼类在其整个生命周期中高度依赖的最为发达和强大的系统。水产养殖环境特别容易发生疾病，因此，确保鱼类健康和福利的策略是当务之急，而营养正逐渐成为一种备受关注的实现工具。本研究旨在评估不同氨基酸对免疫相关机制的影响，以及它们作为增强剂对欧鲈（Dicentrarchus labrax）白细胞功能的潜力。为了实现这些目标，建立了头肾白细胞的原代培养物，并在含有谷氨酰胺、精氨酸、色氨酸或蛋氨酸的氨基酸补充培养基中以两种剂量进行培养。然后，通过测量一氧化氮产生、细胞外呼吸爆发、ATP 和精氨酸酶活性以及免疫相关基因的表达，评估氨基酸处理对鳗弧菌或鳗弧菌脂多糖刺激的影响。谷氨酰胺、精氨酸和色氨酸在细胞能量动力学方面表现得尤为重要；精氨酸和色氨酸的补充也导致了重要免疫相关基因的下调。用蛋氨酸处理的细胞的免疫反应通常会增强，但需要进一步的研究，特别是酶活性的研究，以补充基因表达结果，并更好地理解这种营养素在鱼类中的免疫作用。
