Porter D, Peggs D, McGurk C, Martin S A M
Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Aberdeen, AB24, 2TZ, UK.
Skretting Aquaculture Innovation, Sjøhagen 3, 4016, Stavanger, Norway.
Fish Shellfish Immunol. 2023 Mar;134:108573. doi: 10.1016/j.fsi.2023.108573. Epub 2023 Jan 30.
Functional diets are often given to fish during key stages to improve health through the interaction of the feed components with the host intestine. The additional factors added in these diets are known to modulate the immune response and as such may also offer protection against pathogenic challenges. The present study was undertaken to evaluate whether β-glucan supplementation for 6 weeks can alter the magnitude of immune response to immunological challenges and subsequently offer an improved innate immune response to bacterial challenge in rainbow trout. Two experimental diets were used to study these effects: a basic commercial diet supplemented with β-glucan and a commercially available functional diet (Protec™) that has β-glucan as a functional component in addition to other components were compared to a basic commercial control diet. No significant differences were observed in biometric data. Histological analysis revealed a significantly greater number of goblet cells in the fish fed Protec™ and β-glucan diets compared to those fed a control diet. Cell marker gene expression of distal intestine leucocytes indicated higher expression of T- and B-cells marker genes to both the β-glucan containing diets in comparison to control. The Protec™ diet demonstrated modulation of innate immune markers after 6 weeks of feeding with key antimicrobial genes (SAA, HAMP, IL-1β and TNFα) showing significant increases compared to the other diets. After stimulation with both PAMPs and an immune challenge with A. salmonicida fish fed the β-glucan diet and the Protec™ exhibited modulation of the innate immune response. An immune challenge with A. salmonicida was carried out to identify if dietary composition led to differences in the innate immune response of rainbow trout. Modulation of the magnitude of response in some immune genes (SAA, IL-1β and HAMP) was observed in both the distal intestine and head kidney in the Protec™ and β-glucan fed fish compared to those fed the control diet.
功能性日粮通常在关键阶段投喂给鱼类，通过饲料成分与宿主肠道的相互作用来改善健康状况。已知这些日粮中添加的额外因子可调节免疫反应，因此也可能提供针对病原体挑战的保护。本研究旨在评估补充β-葡聚糖6周是否能改变对免疫挑战的免疫反应强度，并随后提高虹鳟对细菌挑战的先天性免疫反应。使用两种实验日粮来研究这些影响：一种是补充了β-葡聚糖的基础商业日粮，以及一种市售的功能性日粮（Protec™），除其他成分外，该日粮还含有β-葡聚糖作为功能性成分，并将其与基础商业对照日粮进行比较。在生物特征数据方面未观察到显著差异。组织学分析显示，与喂食对照日粮的鱼相比，喂食Protec™和β-葡聚糖日粮的鱼中杯状细胞数量显著更多。远端肠道白细胞的细胞标记基因表达表明，与对照相比，两种含β-葡聚糖的日粮中T细胞和B细胞标记基因的表达更高。在喂食6周后，Protec™日粮显示出对先天性免疫标记物的调节作用，关键抗菌基因（SAA、HAMP、IL-1β和TNFα）与其他日粮相比显著增加。在用PAMPs刺激并以杀鲑气单胞菌进行免疫挑战后，喂食β-葡聚糖日粮和Protec™的鱼表现出先天性免疫反应的调节。进行了以杀鲑气单胞菌进行的免疫挑战，以确定日粮组成是否会导致虹鳟先天性免疫反应的差异。与喂食对照日粮的鱼相比，在喂食Protec™和β-葡聚糖的鱼的远端肠道和头肾中，观察到一些免疫基因（SAA、IL-1β和HAMP）的反应强度受到调节。
