Department of Pharmacy, Section for Pharmacology and Pharmaceutical Biosciences, University of Oslo, Oslo, Norway.
Nofima (Norwegian Institute of Food, Fisheries and Aquaculture Research), Ås, Norway.
PLoS One. 2019 Jul 31;14(7):e0219625. doi: 10.1371/journal.pone.0219625. eCollection 2019.
A pivotal matter to aquaculture is the sourcing of sustainable resources as ingredients to aquafeeds. Levels of plant delivered oils as source of fatty acids (FA) in aquafeeds have reached around 70% resulting in reduced levels of long-chain omega-3 polyunsaturated fatty acids (LC n-3 PUFA), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), in salmon fillet composition. EPA and DHA can modulate inflammation and immune response, so it is crucial to understand how fish immune response is affected by low LC n-3 PUFA diet and if this diet can have a detrimental effect on vaccine response. Atlantic salmon (Salmo salar) can produce EPA/DHA from α-linolenic acid (ALA) and this endogenous capacity can be explored to develop families with higher tolerance to low LC n-3 PUFA diets. Here we analyze innate and adaptive immune response in Atlantic salmon to a commercial vaccine after being fed low levels of EPA and DHA, and we also compare three strains of salmon selected by their endogenous capacity of synthesizing LC- n-3 PUFA. A total of 2,890 differentially expressed genes (DEGs) were identified (p-value adjusted < 0.1) when comparing vaccinated fish against control non-vaccinated. Gene ontology (GO) and KEGG analysis with 442 up/downregulated genes revealed that most DEGs were both related to immune response as well as part of important immune related pathways, as "Toll-like receptor" and "Cytokine-Cytokine interaction". Adaptive response was also addressed by measuring antigen specific IgM, and titers were significantly higher than in the pre-immune fish at 62 days post-immunization. However, diet and strain had no/little effect on vaccine-specific IgM or innate immune responses. Atlantic salmon therefore display robustness in its response to vaccination even when feed low levels of LC n-3 PUFA.
水产养殖的一个关键问题是为水产饲料寻找可持续的资源作为原料。水产饲料中植物来源的油作为脂肪酸 (FA) 的来源的水平已达到约 70%，导致鲑鱼片成分中长链ω-3 多不饱和脂肪酸 (LC n-3 PUFA) 的水平降低，如二十碳五烯酸 (EPA) 和二十二碳六烯酸 (DHA)。EPA 和 DHA 可以调节炎症和免疫反应，因此了解鱼类免疫反应如何受到低 LC n-3 PUFA 饮食的影响以及这种饮食是否会对疫苗反应产生不利影响至关重要。大西洋鲑 (Salmo salar) 可以从α-亚麻酸 (ALA) 中产生 EPA/DHA，这种内源性能力可以被开发出来，以培育对低 LC n-3 PUFA 饮食具有更高耐受性的品系。在这里，我们分析了在喂食低水平 EPA 和 DHA 后大西洋鲑对商业疫苗的先天和适应性免疫反应，并比较了通过内源性合成 LC- n-3 PUFA 的能力选择的三种鲑鱼品系。在比较接种疫苗的鱼与未接种疫苗的对照鱼时，共鉴定出 2890 个差异表达基因 (DEGs) (p 值调整 < 0.1)。GO 和 KEGG 分析显示，442 个上调/下调基因与免疫反应以及重要的免疫相关途径有关，如“Toll-like receptor”和“Cytokine-Cytokine interaction”。通过测量抗原特异性 IgM 也评估了适应性反应，在免疫后 62 天，效价明显高于免疫前的鱼。然而，饮食和品系对疫苗特异性 IgM 或先天免疫反应没有/几乎没有影响。因此，即使在饲料中 LC n-3 PUFA 含量低的情况下，大西洋鲑对疫苗的反应也具有很强的适应性。
