Henard Cyril, Li Hanxi, Nowak Barbara F, von Gersdorff Jørgensen Louise
Department of Veterinary and Animal Sciences, University of Copenhagen, Stigbøjlen 7 Frederiksberg C, 1870 Frederiksberg, Denmark.
Department of Health Technology, Technical University of Denmark, 2800 Kongens Lyngby, Denmark.
Biology (Basel). 2024 Sep 27;13(10):769. doi: 10.3390/biology13100769.
Farmed fish are regularly subjected to various stressors due to farming practices, and their effect in the context of a disease outbreak is uncertain. This research evaluated the effects of unpredictable repeated stress in rainbow trout challenged with the ciliate , known to cause white spot disease in freshwater fish. Before and after the pathogen exposure, fish were handled with a random rotation of three procedures. At 7 days post-infection (dpi), the parasite burden was evaluated in fish and in the tank's water, and the local and systemic immune responses were investigated in the gill and spleen, respectively. The fish mortality was recorded until 12 dpi, when all the fish from the infected groups died. There was no statistical difference in parasite burden (fish and tank's water) and infection severity between the two infected fish groups. The immune gene expression analysis suggested a differential immune response between the gill and the spleen. In gills, a T helper cell type 2 immune response was initiated, whereas in spleen, a T helper cell type 1 immune response was observed. The stress has induced mainly upregulations of immune genes in the gill (, , ) and downregulations in the spleen (, /, ). Our results suggested that the unpredictable repeated stress protocol employed did not impair the fish immune system.
由于养殖方式，养殖鱼类经常受到各种应激源的影响，其在疾病爆发情况下的影响尚不确定。本研究评估了不可预测的重复应激对感染纤毛虫的虹鳟鱼的影响，已知该纤毛虫会在淡水鱼中引起白点病。在病原体暴露之前和之后，对鱼进行三种操作的随机轮换处理。在感染后7天（dpi），评估鱼体和鱼缸水中的寄生虫负荷，并分别在鳃和脾脏中研究局部和全身免疫反应。记录鱼的死亡率直至12 dpi，此时感染组的所有鱼均死亡。两组感染鱼之间的寄生虫负荷（鱼体和鱼缸水）和感染严重程度没有统计学差异。免疫基因表达分析表明鳃和脾脏之间存在不同的免疫反应。在鳃中，启动了2型辅助性T细胞免疫反应，而在脾脏中，观察到1型辅助性T细胞免疫反应。应激主要诱导了鳃中免疫基因的上调（、、）和脾脏中免疫基因的下调（、/、）。我们的结果表明，所采用的不可预测的重复应激方案并未损害鱼类免疫系统。
