Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Hubei Provincial Engineering Laboratory for Pond Aquaculture, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China.
Department of Genetics, Albert Einstein College of Medicine, 1301 Morris Park Ave., Bronx, NY, 10461, USA.
Fish Shellfish Immunol. 2020 Apr;99:353-361. doi: 10.1016/j.fsi.2020.02.023. Epub 2020 Feb 17.
Edwardsiella ictaluri (E. ictaluri) causes severe infections in yellow catfish (Pelteobagrus fulvidraco), which leads to a massive loss in the aquaculture industry especially in catfish commercial production. Previous studies have confirmed that vitamin D is essential in immune regulation in mammals. Based on next-generation sequencing, this study explored the immunomodulatory effects of dietary vitamin D on the head kidney of yellow catfish after E. ictaluri challenge. Current results showed that increasing the content of dietary vitamin D within the experimental concentration range (1120IU/kg-16600IU/kg) could reduce the mortality of the yellow catfish after E. ictaluri challenge. Results of the next-generation sequencing showed that dietary vitamin D regulates the immune mechanism of the head kidney mainly through three pathways i.e. negative regulation of interferon-β production, negative regulation of interleukin-6 production and neutrophil chemotaxis. Proteins HSPA8, MAP4K4 and MRC1 may be involved in vitamin D-mediated immunoregulation in the head kidney. qPCR results showed that increasing the content of dietary vitamin D can improve the immune function of the yellow catfish by down-regulating ifn-β and pro-inflammatory factors tnf-α, il1-β, il-6, il-8 and up-regulating the anti-inflammatory factor il-10. The above results indicated that dietary addition of vitamin D regulated the immune response in head kidney of yellow catfish and helped the fish to resist the negative effects of infection by E. ictaluri in a dose-dependent manner.
爱德华氏菌（E. ictaluri）会引起黄颡鱼（Pelteobagrus fulvidraco）的严重感染，这导致水产养殖业，尤其是黄颡鱼商业养殖，遭受巨大损失。先前的研究已经证实，维生素 D 对哺乳动物的免疫调节至关重要。本研究基于下一代测序技术，探讨了日粮维生素 D 对爱德华氏菌攻毒后黄颡鱼头肾的免疫调节作用。目前的结果表明，在实验浓度范围内（1120IU/kg-16600IU/kg）增加日粮维生素 D 的含量可以降低黄颡鱼感染爱德华氏菌后的死亡率。下一代测序的结果表明，日粮维生素 D 主要通过三条途径调节头肾的免疫机制，即干扰素-β产生的负调控、白细胞介素-6 产生的负调控和嗜中性粒细胞趋化作用。HSPA8、MAP4K4 和 MRC1 蛋白可能参与了维生素 D 介导的头肾免疫调节。qPCR 结果表明，增加日粮维生素 D 的含量可以通过下调 ifn-β和促炎因子 tnf-α、il1-β、il-6、il-8 以及上调抗炎因子 il-10 来改善黄颡鱼的免疫功能。上述结果表明，日粮添加维生素 D 调节了黄颡鱼头肾的免疫反应，帮助鱼类以剂量依赖的方式抵抗爱德华氏菌感染的负面影响。
