Understanding of circadian rhythm in the fish immunity

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K07915
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Aquatic bioproduction science
• Research Institution: University of Miyazaki
• Principal Investigator: Kono Tomoya 宮崎大学, 農学部, 准教授 (60527547)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 魚類 / 免疫 / 概日リズム / 時計遺伝子 / サイトカイン

Outline of Final Research Achievements

The circadian expression of immune-related genes such as TNF-alpha, IL-1beta, CC chemokines (CCL18L, 19, 25L) and CXC chemokines (CXCL11) was revealed. In addition, it was clarified that clock gene response elements exist in the transcription regulatory regions of the said immune-related genes. Subsequently, it was revealed that the clock gene Bmal1:Clock1 heterodimer binds to the transcriptional regulatory region of TNF-alpha gene and regulates the expression. Furthermore, it was confirmed that expression of immune-related genes with circadian rhythm shown above was strongly induced by immuno-stimulation during a time zone showing the acrophase of the clock gene expression. These results suggest that circadian control exists in fish immune responses.

Free Research Field

魚類免疫学

Academic Significance and Societal Importance of the Research Achievements

本研究で魚類の免疫リズムの一端を明らかにしたことは、魚類分野に貢献するばかりでなく、脊椎動物の免疫システムにおける多様性と画一性を解き明かす鍵となり、進化生物学や比較免疫学の発展に寄与するものである。さらに、研究より見出された「異なる時間帯での免疫刺激は、その後誘導される免疫応答に違いをもたらす」という知見は、水産増養殖現場で免疫賦活剤を使用する際の投与タイミングの重要性を示唆しており、将来的には疾病対策の効果改善に大きく寄与するものとなる。