Investigation of effect of milk fat to diversity in mammary macrophages function.

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K06398
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 42020:Veterinary medical science-related
• Research Institution: Rakuno Gakuen University
• Principal Investigator: Ohtsuka Hiromichi 酪農学園大学, 獣医学群, 教授 (40327458)
• Co-Investigator(Kenkyū-buntansha): 村田 亮 酪農学園大学, 獣医学群, 講師 (50590311)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: マクロファージ / M1/M2 / 乳汁 / 脂肪酸 / サイトカイン・ケモカイン

Outline of Final Research Achievements

The effects of fatty acids on M1/M2 phenotypes of macrophages were examined with the presence of milk from dairy cows. The levels of M2-macrophage cytokines in mammary macrophages were higher than in peripheral blood monocytes. Increased IL-10 and TGF-β mRNA expression levels were observed in peripheral blood monocytes after culturing with milk in vitro. It suggested that milk modulates macrophage towards M2 phenotype. Since M2-related cytokines such as IL-10 and TGF-β mRNA expression levels of monocytes increased in culturing with linoleic acid (ω6), exposure to milk containing linoleic acid may up-regulate M2 macrophage function in cows. On the other hand, mRNA expression levels of M1-related cytokines such as IL-6 and IL-8 were high in cells obtained from milk with bacteria. These results suggest that macrophages maintain M2 phenotype in milk from lactating dairy cows, and M1 phenotype macrophages are activated in the invasion of bacteria.

Free Research Field

獣医学

Academic Significance and Societal Importance of the Research Achievements

本研究では泌乳牛の乳汁マクロファージがM2マクロファージを優性に維持されており、細菌の侵入に対してM1マクロファージが反応して炎症に至るのを防いでいることが示唆された。またリノール酸はマクロファージをM2マクロファージに誘導することが考えられ、乳房炎の発症予防を考慮する上で、脂肪酸が過多になるような飼養管理を軽減させるなど実際の飼料設計を計画するための配慮すべき知見となる。