Elucidation of molecular mechanism that promotes IgA production in the mammary gland

2018 Fiscal Year Final Research Report

• Project/Area Number: 16H06207
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Animal production science
• Research Institution: Tohoku University
• Principal Investigator: Nochi Tomonori 東北大学, 農学研究科, 准教授 (10708001)
• Research Collaborator: Aso Hisashi ; Watanabe Kouichi ; Kiyono Hiroshi ; Sato Shintaro
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: IgA / 微生物 / 乳腺 / CCL28 / CCR10

Outline of Final Research Achievements

Breastfeeding is important for mammals, providing immunological and microbiological advantages to neonates from the mother. However, the mechanisms of this functional diversity in the mammary gland remain poorly characterized. Here, we show that the mammary gland develops immune and microbial environments consisting of IgA and the microflora, respectively, both of which are important for protecting neonates and the mother from infectious diseases. The IgA production and microflora development are coordinated in the gastrointestinal tract but seem to be independently regulated in the mammary gland. In particular, CCL28, a crucial molecule for the recruitment of IgA-producing cells into the mammary gland, was expressed normally in germ-free lactating mice but were almost undetectable in postweaning mothers, regardless of the microflora presence. Our findings offer insights into potentially improving the quality of breastfeeding, using both immunological and microbiological approaches.

Free Research Field

粘膜免疫学

Academic Significance and Societal Importance of the Research Achievements

本研究を通して、分娩後の母体が、生体内に存在するIgA産生細胞を乳腺に集結させる分子メカニズムが解明され、乳汁中の移行抗体が産生されるプロセスの大半が明らかにされた。一方で、この乳腺に存在するIgA産生細胞が、生体内のどこで活性化し乳腺に遊走しているのか、その由来の特定は今後の課題とされた。哺育の質の向上は、母子の健全育成を可能にする重要な課題である。従来の授乳生理に関わる学問に加え、免疫学および微生物学的視点を加えた新たなアプローチを駆使することで、哺乳動物特有の母子間の情報伝達機構が解明され、健康社会の実現に貢献可能な免疫・微生物戦略が確立されると期待される。