Manipulation of immune function by dietary folic acid

Research Project

Project/Area Number	18K05507
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Review Section	Basic Section 38050:Food sciences-related
Research Institution	Chiba Institute of Science
Principal Investigator	Okamoto Yoshihiro 千葉科学大学, 薬学部, 教授 (40261036)
Project Period (FY)	2018-04-01 – 2021-03-31
Project Status	Completed (Fiscal Year 2020)
Budget Amount *help	¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000) Fiscal Year 2020: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000) Fiscal Year 2019: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000) Fiscal Year 2018: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
Keywords	制御性Ｔ細胞 / 葉酸 / 4型葉酸受容体 / 制御性T細胞
Outline of Final Research Achievements	Effect of excessive intake or deficiency of folic acid has not been clarified. It has been reported that the type 4 folic acid receptor (FR4) expresses on the cell surface of regulatory T cell (Treg). An excessive intake of FA (0.5 mg folic acid/g diet and 1.5mg folic acid/g diet) increased naturally occurring Treg (nTreg) population compared with healthy mice. Comprehensive gene expression changes with excessive intake or deficiency of dietary FA were examined by microarray analysis. The excessive intake of FA induced 6 genes showed more than twice increase of the expression and 2 genes showed more than twice decrease compared with normal diet. The Those genes include genes related immune system, such as immunoglobulin joining chain immunoglobulin joining chain In summary, our study demonstrated the previously unappreciated role of dietary FA as a critical nutrient that maintains Tregs. Our observation might have been important in manipulation of immune function.
Academic Significance and Societal Importance of the Research Achievements	制御性Ｔ細胞（Treg細胞）は生体内において過剰な免疫応答を制御する機能を担う免疫担当細胞の一つである。Treg細胞膜上には4型葉酸受容体（FR4）が高発現していることが報告されているが、その生理的意義は不明である。葉酸は生体内の様々な酵素の補酵素であり、主に核酸合成に関連するビタミンであるとともに生体が摂取した葉酸はTreg細胞上のFR4を介してTreg細胞機能に何らかの機能変化を及ぼすことが想定される。葉酸摂取量が免疫システムの制御に影響を及ぼすならば、葉酸摂取量の調整などにより、免疫疾患の予防、感染症の予防に応用できる可能性がある。