Manipulation of immune function by dietary folic acid

2020 Fiscal Year Final Research Report

• 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
• Keywords: 制御性Ｔ細胞 / 葉酸

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.

Free Research Field

免疫学

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。