Cholesterol Recognition mechanism of Mincle using nanodisc

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K14633
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 43020:Structural biochemistry-related
• Research Institution: Hokkaido University
• Principal Investigator: Furukawa Atsushi 北海道大学, 薬学研究院, 助教 (30727699)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 自然免疫受容体 / 免疫活性化 / 糖脂質 / コレステロール / ナノディスク / NMR

Outline of Final Research Achievements

Mincle is an immune receptor that is expressed in antigen presenting cells, such as dendritic cells, arecognizes trehalose dimycolate (TDM), which is specifically present on the surface of Mycobacterium tuberculosis and cholesterol crystals, and activates immune cells. We previously perofrmed X-ray structural analysis of Mincle to elucidate the recognition mechanism of TDM. However, analysis of glycolipids and cholesterol has not progressed due to their low solubility in water. Therefore, we prepared "nanodiscs" that imitated lipid bilayer membranes containing glycolipids and cholesterol, and conducted binding experiments. As a result, no binding was found in glycolipids containing cholesterol, whereas binding to Mincle was found in those containing glycolipids.

Free Research Field

分子免疫学

Academic Significance and Societal Importance of the Research Achievements

免疫受容体のMincleは強力な免疫活性化物質である結核菌表面に存在するTDMと呼ばれる分子と結合する。我々はX線構造解析によりMincleの立体構造を明らかにしたが、TDMの難水溶性のためにどのようにMincleがTDMを認識しているのか不明な点が多かった。今回、我々は実際のTDMが結核菌の表面にある状態を模した脂質二重膜にTDM類似体を埋め込んで、認識機構の解明を進めた。その結果、TDM類似体を含まない脂質二重膜はMincleに結合しなかった一方で、TDM類似体を含むものは結合することがわかった。今後、Mincleの認識機構を詳細に明らかにすることで、効果的な免疫活性化物質の探索を目指す。