Host-bacteria interactions through immune evasion mechanism

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H03468
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 49050:Bacteriology-related
• Research Institution: Kanazawa University
• Principal Investigator: Hirayasu Kouyuki 金沢大学, 先進予防医学研究センター, 特任准教授 (30585170)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 免疫逃避機構 / 宿主細菌相互作用 / 免疫レセプター / アリル多様性 / LILR

Outline of Final Research Achievements

Immune system plays an important role in host defense against pathogens and tumor cells. However, it is known that pathogens and tumor cells have acquired various immune evasion mechanisms to escape from the host immune system. This study revealed that certain immune inhibitory receptors recognize specific bacteria and that both immune inhibitory receptors and their bacterial ligands show genetic diversity. These results suggest that host and bacteria have coevolved through immune inhibitory receptor-mediated bacterial immune evasion mechanisms.

Free Research Field

免疫学

Academic Significance and Societal Importance of the Research Achievements

現代では、抗菌薬やワクチンの開発により、様々な細菌感染症に対して治療を行うことができるようになった。しかし、抗菌薬やワクチンがなかった時代では、病原細菌は致死的な感染症を引き起こしていた。本来免疫が細菌を排除する役割を担っているが、なぜ宿主免疫は病原細菌を排除できない場合があるのだろうか。本研究では、免疫を抑制する免疫抑制化レセプターが細菌を認識してしまうことで免疫にブレーキがかかる可能性が示された。