Functional analysis of Legionella effectors using Paramecium as a host model

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K06383
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 42020:Veterinary medical science-related
• Research Institution: Yamaguchi University
• Principal Investigator: Watanabe Kenta 山口大学, 共同獣医学部, 准教授 (20582208)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: レジオネラ / エフェクター / 原生生物 / 自然宿主 / 共生

Outline of Final Research Achievements

This research was focused on determining the function and importance of Legionella type IV secretion systems and effectors in the establishment of relationships with natural hosts. As a tool for this analysis, original methods utilizing the Paramecium strains as a host model were utilized. The results showed that the type IV secretion system was essential for growth and symbiosis within Paramecium cells, but the cytotoxic effects to the host was independent of the type IV secretion system. These results were also confirmed not to be reproduced in different host protist species. These results suggest that the function and dependence of the type IV secretion system is not uniform and varies widely among species and strains of protist hosts.

Free Research Field

細菌学

Academic Significance and Societal Importance of the Research Achievements

レジオネラは基本的にヒトからヒトへの感染が成立せず、菌にとってヒトが最終宿主であることを踏まえると、ヒトに感染した後に、その体内でヒトへの病原性を獲得・進化させた可能性は極めて低いと推察される。すなわち、自然環境中でのレジオネラの生態や宿主生物との関係性を理解し制御することは、ヒトへの感染制御に繋がる重要な視点である。本研究成果を応用することで新たなレジオネラ感染制御法が確立されることが期待できる。