Regulation of virulence expression by small RNA in enterohemorrhagic E. coli in response to host infection stages.

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K16248
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 49050:Bacteriology-related
• Research Institution: Kyorin University (2022-2023); Kitasato University (2020-2021)
• Principal Investigator: Sudo Naoki 杏林大学, 医学部, 講師 (50736105)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 腸管出血性大腸菌 / 小分子RNA / 転写後制御 / ler / LEE

Outline of Final Research Achievements

This study identified small regulatory RNAs (sRNAs) that play a role in the post-transcriptional regulation of the type 3 secretion system, which is important for the pathogenicity of enterohemorrhagic Escherichia coli, and clarified the role of these sRNAs during host cell adhesion.
I attempted to identify sRNAs that interact with mRNA of ler, which encodes a central transcriptional regulator of the type 3 secretion system, and found three sRNAs that repress the expression of the type 3 secretion system through down-regulation of ler expression. Furthermore, we analyzed the expression of these sRNAs during host cell adhesion and non-adhesion, and found that some sRNAs were upregulated in the early or late stages of the adhesion, while others were upregulated during non-adhesion. These results indicate the existence of a complex post-transcriptional regulatory network during host cell adhesion.

Free Research Field

細菌学、分子生物学

Academic Significance and Societal Importance of the Research Achievements

本研究の推進により腸管出血性大腸菌の病原性発現制御機構の一端を解明することができた。三型分泌装置は腸管出血性大腸菌のヒトへの感染に重要な因子であり、この制御機構の理解は、腸管出血性大腸菌感染症の制御に対する基盤的知見となる。
また、本研究では宿主細胞感染時における複数のsRNA発現を解析した結果、感染ステージによって各々のsRNA発現の変動が異なることを見出した。これは腸管出血性大腸菌における宿主細胞感染時のsRNAの挙動を網羅的に捉えた初めての例である。