Development of a method of infection control of EHEC by using outer membrane vesicles

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K15275
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Bacteriology (including mycology)
• Research Institution: Osaka University
• Principal Investigator: Tobe Toru 大阪大学, 医学系研究科, 教授 (70207596)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: OMVs / EHEC / 増殖抑制 / 外膜タンパク質 / 標的特異的結合

Outline of Final Research Achievements

We have developed the method of growth inhibition specific for EHEC. The fusion proteins, constructed with a type V secretion protein and a domain of a binding protein for EHEC-specific outer membrane protein, was expressed and successfully presented on the surface of non-pathogenic E. coli. And also, we constructed the plasmid for the expression of bacterial toxin whose action is dependent on direct contact with target bacteria. We also found the non-pathogenic E. coli strain producing high amount of OMVs. We showed that OMVs from this strain expressing both the fusion protein and the toxin could bind to EHEC specifically and reduce the growth of EHEC. We also found the gene that can reduce the endotoxin activity of LPS. Furthermore, we found the gene and growth conditions which enhance the production of OMVs in E. coli.

Free Research Field

細菌学

Academic Significance and Societal Importance of the Research Achievements

本研究で外膜小胞（OMVs）に任意のタンパク質を積載し表層に提示させることに成功した。また、これを利用し実際にEHECに特異的に結合させ増殖を抑制できることを示せた。この成果は、OMVsが特定の細菌を標的とした増殖阻害法に応用できることを示しており、今後は提示タンパク質や毒素タンパク質を交換することにより様々な病原菌を標的にした増殖抑制剤として展開できる技術基盤を確立した。学術的には、本研究により、エンドトキシン活性を低減するLPSの修飾酵素の発見、OMVs産生を亢進する因子の発見など、新規の知見を得ることができた。