Physiological and pathological roles of outer membrane vesicles released from enteric bacteria in inflammatory response

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K01888
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Applied health science
• Research Institution: Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology
• Principal Investigator: Fujita Yasunori 地方独立行政法人東京都健康長寿医療センター(東京都健康長寿医療センター研究所), 東京都健康長寿医療センター研究所, 研究員 (30515888)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 膜小胞 / 大腸菌 / OMV / LPS

Outline of Final Research Achievements

Recent reports indicate that outer membrane vesicles (OMV) released from enteric bacteria are involved in immunity and inflammation, but their physiological and pathological roles are still fully understood. In this study, we constructed a sandwich ELISA using an anti-LPS antibody for detection of OMV released from Escherichia coli. Further improvement and optimization will make it possible to measure OMV in blood by the detection system, which contribute to in vivo studies of OMV. We also demonstrated that OMV injected to mice may act on Kupffer cells in the liver. Moreover, we showed that an injection with LPS, which covers the surface of OMV released from Escherichia coli, resulted in the increase of extracellular vesicles expressing myeloid marker proteins in blood. These results imply that Escherichia coli-derived OMV may be involved in inflammatory response by increasing extracellular vesicles in blood through stimulation of myeloid cells.

Free Research Field

基礎老化

Academic Significance and Societal Importance of the Research Achievements

腸内に存在するグラム陰性細菌が放出する膜小胞（OMV）の生理的・病理的な役割は未だ不明な点が多い。本研究で構築することができた大腸菌由来OMVの検出系は、今後さらなる改良・最適化を行うことで、OMV研究において有用なツールになる可能性がある。また、本研究により、生体内に投与された大腸菌由来OMVの標的細胞や血中細胞外小胞に対する効果が明らかになり、今後のOMV研究の進展に寄与するものと考えられる。将来的には、腸内細菌と慢性炎症・代謝性疾患・神経変性疾患との関連およびその分子機構の解明に繋がることが期待される。