in vivo imaging of immune responses to influenza virus in mouse lung by using two-photon excitation microscopy

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K14580
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 42020:Veterinary medical science-related
• Research Institution: The University of Tokyo
• Principal Investigator: Ueki Hiroshi 東京大学, 医科学研究所, 特任助教 (70794907)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: インフルエンザ / 生体イメージング / ２光子励起顕微鏡 / 免疫

Outline of Final Research Achievements

The in vivo pathophysiology and dynamics of immune cells in influenza virus-infected lungs are not fully understood. Here, we established an in vivo imaging system that employs two-photon excitation microscopy and fluorescent influenza viruses of different pathogenicity. This approach allowed us to monitor and correlate several parameters and pathophysiological changes including the spread of infection, pulmonary permeability, speed of pulmonary perfusion, the number of pulmonary vascular neutrophils, and neutrophil motion in the lungs of live mice. Several pathophysiological changes were larger and occurred earlier in mice infected with a highly pathogenic H5N1 influenza virus compared with those in mice infected with a PR8 strain. These findings demonstrate the potential of our in vivo imaging system to provide novel information about the pathophysiological consequences of virus infection and the immune response to influenza virus.

Free Research Field

インフルエンザ

Academic Significance and Societal Importance of the Research Achievements

呼吸のために拡張と収縮を繰り返す肺は、視野の固定が難しくこれまでいくつかの方法論が試されてきたが生体イメージングには不向きと考えられており、インフルエンザに代表される重度の炎症を伴う肺を顕微鏡下で観測することは困難であった。本研究において、2光子励起顕微鏡を用いた感染肺の生体イメージング法を確立し、インフルエンザウイルスに対する免疫細胞応答を解析することが可能となった。インフルエンザの病原性発現メカニズムの解明に役立ち、ワクチンや新規抗ウイルス薬の動物実験における評価にも応用できることから、ウイルス学や免疫学などの基礎的な研究からワクチンや薬剤開発に至るまで、幅広く利用されることが期待される。