The role of neutrophils in severe influenza-related pneumonia

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K08507
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 54030:Infectious disease medicine-related
• Research Institution: Nagasaki University
• Principal Investigator: KOSAI Kosuke 長崎大学, 医歯薬学総合研究科(医学系), 准教授 (70644433)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: インフルエンザウイルス / 肺炎球菌 / 好中球

Outline of Final Research Achievements

We analyzed phenotype and function of neutrophils in pneumococcal pneumonia following influenza virus infection. Prior influenza infection enhanced pneumococcal adhesion in lungs. The rate of neutrophils in lungs increased in co-infected group compared to uninfected group.
We observed higher rate of CD49d-positive neutrophils in bone marrow in co-infected group compared to uninfected group. The SOCS3 mRNA expression in lungs increased in co-infected group compared to single pneumococcal infection group. In comparison between high- and low-density cells obtained from bone marrow of co-infected mice, the rate of neutrophils was higher but that of CD49d-positive neutrophils was lower in high-density cells than in low-density cells.

Free Research Field

感染症学、呼吸器病学

Academic Significance and Societal Importance of the Research Achievements

近年、好中球は不均一な細胞集団であり、好中球の中にも表現型や機能が異なるものが含まれる可能性が報告されている。本研究ではインフルエンザ関連細菌性肺炎の病態に関して骨髄や肺における好中球機能に着目して解析を行った。更なる研究によってインフルエンザ関連細菌性肺炎の重症化に関わる特徴的な好中球やその機能を明らかにすることができれば、病態を新しい側面から解明できるとともに治療法の開発などへの発展が期待される。