Investigation of the mechanism of severe viral pneumonia by lung microbiome and single cell RNA sequencing.

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K07748
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 52050:Embryonic medicine and pediatrics-related
• Research Institution: Nagoya University
• Principal Investigator: Kawada Jun-ichi 名古屋大学, 医学系研究科, 准教授 (20532831)
• Co-Investigator(Kenkyū-buntansha): 伊藤 嘉規 名古屋大学, 医学系研究科, 准教授 (20373491)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 微生物叢 / 次世代シーケンス / シングルセルシーケンス / 呼吸器感染症

Outline of Final Research Achievements

The lung microbiome in patients with acute exacerbation of interstitial lung disease (AE-ILDs) was compared with that of sarcoidosis using BALF samples. Structural similarity of the microflora differed significantly between two groups. Dysbiosis in the lung microbiome in patients with AE-ILD may be related to the progression of inflammation. We evaluated the utility of nanopore sequencing for the detection of pathogens in BALF of pediatric patients with respiratory failure. Nanopore sequencing could comprehensively detect respiratory pathogens with equivalent sensitivity as Illumina sequencing. Then, the immune landscape of EBV-HLH and EBV-IM was investigated using single-cell RNA sequencing. The unique CD8+ T cell cluster was explicitly observed in EBV-IM. Conversely, genes involved in type Ⅰ interferon signaling were commonly upregulated in EBV-HLH. Oure results suggest that single-cell RNA sequencing would be useful for analyzing the pathogenesis of severe infectious diseases.

Free Research Field

小児感染症

Academic Significance and Societal Importance of the Research Achievements

本研究では、重症呼吸不全患者の気管支肺胞洗浄液を用いて肺の微生物叢を解析した。重症呼吸不全患者では常在菌の減少が観察され、重症化への関与が示唆された。また、肺の微生物叢の解析に、新規のNGSNの手法であるロングリードシーケンスの手法が応用可能であることを示した。肺の微生物叢には不明な点が多いが、本研究を通じて、その意義や解析手法に関して新たな知見を得ることができた。
また、重症感染症患者の臨床検体でシングルセル解析を行うことで、疾患に特異的な細胞集団や、その遺伝子発現の特徴を明らかにした。本研究では小児重症感染症の病態解析にシングルセル解析の有用性を示すことができ、今後の発展が期待される。