2019 Fiscal Year Final Research Report
Elucidation of the mechanism of T-bet-mediated induction of pulmonary alveolar proteinosis
Project/Area Number |
16K15454
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Research Category |
Grant-in-Aid for Challenging Exploratory Research
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Allocation Type | Multi-year Fund |
Research Field |
Respiratory organ internal medicine
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Research Institution | University of Tsukuba |
Principal Investigator |
Ishii Yukio 筑波大学, 医学医療系, 教授 (80272194)
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Project Period (FY) |
2016-04-01 – 2020-03-31
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Keywords | 肺胞蛋白症 / 転写因子 / T-bet / リンパ球 / マクロファージ / M-CSF / インターフェロンγ |
Outline of Final Research Achievements |
Pulmonary alveolar proteinosis (PAP) is a rare lung disorder characterized by abnormal surfactant accumulation in the alveoli.Here we show a novel mechanism by which acquired PAP develops without dysregulation of GM-CSF signaling. Mice carrying T cells overexpressing T-bet spontaneously developed PAP with pulmonary inflammation. PAP development was found to associate with dysregulation of bone marrow monopoiesis that led to accumulation of bone marrow-driven inflammatory macrophages into the lung while reducing the number of alveolar macrophages. Administration of macrophage colony-stimulating factor restored the impairment of monocytic differentiation. Higher expression of T-bet was observed in the lung lesions of human secondary PAP. These findings suggest that unresolved pulmonary inflammation initiated by T-bet overexpressing T cells reorganizes the subpopulation of macrophages in the lung that results in a reduction of surfactant clearance in alveoli and thus development of PAP.
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Free Research Field |
呼吸器内科学
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Academic Significance and Societal Importance of the Research Achievements |
成人に発症する肺胞蛋白症は特発性と続発性に分けられる。近年特発性肺胞蛋白症の多くの症例で抗GM-CSF抗体が証明され、自己免疫性肺胞蛋白症として、その病態の理解も進んだ。一方、血液疾患等に伴う続発性肺胞蛋白症の病態生理は今尚不明であり、原疾患と相まってその予後は不良である。T-bet高発現マウスの肺胞蛋白症はGM-CSF非依存的であること、骨髄の異常を伴うこと、肺に炎症を伴うことなど、続発性肺胞蛋白症と類似する点が多く、今回解明した発症機構は続発性肺胞蛋白症の病態を理解する上で極めて重要と考える。続発性肺胞蛋白症は極めて稀な疾患で製薬会社の関心も薄く、同領域の研究はアカデミアの責務でもある。
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