The Origin and Function of Lung Megakaryocytes

肺巨核细胞的起源和功能

基本信息

批准号：
10677191
负责人：
Alison Claire Livada
金额：
$ 5.27万
依托单位：
UNIVERSITY OF ROCHESTER
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-09-15 至 2027-09-14
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10677191
关键词：
Acceleration Adult Automobile Driving Biological Models Blood Blood Platelets Blood Vessels Bone Marrow Cardiovascular Diseases Cells Colony-Forming Units Assay Communicable Diseases Data Development Disease Dyes Embryo Environment Flow Cytometry Future Hematopoiesis Hematopoietic Hematopoietic stem cells Heterogeneity Homeostasis Immune Immune response Immunofluorescence Immunologic Immunological Models Immunology Immunophenotyping In Vitro Infection Inflammation Inflammatory Label Large Megakaryocyte Lung Lung Capacity Lung diseases Malaria Megakaryocytes Megakaryocytopoieses Methods Modeling Morphology Mus Oropharyngeal Parents Phenotype Physicians Physiological Ploidies Population Process Production Proto-Oncogene Protein c-kit Reporter Research Role SLAM protein Scientist Sorting Source Spleen Sterility Techniques Testing Thrombocytopenia Thrombopoiesis Thrombosis Tissues Training Transplantation Vascular Diseases career career development daughter cell direct application experimental study improved in vivo insight irradiation migration mouse model novel novel strategies pulmonary function reconstitution self-renewal trafficking transcriptome sequencing

项目摘要

Abstract Platelet parent cells are megakaryocytes (Mks). Studies have historically focused on Mk derived platelet production in the bone marrow (BM) (1). More recently, platelet-producing Mks have been shown to be present in the lung, and our lab and others have described an immune modulatory phenotype of lung Mks (2-4). The recent identification of a low ploidy, immune differentiated BM Mk sub-population (5) highlights the relationship that lower Mk ploidy may correlate with a more immune differentiated Mk. We refer to the development of a Mk immune modulatory sub-population as Mk immune differentiation. The origin of lung Mks and mechanisms of their immune differentiation remain unknown. It is assumed, without experimental evidence, that lung Mks are ‘seeded’ from immature circulating BM Mks. Lefrancais et al. showed the presence of GFP+ Mks in the lung vasculature when a mTmG lung was transplanted to a PF4-Cre-mTmG recipient. The authors argued that the presence of GFP+ intravascular lung Mks demonstrated an extra-pulmonary source. However, intravascular and extravascular lung Mks have morphological and perhaps functional differences, and extravascular lung Mks make up about 70% of all lung Mks. Thus, the majority of circulating Mks would have to leave the blood and tissue migrate to become lung resident. Without direct evidence for this trafficking, the definitive origin of extravascular lung Mks remains unknown, but may have a major impact on their immune differentiation. I hypothesize that extravascular lung Mks derive from a local hematopoietic progenitor pool independent of BM megakaryopoiesis. I will test this hypothesis by using complementary methods, including irradiation and transfer experiments, lineage tracing, and in vitro colony forming unit assays. The impact of Mk immune differentiation on the platelet pool is still not clear. Lung Mks make platelets, although the relative proportion of lung derived platelets remains controversial (4, 6). Emerging evidence from studies of platelet heterogeneity are beginning to suggest that platelet subsets may have functional significance. I hypothesize that lung resident Mks contribute to an immune-differentiated platelet sub-population. To test this hypothesis, I will use a novel strategy to identify lung derived platelets using oropharyngeal CFSE administration in physiologic and thrombocytopenic conditions such as PF4-Cre-iDTR mice and nonlethal murine malaria. Results from my proposed studies will contribute to an improved understanding of immune differentiated megakaryopoiesis, and its role in coordinated immune responses and platelet immune phenotypes, with direct applications to many vascular inflammatory diseases.

抽象的血小板亲代细胞是巨核细胞 (Mks)，历史上的研究主要集中在 Mk 衍生的血小板上。最近，已证明存在骨髓 (BM) 中产生血小板的 Mks。我们的实验室和其他人已经描述了肺 Mks 的免疫调节表型 (2-4)。最近鉴定出低倍性、免疫分化的 BM Mk 亚群 (5) 强调了这种关系较低的 Mk 倍性可能与免疫分化程度较高的 Mk 相关。作为Mk免疫分化的免疫调节亚群肺Mks的起源和机制。它们的免疫分化仍然未知。在没有实验证据的情况下，假设肺 Mks 是从不成熟的循环 BM 中“播种”的 Mks. Lefrancais 等人表明，当 mTmG 肺处于肺血管系统中时，存在 GFP+ Mks。移植到 PF4-Cre-mTmG 受体时作者认为存在 GFP+ 血管内肺。 Mks 表现出肺外来源，然而，血管内和血管外肺 Mks 都有。形态和功能上的差异，血管外肺 Mks 约占所有肺的 70% 因此，大多数循环的 Mks 必须离开血液和组织迁移到肺部。由于没有这种贩运的直接证据，血管外肺 Mks 的明确起源仍然存在。未知，但可能对其免疫分化产生重大影响，我追求的是血管外肺。 Mks 源自独立于 BM 巨核细胞生成的局部造血祖细胞库，我将对此进行测试。通过使用补充方法进行假设，包括辐射和转移实验、谱系追踪、和体外集落形成单位测定。尽管 Mk 免疫分化对血小板池的影响仍不清楚，但 Mks 会产生血小板。肺源性血小板的相对比例仍存在争议 (4, 6)。血小板异质性开始表明血小板亚群可能具有功能意义。培养出肺驻留 Mks 有助于免疫分化的血小板亚群以测试这一点。假设，我将使用一种新策略通过口咽部 CFSE 给药来识别肺源性血小板在生理和血小板减少条件下，例如 PF4-Cre-iDTR 小鼠和非致命性鼠疟疾。我提出的研究结果将有助于加深对免疫分化的理解巨核细胞生成及其在协调免疫反应和血小板免疫表型中的作用，与直接其在许多血管炎性疾病中的应用。