Role of Spi-C in eosinophil development and functional responses

描述（由申请人提供）：嗜酸性粒细胞增多症发生在多种临床疾病中，包括寄生虫感染、嗜酸性粒细胞增多综合征、癌症和特应性疾病。嗜酸性粒细胞来源于表达转录因子加塔-1和白细胞介素-5受体α（IL-5 Ra）的谱系定型造血祖细胞。尽管加塔-1在嗜酸性粒细胞发育中的重要性已得到充分证实，但指导嗜酸性粒细胞谱系定向祖细胞分化为成熟嗜酸性粒细胞的调控途径尚未得到充分理解，尤其是与其他造血谱系相比时。候选人Fulkerson博士的长期目标是确定新的治疗靶点，以阻断嗜酸性粒细胞的产生和募集，用于治疗嗜酸性粒细胞性哮喘和其他炎症性疾病患者。Fulkerson博士致力于学术医学的职业生涯，并成为一名独立的研究调查员。本提案中概述的培训计划将为Fulkerson博士提供一个建立科学利基的机会，并促进Fulkerson博士在提案的第三年提交R 01赠款，使其成为一名独立的医生科学家。这个建议的目的是描绘转录因子Spi-C在嗜酸性粒细胞成熟中的调节活性。Spi-C在成熟嗜酸性粒细胞或嗜酸性粒细胞分化中的作用完全未知。预期所提出的研究将通过调节IL-5 Ra表达和嗜酸性粒细胞颗粒蛋白的表达来提供对嗜酸性粒细胞分化、存活和效应器功能重要的途径的详细理解。确定嗜酸性粒细胞功能和IL-5反应性的分子调节剂无疑将为临床应用提供关键信息，特别是考虑到目前正在积极开发的IL-5 Ra和IL-5导向疗法。该提议的中心假设是转录因子Spi-C与转录因子PU. 1和加塔-1协调，通过调节对嗜酸性粒细胞存活、增殖和效应子功能重要的基因的表达来调节嗜酸性粒细胞分化。我们将以三个具体目标来检验这一假设。首先，我们将使用Fulkerson博士开发的导致表型成熟嗜酸性粒细胞的新型体外培养系统来确定Spi-C在嗜酸性粒细胞成熟中的作用。其次，我们将表征Spi-C和PU对IL-5 Ra的调节。最后，我们将确定Spi-C和PU.1在调节嗜酸性粒细胞颗粒蛋白表达中的作用。总之，拟议的研究将阐明Spi-C在嗜酸性粒细胞分化中的作用。具体而言，这些研究将描述Spi-C和PU对颗粒蛋白表达和IL-5反应性的调节。由于颗粒蛋白的释放是嗜酸性粒细胞的重要效应子功能，并且IL-5信号传导对与疾病相关的嗜酸性粒细胞增多至关重要，因此进一步定义其调节可能导致嗜酸性粒细胞相关疾病的新治疗靶点。 嗜酸性粒细胞在组织中的积聚和激活发生在各种临床疾病中，包括寄生虫感染、嗜酸性粒细胞增多综合征、癌症和特应性疾病，并导致细胞毒性颗粒蛋白的释放，这些蛋白激活并损伤邻近细胞，导致组织损伤、器官功能障碍和患者发病。拟议的研究，预计将提供一个详细的了解的途径重要的嗜酸性粒细胞的分化，生存和效应功能，特别是颗粒蛋白的生产。该提案将提供临床应用的关键信息，特别是考虑到目前正在积极开发的嗜酸性粒细胞靶向治疗。

DESCRIPTION (provided by applicant): Eosinophilia occurs in a variety of clinical disorders including parasitic infections, hypereosinophilic syndrome, cancer, and atopic diseases. Eosinophils are derived from lineage-committed hematopoietic progenitor cells expressing the transcription factor GATA-1 and interleukin-5 receptor alpha (IL-5Ra). Although the significance of GATA-1 in eosinophil development is well established, the regulatory pathways that direct the differentiation of the eosinophil lineage-committed progenitor to mature eosinophils are not well understood, especially when compared with other hematopoietic lineages. The long term goals of the candidate, Dr. Fulkerson, are to identify novel therapeutic targets to block eosinophil production and recruitment for the treatment of patients with eosinophilic asthma and other inflammatory disorders. Dr. Fulkerson is dedicated to a career in academic medicine and to becoming an independent research investigator. The training plan outlined in this proposal will provide Dr. Fulkerson an opportunity to establish a scientific niche and facilitate the maturation of Dr. Fulkerson into an independent physician scientist with submission of a R01 grant in year three of the proposal. The objective of this proposal is to delineate the regulatory activity of the transcription factor Spi-C in eosinophil maturation. The role of Spi-C in mature eosinophils or eosinophil differentiation is completely unknown. The proposed studies are expected to provide a detailed understanding of the pathways important for eosinophil differentiation, survival and effector function via regulation of IL-5Ra expression and expression of eosinophil granule proteins. Defining the molecular regulators of eosinophil function and IL-5 responsiveness will undoubtedly provide key information with clinical applications, especially given the IL-5Ra- and IL-5-directed therapies that are currently under avid development. The central hypothesis of this proposal is that the transcription factor Spi-C coordinates with the transcription factors PU.1 and GATA-1 to regulate eosinophil differentiation via regulation of expression of genes important for eosinophil survival, proliferation and effector function. We will test this hypothesis with three specific aims. First, we will identify the role of Spi-C in eosinophil maturation using a novel in vitro culture system developed by Dr. Fulkerson that results in phenotypically mature eosinophils. Second, we will characterize the regulation of IL-5Ra by Spi-C and PU.1. Finally, we will determine the role of Spi-C and PU.1 in regulating expression of eosinophil granule proteins. Together, the proposed studies will elucidate the role of Spi-C in eosinophil differentiation. Specifically, the studies will delineate the regulation of granule protein expression and IL-5 responsiveness by Spi-C and PU.1. As release of granule proteins is an important effector function of eosinophils and IL-5 signaling is critical to eosinophilia associated with disease, further defining their regulation could lead to new therapeutic targets in eosinophil-associated disorders. Project Narrative Eosinophil accumulation and activation in tissues occurs in a variety of clinical disorders including parasitic infections, hypereosinophilic syndrome, cancer, and atopic diseases and results in the release of cytotoxic granule proteins that activate and damage neighboring cells leading to tissue damage, organ dysfunction and patient morbidity. The proposed studies are expected to provide a detailed understanding of the pathways important for eosinophil differentiation, survival and effector function, particularly production of granule proteins. This proposal will provide key information with clinical applications, especially given the eosinophil- targeted therapies that are currently under avid development.