Biology of the Eosinophilic Leukocyte

嗜酸性白细胞的生物学

• 批准号: 7592297
• 负责人: HELENE ROSENBERG
• 金额: $ 83.55万
• 依托单位: NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7592297
• 关键词: Ablation; Allergic; Ascaridil; Australia; Bibliography; Biology; Blood; Bone Marrow; Cells; Clinical; Clinical Immunology; Coculture Techniques; Condition; Cytoplasmic Granules; Data; Defect; Development; Differentiation and Growth; Disease; Enhancers; Exons; Faculty; Family; Fibroblasts; Functional disorder; GATA1 gene; Helminths; Hematopoietic; Host Defense; Hypersensitivity; Immunology; Inflammation; Interview; Investigation; Journals; Laboratories; Lead; Leukocytes; Lung; Modeling; Mus; Nucleic Acids; Numbers; Paramyxoviridae; Pathway interactions; Play; Proteins; Publications; Publishing; Respiratory syncytial virus; Ribonucleases; Role; Stromal Cells; Structure of parenchyma of lung; Surface; Transcript; Transgenic Mice; Vaccines; Variant; Viral; Virus; Wild Type Mouse; Work; capsule; cytokine; editorial; eosinophil; eosinophil peroxidase; human GATA1 protein; in vivo; interest; member; pathogen; progenitor; programs; promoter; research study; respiratory; respiratory virus; sialic acid binding Ig-like lectin; trafficking

As part of our larger interest in eosinophils and their role in host defense, together with my colleagues in Australia, we have explored the possibility that eosinophils play a direct role in host defense against the prevalent respiratory pathogen, respiratory syncytial virus (RSV). Specifically, we found that virus clearance from lung tissue was more rapid in hypereosinophilic (interleukin5 transgenic) mice than in wild type mice, and that transfer of eosinophils to the lungs of RSVinfected wildtype mice accelerated virus clearance. In terms of mechanism, we demonstrated that eosinophils express TLRs that recognise viral nucleic acids, are activated and degranulate after ssRNA stimulation of the TLR7MyD88 pathway, and provide host defence against RSV that is MyD88dependent. Collectively, our results demonstrate that eosinophils can protect against RSV in vivo, as they promote virus clearance and may thus limit virusinduced lung dysfunction. The results of this work have been accepted for publication (Phipps et al. Blood 2007, in press). We have also continued our exploration of eosinophil differentiation and development, specifically using the deltadblGATA model of eosinophil ablation characterized by Yu and colleagues (JEM 2002) in which a deletion of a palindromic enhancer in the hematopoietic promoter of the transcription factor, GATA1, leads to mice that are completely devoid of eosinophils. Given that these mice are devoid of esoinophils even under conditions of profound Th2 stimulation, we were surprised to find that bone marrow progenitors isolated from deltadblGATA mice could differentiate into mature eosinophils when subjected to cytokine stimulation ex vivo. Cultured deltadblGATA eosinophils contain cytoplasmic granules with immunoreactive major basic protein and they express surface Siglec F and transcripts encoding major basic protein, eosinophil peroxidase, and GATA1, 2, and 3 to an extent indistinguishable from cultured wildtype eosinophils. Fibroblast coculture and bone marrow crosstransplant experiments indicate that the deficit is an intrinsic progenitor defect, and remains unaffected by interactions with stromal cells. Interestingly, and in contrast to those from the wild type, a majority of the GATA1 transcripts from cultured deltadblGATA progenitors express a variant GATA1 transcript that includes a first exon 1E(B), located approximately 3700 bp downstream to the previously described first exon found in hemopoietic cells (1E(A)) and approximately 42 bp upstream to another variant first exon, 1E(C). Taken together, our data suggest that cultured progenitors are able to circumvent the effects of the deltadblGATA ablation by using a second, more proximal, promoter and to use this mechanism to generate quantities of GATA1 that will support eosinophil growth and differentiation. The results of this work have been accepted for publication (Dyer et al. 2007. J. Immunol., in press). I also participated as lead author in a review of eosinophils and eosinophil trafficking published in Journal of Allergy and Clinical Immunology (Rosenberg et al. 2007, JACI 119:13031310) and among the contributors to the chapter Eosinophils to be published in Allergy and Allergic Disorders, 2nd edition, Blackwell Scientific Publishers. Finally, my expertise in eosinophil biology and inflammation has provided me with the opportunity to participate as a member of the Editorial Boards of Blood (since 2003), Journal of Leukocyte Biology (since 1996; promoted to Associate Editor, 2006), Clinical and Vaccine Immunology (since 2003) and Faculty of 1000 Biology (since 2006). As a member of the Editorial Board of Blood, I have been given the opportunity to contribute several Inside Blood capsules profiling original publications (included in bibliography). Most recently, I have assisted in developing an original feature for the Journal of Leukocyte Biology known as Pivotal Advance, and I have taken on the role of interviews editor. We have published seven of these feature interviews in FY2007, which have become an established feature in the journal.

作为我们对嗜酸性粒细胞及其在宿主防御中的作用的更大兴趣的一部分，我们与澳大利亚的同事一起探索了嗜酸性粒细胞在宿主针对流行的呼吸道病原体呼吸道合胞病毒（RSV）的防御中发挥直接作用的可能性。具体来说，我们发现嗜酸性粒细胞增多（白细胞介素5转基因）小鼠的肺组织病毒清除速度比野生型小鼠更快，并且嗜酸性粒细胞转移到RSV感染的野生型小鼠的肺部可加速病毒清除。 在机制方面，我们证明嗜酸性粒细胞表达识别病毒核酸的TLR，在TLR7MyD88途径的ssRNA刺激后被激活和脱粒，并为宿主提供针对MyD88依赖的RSV的防御。 总的来说，我们的结果表明，嗜酸性粒细胞可以在体内预防 RSV，因为它们可以促进病毒清除，从而限制病毒引起的肺功能障碍。 这项工作的结果已被接受发表（Phipps et al. Blood 2007，印刷中）。 我们还继续探索嗜酸性粒细胞的分化和发育，特别是使用Yu及其同事描述的嗜酸性粒细胞消融的deltadblGATA模型（JEM 2002），其中转录因子GATA1的造血启动子中回文增强子的缺失导致小鼠完全没有嗜酸性粒细胞。 鉴于这些小鼠即使在深度 Th2 刺激的条件下也缺乏嗜酸性粒细胞，我们惊讶地发现从 deltadblGATA 小鼠分离的骨髓祖细胞在受到离体细胞因子刺激时可以分化为成熟的嗜酸性粒细胞。培养的 deltadblGATA 嗜酸性粒细胞含有具有免疫反应性主要碱性蛋白的细胞质颗粒，它们表达表面 Siglec F 和编码主要碱性蛋白、嗜酸性粒细胞过氧化物酶以及 GATA1、2 和 3 的转录物，其程度与培养的野生型嗜酸性粒细胞无法区分。成纤维细胞共培养和骨髓交叉移植实验表明，该缺陷是一种内在的祖细胞缺陷，并且不受与基质细胞相互作用的影响。有趣的是，与野生型相比，来自培养的 deltadblGATA 祖细胞的大多数 GATA1 转录物表达变异的 GATA1 转录物，其中包括第一个外显子 1E(B)，位于先前描述的造血细胞中发现的第一个外显子 (1E(A)) 下游约 3700 bp 处，位于另一个变异体第一个外显子上游约 42 bp 处， 1E(C)。综上所述，我们的数据表明，培养的祖细胞能够通过使用第二个更近端的启动子来规避 deltadblGATA 消融的影响，并利用这种机制产生大量的 GATA1，支持嗜酸性粒细胞的生长和分化。 这项工作的结果已被接受发表（Dyer 等人，2007 年。J.Immunol.，出版中）。 我还作为主要作者参与了《过敏和临床免疫学杂志》（Rosenberg et al. 2007，JACI 119:13031310）上发表的嗜酸性粒细胞和嗜酸性粒细胞运输综述，并且是即将发表在 Allergy and Allergic Disorders（第 2 版，Blackwell Scientific Publishers）上的嗜酸性粒细胞章节的贡献者之一。 最后，我在嗜酸性粒细胞生物学和炎症方面的专业知识使我有机会作为《血液》（自 2003 年起）、《白细胞生物学杂志》（自 1996 年起；2006 年晋升为副主编）、《临床和疫苗免疫学》（自 2003 年起）和《Faculty of 1000 Biology》（自 2006 年起）的编辑委员会成员。作为《Blood》编辑委员会的成员，我有机会贡献几篇《Inside Blood》胶囊，介绍原始出版物（包含在参考书目中）。 最近，我协助为《白细胞生物学杂志》开发了一个名为“Pivotal Advance”的原创专题，并担任采访编辑的角色。 我们在 2007 财年发表了其中 7 篇专题访谈，这些访谈已成为该杂志的既定专题。