Defining the Complosome in Human Cells, Tissues and Disease States

摘要 在过去三年半的R01赠款支持期间，我们在以下方面取得了实质性进展： a）评估C3在新发现的细胞内补体系统（ICS或“补体体”）中的作用， 包括其通过CD 46信号传导的调节，B）开发一种测定以定量生物活性形式的 C3称为C3（H2O），c）鉴定大多数细胞类型共有的受体介导的C3（H2O）摄取过程， 和d）确定细胞和器官系统（气道）中对缺血和免疫的ICS反应， 中介攻击我们的近期和持续目标是发表我们描述人类受体的结果， C3（H2O）以及研究表明，在同种异体免疫中， 介导的损伤。我们还进一步描绘了在细胞内的补体激活和调节机制。 RNA和蛋白质水平，并将我们的分析扩展到人类外周血吞噬细胞，上皮细胞和， 尤其是内皮细胞群。另一个目标是剖析ICS的作用，利用体外 具有从肺组织供体分离的原代人细胞和相应的人细胞系的模型系统， 以及在小鼠感染模型中。因此，我们建议继续开发和采用模型系统 为了获得一个细胞类型的补体如何在正常稳态中发挥作用的详细图谱， 对细胞损伤和恶性肿瘤的反应。这些分析可能会引发新的见解， 该系统的功能障碍与人类疾病相关。 该提案的一个重要目标涉及肿瘤学。除了作为抑制剂的作用外， 在宿主细胞上的补体激活和补体体的关键组分中，CD46正在成为关键的 在恶性转化和癌症免疫治疗中的作用。一方面，CD46在细胞表面过表达， 许多肿瘤，但另一方面，它是治疗性溶瘤病毒的靶向， 机制我们对这些研究做出了贡献，现在计划剖析其过度表达的基本原理 以及它对补体的影响，从多发性骨髓瘤开始，与Siteman癌症合作， 中心开发的模型随后将扩展到其他类型的癌症。 总之，我们的提案利用了我们长期致力于以下领域的力量： 补充研究和我们雄心勃勃的事业有关的定义机制和球员的 新发现的ICS我们对这种灵活的拨款机制特别感兴趣。这 提案不仅利用PI的专业知识，而且还利用一个由优秀人才组成的团队， 通过创造更多创新的模型系统并获得 全面的地图，扩大了我们的知识基础相对于“工作”的ICS。

Abstract During the past three and one-half years of R01 grant support, we have made substantial progress in: a) assessing the role of C3 in the newly discovered intracellular complement system (ICS or “complosome”), including its modulation by CD46 signaling, b) developing an assay to quantitate a biologically active form of C3 known as C3(H2O), c) identifying a receptor-mediated C3(H2O) uptake process common to most cell types, and d) determining the ICS response in cells and an organ system (the airway) to ischemic and immune- mediated attack. Our immediate and ongoing goals are to publish our results describing the human receptor for C3(H2O) as well as studies demonstrating that C3 expression by lung transplants is reduced in alloimmune- mediated injury. We are also further delineating complosome activation and regulatory mechanisms at the RNA and protein level and are extending our analyses to human peripheral blood phagocytic, epithelial and, especially, endothelial cell populations. A further goal is to dissect the role of the ICS, utilizing both an in vitro model system with primary human cells isolated from lung tissue donors and corresponding human cell lines, as well as in mouse models of infection. Thus, we propose to continue to develop and employ model systems to obtain a detailed map of how a cell type's complosome functions in normal homeostasis as well as its response to cellular damage and malignancy. Such analyses will likely trigger new insights into how dysfunctions of this system correlate with human diseases. An important goal of this proposal relates to oncology. In addition to its role as an inhibitor of complement activation on host cells and a critical component of the complosome, CD46 is emerging as a key player in both malignant transformation and cancer immunotherapy. On one hand, CD46 is overexpressed on many tumors, yet on the other hand, it is targeted by therapeutic oncolytic viruses that use it as a docking mechanism. We have contributed to these studies and now plan to dissect the rationale of its overexpression and its effect on the complosome, beginning with multiple myeloma in collaboration with the Siteman Cancer Center. The models developed will be extended subsequently to other types of cancers. In summary, our proposal draws on the strength of our long-term commitment to the field of complement research and our ambitious undertakings related to defining the mechanisms and players of the newly discovered ICS. We are especially attracted to this grant mechanism because of its flexibility. This proposal draws not only on the expertise of the PI, but also on a team of talented individuals who are well positioned to continue being leaders the field by creating more innovative model systems and obtaining a comprehensive map that expands our knowledge-base relative to the “workings” of the ICS.