INTEGRATION OF DNA DAMAGE RESPONSES WITH IMMUNE DEVELOPMENT AND FUNCTION

描述(由申请人提供)：淋巴细胞发育受到精确控制，能够产生不同的抗原受体谱系，同时防止有害事件，如易位，促进细胞转化和淋巴样恶性肿瘤。这两个相互依赖的二分过程是通过控制细胞增殖、存活和抗原受体组装的不同细胞信号的合作来管理的。我们描述了前B细胞中一种新的信号通路，它是由抗原受体重组过程中产生的生理性DNA断裂启动的。令人惊讶的是，我们的工作表明，DNA断裂依赖的信号矛盾地激活了生存途径，这些途径对于确保有足够的时间进行抗原受体基因重排非常重要。然而，如果DNA断裂无法修复，同样的DNA损伤反应会引发细胞死亡，以防止易位并保护基因组的完整性。这种生存和凋亡的时间平衡是生理性DNA断裂所特有的，因为遗传毒性伤害，如伽马辐射，会导致细胞立即死亡，而不是最初的存活期。这个项目的目标是阐明协调生存和细胞死亡信号的机制，以响应淋巴细胞中的DNA断裂。利用一种允许分离DNA断裂信号和表面受体信号的实验方法，我们建议：1)定义控制生存动力学的生理性DNA断裂的性质；2)识别响应DNA断裂而调节延迟的凋亡信号的信号；3)定义来自DNA断裂的信号与免疫调节剂(即CD40)在调节淋巴细胞存活中的功能整合。最终，这项工作将阐明平衡细胞存活和细胞死亡的新信号网络 发展淋巴细胞以确保正常成熟和抑制白血病的发生。这些研究将为独立的科学生涯奠定基础，专注于将基础免疫学研究应用于临床疾病的发病机制，特别是免疫缺陷和淋巴恶性肿瘤。该奖项的指导期将提供保护时间，以开发研究淋巴细胞DNA损伤反应的新技术，并获得管理研究实验室所需的新技能。这些工具对于完成概述的实验和独立研究计划的萌芽是必不可少的。一个协作和强大的免疫学研究环境将有助于指导未来的研究方向。这份申请书提出了一项研究计划和职业发展计划，将提供建立独立和竞争外部资金所需的框架和技能。

DESCRIPTION (provided by applicant): Lymphocyte development is precisely controlled to enable generation of a diverse antigen receptor repertoire while, simultaneously, preventing deleterious events, such as translocations, which promote cellular transformation and lymphoid malignancies. These two dichotomous but interdependent processes are managed through the cooperation of diverse cellular signals, which control cell proliferation, survival, and antigen receptor assembly. We describe a novel signaling pathway in pre-B cells that is initiated by the physiologic DNA breaks generated during antigen receptor recombination. Surprisingly, our work demonstrates that DNA break-dependent signals paradoxically activate survival pathways that are important to ensure adequate time for antigen receptor gene rearrangement. However, if DNA breaks cannot be repaired, the same DNA damage responses trigger cell death to prevent translocations and protect genomic integrity. This temporal balance of survival and apoptosis is unique to physiologic DNA breaks as genotoxic insults, such as gamma irradiation, induce immediate cell death without an initial survival period. The goal of this project is to elucidate the mechanisms that coordinate survival and cell death signaling in response to DNA breaks in lymphocytes. Utilizing an experimental approach that permits isolation of DNA break signals and surface receptor signals, we propose to: 1) define the properties of physiologic DNA breaks that control survival kinetics, 2) identify the signals that regulate delayed apoptotic signaling in response to DNA breaks, and 3) define the functional integration of signals from DNA breaks and immune regulators (i.e., CD40) in the regulation of lymphocyte survival. Ultimately, this work will elucidate new signaling networks that balance survival and cell death in developing lymphocytes to ensure normal maturation and inhibit leukemogenesis. These investigations will establish the foundation for an independent scientific career focused on applying basic immunology research to the pathogenesis of clinical diseases, particularly immune deficiencies and lymphoid malignancies. The mentored period of this award will provide protect time to develop new techniques for studying DNA damage responses in lymphocytes and to acquire new skills necessary for managing a research laboratory. These tools will be essential for completion of the outlined experiments and for the germination of an independent research program. A collaborative and robust immunology research environment will help guide future research directions. This application presents a research program and a career development plan that will provide the framework and skills necessary for establishing independence and competing for extramural funding.