INTEGRATION OF DNA DAMAGE RESPONSES WITH IMMUNE DEVELOPMENT AND FUNCTION

描述（由申请人提供）：淋巴细胞发育得到精确控制，能够产生不同的抗原受体库，同时防止有害事件，如促进细胞转化和淋巴恶性肿瘤的易位。这两个二分但相互依赖的过程是通过不同细胞信号的合作来管理的，这些信号控制细胞增殖、存活和抗原受体组装。我们描述了一种新的信号通路在前B细胞，是由抗原受体重组过程中产生的生理DNA断裂。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生存途径，这是重要的，以确保足够的时间抗原受体基因重排。然而，如果DNA断裂无法修复，相同的DNA损伤反应会触发细胞死亡，以防止易位并保护基因组完整性。这种存活和凋亡的时间平衡对于生理性DNA断裂是独特的，因为遗传毒性损伤（例如γ辐射）诱导立即细胞死亡而没有初始存活期。本项目的目标是阐明淋巴细胞中DNA断裂后生存和细胞死亡信号的协调机制。利用允许分离DNA断裂信号和表面受体信号的实验方法，我们提出：1）定义控制存活动力学的生理DNA断裂的性质，2）鉴定响应于DNA断裂调节延迟凋亡信号传导的信号，和3）定义来自DNA断裂和免疫调节剂的信号的功能整合（即，CD40）在调节淋巴细胞存活中的作用。最终，这项工作将阐明新的信号网络，平衡生存和细胞死亡， 发展淋巴细胞以确保正常成熟并抑制白血病发生。这些研究将为独立的科学事业奠定基础，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。该奖项的指导期间将提供保护时间来开发研究淋巴细胞中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至关重要。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。该申请提出了一个研究计划和职业发展计划，将提供建立独立性和竞争校外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.