Dysregulation of Naïve T cell Quiescence during Aging

项目总结/摘要 人类衰老的一个共同特征是对感染的易感性增加。这种与年龄相关的易感性是 与老年人中幼稚T细胞的显著和可重复损失有关。值得注意的是，老化的幼稚细胞 不仅数量减少，而且还显示部分分化的特征，这意味着细胞静止的丧失 可能会导致随着年龄的增长而收缩和功能障碍。幼稚T细胞静止是典型的维持 在次级淋巴组织（SLT）内通过成纤维细胞网状细胞（FRC）。老鼠模型优雅地 证明了FRC促进T细胞存活并直接抑制活化诱导的T细胞增殖的能力。 分化这些数据表明，FRC积极调节幼稚T细胞的静止，并可能发挥作用。 在衰老过程中的重要作用。然而，人类的机制研究受到以下因素的严重混淆： 很少使用单细胞技术，并且受到标准体外培养中幼稚T细胞存活率差的限制， 人源化小鼠。更好地利用新的单细胞技术和开发新的方法 因此，需要在体外维持幼稚T细胞，以进一步了解幼稚T细胞的维持， 人类衰老我们的初步数据表明，人类幼稚T细胞的高度异质性随着年龄的增长而缩小， 这种情况可以通过使用新的SLT样类器官模型系统在体外模拟。为此 目标1将定义幼稚T细胞的总体表型、转录和表观遗传异质性， 在人类衰老过程中的细胞室。此外，Aim 2还将进一步开发用于长期研究的SLT样类器官。 幼稚T细胞静止的长期研究。Aim 3将使用我们的类器官系统，结合体外和体内 体外试验，以确定FRC在维持幼稚T细胞静止及其分解中的作用 随着年龄的增长。这些研究的首要目标是确定基本的幼稚T细胞异质性， 确定与年龄相关的稳态下降的原因-最终确定潜在的治疗干预措施 以增强保护性免疫力，预防老年人的病原性感染。申请人Claire博士 古斯塔夫森概述了一个综合性的五年研究和职业发展计划，以促进她 单细胞技术及其分析管道的知识，并开发一种新的，基于类器官的 研究平台，以研究衰老过程中的T细胞稳态。Gustafson博士的导师Jörg Goronzy博士 在T细胞老化方面的全面专业知识以及广泛的科学合作者网络， 通量分析技术。这种指导与古斯塔夫森博士的专家顾问团队相结合， 斯坦福大学的资源为古斯塔夫森博士提供了一个特殊的研究环境 成功成为人类免疫衰老领域的强大独立研究者。

Project Summary/Abstract A common feature of human aging is an increased susceptibility to infections. This age-related susceptibility is linked with a significant and reproducible loss of naïve T cells in older individuals. Notably, aged naïve cells not only reduce in number but also display features of partial differentiation, implying a loss in cellular quiescence may cause repertoire contraction and dysfunction with age. Naïve T cell quiescence is classically maintained within secondary lymphoid tissues (SLTs) by fibroblastic reticular cells (FRCs). Mouse models have elegantly demonstrated the ability of FRCs to promote T cell survival and directly inhibit activation-induced differentiation. These data suggest that FRCs actively regulate naïve T cell quiescence and likely play an essential role in its loss during aging. However, mechanistic studies in humans are significantly confounded by rare use of single cell technologies and limited by poor naïve T cell survival in standard in vitro culture and humanized mice. Better utilization of new single cell techniques and the development of novel methodologies that sustain naïve T cells in vitro is thus required to gain further insight into naïve T cell maintenance during human aging. Our preliminary data suggests high heterogeneity of human naïve T cells that narrows with age, a situation that can be mimicked in vitro through the use of a novel SLT-like organoid model system. For this proposal, Aim 1 will define the overall phenotypic, transcriptional and epigenetic heterogeneity of the naïve T cell compartment during human aging. In addition, Aim 2 will further develop SLT-like organoids for the long- term study of naïve T cell quiescence. Aim 3 will use our organoid system, in combination with ex vivo and in vitro assays, to determine the role of FRCs in the maintenance of naïve T cell quiescence and its breakdown with aging. The overarching goals of these studies are to define fundamental naïve T cell heterogeneity and determine causes of age-related homeostatic decline – to ultimately identify potential therapeutic interventions to boost protective immunity and prevent pathogenic infections in older individuals. The applicant Dr. Claire Gustafson has outlined an integrative five-year research and career development plan to advance her knowledge in single cell techniques and their analysis pipelines and to develop a novel, organoid-based research platform to study T cell homeostasis during aging. Dr. Gustafson’s mentor, Dr. Jörg Goronzy, has comprehensive expertise in T cell aging as well as an extensive network of scientific collaborators using high throughput analytical techniques. This mentorship combined with Dr. Gustafson’s team of expert advisors and the resources available at Stanford University provides an exceptional research environment for Dr. Gustafson to successfully become a strong independent investigator in the area of human immune aging.