Mechanisms controlling distinct growth and functional characteristics of the perinatal and adult thymus

摘要 该计划提案的综合假设是与年龄相关的细胞和分子特征 小鼠胸腺微环境，与人类胸腺相似的特征，在 塑造围产期胸腺移居T细胞的独特功能潜能与 青少年时期。目前，在老鼠身上几乎没有什么信息，在人类身上就更少了。 胸腺上皮细胞(TECs)、造血抗原提呈细胞(HAPC)的组成和功能 在这一转变过程中的其他基质细胞亚群。鉴于具有效应和调节功能的T细胞是至关重要的 对于新生儿健康，该计划的研究目标是：1)确定组成和 两种小鼠TECs、HAPC和其他胸腺基质细胞在围产期到幼年转变过程中的组织 和人类；2)绘制这些细胞亚群中调控其增殖的转录变化图， 分化、功能和串音；以及3)决定这些变化如何影响围产期的能力 胸腺环境产生具有不同功能的T细胞。 该计划的结构是使用scRNA-seq和多重成像来协作地鉴定候选细胞 小鼠和人胸腺功能显著变化的种群和分子机制 从围产期到青少年过渡的微环境。在发现阶段，RPS将产生scRNA- 来自小鼠和人(核心C)胸腺的TECs(RP1)、基质细胞(RP2)和HAPC(RP3)的SEQ数据集。 这些数据集将由Core B进行分析，以确定候选细胞和分子。在优先级排序中 阶段，RPS将确定哪些候选对象是使用Core B跨物种保守的，然后RPS将进行协作 使用多路复用成像来可视化这些候选人在选举期间位置和/或交互的变化 可能调节重要生物功能的转变。物种保护和成像结果都将 为功能测试确定细胞子集和分子路径的优先顺序提供了理论基础。在测试阶段， 每个RP将评估小说以及之前确定的候选对象的功能重要性 项目的具体目标。总的来说，这些平行的scRNA-seq和成像实验将在三个RPS中进行 协同作用：1)确定转录图谱、细胞组成和组织结构的变化 小鼠和人类从围产期到幼年期的胸腺微环境；和2)使我们能够 测试哪些变化在过渡期间调节这些子集的增殖、分化和功能 对围产期免疫功能的下游影响。计划的组成部分包括： RP1(Richie)：控制TEC动态和围产期胸腺谱系的分子机制 RP2(Manley)：Foxn1在控制胸腺扩张向内稳态转变中的作用 RP3(Ehrlich)：在围产期到成人的转变过程中胸腺APC对中枢耐受的不同贡献 核心A(理查)：管理。核心；核心B(YI)：生物信息学/生物统计核心；核心C：(HALE)人类胸腺核心

Summary The integrated hypothesis of this Program proposal is that age-associated cellular and molecular features of the mouse thymus microenvironment, mirrored by similar features in the human thymus, play a major role in shaping the distinct functional potential of T cells that emigrate from the thymus during the perinatal versus juvenile periods. Currently, there is little information in mice, and even less in humans, on changes in the composition and function of thymic epithelial cells (TECs), hematopoietic antigen presenting cells (HAPCs), and other stromal cell subsets during this transition. Given that T cells with effector and regulatory functions are vital for newborn health, the Program research objectives are to: 1) identify changes in the composition and organization of TECs, HAPCs and other thymus stromal cells over the perinatal to juvenile transition in both mice and humans; 2) map transcriptional changes in these cellular subsets that regulate their proliferation, differentiation, function and cross-talk; and 3) determine how such changes impact the ability of the perinatal thymic environment to generate T cells with distinct functional capabilities. The Program is structured to use scRNA-seq and multiplex imaging to collaboratively identify candidate cell populations and molecular mechanisms underlying functionally significant changes in mouse and human thymus microenvironments across the perinatal to juvenile transition. In the discovery phase, RPs will generate scRNA- seq datasets of TECs (RP1), stromal cells (RP2) and HAPCs (RP3) from mouse and human (Core C) thymus. These datasets will be analyzed by Core B to identify cellular and molecular candidates. In the prioritization phase, RPs will determine which candidates are conserved across species with Core B. RPs will then collaborate to use multiplex imaging to visualize changes in location and/or interactions of these candidates during the transition that may mediate important biological functions. Both species conservation and imaging results will provide a rationale to prioritize cell subsets and molecular pathways for functional testing. In the testing phase, each RP will assess novel, as well as previously identified candidates, for functional significance according to Project specific goals. Collectively, these parallel scRNA-seq and imaging experiments in the three RPs will synergize to: 1) identify changes in the transcriptional profiles, cellular composition and organization of the thymus microenvironment over the perinatal to juvenile transition in both mice and humans; and 2) enable us to test which changes regulate proliferation, differentiation, and function of these subsets across the transition with downstream consequences for perinatal immune function. Program components are: RP1 (Richie): Molecular mechanisms controlling TEC dynamics and lineage hierarchies in the perinatal thymus RP2 (Manley): The role of Foxn1 in controlling the transition from thymus expansion to homeostasis RP3 (Ehrlich): Differential contribution of thymic APCs to central tolerance during the perinatal to adult transition Core A (Richie): Admin. Core; Core B (Yi): Bioinformatics/Biostats Core; Core C: (Hale) Human Thymus Core