Visualizing epithelial network connectivity in thymus biology, aging, and regeneration

胸腺生物学、衰老和再生中上皮网络连接的可视化

• 批准号: 9383719
• 负责人: Dawen Cai
• 金额: $ 47.44万
• 依托单位: SCRIPPS FLORIDA
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-05-20 至 2020-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9383719
• 关键词: Address; Adolescence; Adopted; Age; Aging; Area; Atrophic; Behavior; Belief; Biology; Biology of Aging; Blood; Blood Cells; Castration; Cell Aging; Cell Lineage; Cell Proliferation; Cell physiology; Cells; Cellular Morphology; Cellular Structures; Cellularity; Characteristics; Data; Databases; Dependence; Development; Disease; Elements; Epithelial; Epithelial Cells; Exhibits; Fibroblasts; Gene Expression Regulation; Genes; Genetic; Genetic Transcription; Health; Hematopoietic stem cells; Hemorrhage; Imaging technology; Immune; Immune system; Immunity; Individual; Knowledge; Life; Lymphocyte; Lymphocyte Count; Lymphoid; Memory; Microtomy; Mission; Modeling; Morphology; Mus; Natural regeneration; Nature; Neurosciences; Organ; Organism; Output; Pathologic; Phenotype; Population; Process; Production; Proliferating; Radial; Recruitment Activity; Reporter; Reticular Cell; Role; Self Tolerance; Shapes; Site; Slice; Staining method; Stains; Stem cells; Stimulus; Stromal Cells; Supporting Cell; Surface; T-Cell Development; T-Lymphocyte; Techniques; Testing; Thick; Thymic epithelial cell; Thymus Gland; Tissue imaging; Tissues; Translations; United States National Institutes of Health; age related; aged; cell type; cellular imaging; data mining; experience; middle age; mouse model; optical imaging; organizational structure; premature; progenitor; stem-like cell; Address; Adolescence; Adopted; Age; Aging; Area; Atrophic; Behavior; Belief; Biology; Biology of Aging; Blood; Blood Cells; Castration; Cell Aging; Cell Lineage; Cell Proliferation; Cell physiology; Cells; Cellular Morphology; Cellular Structures; Cellularity; Characteristics; Data; Databases; Dependence; Development; Disease; Elements; Epithelial; Epithelial Cells; Exhibits; Fibroblasts; Gene Expression Regulation; Genes; Genetic; Genetic Transcription; Health; Hematopoietic stem cells; Hemorrhage; Imaging technology; Immune; Immune system; Immunity; Individual; Knowledge; Life; Lymphocyte; Lymphocyte Count; Lymphoid; Memory; Microtomy; Mission; Modeling; Morphology; Mus; Natural regeneration; Nature; Neurosciences; Organ; Organism; Output; Pathologic; Phenotype; Population; Process; Production; Proliferating; Radial; Recruitment Activity; Reporter; Reticular Cell; Role; Self Tolerance; Shapes; Site; Slice; Staining method; Stains; Stem cells; Stimulus; Stromal Cells; Supporting Cell; Surface; T-Cell Development; T-Lymphocyte; Techniques; Testing; Thick; Thymic epithelial cell; Thymus Gland; Tissue imaging; Tissues; Translations; United States National Institutes of Health; age related; aged; cell type; cellular imaging; data mining; experience; middle age; mouse model; optical imaging; organizational structure; premature; progenitor; stem-like cell

Project summary. T lymphocytes are cells of the immune system that, like all blood cells, are routinely lost throughout life and must be replenished. The thymus is the primary site for T lymphocyte production. However, it contains no lymphoid stem cells, and instead depends on continuous importation of stem-like cells that circulate in the blood. Microenvironmental conditions unique to the thymus then instruct these stem-like cells to proliferate and differentiate into T lineage cells that recognize foreign substances but are tolerant to self. The durable thymic microenvironment is established by its stromal cells, consisting primarily of epithelial cells (thymic epithelial cells, TEC). TEC form a pervasive reticular matrix (network) upon which lymphocyte development depends, and competition for the TEC network limits lymphoid cellularity in the thymus, and thus T cell output. For reasons that are still not understood, the thymus exhibits premature and accelerated age-related atrophy, a disorder that is primarily a consequence of changes in TEC. Importantly, the thymus retains latent potential for short-lived regeneration, which can be induced by stimuli such as surgical castration. The mechanisms of this process are not well known, but are believed to require proliferation of TEC cells themselves, or expansion of a TEC precursor population. We have generated a large temporo-spatial database of global stromal gene transcription during induced regrowth. Multiple independent data mining approaches have consistently indicated that genes associated with projection, extension, and outgrowth of cellular processes, such as those that characterize the TEC network, are dynamically regulated during regeneration. To begin to evaluate the role of TEC projections in lymphoid development, thymic aging, and thymic regeneration, we have adopted contemporary neuroscience imaging technologies (Rosa26[Brainbow 2.1], a.k.a. Confetti) in thick organ slices to visualize individual TEC and the TEC network. We find that the morphology of individual TEC, particularly those in the cortex (cTEC), is vastly different than what is suggested by conventional immuno-staining of thin sections, with overall globular rather than radially aligned reticular shapes, each possessing elaborate processes that envelop large numbers of lymphocytes. In the `aged' thymus (from 6 month-old Confetti mice), these processes become both shorter and thinner, and thus provide a diminished surface for lymphoid contact that explains reduced cellularity with age. We predict that rather than TEC proliferation, surgical castration will induce the (transient) lengthening and strengthening of these processes, thus increasing lymphocyte production. Testing this hypothesis is a key objective in this project, but in order to accomplish this, we are first obligated to establish a baseline in the healthy state for TEC and the TEC network. The proposed project relies heavily on established and emerging neuroscience paradigms, and is consistent with the stated mission of the NIH to “to seek fundamental knowledge about the nature and behavior of living systems, and the application of that knowledge to enhance health…and reduce illness.”

项目摘要。 T淋巴细胞是免疫系统的细胞，与所有血细胞一样，它在整个生命中通常会丢失，并且 必须复制。胸腺是T淋巴细胞产生的主要部位。但是，它不包含 淋巴样干细胞，而取决于在循环中循环的干细胞的连续进口 血。胸腺独有的微环境条件，然后指示这些干细胞增殖和 分化为识别异物但宽容自我的谱系细胞。耐用的胸腺 微环境由其基质细胞建立，主要由上皮细胞（胸部上皮组成） 细胞，tec）。 TEC形成一个普遍的网状基质（网络），淋巴细胞发育依赖， TEC网络的竞争限制了胸腺中的淋巴细胞性，从而限制了T细胞输出。为了 尚不清楚的原因，胸腺表现出早熟和与年龄相关的萎缩，一个 疾病主要是TEC变化的结果。重要的是，胸腺保留了潜在的潜力 短暂的再生，可以由刺激（例如手术cast割）诱导。这个机制 过程不是众所周知的，但被认为需要TEC细胞本身的扩散或扩展 TEC前体人口。我们已经产生了一个大的全球基因基因的颞空间数据库 诱发遗憾期间的转录。多种独立的数据挖掘方法始终如一 表明与投影，扩展和生长相关的基因，例如 特征TEC网络的特征在再生过程中受动态调节。开始评估 TEC项目在淋巴机发育，胸腺衰老和胸腺再生中的作用，我们已经采用了 厚器官切片中的当代神经科学成像技术（Rosa26 [Brainbow 2.1]，又名五彩纸屑） 可视化单个TEC和TEC网络。我们发现单个TEC的形态，特别是 皮质中的那些（CTEC）与常规免疫染色所建议的薄 截面，整体全球而不是根本比对的网状形状，每个形状都具有精致 包围大量淋巴细胞的过程。在“老化”胸腺（来自6个月大的五彩纸屑小鼠）中， 这些过程既短又薄，因此为淋巴接触提供了降低的表面 这解释了随着年龄的增长而减少的细胞性。我们预测，手术cast割而不是TEC增殖 诱导这些过程的（瞬态）延长和增强，从而增加淋巴细胞 生产。检验该假设是该项目的关键目标，但是为了实现这一目标，我们是首先 有义务在TEC和TEC网络的健康状态下建立基线。拟议的项目依赖 严重地遵守已建立和新兴的神经科学范式，与既定的使命一致 NIH要“寻求有关生活系统的性质和行为的基本知识，并应用 这些知识以增强健康……并减少疾病。”