The developmental pathway of fetal-derived B cells

胎儿来源的 B 细胞的发育途径

• 批准号: 10735381
• 负责人: Nichol Elizabeth Holodick
• 金额: $ 7万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-01 至 2023-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10735381
• 关键词: Acute; Address; Adult; Animals; Antibodies; Aorta; Autoimmune; Autoimmunity; B-Cell Acute Lymphoblastic Leukemia; B-Cell Development; B-Lymphocyte Subsets; B-Lymphocytes; Bar Codes; Biological; Blood; Blood Cells; Bone Marrow; Bone Marrow Transplantation; Cell Lineage; Cell secretion; Cells; Cellular biology; Cessation of life; Complication; Data; Development; Developmental Process; Disease; Embryo; Embryonic Development; Endothelial Cells; Fetal Liver; Fetus; Frequencies; Functional disorder; Goals; Gonadal structure; Hematological Disease; Hematology; Hematopoiesis; Hematopoietic Stem Cell Transplantation; Hematopoietic stem cells; Immune; Immune System Diseases; Immune system; Immunity; Immunoglobulin A; Immunoglobulin Class Switching; Immunoglobulin M; Immunologic Deficiency Syndromes; Immunology; In Vitro; Infection; Intestines; Invaded; Knowledge; Label; Life; Lymphocyte; Lymphocyte Depletion; Lymphoid; Lymphoid Cell; Lymphopoiesis; Maps; Mature B-Lymphocyte; Mesonephric structure; Microglia; Modeling; Mus; Neonatal; Pathology; Pathway interactions; Peritoneal; Phase; Play; Population; Pregnancy; Production; Recovery; Reporting; Research; Role; Sorting; Spleen; Streptococcus pneumoniae; Technology; Therapeutic; Tissues; Transplant Recipients; Transplantation; Trees; Vaccination; Visualization; Yolk Sac; adaptive immunity; base; blastomere structure; cytokine; embryo cell; endothelial stem cell; fetal; hemogenic endothelium; improved; in vivo; leukemia/lymphoma; lymphoid organ; mast cell; microbial; mouse model; perinatal period; postnatal; progenitor; response; segregation; stem cells; theories; transplantation therapy; γδ T cells

Abstract Stem cell theory states that all the blood cells are derived from hematopoietic stem cells (HSCs) and is a central concept of hematology and immunology. Bone marrow transplant therapy for blood disorders is rooted in the concept that donor HSCs can replace all blood cells in the recipient's body. However, recent research has challenged the stem cell theory by showing that some tissue-resident immune cells develop from endothelial cells (EC) of the embryo in an HSC-independent manner and these immune cells may not be replaced by HSCs. Furthermore, it has been reported that a significant percentage of conventional B cells (B-2 cells) also originate from fetal EC progenitors in the embryo and persist into old mice. These striking results highlight a huge knowledge gap in the hematology and immunology fields because HSC-independent B-2 cell development has yet to be recognized. Since B cells play important roles in protecting against infections and in the pathology of autoimmune and other diseases, it is critically important to understand the developmental pathways of HSC- independent B-cells and their functions compared to HSC-derived counterparts. However, it is challenging to clarify the origins of these B-cells since there are multiple waves of hematopoiesis from ECs in the embryo, in which HSCs and HSC-independent blood progenitors seem to be produced simultaneously. Our preliminary data and other studies suggest that there are at least three waves of B-cell development; 1) innate-immune B-1 cell development, 2) common progenitors for innate B-1 and conventional B-2 cells, and 3) B-2 dominant progenitors derived from HSCs. Our objective is to determine the functional differences of B-cells based on their origins and to establish a revised B-cell development map from embryo to adult, using combinations of various lineage tracing and in vivo barcoding mouse models. To pursue these goals, Aim 1 will utilize HSC-labeling mice (100% labeling of HSCs is achieved) and the HSC-derived lymphoid cell depletion model so that HSC-independent and dependent B-cell subsets will be separated. Then, these HSC-independent and dependent B-cell subsets will be sorted and examined for 1) antibody and cytokine secretion, class switching upon in vitro stimulation, and their IgM repertoire, 2) in vivo repsonse to S. pneumoniae infection, and 3) response to pneumococcal vaccination. In Aim 2, preliminary data identified the earliest innate-immune restricted B-progenitors in the early fetal liver. Also, scRNA-sequencing of the neonatal spleen revealed three separate B-progenitor clusters, supporting our hypothesis. Thus, the EC-lineage tracing mouse model that can mark HSC-independent blood progenitors will be combined with in vivo barcoding, which will enable visualization of the clonal relationships between HSCs and fetal- and HSC-derived B-progenitors. The results obtained from this proposal will revise the current paradigm of B-cell development and will be utilized to understand pathology not previously recognized in the absence of recognizing the existance of various fetal-derived B cell subsets.

摘要 干细胞理论认为，所有的血细胞都来自于造血干细胞(HSCs)，是一种中枢 血液学和免疫学的概念。血液病的骨髓移植疗法植根于 捐献者的造血干细胞可以替代受者体内的所有血细胞。然而，最近的研究表明 挑战干细胞理论，表明一些组织驻留的免疫细胞是从内皮细胞发展而来的 胚胎中的细胞(EC)以不依赖于HSC的方式存在，这些免疫细胞可能不被HSC取代。 此外，据报道，相当大比例的传统B细胞(B-2细胞)也起源于 来自胚胎中的胚胎EC祖细胞，并持续存在于老年小鼠体内。这些惊人的结果突显了一个巨大的 血液学和免疫学领域的知识差距，因为不依赖于HSC的B-2细胞开发 还没有被认可。由于B细胞在预防感染方面发挥着重要作用，并且在 对于自身免疫和其他疾病，了解HSC的发育途径至关重要。 独立的B细胞及其功能与HSC来源的对应细胞相比较。然而，要做到这一点很有挑战性 阐明这些B细胞的来源，因为胚胎中的ECs有多波造血波， 这些造血干细胞和非造血干细胞的造血祖细胞似乎是同时产生的。我们的初步数据 其他研究表明，B细胞的发育至少有三个阶段：1)天然免疫的B-1细胞 发育，2)先天B-1和常规B-2细胞的共同祖细胞，以及3)B-2显性祖细胞 来源于造血干细胞。我们的目标是根据B细胞的来源和功能来确定它们的功能差异 使用不同血统的组合，建立修订的从胚胎到成人的B细胞发育图 追踪和体内条形码小鼠模型。为了实现这些目标，目标1将利用标记HSC的小鼠(100% 实现了HSC的标记)和HSC来源的淋巴样细胞耗竭模型，使得HSC不依赖于HSC和 依赖的B细胞亚群将被分离。然后，这些独立于HSC和依赖于HSC的B细胞亚群 被分类和检查1)抗体和细胞因子分泌，体外刺激下的等级切换，以及 它们的免疫球蛋白M谱系，2)对肺炎链球菌感染的体内应答，以及3)对肺炎球菌的应答 接种疫苗。在目标2中，初步数据确定了最早的先天免疫限制性B祖细胞在早期 胎儿肝脏。此外，对新生儿脾的scRNA测序显示，有三个独立的B祖细胞簇， 支持我们的假设。因此，可以标记HSC非依赖性血液的EC谱系追踪小鼠模型 祖细胞将与体内条形码相结合，这将使克隆关系可视化 HSCs与胎儿和HSC来源的B祖细胞之间的关系。从这项提案中获得的结果将修订 目前B细胞发展的范例，将被用来理解以前没有认识到的病理 在没有认识到各种胎儿来源的B细胞亚群存在的情况下。