Humanized Mouse Models of Severe Combined Immunodeficiency

严重联合免疫缺陷的人源化小鼠模型

基本信息

批准号：
7806422
负责人：
SUNG-YUN PAI
金额：
$ 25.47万
依托单位：
BOSTON CHILDREN'S HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-04-08 至 2011-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7806422
关键词：
Acquired Immunodeficiency Syndrome Affect Animal Model Animals Apoptosis Blood Bone Marrow Bone Marrow Examination Bone Marrow Transplantation CD34 gene CD7 gene Childhood Congenital Disorders Defect Development Engraftment Failure Frequencies Generations Genes Goals Hematopoietic Stem Cell Transplantation Hematopoietic stem cells Hereditary Disease Human Immune Immune response Immune system Immunodeficient Mouse Interleukin 2 Receptor Interleukin 2 Receptor Gamma Intervention Lead Mature Thymocyte Modeling Molecular Morbidity - disease rate Mus Mutation Natural Killer Cells Nature Pathogenesis Pathway interactions Patients Phenotype Research STAT5A gene Sampling Severe Combined Immunodeficiency Signal Pathway Signaling Molecule Staging System T cell differentiation T-Cell Development T-Lymphocyte Testing Thymus Gland Tissues Toxic effect Tumor stage X-Linked Severe Combined Immunodeficiency acquired immunodeficiency base cancer therapy fetal gene therapy human disease in vivo knock-down migration mortality mouse model novel progenitor public health relevance reconstitution small hairpin RNA therapy development thymocyte

项目摘要

DESCRIPTION (provided by applicant): Severe combined immunodeficiency (SCID) is a heterogeneous group of fatal congenital disorders characterized by the absence of T lymphocytes. T cells develop from bone marrow derived T progenitors that migrate to the thymus and differentiate before export to the blood. The most common form, X-linked SCID, is caused by lack of common gamma chain (?c) expression. Because mouse models for X-linked SCID are lacking, we still know surprisingly little about why lack of ?c impairs T cell development. The goal of this project is to determine the stage(s) at which T cell development in the absence of ?c is aberrant, at the level of T progenitor generation, thymus seeding and/or intrathymic development. We hypothesize that T development will be affected at the T progenitor stage and more severely affected at an early stage of intrathymic development. We further hypothesize that failure of differentiation, rather than defects in proliferation/survival, causes an absolute block in development and that this failure can be rescued by reconstituting the specific components of the ?c signaling pathway. In Aim 1, we will examine the normal expression of ?c in human T cell progenitors and investigate whether T progenitors are present in the bone marrow of patients with X-linked SCID. In Aim 2 and Aim 3, we will create humanized mice bearing ?c deficient immune systems, using a new strain of NOD-scid immunodeficient mice that can support human T cell differentiation in vivo (NOD/scid Il2rgnull). In Aim 2 we will reconstitute NOD/scid Il2rgnull mice with normal human bone marrow in which ?c has been knocked down by lentiviral expression of short hairpin RNA. Using these "?c knockdown mice," we will analyze bone marrow and thymus, and characterize the precise nature of the T cell differentiation block. In Aim 3 we will reconstitute NOD/scid Il2rgnull mice with bone marrow from patients with X-linked SCID. We will then use this "humanized X-SCID" mouse model to test whether activation of the STAT5 pathway or Akt pathway can restore T cell development in the absence of ?c. Humanized mice will give us the ability to propagate normal and aberrant human immune systems in a tractable animal system and bridge the gap that currently exists between mouse models and human disease. We believe this model will also ultimately lead to discovery of novel genes critical for human immune development and novel therapies for SCID. PUBLIC HEALTH RELEVANCE: T cells are an essential component of the immune system. Congenital absence of T cells (severe combined immunodeficiency or SCID) or acquired immunodeficiency (such as in AIDS, following bone marrow transplantation or after cancer treatment) all cause significant morbidity and mortality. By studying why T cells fail to develop in the most common form of SCID, we hope to develop therapies that enhance T cell development and thus in turn enhance T cell dependent immune responses.

描述（由申请人提供）：严重联合免疫缺陷 (SCID) 是一组异质性致命性先天性疾病，其特征是 T 淋巴细胞缺失。 T 细胞由骨髓来源的 T 祖细胞发育而来，迁移到胸腺并在输出到血液之前分化。最常见的形式是 X 连锁 SCID，是由于缺乏常见的 γ 链 (?c) 表达而引起的。由于缺乏 X 连锁 SCID 的小鼠模型，我们对为什么缺乏 ?c 会损害 T 细胞发育仍然知之甚少。该项目的目标是确定在缺乏 ?c 的情况下 T 细胞发育在 T 祖细胞生成、胸腺播种和/或胸腺内发育水平上出现异常的阶段。我们假设 T 发育将在 T 祖细胞阶段受到影响，并且在胸腺内发育的早期阶段受到更严重的影响。我们进一步假设分化失败，而不是增殖/存活缺陷，导致发育绝对受阻，并且这种失败可以通过重建 βc 信号通路的特定成分来挽救。在目标 1 中，我们将检查人类 T 细胞祖细胞中 αc 的正常表达，并研究 T 祖细胞是否存在于 X 连锁 SCID 患者的骨髓中。在目标 2 和目标 3 中，我们将使用能够支持人体内 T 细胞分化的新品系 NOD-scid 免疫缺陷小鼠（NOD/scid Il2rgnull）来创建具有免疫系统缺陷的人源化小鼠。在目标 2 中，我们将用正常人骨髓重建 NOD/scid Il2rgnull 小鼠，其中 βc 已被短发夹 RNA 的慢病毒表达敲低。使用这些“?c 敲低小鼠”，我们将分析骨髓和胸腺，并表征 T 细胞分化块的精确性质。在目标 3 中，我们将使用 X 连锁 SCID 患者的骨髓重建 NOD/scid Il2rgnull 小鼠。然后我们将使用这个“人源化X-SCID”小鼠模型来测试STAT5途径或Akt途径的激活是否可以在缺乏?c的情况下恢复T细胞的发育。人源化小鼠将使我们能够在易于驯服的动物系统中繁殖正常和异常的人类免疫系统，并弥合目前小鼠模型和人类疾病之间存在的差距。我们相信这个模型最终也将导致发现对人类免疫发育至关重要的新基因和 SCID 的新疗法。公共卫生相关性：T 细胞是免疫系统的重要组成部分。先天性缺乏 T 细胞（严重联合免疫缺陷或 SCID）或获得性免疫缺陷（例如艾滋病、骨髓移植后或癌症治疗后）都会导致显着的发病率和死亡率。通过研究为什么 T 细胞在最常见的 SCID 形式中无法发育，我们希望开发出增强 T 细胞发育的疗法，从而增强 T 细胞依赖性免疫反应。