Humanized Mouse Models of Severe Combined Immunodeficiency

严重联合免疫缺陷的人源化小鼠模型

• 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
• 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; 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

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）：严重的联合免疫缺陷（SCID）是一组具有T淋巴细胞的特征的致命性先天性疾病。 T细胞从衍生出T祖细胞的骨髓发育，该祖细胞迁移到胸腺并在出口到血液之前分化。最常见的形式是X连锁SCID，是由于缺乏常见的γ链（？c）表达引起的。由于缺乏用于X连锁SCID的小鼠模型，因此我们仍然对为什么缺乏损害T细胞的发展知之甚少。该项目的目的是确定在没有t祖细胞产生，胸腺播种和/或胸膜内发育的水平上，在没有c的情况下T细胞发育的阶段。我们假设T发育将在T祖细胞阶段受到影响，并在胸膜内发育的早期阶段受到更严重的影响。我们进一步假设，分化的失败，而不是增殖/生存中的缺陷会导致发育中的绝对障碍，并且可以通过重新建立？C信号传导途径的特定组件来挽救这种失败。在AIM 1中，我们将检查人类T细胞祖细胞中的正常表达，并研究X连锁SCID患者的骨髓中T祖细胞是否存在。在AIM 2和AIM 3中，我们将使用新的NOD-SCID免疫缺陷小鼠菌株来创建具有人源性的小鼠，以支持人体T细胞分化体内（nod/scID/scid il2rgnull）。在AIM 2中，我们将用正常的人骨髓来重新建立点头/scID IL2RGNULL小鼠，其中c被短发蛋白RNA的慢病毒表达击倒。我们将使用这些“敲击小鼠”，我们将分析骨髓和胸腺，并表征T细胞分化块的精确性。在AIM 3中，我们将用X连锁SCID患者的骨髓来重建点头/SCID IL2RGNULL小鼠。然后，我们将使用此“人源化X-SCID”小鼠模型来测试在没有？c的情况下，STAT5途径或AKT途径的激活是否可以恢复T细胞的发育。人源化的小鼠将使我们能够在易于处理的动物系统中传播正常和异常的人类免疫系统，并弥合小鼠模型和人类疾病之间目前存在的差距。我们认为，这种模型还将最终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（严重的免疫缺陷或SCID）或获得的免疫缺陷（例如在艾滋病中，骨髓移植后或癌症治疗后）都会引起明显的发病率和死亡率。通过研究为什么T细胞无法以最常见的SCID形式发展，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。