Role of Brain Macrophages in the Pathogenesis and Treatment of Globoid Cell Leukodystrophy

脑巨噬细胞在球状细胞脑白质营养不良的发病机制和治疗中的作用

• 批准号: 10179184
• 负责人: Frederick Bennett
• 金额: $ 46.81万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-05-03 至 2026-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10179184
• 关键词: Adopted; Appearance; Astrocytes; Birth; Brain; Brain Diseases; CSF1R gene; Cell Therapy; Cells; Childhood; Data; Disease; Donor person; Effectiveness; Embryo; Engineering; Engraftment; Future; Genetic; Globoid cell leukodystrophy; Hematopoietic Stem Cell Transplantation; Heterogeneity; Immune; Injections; Knowledge; Label; Ligands; Lysosomal Storage Diseases; Maps; Methods; Microglia; Modeling; Mus; Names; Neuraxis; Neurodegenerative Disorders; Pathogenesis; Pathogenicity; Pathologic; Pathology; Pathway interactions; Peripheral; Population; Regulation; Resistance; Role; Synapses; Testing; Therapeutic; Tissues; Transplantation; Treatment Efficacy; Variant; Work; brain cell; brain tissue; cellular engineering; disease-causing mutation; disorder risk; gene function; improved; infancy; inhibitor/antagonist; innovation; leukodystrophy; macrophage; myelination; nervous system disorder; nervous system transplantation; neuropathology; new therapeutic target; novel strategies; preconditioning; receptor; reconstitution; risk variant; single cell sequencing; small molecule inhibitor; targeted treatment; tool; transcriptomics; transplantation therapy; unpublished works

Globoid cell leukodystrophy (GLD), or Krabbe, is a fatal pediatric neurodegenerative disease caused by mutations in GALC. It is so-named due to the appearance of globoid cell macrophages. The major hurdle to curing GLD is treatment of central nervous system (CNS) pathology. Hematopoietic stem cell transplant (HSCT) is the only treatment, but is not curative, and must be administered presymptomatically in early infancy. HSCT is thought to work by therapeutic engraftment of donor macrophages and replacement of globoid cells, but in the brain, does so inefficiently. Despite being pathognomonic for GLD, little is known about globoid cells in the brain - their function, origin, and formation. It is unknown if globoid cells arise from embryonically-derived tissue resident microglia or HSC-derived infiltrating macrophages, the degree to which they are pathogenic, and if their replacement is key to GLD treatment. This is a critical knowledge gap that has limited the advancement of more effective GLD therapies and is the focus of this proposal. Our central hypothesis is that globoid cells are unique reactive microglia and that robust replacement by “true” microglia is sufficient to treat GLD CNS neuropathology. We are experts in the study of brain macrophages by direct CNS transplantation in mice. The twitcher (GALCKO) mouse is a widely accepted model of GLD. We created new methods to 1) distinguish microglia, infiltrating macrophages, and transplanted donor macrophages from each other and 2) replace host brain macrophages with directly injected cells at high efficiency without HSCT, including by engineering the first small molecule inhibitor-resistant variant of CSF1R, a survival receptor for brain macrophages. In this proposal, we will apply these new methods in the GALCKO model to determine the role of brain macrophages in GLD pathogenesis and treatment. In Aim 1, we will define the origin and transcriptomic identity of all reactive brain macrophages, including globoid cells, in GALCKO, including after HSCT. This knowledge promises to reveal new therapeutic targets for GLD. In Aim 2, we will test the hypothesis that direct replacement of GALCKO microglia with healthy surrogates eliminates globoid cells and drives the neurotherapeutic effects of HSCT. If true, this approach has great translational potential to maximize engraftment efficiency and broaden the therapeutic window for cell therapy. Finally in Aim 3, we will determine if HSC-derived cells are effective microglial surrogates, given the distinct functions of non-microglial macrophages in the CNS. This will guide future work to enhance the efficacy of cell therapies for brain diseases. Completion of these aims will fill longstanding knowledge gaps about the role of microglia and other macrophages in the pathogenesis and treatment of pediatric neurodegenerative diseases.

球形细胞白细胞营养不良（GLD）或Krabbe是一种致命的小儿神经退行性疾病 galc中的突变。由于球形细胞巨噬细胞的出现，它被称为命名。主要障碍 Curing GLD是中枢神经系统（CNS）病理学的治疗。造血干细胞移植（HSCT） 是唯一的治疗方法，但不是治愈性的，必须在婴儿早期治疗中施用。 HSCT 被认为是通过植入供体巨噬细胞和替代球形细胞的治疗来起作用的，但是在 大脑，这样做效率低下。尽管对GLD是病理性的，但对大脑中的球形细胞知之甚少 - 它们的功能，起源和形成。未知的球形细胞是否由胚胎衍生的组织产生 居民小胶质细胞或HSC衍生的浸润巨噬细胞，其致病程度，以及它们 替换是GLD治疗的关键。这是一个关键的知识差距，限制了更多的进步 有效的GLD疗法，是该提案的重点。我们的中心假设是球形细胞是 独特的反应性小胶质细胞和“ True”小胶质细胞的稳健替代物足以治疗GLD CNS 神经病理学。我们是通过小鼠的直接中枢神经系统移植研究研究脑巨噬细胞的专家。这 Twitcher（Galcko）小鼠是GLD广泛接受的模型。我们创建了新方法到1）区分 小胶质细胞，浸润巨噬细胞和彼此移植的供体巨噬细胞，2）替换宿主 脑巨噬细胞具有直接注射细胞的高效率，而无需HSCT，包括工程第一个 CSF1R的抗性分子抑制剂的小分子抑制剂，这是一种用于脑巨噬细胞的存活受体。在此提案中， 我们将在Galcko模型中应用这些新方法来确定大脑巨噬细胞在GLD中的作用 发病机理和治疗。在AIM 1中，我们将定义所有反应性大脑的起源和转录组身份 巨噬细胞（包括球形细胞）在加尔科（Galcko），包括HSCT之后。这些知识有望揭示新的 GLD的治疗靶标。在AIM 2中，我们将测试直接替代Galcko小胶质细胞的假设 健康的替代物消除了球形细胞，并驱动HSCT的神经疗法作用。如果是真的，这 方法具有最大化植入效率并扩大治疗的巨大转化潜力 细胞疗法的窗口。最后，在AIM 3中，我们将确定HSC衍生的细胞是否有效小胶质细胞 鉴于中枢神经系统中非微型巨噬细胞的独特功能，替代物。这将指导未来的工作 提高细胞疗法对脑疾病的效率。这些目标的完成将长期填补 关于小胶质细胞和其他巨噬细胞在发病机理和治疗中的作用的知识差距 小儿神经退行性疾病。