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single cell sequencing; small molecule inhibitor; targeted treatment; tool; transcriptomics; transplantation therapy; unpublished works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.

球状细胞脑白质营养不良 (GLD) 或 Krabbe 是一种致命的小儿神经退行性疾病，由 GALC 突变。因出现球形细胞巨噬细胞而得名。主要障碍是 治疗 GLD 是治疗中枢神经系统 (CNS) 病理学的方法。造血干细胞移植（HSCT） 是唯一的治疗方法，但不能治愈，必须在婴儿早期出现症状前进行治疗。造血干细胞移植 人们认为通过治疗性植入供体巨噬细胞和替换球形细胞来发挥作用，但在 大脑，这样做效率很低。尽管是 GLD 的特有特征，但人们对大脑中的球状细胞知之甚少 - 它们的功能、起源和形成。目前尚不清楚球状细胞是否来自胚胎来源的组织 常驻小胶质细胞或 HSC 衍生的浸润巨噬细胞，它们致病的程度，以及它们是否 更换是 GLD 治疗的关键。这是一个关键的知识差距，限制了更多技术的进步 有效的 GLD 疗法是本提案的重点。我们的中心假设是球状细胞是 独特的反应性小胶质细胞和“真正的”小胶质细胞的强有力替代足以治疗 GLD CNS 神经病理学。我们是通过直接中枢神经系统移植研究小鼠脑巨噬细胞的专家。这 twitcher (GALCKO) 小鼠是广泛接受的 GLD 模型。我们创建了新方法来 1) 区分 小胶质细胞、浸润巨噬细胞和移植的供体巨噬细胞相互排斥，2) 替换宿主 无需 HSCT 即可高效直接注射细胞的脑巨噬细胞，包括通过工程设计第一个 CSF1R 的小分子抑制剂抗性变体，CSF1R 是脑巨噬细胞的存活受体。在这个提案中， 我们将在 GALCKO 模型中应用这些新方法来确定脑巨噬细胞在 GLD 中的作用 发病机制和治疗。在目标 1 中，我们将定义所有反应性大脑的起源和转录组身份 GALCKO 中的巨噬细胞，包括球状细胞，包括 HSCT 后的巨噬细胞。这些知识有望揭示新的 GLD 的治疗靶点。在目标 2 中，我们将检验直接替换 GALCKO 小胶质细胞的假设 与健康替代者一起消除球状细胞并促进 HSCT 的神经治疗效果。如果属实的话，这 该方法具有巨大的转化潜力，可以最大限度地提高植入效率并扩大治疗范围 细胞治疗的窗口期。最后在目标 3 中，我们将确定 HSC 衍生细胞是否是有效的小胶质细胞 考虑到中枢神经系统中非小胶质细胞巨噬细胞的独特功能。这将指导今后的工作 增强细胞疗法对脑部疾病的疗效。这些目标的完成将填补长期以来的空白 关于小胶质细胞和其他巨噬细胞在糖尿病发病机制和治疗中的作用的知识差距 小儿神经退行性疾病。