Investigation of the innate and adaptive immune responses to TDP-43 aggregates in Amyotrophic Lateral Sclerosis

肌萎缩侧索硬化症中 TDP-43 聚集体的先天性和适应性免疫反应的研究

• 批准号: 10383924
• 负责人: Baggio Angelo Evangelista
• 金额: $ 3.93万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-01 至 2025-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10383924
• 关键词: ALS pathology; ALS patients; Affect; Amyotrophic Lateral Sclerosis; Antigen Presentation; Antigens; Area; Atrophic; Autopsy; B-Lymphocytes; Biological Assay; Biological Models; Brain; CD8-Positive T-Lymphocytes; Caliber; Cell Death Signaling Process; Cells; Cessation of life; Clinical; Coculture Techniques; Cytotoxic T-Lymphocytes; DNA-Binding Proteins; Data; Development; Diagnosis; Exposure to; Functional disorder; Human; Immune; Immune response; Immunoassay; Immunologic Factor Activation; Immunology; In Vitro; Individual; Inflammation; Inflammatory; Interferon Type II; Investigation; Knowledge; Mass Spectrum Analysis; Mediating; Metabolic; Microglia; Modeling; Molecular; Monitor; Motor Neuron Disease; Motor Neurons; Nerve Degeneration; Neuraxis; Neurodegenerative Disorders; Neurons; Neurosciences; Neurosciences Research; Pathogenesis; Pathologic; Pathology; Patients; Peripheral; Phagocyte Bactericidal Dysfunction; Phagocytosis; Phagolysosome; Phagosomes; Phenotype; Proteomics; RNA; RNA analysis; Reporting; Resolution; Role; Route; Rupture; Source; Spinal Cord; Surface; Survival Rate; Symptoms; System; T cell response; T-Cell Activation; T-Lymphocyte; Testing; Transact; Translational Research; Vesicle; Work; adaptive immune response; base; biomarker development; cell killing; cell type; cytotoxic CD8 T cells; diagnostic strategy; imaging modality; immunological status; improved; in vitro Model; induced pluripotent stem cell; insight; interdisciplinary approach; live cell imaging; macrophage; misfolded protein; neuroinflammation; neuron loss; neurotoxic; neurotoxicity; novel; protein aggregation; response; sporadic amyotrophic lateral sclerosis; therapeutic development; therapeutic target; training opportunity; transcriptome sequencing; transcriptomics; transmission process; treatment strategy; uptake

PROJECT SUMMARY Sporadic amyotrophic lateral sclerosis (sALS) is the most common progressive motor-neuron disease, affecting 3 in 100,000 individuals 50 years or older worldwide. sALS is pathologically characterized by the presence of hyper-phosphorylated, insoluble aggregates of the RNA/DNA binding protein Transactive Response DNA Binding Protein (TDP-43). It is well established that aggregated TDP-43 causes dysfunction throughout the central nervous system (CNS), ultimately resulting in neuronal cell death and symptom onset. However, the exact molecular mechanism(s) by which aggregated TDP-43 imparts neurotoxicity has not yet been determined. Recent evidence implicates innate immune cells, particularly infiltrating peripheral macrophages and microglia, as a source of inflammation when stimulated by misfolded protein aggregates. This neuroinflammatory response is therefore expected to compromise neuron integrity and contribute to neurodegeneration. Furthermore, and adaptive immune cells, T- and B-lymphocytes, have been reported in post-mortem analyses of ALS brain and spinal cord, however their mechanistic role in pathology remains unclear. This implicates both innate and adaptive immune responses in sALS pathogenesis. Recent developments also suggest that microglia promote secondary T-cell responses when stimulated by protein aggregates. This T-cell activation may then result in direct neuronal death. Therefore, I hypothesize that aggregated TDP-43 causes a pro-inflammatory, neurodegenerative cascade mediated by innate and adaptive immune responses that drives neurotoxicity in sALS. In Aim 1, I will treat microglia with aggregated mammalian-derived TDP-43 and monitor modulation of phagolysosomal integrity and inflammatory activation. Preliminary data using models of microglia treated with TDP-43 aggregates demonstrate robust aggregate uptake and phagosome rupture. Additionally, mass spectrometry analysis of TDP-43-treated macrophage cultures revealed an increase in pro-inflammatory and immune activation factors, and markers of phagocytic dysfunction. In Aim 2, I will assess the ability of TDP-43- treated microglia to promote motor-neuron death by way of T-cell activation. I will determine if TDP-43- treated microglia engage with and promote CD4+ and CD8+ T-cell activation in culture. Finally, I will determine if activated cytotoxic CD8+ T-cells prompt motor-neuron death in vitro using sALS patient-derived T-cells and induced pluripotent stem cell (iPSC)-derived motor-neurons. In all, this work will use novel in vitro models to elucidate the unknown mechanism by which TDP-43 aggregation leads to motor-neuron death and sALS onset. This knowledge lends itself to biomarker and therapeutic development to improve diagnostic and treatment strategies for sALS patients.

项目总结