Molecular Mechanism of Immune Therapy for Bone Marrow Failures

骨髓衰竭免疫治疗的分子机制

• 批准号: 8392110
• 负责人: Pearlie K Burnette
• 金额: --
• 依托单位: JAMES A. HALEY VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-10-01 至 2014-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8392110
• 关键词: Acute; Address; Adhesions; Adoptive Transfer; Aftercare; Age; Aging; Animal Model; Animals; Antigens; Antithymoglobulin; Aplastic Anemia; Applications Grants; Autoimmune Diseases; Autoimmune Process; Autoimmunity; Binding; Blood; Bone Marrow; Bone Marrow Cells; Bone Marrow Suppression; CD8B1 gene; Caring; Cell Adhesion Molecules; Cells; Cleaved cell; Clinical; Clinical Data; Clinical Research; Complex; Cyclophosphamide; Cyclosporine; Cytolysis; Data; Defect; Development; Diagnosis; Diagnostic; Disease; Disease Progression; Disease model; Dose; Dysmyelopoietic Syndromes; Effectiveness; Endothelial Cells; Equilibrium; Etiology; Event; Failure; Foundations; Funding; Future; Genetic Transcription; Goals; Hematopoiesis; Home environment; Homing; Immune; Immune response; Immune system; Immunosuppressive Agents; Immunotherapy; In Vitro; Incidence; Individual; Inflammatory; Integrin alpha4beta1; Integrins; L-Selectin; Laboratories; Large granular lymphocyte; Lead; Life Expectancy; Ligands; Link; Lymphocyte; Lymphocyte Homing Receptors; Lymphocytosis; Lymphoid; Manuscripts; Matrix Metalloproteinases; Mediating; Membrane; Metalloproteases; Methotrexate; Modeling; Molecular; Monitor; Mus; Myelogenous; Myelopoiesis; Pancytopenia; Pathogenesis; Pathology; Patients; Peripheral; Pharmaceutical Preparations; Pharmacotherapy; Population; Process; Production; Progress Reports; Publishing; Quality of life; Regulation; Rheumatoid Arthritis; Role; SELL gene; Spleen; Surface; Syndrome; System; T-Cell Activation; T-Cell Depletion; T-Lymphocyte; TNF-alpha converting enzyme; Testing; Theophylline; Therapeutic; Therapeutic immunosuppression; Time; Transgenic Mice; Tumor Necrosis Factor-alpha; Vascular Cell Adhesion Molecule-1; Vasculitis; Veterans; Work; abstracting; alpha secretase; base; bone; chronic T-cell leukemia; cytokine; cytopenia; design; effective therapy; improved; in vivo; inhibitor/antagonist; lymph nodes; meetings; migration; mouse model; novel therapeutics; pre-clinical; preclinical study; progenitor; receptor; research study; trafficking; treatment strategy

Abstract: Clonal diseases of large granular lymphocytes (LGL) are characterized by lymphocytosis and T cell-mediated cytopenias of the myeloid compartment. Several syndromes of T cell-mediated bone marrow failure have similar pathology including aplastic anemia (AA), paroxysmal nocturnal hemaglobinuria (PNH), and a subset of patients with Myelodysplastic Syndrome (MDS). All of these syndromes are characterized by clinical improvement with immunosuppressive therapy (IST) such as low-dose methotrexate (MTX), low- dose cyclophosphamide (CY) or cyclosporine A (CyA) and, in the case of aplastic anemia and MDS, T cell depletion with anti-thymocyte globulin (ATG). The broad long-term goal of this proposal is to improve the diagnosis and treatment of patients with LGL leukemia and these other bone marrow failure diseases. In patients with these T-cell mediated bone marrow failure syndromes, it is not clear whether the T lymphocytes become activated locally in the bone marrow against specific bone marrow antigens, or within the peripheral lymphoid system and then home to the bone marrow. The prevailing idea during the last funding period was that an antigen, presumably a common antigen on myeloid progenitors was responsible for suppression of myelopoiesis. This was thought to be due to the direct interaction between this "putative myeloid-specific antigen" and the expanded antigen-specific T cell clone. In the Progress Report, our data strongly suggests that a multi-step model of autoimmunity for this disease process based on work during the last funding period. We show in preliminary results that the lymph node homing receptor L-selectin (CD62L) is dramatically lost from CD8+ T cells in LGL leukemia patients (manuscript published in Blood 2009). The main hypothesis to be addressed in this proposal is that altered bone marrow homing is critical for LGL leukemia pathogenesis. We hypothesize that acute activation in the primary lymphoid system leads to cleavage and shedding of CD62L by the Tumor Necrosis Factor-¿ Converting Enzyme (TACE), which also known as ADAM-17. This matrix metalloproteinase (MMP) cleaves not only CD62L to control the egress of T cells from the lymph node but it is also necessary for the activity of several inflammatory cytokines with known importance in LGL leukemia and other autoimmune diseases. In Specific Aim 1, we will confirm our hypothesis that loss of CD62L expression is mediated primarily by ectodomain shedding by the ADAM-17 matrix metalloproteinase. Because CD62L is a lymphoid homing receptor, we hypothesize that loss of this receptor then allows these activated T cells to exit the lymph node but loss of CD62L alone is not expected to trigger migration and colonization in the bone marrow where these cells suppress hematopoiesis. The focus of Specific Aim 2 is to determine the mechanism of bone marrow homing by T cells in LGL leukemia using an in vitro system. Homing and migration are complex events that are optimally monitored in vivo and there is no mouse model of LGL leukemia or bone marrow failure disease currently available. Moreover, the regulation of homing to the bone marrow even under normal conditions is incompletely understood. Since the antigen that activates T cells in LGL leukemia is unknown, we will use a well defined transgenic mouse model to study important aspects of bone marrow homing and hemosuppression by antigen-specific T cells. This will allow us to test the importance of CD62L, VLA-4, and ADAM-17 in vivo. Additionally, the efficacy of pharmacological inhibitors to block homing to the bone marrow will be tested to provide critical pre-clinical data for application to clinical studies in patients in the future.

摘要：大颗粒淋巴细胞（LGL）克隆性疾病的特点是淋巴细胞增多和 T 细胞介导的髓系细胞减少症。 T细胞介导的骨髓的几种综合征 失败具有相似的病理学，包括再生障碍性贫血（AA）、阵发性睡眠性血红蛋白尿（PNH）、 以及一部分患有骨髓增生异常综合征 (MDS) 的患者。所有这些综合症的特征都是 通过免疫抑制治疗（IST）如低剂量甲氨蝶呤（MTX）、低剂量甲氨蝶呤（MTX）等临床改善 剂量环磷酰胺 (CY) 或环孢菌素 A (CyA)，在再生障碍性贫血和 MDS 的情况下，T 细胞 用抗胸腺细胞球蛋白（ATG）耗尽。该提案的广泛长期目标是改善 LGL白血病和其他骨髓衰竭疾病患者的诊断和治疗。 在患有这些 T 细胞介导的骨髓衰竭综合征的患者中，尚不清楚 T 细胞是否 淋巴细胞在骨髓中针对特定的骨髓抗原被局部激活，或在 外周淋巴系统，然后回到骨髓。过去一段时间流行的想法 资助期间是一种抗原，大概是骨髓祖细胞上的常见抗原造成的 用于抑制骨髓细胞生成。这被认为是由于这种“假定的 骨髓特异性抗原”和扩展的抗原特异性 T 细胞克隆。在进度报告中，我们的数据 强烈建议基于工作期间的工作建立针对这种疾病过程的多步骤自身免疫模型 最后一个资助期。我们在初步结果中表明，淋巴结归巢受体 L-选择素 LGL 白血病患者的 CD8+ T 细胞 (CD62L) 显着丢失（手稿发表于 Blood 2009）。该提案要解决的主要假设是改变的骨髓归巢是 对于 LGL 白血病发病机制至关重要。我们假设初级淋巴的急性激活 系统导致 CD62L 被肿瘤坏死因子-¿ 转换酶裂解和脱落 （TACE），也称为 ADAM-17。这种基质金属蛋白酶 (MMP) 不仅将 CD62L 裂解为 控制 T 细胞从淋巴结的流出，但它对于一些细胞的活性也是必要的 炎症细胞因子在 LGL 白血病和其他自身免疫性疾病中具有已知的重要性。在 具体目标 1，我们将证实我们的假设，即 CD62L 表达的丧失主要由 ADAM-17 基质金属蛋白酶的胞外域脱落。因为 CD62L 是淋巴归巢 受体，我们假设失去该受体后，这些激活的 T 细胞就会离开淋巴 淋巴结，但仅损失 CD62L 预计不会引发骨髓中的迁移和定植 这些细胞抑制造血作用。具体目标 2 的重点是确定 使用体外系统在 LGL 白血病中 T 细胞归巢到骨髓。归巢和迁徙是 复杂的事件在体内得到最佳监测，并且没有 LGL 白血病或骨的小鼠模型 目前可获得骨髓衰竭疾病。此外，归巢到骨髓的调节甚至 在正常情况下是不完全理解的。由于 LGL 中激活 T 细胞的抗原 白血病尚不清楚，我们将使用明确的转基因小鼠模型来研究白血病的重要方面 抗原特异性 T 细胞的骨髓归巢和血液抑制。这将使我们能够测试 CD62L、VLA-4 和 ADAM-17 在体内的重要性。此外，药物抑制剂的功效 将测试阻止归巢到骨髓的方法，以便为应用提供关键的临床前数据 未来对患者进行临床研究。