Pathogenesis And Treatment Of Aplastic Anemia

再生障碍性贫血的发病机制和治疗

• 批准号: 7734972
• 负责人: Neal S Young
• 金额: $ 504.97万
• 依托单位: NATIONAL HEART, LUNG, AND BLOOD INSTITUTE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7734972
• 关键词: Acute Myelocytic Leukemia; Affect; Alternative Therapies; Anemia; Aneuploidy; Animals; Annual Reports; Antigens; Antithymoglobulin; Aplastic Anemia; Apoptosis; Autoimmune Diseases; Autoimmune Process; Basic Science; Biology; Blood; Bone Marrow; Breeding; Cell Death; Cell Differentiation process; Cells; Cellular biology; Chemicals; Childhood; Chromosomes; Clinic; Clinical; Clinical Protocols; Count; Cyclosporine; Cyclosporins; Cytogenetics; Data; Defective spinal cord development; Detection; Disease; Dose; Dysmyelopoietic Syndromes; Employee Strikes; Employment; Enrollment; Equus caballus; Erythroid Cells; Etiology; Evolution; Family; Fibrosis; Fluorescent in Situ Hybridization; Functional disorder; Gene Expression; Genes; Genetic; Genetic Polymorphism; Genomic Instability; Genomics; Goals; Granzyme; Hematological Disease; Hematopoietic; Hepatitis; High Prevalence; Histopathology; Human; Human Parvovirus B19; Immune; Immune response; Immune system; Immunoblotting; Immunosuppression; Immunosuppressive Agents; In Vitro; Individual; Infectious Agent; Inflammation; Investigation; Knock-out; Laboratories; Lesion; Liver Cirrhosis; MabCampath; Malignant - descriptor; Mediating; Medical; Mennonite; Methodology; Methods; Modeling; Monoclonal Antibodies; Mus; Mutation; Myeloproliferative disease; Numbers; Oryctolagus cuniculus; Pancytopenia; Parvovirus Infections; Pathogenesis; Pathway interactions; Patients; Pattern; Persons; Pharmaceutical Preparations; Polymerase Chain Reaction; Protocols documentation; Rate; Refractory; Regulation; Relapse; Repair Complex; Research; Role; Signal Transduction Pathway; Staging; Stem cell transplant; Supportive care; Suspension Culture; Syndrome; Telomere Shortening; Therapeutic immunosuppression; Time; Tissue Sample; Treatment Protocols; Tumor Antigens; Tumor Necrosis Factor Ligand Superfamily Member 6; Virus; Virus Diseases; Work; base; comparative genomic hybridization; cytokine; experience; human disease; improved; interest; kindred; leukemia; novel; perforin; predictive modeling; prevent; programs; protein expression; rat Piga protein; response; success; telomere; tissue culture; virology

This years annual report incorporates both the work of the Cell Biology Section in bone marrow failure diseases and also of the Virus Discovery Section. Aplastic anemia (AA) and other types of bone marrow failure have clinical and laboratory features consistent with an autoimmune pathophysiology, with a diversity of putative inciting antigens, including viruses, chemicals, medical drugs, and tumor antigens. Whatever its specific etiology, a majority of patients respond with hematologic improvement after immunosuppressive therapies. One important clinical feature of AA is its association with clonal hematologic diseases, especially paroxysmal nocturnal hemoglobinuria (PNH) and myelodysplastic syndromes (MDS). In the clinic, studies have been directed towards more effective immunosuppression in AA and the application of immunosuppressive regimens to related bone marrow failure syndromes. Among current clinical protocols, our major study is a direct comparison two commercially available antithymocyte globulins, horse ATG versus rabbit ATG; more than 70 patients have been enrolled and a preliminary glimpse at the data suggests that these agents are not equivalent. A component of this study is to determine if low dose cyclosporine will prevent relapse, a common problem after successful immunosuppressive therapy. In other protocols, we are continuing to examine the role of rabbit ATG and the monoclonal antibody anti-CD52 (campath), in aplastic anemia refractory to a single course of horse ATG. Campath also is now utilized in a research setting for relapsed aplastic anemia, avoiding the use of cyclosporine. Retrospective examination of our large experience with aplastic anemia has allowed us to determine a new predictive model for response to immunosuppressive therapy and long-term survival, based on blood counts at presentation. Also, we have noted a striking improvement in both short and long-term survival in patients with aplastic anemia, due in part to better supportive care and also to the employment of alternative therapies, such as repeat immunosuppression and stem cell transplantation. In the laboratory, our murine model of immune-mediated bone marrow failure continues to yield interesting results. In addition to demonstrating that a type 1 cytokine response dominates in these animals, we have also shown that T-regulatory cells can abrogate disease, parallel with the observation of low T-regs in patients with aplastic anemia and suggesting potential utility of these cells in autoimmune diseases. We also have utilized cross-breeding with knock-out animals to determine that the Fas-ligand cell death pathway, rather than perforin-granzyme, dominates in mediating bone marrow failure in our model. In studies of the human immune system in aplastic anemia, we have identified lesions in modulating signal transduction pathways, including decreased zeta chain expression and diminished sap protein expression, consistent with dysregulated immune response. In studies of telomere biology as they related to human disease, we have extended our original observations of TERT mutations in acute myeloid leukemia to include collaborative studies of an infrequent polymorphism in Canadian patients, again demonstrating a higher prevalence in AML. The relationship of TERT mutations to hepatic cirrhosis, observed initially in a large Mennonite kindred, has now been extended to other families, including detailed histopathology disclosing an unusual combination of inflammation and fibrosis. The relationship between telomere shortening and genomic instability is being pursued, with some evidence of early success, with several strategies. We utilize cells from patients with telomere repair complex mutations with disease as well as clinically healthy persons from the same families who also have mutations. Results to date include the detection of an increased rate of aneuploidy after in vitro tissue culture, as determined by fluorescent in situ hybridization (FISH), end-to-end chromosome joining by conventional cytogenetics as well as spectrakaryotyping (SKY), and the establishment of a method to perform comparative genomic hybridization (CGH) on limited numbers of human hematopoietic cells from individual colonies from normal and patient bone marrows. In our virus discovery group, we have developed an efficient method of propogating B19 parvovirus in normal human hematopoietic cells in suspension culture. An important new observation is that parvovirus infection hijacks the erythroid cells differentiation program. In studies involving microarray, real time PCR, and immunoblot, determined regulation of multiple significant erythropoietic genes as they are affected at early stages of viral infection, prior to apoptosis of target cells. E2F-mediated control gene expression appears to be critical in this dramatic alteration in the pattern of gene expression. Finally, we have subjected tissue samples from patients with seronegative hepatitis to high throughput sequencing and identified potential novel infectious agents that may be responsible for this disease as well as for hepatitis-associated aplastic anemia and fulminant hepatitis of childhood.

今年的年度报告既包括细胞生物学科在骨髓衰竭疾病方面的工作，也包括病毒发现科的工作。再生障碍性贫血（AA）和其他类型的骨髓衰竭具有与自身免疫病理生理一致的临床和实验室特征，具有多种推定的刺激性抗原，包括病毒、化学物质、药物和肿瘤抗原。无论其具体病因如何，大多数患者在免疫抑制治疗后血液学改善。AA的一个重要临床特征是其与克隆性血液病，特别是阵发性夜间血红蛋白尿（PNH）和骨髓增生异常综合征（MDS）的相关性。在临床上，研究的方向是在AA中更有效的免疫抑制，以及将免疫抑制方案应用于相关的骨髓衰竭综合征。在目前的临床方案中，我们的主要研究是直接比较两种市售的抗胸腺细胞球蛋白，马ATG和兔ATG；超过70名患者被纳入研究，初步数据显示这些药物并不等同。这项研究的一个组成部分是确定低剂量环孢素是否会预防复发，这是免疫抑制治疗成功后的一个常见问题。在其他方案中，我们正在继续研究兔ATG和抗cd52单克隆抗体（campath）在马ATG单疗程难治性再生障碍性贫血中的作用。Campath现在也被用于研究复发性再生障碍性贫血，避免使用环孢素。我们对再生障碍性贫血的大量经验进行回顾性检查，使我们能够确定一种新的预测模型，用于免疫抑制治疗的反应和长期生存，基于就诊时的血细胞计数。此外，我们注意到再生障碍性贫血患者的短期和长期生存率都有显著改善，部分原因是更好的支持性护理和替代疗法的采用，如重复免疫抑制和干细胞移植。在实验室中，我们的小鼠免疫介导的骨髓衰竭模型继续产生有趣的结果。除了证明1型细胞因子反应在这些动物中占主导地位外，我们还表明t调节细胞可以消除疾病，与再生障碍性贫血患者低T-regs的观察平行，并提示这些细胞在自身免疫性疾病中的潜在效用。我们还利用敲除动物的杂交来确定在我们的模型中，fas配体细胞死亡途径，而不是穿孔蛋白颗粒酶，在介导骨髓衰竭中起主导作用。在再生障碍性贫血的人体免疫系统研究中，我们发现了信号转导通路的调节病变，包括zeta链表达减少和sap蛋白表达减少，这与免疫反应失调相一致。在与人类疾病相关的端粒生物学研究中，我们扩展了对急性髓性白血病中TERT突变的原始观察，包括对加拿大患者中罕见多态性的合作研究，再次证明了AML中较高的患病率。TERT突变与肝硬化的关系最初是在一个大的门诺派家族中观察到的，现在已经扩展到其他家族，包括详细的组织病理学，揭示了一种不寻常的炎症和纤维化的组合。端粒缩短和基因组不稳定性之间的关系正在研究中，有一些早期成功的证据，有几种策略。我们利用的细胞来自端粒修复复合体突变患者的疾病，以及临床健康的人从同一家庭谁也有突变。迄今为止的结果包括通过荧光原位杂交（FISH）检测到体外组织培养后非整倍体率增加，通过传统细胞遗传学和光谱核型（SKY）进行端到端染色体连接，并建立了一种方法，对来自正常和患者骨髓的单个菌落的有限数量的人造血细胞进行比较基因组杂交（CGH）。在我们的病毒发现小组中，我们开发了一种在悬浮培养的正常人造血细胞中有效繁殖B19细小病毒的方法。一个重要的新发现是细小病毒感染劫持了红细胞分化程序。在涉及微阵列、实时PCR和免疫印迹的研究中，在病毒感染的早期阶段，在靶细胞凋亡之前，确定了多个重要的红细胞生成基因受到影响时的调控。e2f介导的控制基因表达似乎在基因表达模式的这种戏剧性改变中至关重要。最后，我们对血清阴性肝炎患者的组织样本进行了高通量测序，并确定了可能导致这种疾病以及肝炎相关再生障碍性贫血和儿童暴发性肝炎的潜在新型感染性病原体。

项目成果

Research directions in paroxysmal nocturnal hemoglobinuria.

研究方向为阵发性睡眠性血红蛋白尿症。

• DOI: 10.1016/s0167-5699(98)01424-8
• 发表时间: 1999
• 期刊: Immunology today
• 作者: Dunn,DE;Ware,RE;Parker,CJ;Mishoe,HO;Young,NS
• 通讯作者: Young,NS

Expression of interferon-gamma by stromal cells inhibits murine long-term repopulating hematopoietic stem cell activity.

• DOI: 10.1016/s0301-472x(99)00009-0
• 发表时间: 1999-05
• 期刊: Experimental hematology
• 影响因子: 2.6
• 作者: J. Yu;R. Emmons;Y. Hanazono;S. Sellers;N. Young;C. Dunbar

Is there a direct effect of antithymocyte globulin on hematopoiesis?

抗胸腺细胞球蛋白对造血有直接影响吗？

• DOI: 10.1038/sj.thj.6200398
• 发表时间: 2004
• 期刊: The hematology journal : the official journal of the European Haematology Association / EHA
• 作者: Chen,Guibin;Kook,Hoon;Zeng,Weihua;Young,NealS;Maciejewski,JaroslawP
• 通讯作者: Maciejewski,JaroslawP

Cyclosporine is required to prevent severe acute GVHD following T-cell-depleted peripheral blood stem cell transplantation.

需要环孢素来预防 T 细胞耗尽的外周血干细胞移植后的严重急性 GVHD。

• DOI: 10.1038/sj.bmt.1703928
• 发表时间: 2003
• 期刊: Bone marrow transplantation
• 影响因子: 4.8
• 作者: Solomon,SR;Nakamura,R;Read,EJ;Leitman,SF;Carter,C;Childs,R;Dunbar,CE;Young,NS;Barrett,AJ
• 通讯作者: Barrett,AJ

Age-dependent accumulation of mtDNA mutations in murine hematopoietic stem cells is modulated by the nuclear genetic background.

• DOI: 10.1093/hmg/ddl457
• 发表时间: 2007-02
• 期刊: Human molecular genetics
• 影响因子: 3.5
• 作者: Yong-Gang Yao;Felicia M. Ellison;J. McCoy;Jichun Chen;N. Young