Pathogenesis And Treatment Of Aplastic Anemia

再生障碍性贫血的发病机制和治疗

基本信息

批准号：
7594394
负责人：
Neal S Young
金额：
$ 449.96万
依托单位：
NATIONAL HEART, LUNG, AND BLOOD INSTITUTE
依托单位国家：
美国
项目类别：
财政年份：
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/7594394
关键词：
Acute Myelocytic Leukemia Androgen Antagonists Androgen Receptor Androgens Anemia Aneuploidy Annual Reports Antigens Antithymoglobulin Aplastic Anemia Autoimmune Process Basic Science Bone Marrow CD34 gene CD36 gene CD4 Positive T Lymphocytes Cancer Center Capsid Cause of Death Cell Culture System Cells Cellular biology Chemicals Child Chromosomes Clinic Clinical Confocal Microscopy Consent Cultured Cells Cyclosporine Cyclosporins Cytokine Gene Data Defective spinal cord development Disease Distant Dose Dysmyelopoietic Syndromes End Point Equus caballus Estrogen Antagonists Estrogens Etiology Evolution Family member Fathers Female Fibrosis Functional disorder Gene Expression Genetic Genetic Transcription Genomic Instability Genomics Goals Hematological Disease Hematopoietic Hemolysis Hepatic Hormones Human Human Parvovirus B19 Human Volunteers Immune Immune system Immunosuppression Immunosuppressive Agents In Vitro Infection Inflammation Interferon Type II Investigation Laboratories Laboratory Study Liver diseases Malignant - descriptor Marketing Measures Mediating Medical Mennonite Methodology Methods Modeling Molecular Monoclonal Antibodies Mus Mutation Myeloproliferative disease Numbers Oryctolagus cuniculus Pancytopenia Parvovirus Pathogenesis Patients Pharmaceutical Preparations Phase I Clinical Trials Phase III Clinical Trials Population Procedures Production Protocols documentation Randomized Rate Recombinants Refractory anemias Relapse Relative (related person)Role Sampling Sickle Cell Anemia Signal Transduction Staging Standards of Weights and Measures Symptoms Syndrome T-Lymphocyte TERT gene Telomerase Telomere Shortening Testing Therapeutic immunosuppression Thrombosis Tissues Treatment Protocols Tumor Antigens United States Food and Drug Administration Upper arm Ursidae Family Vaccines Viral Genes Virus Work cytokine erythroid differentiation improved kindred leukemia liver transplantation loss of function male neutralizing antibody novel prevent proband rat Piga protein receptor repaired response telomere virology

项目摘要

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 in parvoviruses, as the latter has been incorporated into the former due to the departure of Dr. Kevin Brown. 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. Multiple studies are in progress. While we observed some responses in first presentation aplastic anemia to the monoclonal antibody CAMPATH, this arm of our three-arm randomized protocol was discontinued early when it became clear that anti-CD52 was unlikely to be as effective as standard therapy. A comparison of horse and rabbitt ATG continues in this patient population. In AA refractory to standard horse ATG plus cyclosporine, both rabbit ATG and CAMPATH show activity about 30% salvage rate. We are also testing CAMPATH in the treatment of relapsed AA and in MDS. Our participation in a mulit-center trial of eculuzimab was completed; in addition to leading to FDA approval for this agent, now marketed as Soliris, for the indications of symptoms and/or severe anemia due to intravassular hemolysis in PNH, further analysis of end points has shown that the monoclonal antibody is also strikingly effective in reducing the rate of thrombosis, the major cause of death in PNH. In the laboratory, studies of immune destruction of hematopoietic cells has continued in several directions. We have examined the mechanism of action of the ATGs, especially as horse and rabbit products do not appear to be equally effective in the treatment of aplastic anemia. In cell culture and molecular studies, we have confirmed that rabbit ATG in vitro induces T-regulatory cells from CD25-FoxP3-CD4 cells while horse ATG lacks this activity. In order to study T-cells intensively, lymphocytopheresis in now being performed in patients who consent to this procedure prior to therapy and at the completion of a six month course in order to perform molecular studies of cytokine gene expression. Preliminary data suggests that T-cell clones that persist in patients who have fully recovered hematopoietic capacity lack production of gamma-interferon and other type-1 cytokines and therefore may be tolerant. In studies of the genetics of acquired AA with a focus of telomere repair, we have extended our findings from a large mennonite kindred bearing a novel TERT mutation, which disclosed a relationship to both acute myeloid leukemia in the proband's father and to severe hepatic disease in the proband's aunt and two more distant female relatives all of whom bear the mutation. In two separate cohert studies, one of 100 Brazilian patients with AML and the other of 92 patients collected at MD Anderson Cancer Center, we found a rate of approximately 6% of TERT mutations in this leukemia. In vitro studies have suggested that these are loss of function alterations; germline inheritance by study of non-bone marrow tissues and of family members. Similarly, preliminary data among samples collected of patients who have undergone liver transplant have also show several with TERT mutations. These results implicate telomere repair in the initiation of leukemia and also in severe liver disease, characterized at this point as a combinnation of fibrosis and inflammation. In our studies of the mechanism of action of male hormones in hematologic disease, we have demonstrated in vitro that synthetic and natural androgens and also estrodiol increase transcription of the TERT gene and of telomerase activity. The inhibitory activity of tamoxofin and of both anti-estrogen and anti-androgen receptor agents indicates that both aromatization of androgens to estrodiol and the estrogen and androgen receptors are involved in this effect on hematopoietic cells. We are pursuing our hypothesis that telomere shortening results in aneuploidy due to chromosome fusion and genomic instability, as has been demonstrated in murine models. In studies from the Virus Discovery Group related to parvoviruses, there have been a number of signal advances. First, a recombinant B19 parvovirus vaccine is now in its second phase 1 trial among human volunteers to determine the appropriate dose of empty capsids needed to elicit neutralizing antibodies, prior to a planned phase III trial in children with sickle cell disease with the goal of preventing transient aplastic crisis. Second, we have developed a practical infectious clone of B19 parvovirus, which has been useful to define by molecular studies and confocal microscopy the role of specific viral genes in infection of human cells. Finally, we have utilized our ability to obtain CD34 cells in bulk and to induce erythroid differentiation to develop a highly productive cell culture system for B19 parvovirus. CD34 cell-derived CD36 cells recapitulate normal erythropoeisis, including expression of the glogoside receptor, and they are useful also as a much more sensitive method to measure neutralizing antibodies, of use in our vaccine trials, and for molecular and cell biology studies of virus interaction with its known pathogenic target cell.

今年的年度报告既包含了细胞生物学部分在骨髓衰竭疾病中的工作，又包含细胞视病病毒发现部分的工作，因为由于凯文·布朗（Kevin Brown）的离开，后者已纳入了前者。性障碍性贫血（AA）和其他类型的骨髓衰竭具有临床和实验室特征，与自身免疫性病理生理学一致，具有多样性的推定煽动性抗原，包括病毒，化学物质，医疗药物和肿瘤抗原。无论其具体的病因如何，大多数患者在免疫抑制疗法后会以血液学改善反应。 AA的一个重要临床特征是它与克隆血液学疾病的关联，尤其是阵发性夜间血红蛋白尿（PNH）和骨髓增生性综合征（MDS）。在诊所中，研究已针对AA中的更有效的免疫抑制，并将免疫抑制方案应用于相关的骨髓衰竭综合征。多次研究正在进行中。虽然我们在第一次表现性贫血对单克隆抗体营地中观察到了一些反应，但是当我们的三臂随机方案的这一部门很早就停止了，因为很明显抗CD52不太可能像标准疗法那样有效。在该患者人群中，马和拉比特ATG的比较仍在继续。在AA对标准马ATG加环孢菌素的难治性中，兔子ATG和Campath均显示出约30％的救助率。我们还正在测试Campath在治疗复发AA和MD中的治疗。我们参加了对eculuzimab的Mulit-Center试验，已完成；除了导致该药物的FDA批准外，现在以Soliris的销售，由于PNH中腔内溶血引起的症状和/或严重贫血的迹象，对终点的进一步分析还表明，单克隆抗体在降低血栓形成率，主要导致PNH死亡的主要原因也有效。在实验室中，对造血细胞的免疫破坏的研究一直在多个方向上。我们已经检查了ATG的作用机理，尤其是因为马和兔子产品在治疗性贫血方面似乎没有同样有效。在细胞培养和分子研究中，我们已经证实，体外兔子ATG从CD25-FOXP3-CD4细胞中诱导T调节细胞，而马ATG缺乏这种活性。为了深入研究T细胞，目前正在接受治疗前同意该手术的患者和六个月的课程完成后进行淋巴细胞结构，以便对细胞因子基因表达进行分子研究。初步数据表明，完全恢复造血能力的患者持续存在的T细胞克隆缺乏产生γ-互化剂和其他1型细胞因子，因此可能是耐受性的。在研究获得端粒修复重点的AA遗传学的研究中，我们从具有新的TERT突变的大型门诺派犬类中扩展了发现，该发现揭示了与Proband父亲的急性髓样白血病之间的关系，并在Proband的姨妈和两个更远的女性亲戚中都披露了严重的肝病。在两项单独的同伴研究中，AML的100例巴西患者之一，另一名在MD Anderson癌症中心收集的92例患者中，我们发现该白血病中约有6％的TERT突变发生率。体外研究表明，这些是功能改变的丧失。通过研究非骨骨髓组织和家庭成员的种系遗传。同样，接受过肝移植的患者收集的样品中的初步数据也显示了一些具有TERT突变的患者。这些结果暗示着端粒修复在白血病的开始和严重的肝病中，此时的特征是纤维化和炎症的组合。在我们对雄性激素在血液学疾病中的作用机理的研究中，我们已经证明了合成和天然雄激素的体外，以及雌异端的雌激素以及雌激素的转录增加了TERT基因的转录和端粒酶活性。他氧蛋白和抗雌激素和抗雄激素受体的抑制活性都表明，雄激素对雌激素的芳香剂均参与了这种对造血细胞的作用。我们正在提出假设，即由于鼠模型中所证明的，由于染色体融合和基因组不稳定性，端粒缩短了非整倍性的结果。在与细节病毒有关的病毒发现组的研究中，已经有许多信号进展。首先，重组B19小parvovirus疫苗现在正在人类志愿者中进行第二阶段的1次试验，以确定在镰状细胞病儿童进行计划的III期试验之前，以防止短暂的相位危机。其次，我们开发了B19细小病毒的实用传染性克隆，该克隆对于通过分子研究和共聚焦显微镜来定义特定病毒基因在人类细胞感染中的作用很有用。最后，我们利用了我们在批量上获得CD34细胞并诱导红细胞分化的能力，以开发用于B19细小病毒的高生产性细胞培养系统。 CD34细胞衍生的CD36细胞概括了正常的红细胞磷酸化，包括表达Glogoside受体，它们在我们的疫苗试验中的中和抗体的使用也更为灵敏，用于我们的疫苗试验中中和抗体的使用，以及用于与其已知病原病原靶靶细胞的分子和生物学相互作用。