Improving gene transfer to provide intracellular immuniz

改善基因转移以提供细胞内免疫

• 批准号: 6988880
• 负责人: DAVID M. BODINE
• 金额: --
• 依托单位: NATIONAL HUMAN GENOME RESEARCH 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/6988880
• 关键词: AIDS education /prevention; AIDS therapy; HIV infections; antiAIDS agent; biotechnology; cell cycle; cellular immunity; family genetics; gene delivery system; gene induction /repression; gene therapy; genetic counseling; genetic mapping; genetic screening; helper T lymphocyte; hematopoietic stem cells; human subject; immunogenetics; inborn immunodeficiency; laboratory mouse; patient oriented research; receptor binding; sheep; stem cell transplantation; technology /technique development; transfection /expression vector; vaccine development; virus envelope; virus genetics; virus receptors

Summary: The NHGRI intramural program has expanded research efforts to integrate virus vectors into adult hematopoietc stem cells (HSC) to combat HIV infection. The HSC is the ultimate progenitor of all peripheral blood cells, including the CD4+ lymphocytes that are infected by HIV and the macrophages that can sequester HIV for long periods of time in tissues. If an anti-HIV element can be introduced into HSC, it will be passed along to all of the progeny of that HSC, ensuring the continuous, life-long production of HIV resistant cells. If this therapy were completely successful, this treatment would permanently protect the patient from HIV spread and no further treatments would be required. The successful modification of HSC by viral vectors has three important steps. First the viral vector must bind to a specific receptor on the surface of the HSC. We have determined that the receptors for two novel retroviruses RD114 and FeLV-C are plentiful on HSC, unlike the conventional retrovirus receptors, which are not present on HSC. We have demonstrated high levels of gene transfer into human HSC using retrovirus vectors with these new envelopes using mouse and sheep xenograft models. In the coming year, we will extend these studies to include pseudotyping lentivirus vectors that carry anti HIV genes. The second important step in the modification of HSC requires the vector to become integrated into the DNA of the target cell. Because of new safety concerns regarding insertional leukemogenesis in a gene therapy trial, NHGRI intramural researchers are comparing the integration sites of lentivirus and oncoretrovirus vectors. We are also studying several genes that regulate hematopoietic cell cycle progression. The final important step for successful modification of HSC with anti-HIV elements is that the anti-HIV elements have to be produced in the mature progeny of the HSC at all times so that the cells are always prepared to interrupt HIV infection. Many groups have shown that viral vectors can become silenced over time and stop making the critical elements. To combat silencing, NHGRI intramural investigators are developing and evaluating different virus vectors that contain genetic elements to prevent silencing. Among the vectors under development are vectors containing insulator elements that prevent the type of changes associated with gene silencing. Novel insulators are being incorporated into vectors to evaluate gene silencing in mouse models. The combination of these three initiatives should significantly improve the prospects for successful HSC based AIDS gene therapy. It is anticipated that the results of these studies can be combined into a clinical trial for AIDS gene therapy in the near future. NHGRI has initiated a genetic approach to AIDS that takes full advantage of the strengths of the intramural NHGRI clinical research program. NHGRI clinical researchers study inherited immune disorders building knowledge that will bear on the ultiumate production of HIV vaccines and provide an understanding of how HIV deactivates the immune system. The NHGRI Genetic Counseling program will initiate an effort to counsel and educate individuals with AIDS. The Genetic Counseling program has completed an extensive study of the most effective counseling techniques for families with inherited immune disorders. The NHGRI AIDS initiative will compare counseling approaches that have been shown to be effective in inherited immunodeficiency diseases with counseling for AIDS families. Such psychological studies are expected to reveal whether different approaches are necessary to help families cope with AIDS and its consequences.

摘要：NHGRI壁内计划扩大了研究工作，以将病毒向量整合到成年造血干细胞（HSC）中以打击HIV感染。 HSC是所有外周血细胞的最终祖细胞，包括被HIV感染的CD4+淋巴细胞和可以长时间在组织中长时间隔离HIV的巨噬细胞。如果可以将抗HIV元件引入HSC中，则将其传递到该HSC的所有后代，以确保抗HIV抗HIV的抗HIV细胞的连续生产。如果这种疗法完全成功，则这种治疗将永久保护患者免受艾滋病毒蔓延的侵害，并且不需要进一步治疗。病毒载体成功修改HSC具有三个重要步骤。首先，病毒载体必须与HSC表面上的特定受体结合。我们已经确定，与HSC上不存在的常规逆转录病毒受体不同，HSC的两个新型逆转录病毒RD114和FELV-C的受体在HSC上很丰富。我们使用小鼠和绵羊异种移植模型使用逆转录病毒载体证明了高水平的基因转移到人HSC中。在来年，我们将把这些研究扩展到包括携带抗HIV基因的慢病毒载体。 HSC修饰的第二个重要步骤要求向量积分为目标细胞的DNA。由于在基因治疗试验中对插入性白血病发生的新安全问题，NHGRI壁内研究人员正在比较慢病毒和肠疾病病毒载体的整合位点。我们还研究了调节造血细胞周期进程的几种基因。使用抗HIV元件成功修饰HSC的最后一步是，必须始终在HSC的成熟后代中产生抗HIV元素，以便始终准备好中断HIV HIV感染。许多小组表明，随着时间的流逝，病毒载体可能会变得沉默，并停止制造关键要素。为了打击沉默，NHGRI壁内研究人员正在开发和评估包含遗传因素以防止沉默的不同病毒载体。在开发中的载体中，有包含绝缘元件的向量，这些媒介可以防止与基因沉默相关的变化类型。新型绝缘子被掺入向量中，以评估小鼠模型中的基因沉默。这三个举措的结合应显着改善成功基于HSC的艾滋病基因治疗的前景。预计这些研究的结果可以在不久的将来将AIDS基因治疗的临床试验合并为临床试验。 NHGRI启动了一种遗传方法，以充分利用壁内NHGRI临床研究计划的优势。 NHGRI临床研究人员的研究遗传了建立知识的免疫疾病，该知识将依靠HIV疫苗的终极生产，并对HIV如何停用免疫系统提供了理解。 NHGRI遗传咨询计划将发起努力，以咨询和教育艾滋病的人。该遗传咨询计划已经完成了针对具有遗传性免疫疾病家庭的最有效咨询技术的广泛研究。 NHGRI AIDS倡议将比较咨询方法，这些方法已证明在遗传的免疫缺陷疾病中与艾滋病家庭的咨询有关。这种心理学研究有望揭示是否需要采用不同的方法来帮助家庭应对艾滋病及其后果。