Safety and Efficacy of AIDS Gene Therapy in Monkeys

猴子艾滋病基因治疗的安全性和有效性

• 批准号: 6850621
• 负责人: HANS-PETER KIEM
• 金额: $ 47.57万
• 依托单位: BECKMAN RESEARCH INSTITUTE/CITY OF HOPE
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-08-01 至 2008-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6850621
• 关键词: AIDS therapy; HIV infections; Lentivirus; Macaca nemestrina; RNA interference; T lymphocyte; antiAIDS agent; busulfan; flow cytometry; gene therapy; hematopoietic stem cells; human immunodeficiency virus; method development; nonhuman therapy evaluation; polymerase chain reaction; simian immunodeficiency virus; stem cell transplantation; therapy design /development; transfection /expression vector; whole body irradiation dosage

Despite the advent of highly active antiretroviral therapy (HAART), AIDS continues to be a major health problem. There are currently an estimated 30 to 40 million cases of HIV worldwide and projections indicate that if the pandemic proceeds there will be 45 million new infections by 2010 and nearly 70 million deaths by 2020. While HAART has substantially reduced the morbidity and mortality associated with HIV infection, emergence of resistant viral variants, toxicity and other compliance or availability issues have presented significant obstacles in controlling the disease. Thus alternative treatment strategies will be required. Anti-HIV gene therapy strategies based on RNAi technology have been proposed using T cells or hematopoietic stem cells (HSCs). We propose to genetically modify HSCs to protect all hematopoietic progeny including T lymphocytes and macrophages from HIV infection. Unfortunately murine or in vitro models have not been predictive for stem cell transduction in humans. Results in large animal models, in particular nonhuman primates, have correlated much better with human studies. We have successfully used the nonhuman primate model to develop efficient stem cell transduction strategies. In the past we have shown efficient oncoretroviral gene transfer to long-term repopulating cells in nonhuman primates after myeloablative conditioning. Unfortunately, oncoretroviral gene transfer protocols require prolonged transduction cultures for efficient stem cell transduction, which will in turn lead to a significant loss of stem cells. While this may be acceptable in a myeloablative setting in which endogenous stem cells are maximally depleted, this approach will most likely not lead to efficient gene !transfer in a nonmyeloablative setting, likely necessary for the treatment of AIDS patients, because a significant number of endogenous stem cells will survive the conditioning regimen and be able to compete with the transduced stem cells. Thus, we propose to use lentiviral vectors to significantly shorten the transduction culture, which should minimize stem cell loss and therefore maximize the ability to compete with endogenous stem cells and thereby improve engraftment. We propose to 1) develop nonmyeloablative strategies to achieve engraftment of lentivirally modified stem cells, 2) develop in vivo selection strategies to further expand lentivirally modified cells in nonhuman primates, and 3) test whether these strategies will allow for efficient protection of hematopoietic cells from HIV/SHIV infection. Performing these studies in a clinically highly relevant nonhuman primate AIDS model will allow us to generate the necessary preclinical safety and efficacy data for future clinical anti-HIV studies using lentivirally transduced stem cells.

尽管高度活跃的抗逆转录病毒疗法（HAART）出现，但艾滋病仍然是一个主要的健康问题。目前，全球估计有30至4000万例HIV病例，预测表明，到2010年的大流行期限将有4500万新的感染，到2020年到2020年将有近7000万例死亡。尽管Haart已大大降低了与HIV感染相关的发病率和死亡率，而与毒性变异的出现相关，毒性，毒性和其他疾病的疾病或其他问题既有疾病又有障碍。因此，将需要替代治疗策略。使用T细胞或造血干细胞（HSC）提出了基于RNAi技术的抗HIV基因治疗策略。我们建议对HSC进行遗传修改，以保护所有造血后代，包括HIV感染的T淋巴细胞和巨噬细胞。不幸的是，鼠或体外模型尚未预测人类干细胞的转导。大型动物模型，尤其是非人类灵长类动物的结果，与人类研究更好地相关。我们已经成功使用了非人类灵长类动物模型来制定有效的干细胞转导策略。过去，我们在骨髓性调节后表现出有效的癌症病毒基因转移到非人类灵长类动物中的长期再植物细胞。不幸的是，癌症病毒基因转移方案需要长时间的转导培养物才能有效地进行干细胞转导，这反过来又导致干细胞的显着丧失。虽然这可能是可以接受的 内源性干细胞最大耗尽的设置，这种方法很可能不会导致在非甲状腺不可公动环境中的有效基因转移，这可能是治疗艾滋病患者所必需的，因为大量的内源性干细胞会在调节方案中幸存下来，并能够与转导的干细胞竞争。因此，我们建议使用慢病毒载体显着缩短转导培养物，应 最大程度地减少干细胞损失，从而最大程度地提高与内源性干细胞竞争的能力，从而改善植入。我们建议1）制定非甲状腺素策略以实现慢病毒修饰的干细胞的植入，2）制定体内选择策略，以进一步扩大非人类灵长类动物中的慢病毒修饰细胞，3）测试这些策略是否允许有效地保护来自HIV/SHIV感染的造血细胞。 在临床上高度相关的非人类灵长类动物艾滋病模型中进行这些研究将使我们能够使用慢病毒转导的干细胞生成必要的临床前安全性和有效性数据，以实现未来的临床抗HIV研究。