Improve the engraftment of combinatorial anti-HIV-1 gene modified HSPC

总结/摘要（项目1 - AN） 我们的总体目标是提高抗HIV基因修饰的造血干细胞的植入率， 干/祖细胞（HSPC）。基于HSPC的基因治疗具有很大的前景，可以提供长期的 预防艾滋病毒，并有可能实现治愈。然而，迄今为止的研究已经遇到了 有限的成功很大程度上是由于基因递送到HSPC中的效率低， 用抗HIV基因修饰的细胞进行造血重建。总的来说，我们假设效率 对于基于HSPC的基因治疗的疗效来说，再增殖的重要性在第一例 最近通过CCR 5缺陷的几乎完全骨髓替代实现了HIV治愈 移植供体细胞然而，与第一例艾滋病毒治愈患者不同的是， 由于抗HIV基因的效率有限，因此可能不会发生基因修饰的HSPC替代 改良HSPC植入。此外，由于骨髓瘤， 在这第一例艾滋病毒治愈病例中允许的白血病的存在在临床上构成了高风险。因此在 为了通过HSPC基因治疗策略提供临床益处，需要进行更多的研究， 有效和安全的程序，可以为患者提供转基因HSPC的阳性选择。 在这个建议中，我们将测试一种新的体内选择策略，该策略专门采用6-硫代鸟嘌呤， HPRT下调基因工程HSPC的预处理和化学选择，即 能够丰富基因工程多管齐下的植入和长期重建， HIV抗性HSPC和使用HIV感染的后代建立人源化小鼠模型。我们 该研究有望突破HSPC基因治疗领域的主要障碍 富集和有效地重新填充基因修饰的细胞，以成功控制艾滋病毒疾病， 终身药物治疗和艾滋病毒治愈。

SUMMARY/ABSTRACT (PROJECT 1 - AN) Our overall goal in this proposal is to improve engraftment of anti-HIV gene modified hematopoietic stem/progenitor cells (HSPC) in vivo. HSPC based gene therapy holds great promise to provide long-term protection against HIV with the possibility of achieving a cure. However, studies to date have met with limited success largely due to the low efficiency of gene delivery into HSPC and subsequent hematopoietic reconstitution with anti-HIV gene modified cells. Overall we hypothesize that the efficiency of repopulation is important for the efficacy of HSPC-based gene therapy as apparent for the first case of HIV cure that was recently achieved by nearly complete bone marrow replacement by CCR5 deficient transplanted donor cells. However, unlike the first case of the HIV cured patient, complete bone marrow replacement by gene modified HSPC may not occur because of the limited efficiency of anti-HIV gene modified HSPC engraftment. Additionally, use of the intensive myeloablation procedure because of the presence of leukemia allowed in this first case of an HIV cure poses a high risk clinically. Therefore, in order to provide clinical benefit by HSPC gene therapy strategies, research is required to achieve more effective and safe procedures that can provide positive selection of genetically modified HSPC in patients. In this proposal, we will test a novel in vivo selection strategy that exclusively employs 6-thioguanine for both pre-conditioning and chemoselection of HPRT down-regulated genetically engineered HSPC, that is capable of enriching engraftment and long-term reconstitution of genetically engineered multi-pronged HIV resistant HSPC and progenies using a HIV infection established humanized mouse model. Our proposed research has a potential to break through the major obstacle in the field for HSPC gene therapy to enrich and efficiently repopulate gene-modified cells for the successful control of HIV disease without life long drug treatment and for HIV cure.