Hematopoietic Stem Cell Gene Transfer

描述(由申请人提供)：造血干细胞(HSC)在所有造血系的产生中起着核心作用。HSC在功能上被定义为具有两个重要的特征：自我更新和分化为所有成熟的造血系的能力。这两个特征与成熟细胞的特点形成鲜明对比，成熟细胞的增殖和分化潜力有限，缺乏自我更新特性。为了维持一个有功能的造血系统，造血干细胞群体必须能够定期再生整个造血库。虽然HSC很容易通过在小鼠身上移植来评估，但在人类身上进行分析是相当困难的。HSC特征的研究进展在很大程度上依赖于克隆形成试验(CFCs)和长期培养试验(LTC-IC)等体外试验。由于其在移植、清除肿瘤细胞和基因治疗等方面的许多可能的临床应用，对HSC的兴趣是广泛的。最近，异种移植物的使用促进了对HSC的分析。这些模型是基于这样一个事实，即来自胎肝、骨髓、脐带血或外周血的人造血细胞(动员后)可以在严重联合免疫缺陷(SCID)小鼠的骨髓中重新填充。在这一竞争性更新应用中，研究人员建议使用两种不同但互补的异种移植模型来评估体内再生潜力和从HIV感染者进行HSC基因转移的适宜性。因为最终这是未来基因治疗方案细胞的唯一来源。这项建议的具体目的是：1)确定来自HIV-1感染者的造血干细胞在体内的定量再繁殖潜力；2)确定来自HIV-1感染者的T细胞前体细胞的体内淋巴造血能力；以及3)表征HIV-1感染者的原始造血干细胞室。

DESCRIPTION (provided by the applicant): Hematopoietic stem cells (HSC) play a central role in the production of all hematopoietic lineages. HSC are functionally defined as having two important characteristics: self-renewal and the capacity to differentiate into all mature hematopoietic lineages. These two characteristics are in sharp contrast to those of mature cells that have limited proliferation and differentiation potential and lack self-renewal properties. In order to maintain a functional hematopoietic system, a population of HSC must be able to regenerate the entire hematopoietic repertoire on a regular basis. Whereas HSC are readily evaluated by transplantation in mice, analysis in humans is quite difficult. Progress in the characterization of HSC has relied, for the most part, on in vitro assays such clonogenic assays (CFCs) and of long-term cultures (LTC-IC). Interest in HSC is widespread because of their many possible clinical applications including transplantation, purging of tumor cells, and gene therapy. Recently, the use of xenografts has facilitated the analysis of the HSC. These models are based on the fact that human hematopoietic cells from fetal liver, bone marrow, umbilical core or peripheral blood (after mobilization) can repopulate the bone marrow of severe combined immune deficient (SCID) mice. In this competitive renewal application in which the investigators propose to use two different but complementary xenograft models to evaluate the in vivo repopulating potential and the suitability for gene transfer of HSC from HIV infected individuals. Since ultimately this is the only source available for cells of future gene therapy protocols. The specific aims of this proposal are: 1) To determine the quantitative in vivo repopulating potential of hematopoietic stem cells from HIV-1 infected individuals; 2) To determine the in vivo lymphopoietic capacity of T-cell progenitors from HIV-1 individuals; and 3) To characterize the primitive hematopoietic stem cell compartment in HIV-1 infected individuals.