Hematopoietic Stem Cell Gene Transfer

描述（由申请人提供）：造血干细胞（HSC）在所有造血谱系的产生中发挥核心作用。造血干细胞在功能上被定义为具有两个重要特征：自我更新和分化为所有成熟造血谱系的能力。这两个特征与成熟细胞形成鲜明对比，成熟细胞的增殖和分化潜力有限，缺乏自我更新能力。为了维持造血系统的功能，造血干细胞群体必须能够定期再生整个造血系统。虽然造血干细胞很容易通过移植在小鼠中进行评估，但在人类中进行分析是相当困难的。在大多数情况下，HSC表征的进展依赖于体外分析，如克隆性分析（cfc）和长期培养（LTC-IC）。对造血干细胞的兴趣是广泛的，因为它们有许多可能的临床应用，包括移植、肿瘤细胞清除和基因治疗。最近，异种移植物的使用促进了HSC的分析。这些模型是基于这样一个事实，即来自胎儿肝脏、骨髓、脐带核心或外周血（动员后）的人类造血细胞可以重新填充严重联合免疫缺陷（SCID）小鼠的骨髓。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物模型来评估来自HIV感染个体的HSC的体内再生潜力和基因转移的适用性。因为最终这是未来基因治疗方案中唯一可用的细胞来源。本建议的具体目的是：1)确定HIV-1感染个体的造血干细胞在体内的定量再生潜力；2)测定HIV-1个体t细胞祖细胞的体内淋巴功能；3)鉴定HIV-1感染个体的原始造血干细胞区室。

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.