Targeted Manipulation of Stem Cells for AIDS Therapy

描述(申请人提供)：这项建议集中在成人造血干细胞(HSC)的细胞内在调节上。最终目标是定义干细胞增殖和自我更新的分子介质，以便能够操纵这些介质用于治疗，特别是治疗血液疾病，如艾滋病。之前的授权期强调了细胞周期蛋白依赖性激酶抑制物(CDKI)，确定了它们在干细胞稳态中的作用，以及如何操纵它们来改变干细胞的功能。他们详细定义了与p21Cip1(P21)、p27Kip1(P27)、p18INK4c(P18)和p16INK4a(P16)遗传缺陷相关的独特表型。每种基因型的表型不同，特别是在干细胞周期及其三个潜在结果：自我更新、分化和程序性细胞死亡方面。这项提议将完善并建立在这些信息的基础上，使用独立的、互补的遗传策略来研究这些过程的分子基础，以定义干细胞如何完成自我更新的细胞分裂。它们将解决以下具体目标： 1.使用无偏正向遗传筛选来确定控制HSC自我更新和增殖的分子参与者。这些实验利用体外维持HSC的有限能力来选择shRNA使HSC能够扩展，如体内功能所证明的那样。 2.通过对不同表型cdki缺陷小鼠的比较遗传学分析，确定HSC自我更新和增殖的分子介体。 3.通过体内分析验证候选的自我更新和增殖的分子介体。 该项目的成功将提供对成人HSC关键调控途径的深入了解，并创建有针对性的方法来操纵干细胞自我更新以达到治疗目的。

DESCRIPTION (provided by applicant): This proposal is focused on cell intrinsic regulation of adult hematopoietic stem cells (HSC). The ultimate goal is to define molecular mediators of stem cell proliferation and self-renewal to enable manipulation of these for therapies, specifically therapies for blood disorders such AIDS. The prior grant period emphasized cyclin dependent kinase inhibitors (cdki), determining their role in stem cell homeostasis and how they could be manipulated to alter stem cell function. They defined in detail distinctive phenotypes associated with the genetic deficiency of p21Cip1 (p21), p27Kip1 (p27), p18INK4c (p18) and p16INK4a (p16). The phenotypes were different for each genotype, specifically in the areas of stem cell cycling and its three potential outcomes: self-renewal, differentiation and programmed cell death. This proposal will complete and build on that information, examining the molecular basis for these processes using independent, complementary genetic strategies to define how stem cells accomplish a self-renewing cell division. They will address the following specific aims: 1. Use an unbiased forward genetic screen to identify molecular participants controlling HSC self-renewal and proliferation. These experiments exploit the limited ability to maintain HSC ex vivo to select for shRNA enable expansion of HSC as demonstrated by in vivo function. 2. Identify the molecular mediators of HSC self-renewal and proliferation by comparative genetic analysis of cdki deficient mice with distinctive phenotypes 3. Validate the candidate molecular mediators of self-renewal and proliferation using in vivo analyses. Success of this project will provide both in depth understanding of key regulatory pathways for adult HSC and create targeted approaches to manipulate stem cell self-renewal for therapeutic purposes.