Lineage bias and clonal expansion of hematopoietic stem cell differentiation

项目摘要： 我近期的职业目标是成为一名独立的干细胞研究者， 造血干细胞在临床相关应激下在单细胞水平分化。我的长期 研究目标是确定造血干细胞在维持血液平衡中是如何协调的 系统以及这种协调的调节机制如何与血液疾病相关。我有一种强烈 我在普林斯顿大学的博士培训中，在Ihor博士的指导下，有分子生物学的背景 R. Lemischka和专业知识的细胞生物学博士的指导下，欧文L。韦斯曼在斯坦福大学 大学我精通几种编程语言，包括C/C++，R，Matlab和Python，我 能够独立设计和执行现代定量分析所需的高级统计分析， 生物学利用这些跨学科的技能，我最近开发了一种新颖的，单细胞体内跟踪 系统具有高灵敏度和高通量。我们对这个系统的初步研究证实 之前关于小鼠HSC谱系偏好的报道。另外，我们还发现了一种以前未被发现的 现象：辐射介导移植后的大部分血细胞来自于 移植的HSC克隆的一小部分的急剧扩增。更引人注目的是，虽然血统偏见和克隆 扩增通常在辐射介导的移植后观察到，它们在移植后不存在。 无条件移植因此，我们假设谱系偏好和克隆扩张不是先天的 HSC的特性，而是由外源性造血应激，如 辐照在这项研究中，我们建议在各种移植条件下的小鼠中进一步验证这一假设。 以及确定谱系偏好和克隆扩增是否相关（K99 期/R 00期）以及它们是否是HSC克隆（R 00期）的先天决定性特征。此外 除了这些在小鼠体内的研究，我们还将研究人HSC异种移植到小鼠中的克隆， 水平（R 00阶段）。这些拟议的研究将阐明造血稳态是如何重建的 并将辐射诱导效应与天然固有细胞特性分开。结果 将有助于改善与血液系统不平衡相关的疾病的治疗，并可能导致 在临床应用和低辐射职业中减少辐射副作用的解决方案 辐射暴露水平。我的K99阶段训练将由杰出的造血干细胞 细胞专家欧文L.韦斯曼在干细胞研究所的世界级机构环境中， 斯坦福大学医学院的生物学和再生医学。除了允许我 我完成了计划中的研究，K99培训也将大大提高我的知识和经验 我的研究成果的临床应用此外，它将帮助我找到一个独立的研究职位 并为我的第一个R 01应用程序提供初步支持。

Project Summary: My immediate career goal is to become an independent investigator of stem cells, focusing on hematopoietic stem cell differentiation at the single cell level under clinically relevant stresses. My long-term research goal is to determine how hematopoietic stem cells are coordinated in sustaining a balanced blood system and how the regulatory mechanisms of this coordination are related to blood disorders. I have a strong background in molecular biology from my PhD training at Princeton University under the guidance of Dr. Ihor R. Lemischka and expertise in cell biology under the mentoring of Dr. Irving L. Weissman at Stanford University. I am proficient with several programming languages including C/C++, R, Matlab, and Python, and I can independently design and carry out the advanced statistical analyses required for modern quantitative biology. Using these cross-disciplinary skills, I have recently developed a novel, single cell in vivo tracking system featuring high sensitivity and high throughput. Our preliminary studies using this system confirm previous reports of HSC lineage bias in mice. In addition, we have discovered a previously undetected phenomenon: the majority of blood cells after irradiation-mediated transplantation are derived from the dramatic expansion of a small subset of engrafted HSC clones. More strikingly, while lineage bias and clonal expansion are commonly observed after irradiation-mediated transplantation, they are not present after unconditioned transplantation. Therefore, we hypothesize that lineage bias and clonal expansion are not innate HSC characteristics, but instead are behaviors initiated by exogenous hematopoietic stresses such as irradiation. In this grant, we propose to further test this hypothesis in mice under various transplantation conditions (K99 phase) as well as to determine whether lineage bias and clonal expansion are related (K99 phase / R00 phase) and whether they are innate deterministic features of HSC clones (R00 phase). In addition to these in vivo mice studies, we will also investigate human HSCs xenotransplanted into mice at the clonal level (R00 phase). These proposed studies will elucidate how hematopoietic homeostasis is re-established after disruption and will separate irradiation-induced effects from natural innate cellular properties. The results will help to improve the treatment of diseases associated with an unbalanced blood system and may lead to solutions that reduce the side effects of radiation in clinical applications and in occupations with constant low levels of radiation exposure. My K99 phase training will be mentored by the distinguished hematopoietic stem cell expert Dr. Irving L. Weissman, in a world-class institutional environment at the Institute for Stem Cell Biology and Regenerative Medicine at Stanford University School of Medicine. In addition to allowing me to finish the proposed research, the K99 training will also substantially enhance my knowledge and experience with the clinical applications of my research. In addition, it will help me locate an independent research position and provide the initial support to prepare for my first R01 application.