Lineage bias and clonal expansion of hematopoietic stem cell differentiation

项目总结： 我的直接职业目标是成为一名干细胞的独立研究员，专注于 临床相关应激条件下单细胞水平的造血干细胞分化。我的长期生活 研究目标是确定造血干细胞在维持平衡血液中是如何协调的 以及这种协调的调节机制如何与血液疾病相关。我有一个很强的 我在普林斯顿大学在伊霍尔博士的指导下接受博士培训，获得了分子生物学背景 R.Lemischka和斯坦福大学欧文·L·魏斯曼博士指导下的细胞生物学专业知识 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的单细胞活体跟踪 系统具有高灵敏度和高吞吐量的特点。我们使用这个系统的初步研究证实 先前关于小鼠的HSC谱系偏向的报道。此外，我们还发现了一种以前未被检测到的 现象：放射介导的移植后的大多数血细胞来自于 移植的一小部分HSC克隆的戏剧性扩展。更引人注目的是，当血统偏见和克隆 放射介导的移植后通常会观察到扩张，而在移植后不会出现 无条件移植。因此，我们假设谱系偏见和克隆扩张不是与生俱来的 HSC的特征，而不是由外源性造血应激引发的行为，如 辐射。在这项资助中，我们建议在不同移植方式的小鼠身上进一步测试这一假说。 条件(K99阶段)以及确定谱系偏见和克隆扩展是否相关(K99 阶段/R00阶段)，以及它们是否是HSC克隆的固有确定性特征(R00阶段)。此外 对于这些在体小鼠的研究，我们还将研究人HSCs移植到小鼠体内的克隆性。 级别(R00阶段)。这些拟议的研究将阐明造血平衡是如何重建的。 在破坏之后，将把辐射诱导的效应与自然的固有细胞特性分开。结果是 将有助于改善与血液系统失衡相关的疾病的治疗，并可能导致 在临床应用和持续较低的职业中减少辐射副作用的解决方案 辐射暴露水平。我的K99期训练将由杰出的造血干细胞指导 干细胞研究所世界级机构环境中的细胞专家欧文·L·魏斯曼博士 斯坦福大学医学院的生物学和再生医学。除了允许我 完成建议的研究，K99培训也将大大提高我的知识和经验 随着我的研究在临床上的应用。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R01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.