Targeted non-genotoxic hematopoietic stem cell transplant conditioning approach

项目摘要 造血干细胞移植(HSCT)和基因治疗越来越多地被用于明确的治疗 影响淋巴造血室的疾病。调理养生法是关键之一。 组件HSCT。今天使用的大多数调理方案要么是基于烷基化 化疗，如丁硫丹，或涉及不同剂量的全身照射(TBI)。这些特工是 基因毒性和影响造血室以外的器官，导致无数的急性和长期 HSCT相关并发症。我们的首要目标是开发一种无遗传毒性的调理疗法 靶向造血干细胞和祖细胞(HSPC)。我们实验室的初步数据显示MPL (血小板生成素受体)是造血干细胞(HSCs)中的关键生存信号，可能是理想的 HSPC靶向HSCT条件化方法的开发候选。受限制的表达模式 在造血室内，与造血细胞相比，HSC的表达更高 祖细胞隔间，使MPL成为一个非常有吸引力的目标。我们已经制定了两个战略来瞄准 MPL表达HSPC间隔区。首先，一种免疫毒素方法，通过结合MPL抗体产生 与核糖体毒素Saporin(MPL-ab-SAP)结合，第二种是与血小板生成素结合的MPL受体 CAR-T细胞(TPO-CAR-T细胞)。我们假设靶向MPL受体的调节剂将会产生 在选择性的HSPC耗尽，从而创造足够的利基空间，以允许供体植入，并将 在造血室外的细胞毒性风险最小。我们将确定机制，并 Mpl-ab-SAP介导的HSC细胞毒性的关键决定因素。然后，我们将确定 MPL-ab-SAP耗竭HSPC能否作为HSCT的一种有效的条件化策略 基于自体造血干细胞的基因治疗。TPO-CAR-T细胞作为造血干细胞移植的条件作用也将被研究。 K08奖将用来保护我的研究时间，帮助我拓宽研究技能和知识， 并为在基础和转化性造血干细胞移植和基因治疗方面的职业生涯提供了出色的基础。这位导师 培训阶段将允许我进一步整合和发展我作为一名内科科学家的研究技能。完毕 在接下来的五年里，我将(1)获得开发治疗药物所需的分子方法方面的专业知识 抗体和基于基因治疗的疗法，(2)进一步接触HSC生物学，移植 免疫学和小鼠造血干细胞移植，(3)获得细胞成像和生物信息学技能，(4)获得 翻译研究方法、赠款精神和领导力，以及(5)建立在我的出版记录和 为独立调查员拨款发展研究思路。为了实现这些目标，我开发了一种 结构良好的培训计划，我已经组建了一支高度合格的Spencer博士指导团队(专业知识 BINTING博士(HSC生物学)，Waller博士(HSPC生物学和临床移植)，以及 埃默里大学的拉森博士(移植免疫学)。

Project Summary Hematopoietic stem cell transplant (HSCT) and gene therapy are increasingly utilized for definitive management of disorders affecting the lymphohematopoietic compartment. Conditioning regimens are one of the critical components HSCT. The majority of conditioning regimens used today are either based on alkylating chemotherapy, such as busulfan, or involve varying doses of total body irradiation (TBI). These agents are genotoxic and affect organs other than the hematopoietic compartment, leading to myriad acute and long-term HSCT associated complications. Our overarching goal is to develop a non-genotoxic conditioning regimen targeting hematopoietic stem and progenitor cells (HSPCs). Preliminary data from our lab indicates MPL (thrombopoietin receptor), a critical survival signal in hematopoietic stem cells (HSCs), could be an ideal candidate for development of HSPC-targeted HSCT conditioning approaches. Restricted expression profiles within the hematopoietic compartment, with a higher expression in HSC when compared to the hematopoietic progenitor compartment, make MPL a very attractive target. We have developed two strategies to target the MPL expressing HSPC compartment. First, an immunotoxin approach, generated by conjugating MPL antibody to a ribosomal toxin, saporin (MPL-ab-SAP), and the second, a MPL receptor engaging thrombopoietin based CAR-T cell (TPO-CAR-T cells). We hypothesize that a conditioning agent targeting the MPL receptor will result in selective HSPC depletion thereby creating adequate niche space to allow donor engraftment and will have minimal risk of cytotoxicity outside the hematopoietic compartment. We will determine the mechanism, and critical determinants of MPL-ab-SAP-mediated cytotoxicity in the HSC compartment. Then, we will determine whether HSPC depletion by MPL-ab-SAP could be utilized as an effective conditioning strategy for HSCT and autologous HSC-based gene therapy. The role of TPO-CAR-T cells as an HSCT conditioning will also be studied. The K08 Award will be used to protect my time for research, help broaden my research skills and knowledge, and provide an outstanding basis for a career in basic and translational HSCT and gene therapy. This mentored phase of training will allow me to further integrate and build on my research skills as a physician-scientist. Over the next five years, I will (1) gain expertise in molecular methods needed for development of therapeutic antibodies, and gene therapy based therapeutics, (2) gain further exposure in HSC biology, transplant immunology, and murine HSCT, (3) acquire skills in cell imaging and bioinformatics, (4) acquire skills in translational research methodology, grantsmanship and leadership, and (5) build on my publication record and develop research ideas for independent investigator grants. To accomplish these goals, I have developed a well-structured training plan, and I have assembled a highly-qualified mentorship team of Dr. Spencer (expertise in cell and gene therapy), Dr. Bunting (HSC biology), Dr. Waller (HSPC biology and clinical transplantation), and Dr. Larsen (transplant immunology) at Emory University.