Pro-inflammatory cytokines in hematopoietic stem cell function

描述(申请人提供)：候选人：Eric M.Pietras是一名博士后学者，他在加州大学洛杉矶分校(UCLA)获得博士学位，主要研究细胞内病原体检测机制以及促炎细胞因子在协调免疫细胞动员以应对细菌感染方面的作用。他的 郑根红博士实验室的研究发现，促炎细胞因子白介素1和干扰素-γ是体内细菌攻击后小鼠髓系细胞募集的关键诱导物。作为加州大学旧金山分校(UCSF)Emmanuelle PasSegue博士实验室的博士后学者，他一直在正常和白血病造血的背景下继续研究这些促炎细胞因子的功能。利用人类骨髓增生性肿瘤(MPN)的小鼠模型，他证明了MPN与全身许多促炎细胞因子水平的升高有关，并通过改变BM利基中造血祖细胞和细胞的生物学来帮助证明它们在促进疾病发病中的关键作用。他现在专注于了解I型干扰素(干扰素-1s)和IL-1在调节造血干细胞(HSC)功能和命运选择中的作用。候选人的短期目标是继续他的有指导的研究，以发展他的独立研究方向，并获得生物信息学、单细胞表达分析和单细胞时间推移显微镜方面的进一步培训，长期目标是作为一名独立的教职研究员，了解系统细胞因子环境如何影响稳态和慢性炎症期间的HSC生物学。环境：拟议的工作将在加州大学旧金山分校(UCSF)血液学/肿瘤科医学系Emmanuelle PasSegue博士的实验室进行，Eli和Edythe Bright Center再生医学和干细胞研究中心是一所世界级的生物医学研究型大学。导师的实验室在造血干细胞生物学领域备受推崇，在使用人类血液系统恶性肿瘤的小鼠模型研究正常和转化的造血干细胞生物学方面一直非常富有成效。候选人可以使用加州大学旧金山分校的重要资源，包括专门的细胞分选设施和一系列用于鼠标工作、显微镜和细胞培养的核心。 候选人将接受帕斯格博士的指导和科学培训，并指定了一位共同导师杰森·塞斯特博士，他是一位成就卓著的免疫学家，专门研究系统性免疫细胞交易。他还与瑞士理工学院的蒂姆·施罗德博士建立了强有力的合作关系，施罗德博士开发了开创性的单细胞跟踪技术，将用于拟议的工作。他还组建了一个由加州大学旧金山分校资深领导人组成的指导委员会，以监督和加强他的指导培训经验。研究：造血干细胞(HSCs)是一种罕见的自我更新的骨髓(BM)细胞群体，能在生物体的一生中产生所有成熟的血细胞谱系。造血干细胞通常处于休眠状态，它们能够快速进入细胞周期并分化，以产生所需的成熟后代，以应对感染或损伤。虽然这种应激与成熟的免疫细胞和其他组织产生一系列复杂的炎性细胞因子有关，但这些促炎和抗炎细胞因子对HSCs生物学的直接影响在很大程度上仍不清楚。此外，全身炎症细胞因子水平在多大程度上调节HSC的稳态还没有得到广泛的研究。尤其是在慢性炎症性疾病的背景下，促炎症细胞因子水平的升高可能会改变HSC的自我更新和分化活动，从而导致在人类患者中观察到的HSC功能下降。我们的初步数据表明，促炎症细胞因子如IL-1和干扰素-1对HSC的命运选择有深远的影响，并改变生存、分化和自我更新活动。在这里，我们建议全面研究IL-1和干扰素-1，以及抗炎细胞因子IL-10对HSC功能和体内平衡的影响，将其作为高度保守的造血模型。在目标1中，我们将评估IL-1、干扰素-1和IL-10如何指导HSC的命运选择，并影响控制HSC分化和自我更新的分子网络。在目标2中，我们将使用Ifnar-/-、IL1r1-/-和IL10-/-小鼠研究IL-1、干扰素-1和IL-10在调节稳态HSC动态平衡中的作用以及它们对急性应激的反应。我们还将研究这些 细胞因子影响HSC与其BM生态位之间的相互作用及其在调节HSC功能中的作用。在目标3中，我们将探讨慢性干扰素-1和IL-1驱动的炎症如何在体内降低HSC的功能。我们将评估暴露在慢性炎症中如何改变调节HSC功能的分子网络，以及阻断促炎性干扰素-1和IL-1信号是否可以逆转这些有害影响，恢复HSC的健康和血液生产。综上所述，这些令人兴奋的研究将极大地增强我们对炎症和造血之间关键关系的理解，并将为旨在恢复慢性炎症性疾病患者正常HSC功能的治疗提供基础。

DESCRIPTION (provided by applicant): Candidate: Eric M. Pietras is a postdoctoral scholar who received his Ph.D. at the University of California, Los Angeles (UCLA) for work characterizing intracellular pathogen detection mechanisms and the role of pro- inflammatory cytokines in orchestrating the mobilization of immune cells in response to bacterial infection. His research in the laboratory of Dr. Genhong Cheng identified the pro-inflammatory cytokines interleukin (IL)-1 and interferon (IFN)-gamma as key inducers of myeloid cell recruitment following in vivo bacterial challenge in mice. As a postdoctoral scholar in the laboratory of Dr. Emmanuelle Passegue at the University of California, San Francisco (UCSF), he has continued to investigate the function of these pro-inflammatory cytokines but in the context of normal and leukemic hematopoiesis. Using mouse models of human myeloproliferative neoplasms (MPNs), he showed that MPNs are associated with increased systemic levels of many pro- inflammatory cytokines, and helped demonstrate their key roles in promoting disease pathogenesis by altering the biology of hematopoietic progenitors and cells in the BM niche. He is now focused on understanding the role of type I interferons (IFN-1s) and IL-1 in regulating hematopoietic stem cell (HSC) function and fate choice. The candidate's short-term goal is to continue his mentored studies to develop his independent line of research and obtain further training in bioinformatics, single-cell expression analysis, and single-cell time lapse microscopy, with a long-term goal of understanding how the systemic cytokine milieu affects HSC biology at steady state and during chronic inflammation, as an independent faculty researcher. Environment: The proposed work will take place in the laboratory of Dr. Emmanuelle Passegue, in the Department of Medicine, Division of Hematology/Oncology, Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research at UCSF, a world-class biomedical research university. The mentor's laboratory is highly respected in the field of HSC biology and has been very productive in using mouse models of human hematological malignancies to study the biology of normal and transformed HSCs. The candidate has access to significant resources at UCSF, including dedicated cell sorting facility and an array of cores for mouse work, microscopy, and cell culture. The candidate will receive guidance and scientific training from Dr. Passegue, and has designated a co-mentor, Dr. Jason Cyster, a highly accomplished immunologist who specializes in the study of systemic immune cell trafficking. He has also established a strong collaboration with Dr. Timm Schroeder at the Swiss Institute of Technology, who developed pioneering single-cell tracking techniques that will be used in the proposed work. He has also assembled a mentorship committee composed of established leaders from UCSF to oversee and enhance his mentored training experience. Research: Hematopoietic stem cells (HSCs) are a rare population of self-renewing bone marrow (BM) cells that generate all mature lineages of blood cell for the lifetime of an organism. HSCs are typically kept in a dormant state, they are capable of rapidly entering the cell cycle and differentiating to produce needed mature progeny in response to infection or injury. While such stresses are associated with the production of a complex array of inflammatory cytokines by mature immune cells and other tissues, the direct effects of these pro- and anti-inflammatory cytokines on the biology of HSCs remain largely unknown. Moreover, the extent to which systemic levels of inflammatory cytokines regulate HSC homeostasis has not been extensively explored. This is particularly true in the context of chronic inflammatory diseases, a range of conditions where elevated levels of pro-inflammatory cytokines may alter HSC self-renewal and differentiation activities, hence leading to the degraded HSC function observed in human patients. Our preliminary data suggest that pro-inflammatory cytokines such as IL-1 and IFN-1s have profound effects on HSC fate choices and alter survival, differentiation and self-renewal activities. Here, we propose to comprehensively investigate the effects of IL-1 and IFN-1s, as well as the anti-inflammatory cytokine IL-10, on HSC function and homeostasis using the mouse as a highly conserved model of hematopoiesis. In Aim 1, we will assess how IL-1, IFN-1s, and IL-10 direct HSC fate choices and affect the molecular networks governing HSC differentiation and self-renewal. In Aim 2, we will address the roles of IL-1, IFN-1s, and IL-10 in regulating steady-state HSC homeostasis and their response to acute stress using Ifnar-/-, Il1r1-/-, and Il10-/- mice. We will also examine how these cytokines affect the interaction between HSCs and their BM niche and their role in governing HSC function. In Aim 3, we will explore how chronic IFN-1- and IL-1-driven inflammation degrades HSC function in vivo. We will assess how exposure to chronic inflammation alters the molecular networks regulating HSC function and whether blockade of pro-inflammatory IFN-1 and IL-1 signaling can revert these deleterious effects and restore HSC fitness and blood production. Taken together, these exciting studies will greatly enhance our understanding of the critical relationship between inflammation and hematopoiesis, and will provide a basis for therapies aimed at restoring normal HSC function in patients suffering from chronic inflammatory diseases.