The effects of PD-1 on tumor-mediated “emergency” myelopoiesis and fate commitment of myeloid cells: Implications for anti-tumor immunity

PD-1 对肿瘤介导的“紧急”骨髓生成和骨髓细胞命运决定的影响：抗肿瘤免疫的意义

• 批准号: 10547788
• 负责人: VASSILIKI A BOUSSIOTIS
• 金额: $ 59.12万
• 依托单位: BETH ISRAEL DEACONESS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-02-10 至 2025-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10547788
• 关键词: ATAC-seq; Ablation; Affect; Antibodies; B-Lymphocytes; Biogenesis; Blocking Antibodies; CD8-Positive T-Lymphocytes; Cancer Patient; Cell Differentiation process; Cell Lineage; Cell physiology; Cells; ChIP-seq; Clinical Trials; Dendritic Cells; Development; Emergency Situation; Environment; Epigenetic Process; FRAP1 gene; Generations; Genes; Genetic; Growth Factor Receptors; Hematopoietic; Hematopoietic stem cells; IL17 gene; ITGAM gene; Immune; Immune system; Immunity; Immunologics; Immunotherapy; Innate Immune System; Knockout Mice; Knowledge; Lead; Ligands; Macrophage; Malignant Neoplasms; Mediating; Metabolic; Metabolism; Mitochondria; Modeling; Molecular; Mus; Myelogenous; Myeloid Cells; Myeloid Progenitor Cells; Myeloid-derived suppressor cells; Myelopoiesis; Outcome; Output; PD-1 blockade; PD-1 pathway; PDL1 pathway; Pathway interactions; Patients; Phosphorylation; Property; Regulatory T-Lymphocyte; Role; Signal Transduction; Stress; T cell response; T-Lymphocyte; Training; Tumor Immunity; Work; anti-cancer therapeutic; cancer cell; cancer therapy; cholesterol biosynthesis; glucose uptake; granulocyte; immune activation; improved outcome; inhibitor; metabolomics; mevalonate; monocyte; novel; pathogen; pharmacologic; preservation; prevent; progenitor; programmed cell death ligand 1; programmed cell death protein 1; programs; response; stable isotope; success; terminally differentiated effector memory (TEM) T cells; transcriptome sequencing; tumor; tumor growth; tumor microenvironment

PD-1 blocking agents have achieved significant success as anti-cancer therapeutics. The mechanism(s) of how PD-1 compromises anti-tumor function remain poorly understood. We generated an antibody that recognizes PD-1pY248 that is required for PD-1 inhibitory signaling. In three mouse tumor models, we identified PD-1 expression and phosphorylation in CD4+ and CD8+ T cells of the tumor microenvironment (TME) but more prominently in myeloid cells. These findings prompted us to examine the role of PD-1 in myeloid cell differentiation and function in cancer immunity. The rapid change in hematopoietic cell output that occurs in response to immunologic stress is known as “emergency” myelopoiesis”. During continuous low-level stimulation mediated by cancer-derived factors, common myeloid progenitors (CMP) and granulocyte/macrophage progenitors (GMP), undergo modest but continuous expansion with hindered differentiation leading to the output of immature myeloid-derived suppressor cells (MDSC). We analyzed the myeloid compartment of tumor-bearing mice and determined that myeloid cells that expand during cancer-driven emergency myelopoiesis express PD- 1 and PD-L1. Using PD-1 KO mice or WT mice treated with PD-1 blocking antibody we determined that PD-1 deletion or blockade prevented the accumulation of immature myeloid progenitor cells and stimulated differentiation and output of Ly6Chi effector monocytes, macrophages and dendritic cells (DC). To determine whether these outcomes were mediated by a myeloid-intrinsic impact of PD-1 ablation or by the effects of PD- 1neg T cells on myeloid cells, we generated mice with conditional targeting of the Pdcd1 gene (PD-1f/f) and selectively eliminated PD-1 in myeloid cells or T cells. Compared to T cell-specific, myeloid cell-specific PD-1 ablation more effectively decreased tumor growth. Cancer-driven emergency myelopoiesis was differentially affected. Both myeloid-specific and T cell-specific PD-1 ablation resulted in expansion and accumulation of CMP but only myeloid-specific PD-1 ablation prevented the accumulation of GMP and switched the myeloid cell fate from MDSCs to differentiated effector monocytes, macrophages, DC. Our findings reveal a previously unidentified role of the PD-1: PD-L1 pathway and support the novel hypothesis that switch of myeloid cell fate commitment might be a key mechanism by which PD-1 blockade mediates its anti-tumor function. To investigate this, we will pursue the following specific aims to determine: 1. How PD-1 signaling mediates lineage fate determination of myeloid progenitor cells in response to emergency myelopoiesis. 2. How PD-1 targeting impacts the metabolic and epigenetic program of myeloid cells. 3. How PD-1 affects anti-tumor immunity by regulating the crosstalk between innate and tumor- associated T cells.

PD-1阻断剂作为抗癌治疗剂已经取得了显著的成功。机制如何 PD-1的抗肿瘤功能仍然知之甚少。我们制造了一种抗体 PD-1抑制信号传导所需的PD-1 pY 248。在三种小鼠肿瘤模型中，我们鉴定了PD-1， 肿瘤微环境（TME）的CD 4+和CD 8 + T细胞中的表达和磷酸化，但更多 在骨髓细胞中尤为突出。这些发现促使我们研究PD-1在骨髓细胞中的作用。 分化和癌症免疫功能。造血细胞输出的快速变化发生在 对免疫应激的反应被称为“紧急”骨髓生成”。在连续低水平刺激期间 由癌源性因子、共同髓系祖细胞（CMP）和粒细胞/巨噬细胞介导 祖细胞（GMP），经历适度但持续的扩增，分化受阻，导致输出 未成熟骨髓源性抑制细胞（MDSC）。我们分析了肿瘤细胞的髓样区室 小鼠，并确定在癌症驱动的紧急骨髓生成期间扩增的骨髓细胞表达PD-1。 1和PD-L1。使用用PD-1阻断抗体处理的PD-1 KO小鼠或WT小鼠，我们确定PD-1抑制剂在小鼠中的表达。 缺失或阻断阻止了未成熟髓系祖细胞的积累，并刺激了 Ly 6Chi效应子单核细胞、巨噬细胞和树突细胞（DC）的分化和输出。以确定 这些结果是否由PD-1消融的骨髓内在影响或PD-1消融的影响介导， 1 neg T细胞对骨髓细胞，我们产生了小鼠与条件靶向的Pdcd 1基因（PD-1f/f）， 选择性地消除骨髓细胞或T细胞中的PD-1。与T细胞特异性、骨髓细胞特异性PD-1相比 消融更有效地降低了肿瘤生长。癌症驱动的紧急骨髓细胞生成与 影响。骨髓特异性和T细胞特异性PD-1消融均导致CMP扩增和积聚 但只有骨髓特异性PD-1消融阻止了GMP的积累并改变了骨髓细胞的命运， 从MDSC到分化的效应单核细胞、巨噬细胞、DC。我们的发现揭示了一个以前 PD-1：PD-L1通路的未鉴定作用，并支持髓样细胞命运转换的新假设 承诺可能是PD-1阻断介导其抗肿瘤功能的关键机制。探讨 为此，我们将努力实现以下具体目标： 1. PD-1信号传导如何介导髓系祖细胞响应于 紧急骨髓增生 2. PD-1靶向如何影响骨髓细胞的代谢和表观遗传程序。 3. PD-1如何通过调节先天和肿瘤之间的串扰影响抗肿瘤免疫 相关的T细胞