Deciphering the immunoregulatory network governing antigen presenting myeloid cells

破译控制抗原呈递骨髓细胞的免疫调节网络

• 批准号: 10629283
• 负责人: Michael W Lipscomb
• 金额: $ 38.75万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-01 至 2027-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10629283
• 关键词: Antigen Presentation; Autoimmune Diseases; Biology; Calcium; Calcium Signaling; Cells; Complex; Coupled; Cyclic AMP-Dependent Protein Kinases; Dendritic Cells; Disease; Generations; Genes; Goals; Health; Hematopoiesis; Hematopoietic stem cells; Immune; Immune response; Immunity; Immunobiology; Immunologic Deficiency Syndromes; Immunotherapy; Infectious Agent; Inflammation; Knockout Mice; Knowledge; Laboratories; Macrophage; Malignant Neoplasms; Molecular; Myeloid Cells; Pathology; Pharmacotherapy; Physiological Processes; Play; Process; Protein Kinase C; Proteins; Publishing; RNA Interference; Research; Role; Signal Transduction; T cell response; Tissues; Work; allograft inflammatory factor-1; autoreactive T cell; combat; design; immunoregulation; in vivo; innovation; insight; insulitis; molecular mechanics; monocyte; novel; pathogen; phosphoric diester hydrolase; public health relevance; recruit; response; scaffold; screening; selective expression; success; tool; transcriptomic profiling

SUMMARY Dendritic cells (DC) are responsible for directing T cell responses and macrophages important for modulating tissue inflammation. A hallmark of these immune cells is their inherent plasticity to govern immunity vs. tolerance. However, much remains unknown regarding the complex molecular networks that collectively govern hematopoiesis, inflammation and antigen presentation. Incomplete understanding presents major obstacles to delineating their underlying roles in health and disease, which has also hindered success in developing effective immunotherapies. The long-term goal of the proposed research is to determine how pivotal immunoregulatory proteins govern DC and macrophage differentiation and immune responses. Published findings by my laboratory have begun to mechanistically define the functional roles of several important genes uniquely expressed in these myeloid cells. These genes, which include Allograft Inflammatory Factor-1 (AIF1) and Phosphodiesterase 1b (Pde1b), among others, were identified using a combination of high throughput transcriptomic profiling coupled with rigorous RNAi functional screening. My laboratory demonstrated that AIF1 is selectively expressed in conventional type 1 DC (cDC1), monocyte-derived DC (MoDC) and macrophages and serves as a scaffold to recruit protein kinase C (PKC) in a calcium-responsive manner to promote inflammation and type 1 polarized immune responses. Furthermore, AIF1 expression was required for successful generation of cDC1 from hematopoietic progenitors and both MoDC and macrophages from monocyte precursors. In the context of disease, AIF1 expression in DC and macrophages is required for initiating and sustaining insulitis and in regulating effector responses to intracellular pathogens. In another line of studies, the phosphodiesterase protein Pde1b was found to depress protein kinase A (PKA) activity in a calcium-dependent manner by regulating cyclonucleotide levels in cDC1, MoDC and macrophages to promote immune effector responses. Thus, my research group has begun to unravel how Pde1b works in concert with AIF1 to govern immunity by balancing PKC vs. PKA activities. As important as these initial findings are, there remains several gaps in understanding the molecular mechanics of how these genes govern immunobiology. As such, our research builds on prior studies by now employing conditional and global knockout mice and use of innovative experimental tools to rigorously study mechanistic roles in vivo. My laboratory will pursue the following major goals over the next five years: (1) delineate how AIF1 and Pde1B govern differentiation of DC and macrophages in vivo; (2) describe the intracellular processes by which other key novel immunoregulatory genes orchestrate immune responses; (3) determine the contributing role of AIF1 in initiating inflammation and sustaining autoreactive T cell responses; and (4) identify how intracellular pathogens antagonize AIF1 and Pde1b through disruption of calcium signaling and cyclonucleotide levels to evade host immunity. Knowledge gained will fill key gaps in our understanding of DC and macrophage biology and provide important insights into the molecular networks governing immunity.

概括 树突状细胞 (DC) 负责指导 T 细胞反应，而巨噬细胞对于调节非常重要 组织炎症。这些免疫细胞的一个标志是它们固有的可塑性来控制免疫与耐受性。 然而，关于共同控制的复杂分子网络，仍有许多未知之处。 造血、炎症和抗原呈递。不完全的理解是实现这一目标的主要障碍 描述它们在健康和疾病中的潜在作用，这也阻碍了成功开发有效的 免疫疗法。拟议研究的长期目标是确定关键的免疫调节如何 蛋白质控制 DC 和巨噬细胞的分化和免疫反应。我的实验室发表的研究结果 已经开始机械地定义在这些细胞中独特表达的几个重要基因的功能作用 骨髓细胞。这些基因包括同种异体移植物炎症因子 1 (AIF1) 和磷酸二酯酶 1b (Pde1b) 等是通过结合高通量转录组分析和 通过严格的RNAi功能筛选。我的实验室证明 AIF1 选择性表达于 传统的 1 型 DC (cDC1)、单核细胞衍生的 DC (MoDC) 和巨噬细胞，并作为支架 以钙反应方式招募蛋白激酶 C (PKC)，以促进炎症和 1 型极化 免疫反应。此外，AIF1 表达对于成功生成 cDC1 是必需的。 造血祖细胞以及来自单核细胞前体的 MoDC 和巨噬细胞。在这样的背景下 在疾病中，DC 和巨噬细胞中的 AIF1 表达是引发和维持胰岛素炎所必需的，并且在 调节对细胞内病原体的效应反应。在另一项研究中，磷酸二酯酶蛋白 研究发现 Pde1b 通过调节钙依赖性方式抑制蛋白激酶 A (PKA) 活性 cDC1、MoDC 和巨噬细胞中的环核苷酸水平可促进免疫效应反应。因此，我的 研究小组已开始揭示 Pde1b 如何与 AIF1 协同作用，通过平衡来控制免疫力 PKC 与 PKA 活动。尽管这些初步发现很重要，但在理解方面仍存在一些差距 这些基因如何控制免疫生物学的分子机制。因此，我们的研究建立在先前的基础上 目前的研究采用条件性基因敲除小鼠和全局基因敲除小鼠，并使用创新的实验工具 严格研究体内的机制作用。我的实验室将在未来五年内追求以下主要目标 年：（1）描述AIF1和Pde1B如何控制体内DC和巨噬细胞的分化； (2) 描述 其他关键的新型免疫调节基因协调免疫反应的细胞内过程； (3) 确定 AIF1 在引发炎症和维持自身反应性 T 细胞反应中的贡献作用； (4) 确定细胞内病原体如何通过破坏钙信号传导来拮抗 AIF1 和 Pde1b 和环核苷酸水平以逃避宿主免疫。获得的知识将填补我们理解上的关键空白 DC 和巨噬细胞生物学，并为控制免疫的分子网络提供重要见解。