Deciphering the immunoregulatory network governing antigen presenting myeloid cells

总结 树突状细胞（DC）负责指导T细胞应答，巨噬细胞对于调节T细胞应答是重要的。 组织炎症这些免疫细胞的一个标志是它们固有的可塑性，以控制免疫与耐受。 然而，关于共同控制的复杂分子网络， 造血、炎症和抗原呈递。不完整的理解是主要的障碍， 这也阻碍了成功地制定有效的 免疫疗法这项研究的长期目标是确定免疫调节的关键机制， 蛋白质控制DC和巨噬细胞分化和免疫应答。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（AIF 1）和磷酸二酯酶1b （Pde 1b），其中包括使用高通量转录组学分析结合 通过严格的RNAi功能筛选。我的实验室证明，AIF 1选择性地表达于 常规的1型DC（cDC 1）、单核细胞衍生的DC（MoDC）和巨噬细胞，并作为支架， 以钙响应方式募集蛋白激酶C（PKC），以促进炎症和1型极化 免疫反应。此外，AIF 1表达是成功产生cDC 1所必需的。 造血祖细胞和来自单核细胞前体的MoDC和巨噬细胞。背景下 在疾病中，DC和巨噬细胞中的AIF 1表达是启动和维持胰岛炎所必需的， 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 发现Pde 1b通过调节蛋白激酶A（PKA）的活性，以钙依赖的方式抑制PKA的活性。 cDC 1、MoDC和巨噬细胞中的cycloprotide水平，以促进免疫效应子应答。所以我的 一个研究小组已经开始揭示Pde 1b如何与AIF 1协同工作，通过平衡来管理免疫力。 PKC与PKA活性。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。 研究现在采用条件和全球基因敲除小鼠和使用创新的实验工具， 严格研究体内的机械作用。我的实验室将在未来五年内实现以下主要目标 年：（1）描述AIF 1和Pde 1B如何在体内调控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应答的细胞内过程;（3） 确定AIF 1在引发炎症和维持自身反应性T细胞应答中的作用; 以及（4）确定胞内病原体如何通过破坏钙信号传导拮抗AIF 1和Pde 1b 和环磷酰胺水平来逃避宿主免疫所获得的知识将填补我们理解的关键空白， DC和巨噬细胞生物学，并提供了重要的见解的分子网络管理免疫。

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.