Mapping the impact of sex hormones on macrophage fates and functions

在激素控制的组织中，如女性生殖道(FRT)和乳房，细胞和分子功能受到内分泌系统和免疫系统的协调控制。FRT的免疫细胞必须维持一个微环境，该微环境同时允许受精，但对外来病原体和感染具有抵抗力，导致细胞类型和状态的复杂环境。FRT和乳房内类固醇性激素水平的周期性变化，再加上FRT中不同的物理分区，每个分区都有不同的趋化因子、细胞和代谢物谱，因此有必要采用系统水平的方法来评估这些细胞的命运和功能。特别令人感兴趣的是单核细胞和巨噬细胞，既有组织驻留的，也有单核细胞来源的，因为它们在动态平衡和致病条件下的不同功能，以及它们快速适应变化的组织环境的能力。尽管性激素对健康和疾病很重要，但使用系统方法了解性激素对巨噬细胞的影响的研究很少。我们将通过采用系统生物学的方法来全面描述性激素对巨噬细胞命运和功能的影响，从而具体解决这一突出的知识鸿沟。我们将首先深入描述荷尔蒙如何影响巨噬细胞的功能和转录，作为暴露时间和剂量的函数(目标1)。然后，我们将使用纵向单细胞RNA测序(scRNA-seq)和转座酶可访问染色质的分析然后测序(scATAC-seq)，以便完全映射性激素对单核细胞向巨噬细胞分化的转录和调控影响(目标2)。综上所述，通过计算推断分化轨迹，确定支持性激素如何改变巨噬细胞行为的关键调控元件，以及评估细胞因子分泌表型，我们将建立一个系统层面的理解，即通过性激素改变细胞程序来驱动特定的巨噬细胞命运和功能。这项研究对合理安排巨噬细胞的功能具有长期的意义，并对理解巨噬细胞群体在激素控制的组织中的不同作用具有实际意义。

Cellular and molecular functions in hormonally-controlled tissues, like the female reproductive tract (FRT) and breast, are coordinately controlled by both the endocrine system and the immune system. Immune cells of the FRT must maintain a microenvironment that simultaneously is permissible to fertilization but resistant to foreign pathogens and infection, resulting in a complex milieu of cell types and states. Cyclic changes in steroid sex hormone levels within the FRT and breast, coupled with heterogenous physical compartments in the FRT that each have distinct chemokine, cellular, and metabolite profiles, necessitate a systems-level approach to evaluating the fates and functions of these cells. Of particular interest in are monocytes and macrophages, both tissue resident and monocyte-derived, due to their diverse functions in homeostatic and pathogenic conditions, and their ability to rapidly adapt to shifting tissue milieus. Despite their importance to health and disease, there is a paucity of studies that have used systems approaches to understand the impact of sex hormones on macrophages. We will specifically address this outstanding knowledge gap by employing a systems biology approach to comprehensively characterize the impact that sex hormones have on macrophage fates and functions. We will first deeply profile how hormones impact the functions and transcriptomes of macrophages as a function of exposure time and dose (Aim 1). We will then use longitudinal single-cell RNAs-sequencing (scRNA-seq) and assay for transposase-accessible chromatin followed by sequencing (scATAC-seq) in order to fully map transcriptional and regulatory impacts of sex hormones on the differentiation of monocytes into macrophages (Aim 2). Taken together, by computationally inferring differentiation trajectories, identifying key regulatory elements that underpin how sex hormones modify macrophage behavior, and assessing cytokine secretion phenotypes, we will build a systems level understanding of the cellular programs that are modified by sex hormones to drive specialized macrophage fates and functions. This research has long-term implications for rationally orchestrating macrophage functions and has practical implications for understanding the diverse roles of macrophages populations in hormonally-controlled tissues.