The immune system beyond protection: role of innate lymphoid cells in the regulation of the estrous cycle.

对稳态条件的扰动由组织驻留的免疫细胞感知，它们对接收到的信息进行细化，并通过产生影响其他免疫细胞和非免疫细胞功能的信号作出反应。近年来，人们清楚地认识到，这种扰动不仅是由有害病原体引起的，而是免疫细胞在许多与宿主保护无关的生理过程中起着重要作用。这些情况的主要参与者是先天淋巴样细胞（ILCs）和髓样细胞，它们分布在屏障器官上皮层下的结缔组织中，并通过产生不同的细胞因子来引发炎症反应。然后，这些信号导致循环淋巴细胞的募集和激活，从而介导反应。在本研究项目中，我们拟研究女性生殖道中的免疫细胞，这是一个在发情周期中发生剧烈变化的动态系统。我们的工作假设是免疫细胞是发情周期中发生的动态变化的重要调节器。我们将与生殖生物学专家Vanderhyden博士合作开展这个项目。根据我们的研究计划，这项发现基金的短期目标是：1)建立女性生殖系统先天淋巴细胞图谱：我们将使用单细胞rna测序（scRNA-seq）来表征女性生殖系统的免疫组成。将对处于发情周期和排卵期不同阶段的小鼠的卵巢、输卵管和子宫进行分析。这一分析将揭示哪些免疫细胞群和哪些途径在发情周期的不同阶段被调节。免疫组织化学、qPCR和流式细胞术将证实scRNA-seq结果。特别强调的是先天淋巴样细胞，这在女性生殖道中被大大忽视了。2)确定先天淋巴样细胞是否以及如何调节发情周期的进程：我们假设先天淋巴样细胞是发情周期动力学的重要协调者，我们将确定这种免疫区的实验扰动如何影响发情周期。3)了解内分泌信号如何调节先天淋巴样细胞在发情周期中的功能：先天淋巴样细胞表达神经递质和激素受体，我们将研究它们是否直接受到神经内分泌系统的调节。我们将进行体内和离体功能实验，以确定哪些神经内分泌信号调节免疫功能。该项目将阐明免疫细胞如何调节发情周期，并将为我们确定免疫系统如何在没有致病挑战的情况下对宿主生理做出贡献这一更广泛的目标奠定基础。

Perturbations to steady state conditions are sensed by tissue resident immune cells, which elaborate the information received and respond by producing signals that shape the functions of other immune, as well as non-immune, cells. In recent years, it became clear that such perturbations are not only caused by harmful pathogens, rather immune cells play fundamental roles in many physiological processes not related to host protection. Major players in these scenarios are Innate Lymphoid Cells (ILCs) and myeloid cells, which populate the connective tissues underneath the epithelial layer of barrier organs and prime inflammatory responses through the production of different cytokines. Such signals then lead to the recruitment and activation of circulating lymphocytes, which mediate a response. In this research program, we propose to study immune cells in the female reproductive tract, a dynamic system which undergoes dramatic changes during the estrous cycle. Our working hypothesis is that immune cells are important regulators of the dynamic changes occurring during the estrous cycle. We will carry this project in collaboration with Dr. Vanderhyden, an expert in reproductive biology. In line with our research program, the short-term objectives of this Discovery Grant are: 1)To build an atlas of innate lymphoid cells in the female reproductive system: We will use single-cell RNA-sequencing (scRNA-seq) to characterize the immune composition of the female reproductive system. Ovaries, oviducts and uteri will be analyzed from mice at various stages of the estrous cycle and the periovulatory period. This analysis will reveal which immune cell populations and which pathways are modulated at the different stages of the estrous cycle. Immunohistochemistry, qPCR and flow cytometry will be employed to corroborate the scRNA-seq results. A particular emphasis will be given to innate lymphoid cells, which have been vastly overlooked in the female reproductive tract. 2)To determine if and how innate lymphoid cells regulate the progression through the estrous cycle: As we hypothesize that innate lymphoid cells are important coordinators of the dynamics of the estrous cycle, we will determine how experimental perturbation of this immunological compartment affects the estrous cycle. 3)To understand how endocrine signals regulate innate lymphoid cell functions during the estrous cycle: As innate lymphoid cells express receptors for neurotransmitters and hormones, we will study if they are directly regulated by the neuro-endocrine system. We will conduct functional in vivo and ex vivo experiments to determine which neuro endocrine signals regulate immune functions. This project will shed light on how immune cells regulate the estrous cycle and will represent a stepping stone to our broader goal of determining how the immune system contributes to the host physiology in the absence of a pathogenic challenge.