Neurotransmitter Regulation of Immunity Through Effects on Endothelial Cells

描述（由申请人提供）：本申请旨在研究最近发现的神经递质（nt）调节辅助性T （Th）细胞反应的特征和强度的新机制。初步数据表明，NTs可以作用于内皮细胞（ECs），从而指导Langer- hans细胞（LCs）向T细胞递呈抗原过程中产生的免疫反应类型。这个新概念是基于初步数据，显示ec暴露于(a)神经肽降钙素基因相关肽（CGRP）（通过CGRP 1型受体作用）或(b)肾上腺素能NT去甲肾上腺素（NE），在向T细胞提呈Ag之前，导致IL-17A（银屑病病理生理中的关键细胞因子）的释放增加和干扰素-γ的减少。通过NE或CGRP对ECs的影响，Ag呈递偏向于IL-17A反应，这可能解释了应激导致Th17细胞介导的疾病加剧。感觉和交感神经对真皮血管、淋巴管（可能）和淋巴结的神经支配提供了一种解剖基质，NTs可以通过ECs影响免疫细胞。这一途径的体内相关性得到了以下观察结果的支持：皮肤的神经支配对人类牛皮癣的表达很重要，牛皮癣样皮炎小鼠模型中的皮疹依赖于神经支配。这一调控途径的发现可能对更全面地了解皮肤免疫，特别是在病理状态下的皮肤免疫具有重要意义。我们假设神经系统通过释放作用于EC靶点的nt来调节应答性CD4+ T细胞的分化途径，从而调节免疫系统对特定类型的反应。我们将在两个目标中探讨这一假设：目标1A。目的：确定CGRP、PACAP、VIP、NE或EPI是否通过作用于内皮细胞调节细胞向CD4+ T细胞呈递银的结果。我们将通过研究其他相关的皮肤银呈递细胞，包括真皮树突状细胞（ddc）和单核细胞来源的dc（作为炎性真皮dc的替代品）来检验这一假设的普遍性。Aim1B。目的：探讨在银呈递过程中，NTs诱导的内皮细胞中调控Th细胞分化的细胞和分子生物学事件。我们将测试分泌分子和细胞-细胞接触的重要性。目的2：通过使用可诱导的条件KO小鼠，在EC中相关NT受体的表达失活，来测试NT诱导EC信号传导的体内相关性。由于我们已经确定CGRP 1型受体在这一途径中介导CGRP的作用，我们将首先产生小鼠，我们可以使CGRP 1型受体失活，并在银屑病样皮炎模型中测试通过该受体的信号传导在免疫反应和皮疹发展中的作用。这些研究将深入了解神经系统在调节皮肤免疫反应中的作用，提供对皮肤病理生理学的更好理解，并为开发可以调节皮肤免疫反应的药物（包括一些可能通过EC受体起作用的药物）创造合理的基础。由于许多组织中的血管受神经支配，我们的工作可以作为其他组织中免疫功能调节的范例。它将增强我们对神经系统和免疫系统之间相互作用的认识，并可能为自身免疫性疾病和对癌症的免疫反应的调节提供见解。

DESCRIPTION (provided by applicant): This application proposes to study a recently discovered novel mechanism by which neurotransmitters (NTs) regulate the character and magnitude of T helper (Th) cell responses. Preliminary data demonstrate that NTs can act on endothelial cells (ECs), which then direct the types of immune responses generated in the course of antigen presentation by Langer- hans cells (LCs) to T cells. This novel concept is based on preliminary data showing that exposure of ECs to either (a) the neuropeptide calcitonin gene-related peptide (CGRP) (acting through the CGRP type 1 receptor) or (b) the adrenergic NT norepinephrine (NE), prior to addition to cultures of LCs presenting Ag to T cells, results in an increase in the release of IL-17A (a key cytokine in the pathophysiology of psoriasis) and a decrease in interferon-γ. Bias of Ag presentation toward an IL-17A response via NE or CGRP effects on ECs may explain exacerbation of Th17 cell-mediated diseases by stress. Innervation of dermal blood vessels, lymphatics (probably) and lymph nodes by both sensory and sympathetic nerves provides an anatomic substrate by which NTs can impact immune cells via ECs. The in vivo relevance of this pathway is supported by the observation that innervation of the skin is important for the expression of human psoriasis and that the rash in murine models of psoriasiform dermatitis depends on innervation. The discovery of this regulatory pathway may have important implications for a more complete understanding of cutaneous immunity, particularly in pathologic states. We hypothesize that the nervous system regulates the immune system toward particular types of responses by regulating the differentiation pathway of responsive CD4+ T cells through release of NTs acting on EC targets. We will explore this hypothesis in 2 aims: Aim 1A. To determine if CGRP, PACAP, VIP, NE or EPI regulate the outcome of Ag presentation by LCs to responsive CD4+ T cells through actions on ECs. We will test the generality of the hypothesis by studying other relevant skin Ag presenting cells, including dermal dendritic cells (DDCs) and monocyte-derived DCs (as a surrogate for inflammatory dermal DCs). Aim1B. To identify the cell and molecular biologic events in ECs induced by NTs that regulate Th cell differentiation during Ag presentation. We will test the importance of secreted molecules and cell-cell contact. Aim 2: To test the in vivo relevance of NT-induced EC signaling through the use of inducible, conditional KO mice where the expression of the relevant NT receptors is inactivated in EC. As we have determined that the CGRP type 1 receptor mediates the effect of CGRP in this pathway, we will initially generate mice in which we can incactivate the CGRP type 1 receptor and test the role of signaling through this receptor on immune responsiveness and on the development of rash in a a model of psoriasiform dermatitis. These studies will provide insight into the role of the nervous system in regulating skin immune responses, providing a better understanding of pathophysiology in the skin and creating a rational basis for developing drugs that can modulate skin immune responses, including some that may act via EC receptors. Since vessels in many tissues are innervated, our work may serve as a paradigm for the regulation of immune function in other tissues. It will enhance our appreciation of interactions between the nervous and immune systems, and may provide insights into autoimmune disorders and regulation of the immune response to cancer.