Neurotransmitter Regulation of Immunity Through Effects on Endothelial Cells

描述(申请人提供)：本申请建议研究最近发现的一种新机制，通过该机制，神经递质(NTS)调节辅助性T细胞(Th)反应的性质和大小。初步数据表明，NTS可以作用于内皮细胞，然后内皮细胞将朗格-汉斯细胞(LCs)在抗原提呈过程中产生的免疫反应导向T细胞。这一新概念是基于初步数据显示，内皮细胞暴露于(A)神经肽降钙素基因相关肽(CGRP)(通过CGRP 1型受体起作用)或(B)肾上腺素能NT去甲肾上腺素(NE)，在加入呈递抗原给T细胞的LC培养之前，导致IL-17A(银屑病病理生理学中的关键细胞因子)的释放增加和干扰素-β的减少。通过去甲肾上腺素或降钙素基因相关肽对内皮细胞的作用，使抗原呈递偏向于IL-17A反应，这可能是应激加重Th17细胞介导的疾病的原因。感觉神经和交感神经对真皮血管、淋巴管和淋巴结的支配为NTS通过内皮细胞影响免疫细胞提供了解剖学基础。皮肤的神经支配对人类银屑病的表达是重要的，而银屑病小鼠模型中的皮疹依赖于神经支配，这一观察结果支持了这一途径的体内相关性。这一调节途径的发现可能对更全面地了解皮肤免疫，特别是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NTS来调节反应性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索这一假设：目标1A。为了确定CGRP、PACAP、VIP、NE或EPI是否通过对内皮细胞的作用调节LCS向反应性CD4+T细胞递送抗原的结果。我们将通过研究其他相关的皮肤抗原提呈细胞，包括真皮树突状细胞(DDCS)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。鉴定NTS诱导的内皮细胞在抗原提呈过程中调节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间接触的重要性。目的：利用内皮细胞相关NT受体表达失活的可诱导条件性KO小鼠，检测NT诱导的EC信号在体内的相关性。由于我们已经确定CGRP 1型受体在这一途径中介导了CGRP的作用，我们将首先建立小鼠，在其中我们可以灭活CGRP 1型受体，并在牛皮癣样皮炎模型中测试通过该受体的信号在免疫反应性和皮疹发生中的作用。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，更好地了解皮肤的病理生理学，并为开发能够调节皮肤免疫反应的药物创造合理的基础，包括一些可能通过EC受体发挥作用的药物。由于许多组织中的血管是神经支配的，我们的工作可能为调节其他组织的免疫功能提供一个范例。它将增强我们对神经系统和免疫系统之间相互作用的理解，并可能为自身免疫紊乱和癌症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-?. 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.