Use of Substance P antagonists to regulate the skin immune function

描述（由申请人提供）：复发性炎症性疾病是具有高度社会经济影响的常见皮肤疾病。接触性超敏反应（CHS）是一种典型的复发性皮肤炎性疾病，它依赖于免疫系统和神经系统的相互作用。CHS需要活化识别皮肤细胞中存在的半抗原的CD4+和CD8+效应T细胞。CHS中效应T细胞的活化需要免疫刺激性皮肤树突状细胞DC（sDC），包括表皮朗格汉斯细胞（LC）和真皮DC（DDC），其将半抗原转运至皮肤引流淋巴结（sDLN）并活化初始T细胞。因此，抑制免疫刺激性DC将是预防和治疗皮肤免疫疾病的理想方法。然而，由于皮肤免疫系统的复杂调节，靶向刺激性sDC的疗法的开发一直极其困难。免疫刺激性DC的产生需要在DC-抗原（Ag）/半抗原相互作用时的促炎微环境。这种炎症微环境由皮肤暴露于Ag/半抗原后释放的促炎神经肽启动。P物质（SP）是原型促炎神经肽，其通过促进免疫细胞的活化、增殖和存活而有利于细胞免疫。在皮肤中，SP主要由感觉C-纤维分泌，所述感觉C-纤维将细胞与免疫功能例如LC、肥大细胞（MC）和角质形成细胞互连。SP通过结合神经激肽1受体（NK1R）发挥其免疫刺激功能，我们已经描述了sDC表达功能性NK1R，并通过诱导Th1和CTL效应子对蛋白Ag的免疫应答来应答NK1R激动性结合。然而，在皮肤CHS的起始和复发期间，缺乏解决局部分泌的SP对sDC的成熟和T细胞免疫刺激功能的作用的相关研究。我们假设：“在皮肤Ag/半抗原穿透的瞬间，SP通过NK1R的促炎信号传导促进免疫刺激性sDC及其前体的活化，导致皮肤免疫疾病的开始、持续和复发，这可以通过局部施用NK1R拮抗剂来限制”。为了验证我们的假设，我们提出了以下具体目标：具体目标1：分析SP在CHS致敏阶段诱导免疫刺激性sDC的机制。具体目标二：分析SP在CHS的致敏、诱导和消退过程中，由sDC刺激的T细胞应答中的作用和机制。具体目标3：分析使用特异性NK1R拮抗剂局部给药通过下调sDC及其前体的T细胞刺激功能来抑制CHS的可能性。公共卫生相关性：复发性炎症性皮肤病是具有高度社会经济影响的常见疾病。接触性超敏反应（CHS）是一种依赖于免疫系统和神经系统相互作用的典型复发性皮肤炎性疾病。CHS的发生和复发是由抗原暴露时皮肤局部释放的促炎神经肽触发的。P物质（SP）是一种有效的神经肽，负责皮肤炎症的起始和复发以及树突状细胞群体的活化，树突状细胞是最有效的皮肤驻留抗原呈递细胞。在本申请中，我们提出通过在Ag暴露的时刻在皮肤中局部递送合成的非肽NK1R拮抗剂来特异性地阻断其功能性神经激肽-1受体（NK1R）来抑制SP的作用。这将使用鼠和我们开发的独特的人类皮肤外植体模型来完成，以促进临床试验的转化。我们提出的研究有可能克服复发性皮肤炎症和免疫疾病，它们包括作为人类临床试验直接前奏而设计的转化临床前模型。

DESCRIPTION (provided by applicant): Recurrent inflammatory diseases are common skin disorders with high socioeconomic impact. Contact hypersensitivity (CHS) is the prototype recurrent skin inflammatory disease that relays on the interaction of the immune and nervous systems. CHS requires activation of CD4+ and CD8+ effector T cells recognizing haptens present in skin cells. Activation of effector T cells, in CHS requires immunostimulatory skin dendritic cells DCs (sDCs) including epidermal Langerhans cells (LCs) and dermal DCs (DDCs) that transport haptens to skin draining lymph nodes (sDLNs) and activate naive T cells. Thus, inhibition of immunostimulatory DCs would be ideal for the prevention and treatment of skin immune diseases. However, the development of therapies targeting stimulatory sDCs has been extremely difficult due to the complex regulation of the skin immune system. The generation of immunostimulatory DCs requires a pro- inflammatory microenvironment at the moment of DC-antigen (Ag) /hapten interaction. This inflammatory microenvironment is initiated by pro-inflammatory neuropeptides released after skin exposure to Ag/haptens. Substance-P (SP) is the prototype pro-inflammatory neuropeptide which favors cellular immunity by promoting the activation, proliferation and survival of immune cells. In the skin, SP is mainly secreted by sensory C-fibers that interconnect cells with immune function such as LCs, mast cells (MCs), and keratinocytes. SP exerts its immunostimulatory functions by binding the neurokinin 1 receptor (NK1R).We have described that sDCs express functional NK1R and respond to NK1R agonistic binding by inducing Th1 and CTL effector immune responses to protein Ag. Nevertheless, relevant studies addressing the role of locally secreted SP, on the maturation and T cell immunostimulatory function of sDCs during the initiation and recurrence of skin CHS are lacking. We hypothesize that: "Pro-inflammatory signaling by SP through the NK1R, at the moment of skin Ag/hapten penetration, promotes the activation of immunostimulatory sDCs and their precursors resulting in the initiation, persistence and recurrence of skin immune diseases which can be limited by local administration of NK1R antagonists". To test our hypothesis we propose the following specific aims: Specific Aim 1: To analyze the mechanisms employed by SP to induce immunostimulatory sDCs during the sensitization phase of CHS. Specific Aim 2: To analyze the role and mechanisms employed by SP in T cell responses, stimulated by sDCs during sensitization, elicitation and resolution of CHS. Specific Aim 3: To analyze, the possibility of using local administration of specific NK1R antagonists to suppress CHS by down-regulating the T cell-stimulatory function of sDCs and their precursors. PUBLIC HEALTH RELEVANCE: Recurrent inflammatory skin diseases are common disorders with high socioeconomic impact. Contact hypersensitivity (CHS), is the prototype recurrent skin inflammatory disease that depends on the interaction of the immune and nervous systems. The initiation and recurrence of CHS is triggered by pro-inflammatory neuropeptides released locally in the skin at the moment of antigen exposure. Substance-P (SP), a potent neuropeptide, is responsible for the initiation and recurrence of skin inflammation and for the activation of the population of dendritic cells, the most potent skin resident antigen presenting cells. In this application we propose to inhibit the effects of SP by blocking specifically its functional neurokinin-1 receptor (NK1R) by delivering synthetic non-peptide NK1R antagonists locally in the skin at the moment of Ag exposure. This will be accomplished using both murine, and a unique model of human skin explants that we have developed to facilitate translation to clinical trials. The studies we propose have the potential to overcome recurrent skin inflammatory and immune diseases and they include translational preclinical models designed as a direct prelude to human clinical trials.