TNF family members for lymph angiogenesis and lymph node hypertrophy

描述（由申请方提供）：外周组织中淋巴管（LV）和高内皮微静脉（HEV）的快速发育导致炎症/疫苗接种期间引流淋巴结（LN）肥大，但调节LN肥大的分子机制尚不清楚。免疫接种后或炎症期间，LN肥大的调节都涉及到光敏素（LT）、TNF、肥大细胞和树突状细胞。出乎意料但令人感兴趣的是，我们的初步研究揭示了与LT共享LT 2 R受体的LIGHT（TNFRSF 14）也是LN肥大所需的，因为LIGHT KO小鼠在CFA免疫后未能经历LN肥大。在使用小鼠模型的初步研究中，我们还确定了朗格汉斯细胞、特化的真皮DC和肥大细胞对于CFA免疫后的LN肥大是必需的。我们假设LIGHT从LC协调膜LT调节LV/HEV的激活和增殖，以及白细胞迁移到LN响应免疫损伤，导致LN肥大。具体来说，我们将探索来自朗格汉斯细胞的LIGHT是否是通过LT 2 R信号激活肥大细胞以产生用于LV和HEV快速发展的炎症介质所必需的。我们还将研究B细胞是否是LN肥大所需的膜LT的来源，以及LT如何与LIGHT协调以放大HEV活化并促进LV/HEV内皮细胞生长。在目标1中，我们将研究LIGHT如何在细胞水平上介导LN肥大，通过确定在LN肥大期间需要哪些细胞产生和响应LIGHT。我们将测试朗格汉斯细胞是否是LN肥大的必需LIGHT产生细胞。我们还将鉴定光反应细胞，根据我们的初步数据，我们假设这些细胞是肥大细胞。目的2：从分子水平研究LIGHT如何介导LN肥大。我们将确定LIGHT通过肥大细胞活化和TNF-1产生直接和/或间接调节LV/HEV内皮细胞的分子机制。我们还将研究LIGHT和TNF-1如何在疫苗接种早期协调LV/HEV激活。在目标3中，我们将测试B细胞是否是LN肥大的LT的主要来源，并确定LIGHT和LT在LN肥大期间是否以及如何合作。在目标4中，我们将确定LIGHT介导的LN肥大在肿瘤免疫中的作用。我们将定义LIGHT介导的（淋巴）血管生成在抗肿瘤T细胞引发中的作用，并探索使用Ad-LIGHT作为佐剂来增强（淋巴）血管生成和DC/T细胞迁移以改善肿瘤免疫治疗的治疗潜力。总之，我们的研究将阐明炎症反应中驱动LN肥大的细胞和分子机制，以及研究LIGHT介导的DC迁移在功能性抗肿瘤免疫应答和更有效疫苗开发中的作用。 公共卫生相关性：了解LN肥大的过程并确定调节白细胞免疫细胞迁移的参数将有助于我们确定治疗性操纵免疫反应的方法，以更好地保护免受感染，癌症和其他免疫介导的疾病。我们的研究将揭示LN肥大的细胞和分子机制。这些知识对于提供新的和新颖的策略以更有效地调节免疫应答以保护免受感染和癌症将是至关重要的。

DESCRIPTION (provided by applicant): Rapid development of lymphatic vessels (LV) and high endothelial venules (HEV) in peripheral tissues leads to hypertrophy of draining lymph nodes (LN) during inflammation/vaccination, but the molecular mechanism regulating LN hypertrophy is poorly understood. Lymphotoxin (LT), TNF, mast cells, and dendritic cells have all been implicated in the regulation of LN hypertrophy after vaccination or during inflammation. Unexpectedly but intriguingly, our preliminary studies have revealed that LIGHT (TNFRSF14), which shares the LT2R receptor with LT, is also required for LN hypertrophy, since LIGHT KO mice fail to undergo LN hypertrophy after CFA immunization. In preliminary studies using mouse models, we have also determined that Langerhans' cells, specialized dermal DCs, and mast cells are essential for LN hypertrophy after CFA immunization. We hypothesize that LIGHT from LC coordinates with membrane LT to regulate LV/HEV activation and proliferation as well as leukocyte migration into the LN in response to immune insult, leading to LN hypertrophy. Specifically, we will explore whether LIGHT from Langerhans' cells is essential to activate mast cells via LT2R signaling to produce inflammatory mediators for rapid development of LVs and HEVs. We will also study whether B cells are the source of membrane LT required for LN hypertrophy, and how LT coordinates with LIGHT to amplify the HEV activation and promote LV/HEV endothelial cell growth. In aim 1, we will study how LIGHT mediates LN hypertrophy on a cellular level by determining which cells are required to produce and respond to LIGHT during LN hypertrophy. We will test whether Langerhans' cells are the essential LIGHT-producing cells for LN hypertrophy. We will also identify LIGHT-responding cells, which we hypothesize to be mast cells based on our preliminary data. In aim 2, we will study how LIGHT mediates LN hypertrophy on a molecular level. We will define the molecular mechanisms by which LIGHT regulates LV/HEV endothelial cells directly and/or indirectly through mast cell activation and TNF-1 production. We will also investigate how LIGHT and TNF-1 coordinates for LV/HEV activation at the early stage of vaccination. In aim 3, we will test whether B cells are major source of LT for LN hypertrophy and determine whether and how LIGHT and LT cooperate during LN hypertrophy. In aim 4, we will determine the role of LIGHT-mediated LN hypertrophy in tumor immunity. We will define the role of LIGHT-mediated (lymph)angiogenesis in antitumor T cell priming and explore the therapeutic potential of using Ad-LIGHT as an adjuvant to enhance (lymph)angiogenesis and DC/T cell migration for improved tumor immunotherapy. In sum, our study will elucidate cellular and molecular mechanisms that drive LN hypertrophy in response to inflammation, as well as examining the role of LIGHT-mediated DC migration in the development of functional anti-tumor immune responses and more effective vaccines. PUBLIC HEALTH RELEVANCE: Lay summary Understanding the process of LN hypertrophy and defining the parameters regulating leukocyte immune cell migration will help us identify ways to therapeutically manipulate immune responses for better protection against infection, cancer and other immune-mediated diseases. Our study will reveal the cellular and molecular mechanisms underlying LN hypertrophy. This knowledge will be of utmost importance to provide new and novel strategies to more effectively modulate immune responses for the protection against infection and cancer.