Characterization of innate and IgE-mediated mast cell functions in honeybee venom allergy using Collaborative Cross mice

项目摘要/摘要 我们将使用合作杂交(CC)小鼠来定义遗传特征如何影响先天和/或IgE介导的 肥大细胞(MC)对蜜蜂毒素的反应。在IgE依赖的过敏反应中，MC的交联性 二价或多价变应原与抗原特异性IgE结合的高亲和力IgE受体(即FceRI) 激活MC分泌三类主要产物：1)储存在细胞质中的预制介质 颗粒；2)新合成的脂源性介质；3)细胞因子、趋化因子和生长因子。 这些MC产品导致了过敏性疾病的许多体征和症状。MC激活， 无论有没有IgE的参与，也被认为是导致炎症、组织损伤和 甚至由毒液引起的致命休克。膜翅目毒液成分(如蜜蜂毒液)， 药物和食物是人类过敏反应最常见的诱因。很多人都有 对膜翅目昆虫毒液敏感，一些不幸的个体在接触这种昆虫后会产生反应 严重的全身反应，甚至是致命的过敏反应。然而，最近在小鼠和 斑马鱼证明，MC衍生的蛋白酶可以降解动物毒液，降低它们的毒性。另外， Ige/FceRI介导的MC活化可提高蜂毒或AFP攻击小鼠的存活率 蛇毒，或带有金黄色葡萄球菌的细菌。然而，由IgE/MC介导的“过敏性免疫反应”的好处是- 依赖机制，还没有得到广泛的认识。虽然确切的机制决定了 膜翅目毒化的结果是有害的还是有利的一直难以捉摸，我们知道 遗传因素可以显著影响过敏的发展、进展和严重程度 过敏反应。我们假设，通过调节MC的强度和/或组成，遗传特征 对蜂毒和/或Th2-IgE-MC免疫轴的反应可以影响 蜜蜂叮人。在这个项目中，我们建议使用遗传多样性的CC小鼠来识别遗传修饰物 调节MC在昆虫毒液过敏中的作用。在目标1中，我们将筛选一组CC小鼠 对蜜蜂毒液毒性的敏感性，毒液特异性2型免疫的发展和特征， 用或不用蛇毒特异性IgE/FceRI的交联物诱导MC活化。我们还将表演 CC小鼠毒液诱导表型的QTL定位 与MC依赖的蜂毒易感性与抗药性相关的基因座和新的调节因子。在……里面 目的2，我们将在小鼠MC中确认通过筛选CC鉴定的MC功能的重要调节因子 利用QTL分析评估这些调节因子在先天和/或IgE介导的MC中的作用 功能。我们认为，识别基因修饰物来区分对人类健康有益和有害的影响 对蜂毒的天然和/或过敏性免疫反应将改善对严重反应的治疗 昆虫毒液，可能还有其他免疫球蛋白E和巨噬细胞在其中起关键作用的疾病。 1

PROJECT SUMMARY/ABSTRACT We will use Collaborative Cross (CC) mice to define how genetic traits influence innate and/or IgE-mediated responses of mast cells (MCs) to honeybee venom. In IgE-dependent allergic reactions, crosslinking of MC high affinity IgE receptors (i.e., FceRI) by the binding of bivalent or multivalent allergen to antigen-specific IgE activates MCs to secrete three major classes of products: 1) preformed mediators stored in cytoplasmic granules, 2) newly synthesized lipid-derived mediators, and 3) cytokines, chemokines and growth factors. These MC products are responsible for many of the signs and symptoms of allergic diseases. MC activation, with or without the involvement of IgE, is also thought to contribute to the inflammation, tissue damage, and even fatal shock induced by envenomation. Components of hymenoptera venoms (e.g., honeybee venom), pharmaceutical agents, and foods are the most common triggers for anaphylaxis in humans. Many people have been sensitized to hymenoptera venoms and some unfortunate individuals react after exposure to such insect stings with serious systemic reactions and even fatal anaphylaxis. However, recent experiments in mice and zebra fish demonstrate that MC-derived proteases can degrade animal venoms and diminish their toxicity. Also, IgE/FceRI-mediated MC activation can enhance the survival of mice challenged with honeybee venom or a snake venom, or with S. aureus bacteria. Yet the benefits of “allergic immune responses”, mediated by IgE/MC- dependent mechanisms, have not been widely recognized. While the exact mechanisms determining whether the outcomes of hymenoptera envenomation are detrimental or favorable have been elusive, we know that genetic factors can significantly influence the development, progression, and severity of allergy and anaphylaxis. We hypothesize that genetic traits, by modulating the strength and/or composition of MC responses to honeybee venom and/or the Th2-IgE-MC immune axis, can influence the outcomes of honeybee stings. In this project, we propose to use genetically diverse CC mice to identify genetic modifiers regulating MC functions in insect venom allergy. In Aim 1, we will screen a panel of CC mice for their susceptibility to the toxicity of honeybee venom, development and features of venom-specific type 2 immunity, and induction of MC activation with or without crosslinking of venom-specific IgE/FceRI. We will also perform quantitative trait locus (QTL) mapping of the venom-induced phenotypes in CC mice to identify distinct genetic loci and novel regulators associated with MC-dependent susceptibility vs. resistance to honeybee venom. In Aim 2, we will confirm, in mouse MCs, important regulators of MC functions that are identified by screening CC mice using QTL analysis to assess the involvement of these regulators in innate and/or IgE-mediated MC functions. We think that the identification of genetic modifiers that distinguish beneficial vs. harmful effects of innate and/or allergic immune responses to honeybee venom will improve the treatment of severe reactions to insect venom and probably other disorders in which IgE and MCs have a critical role. 1