Cellular & Inflammatory Pathways in Ashtma & Allergic Diseases: From IgE to Cells

描述(申请人提供)：哮喘和过敏性疾病是多因素的、复杂的疾病，涉及先天性和获得性免疫系统以及环境因素。过敏性哮喘的特征是呼吸道高反应性(AHR)、含有嗜酸性白细胞、淋巴细胞和肥大细胞的炎性浸润物、粘液分泌增加和血清IgE水平升高。2型辅助性T淋巴细胞(Th2)在调节过敏性呼吸道炎症中起关键作用。在识别其同源抗原后，Th2细胞产生细胞因子，调节IgE的合成(IL-4和IL-13)，以及嗜酸性粒细胞(IL-5)和肥大细胞(IL-3和IL-4)的生长和激活。IL-13和IL-9控制粘液产生和AHR。过敏原诱导的呼吸道炎症可由NKT细胞触发，并被调节性T(Treg)细胞拮抗。尽管我们对过敏发病机制的了解和治疗方法的改进取得了这些进展，但要更好地控制哮喘和其他过敏性疾病，仍有大量的知识需要学习。要对付这些复杂的疾病，我们的调查方法需要多方面的。在这个小组项目中，我们将研究Th2细胞协调的过敏性炎症是如何在细胞和分子水平上调节的。为了实现这一共同目标，在项目1中，我们将研究先天免疫(树突状细胞和NKT细胞)对环境因素--屋尘提取物(HDE)的反应。我们将研究Th2细胞如何受到蛋白激酶C的调节？(PKC？)在项目2中，不同的IgE如何在项目3中差异地影响肥大细胞的激活，在项目4中，Treg细胞如何被E3泛素连接酶Itch调节。因此，我们将研究属于先天免疫系统和获得性免疫系统的细胞的致病作用。关于过敏发病机制，我们所描述的分子种类繁多，包括环境因子(HDE)、分泌分子(IgE)和细胞内信号分子(PKC9和Itch)。如上所述，这些细胞和分子元素都可能在过敏性哮喘和其他过敏性疾病的发病机制的各个方面做出贡献。作为一个单独的研究项目，这个组中的每个组成部分都可以独立处理过敏性疾病的一个重要、独特的方面。然而，各个组成部分之间的合作将是多层次的，例如，思想交流、共享试剂、方案和数据，以及正式和非正式的合作，以实现我们更好地了解疾病的共同目标，就像过敏性疾病涉及细胞外、细胞和细胞内各层元素一样。项目完成后，我们将对所有这些层面的过敏性疾病有一套新颖、独特、完整的见解。 项目1：人类肥大细胞脱敏：减轻哮喘和过敏性疾病的机制和潜在效用(施瓦茨，L) 项目1说明(申请人提供)：哮喘和过敏性疾病是重要的健康问题，肥大细胞和可能的嗜碱性粒细胞是人类免疫球蛋白E介导的即刻超敏反应的主要效应细胞。参与项目1的研究人员之前的工作包括开发类胰蛋白酶作为肥大细胞激活的临床标记物；发现哮喘气道中的肥大细胞和全身过敏反应期间的肥大细胞的激活；根据肥大细胞分泌颗粒的蛋白酶含量和CD88的表面表达鉴定两种类型的人肥大细胞(MCT和MCTC)；发现FcyRII，CD32a的激活形式，组成地表达在皮肤MCTC细胞表面；以及在体外发现非释放表型的嗜碱性细胞和抗原脱敏后的肥大细胞缺乏Syk。本项目的三个具体目标是：1.验证体外培养的人肥大细胞和嗜碱性粒细胞对不同抗原发生交叉脱敏的假设，以及通过FcyRI和FcyR11a进行异源脱敏的假设。事实上，初步数据表明，当MCTC类型的肥大细胞被IgE抗DNP致敏，然后用低剂量的DNP-BSA脱敏时，交叉脱敏和异源脱敏都会发生。2.探讨人肥大细胞对Src和/或Syk酪氨酸激酶的脱敏机制(S)。尽管Syk似乎有可能枯竭，但LYN和/或FYN的参与尚不确定。此外，还将研究脱敏和激活信号的亚细胞区隔不同的可能性。与项目3合作研究Lyn激酶参与脱敏，与项目4合作研究鞘氨醇激酶-1参与人类肥大细胞和嗜碱性粒细胞脱敏，促进了这些机制研究。3.确定人体内青霉素脱敏是否对肥大细胞和嗜碱性粒细胞产生抗原交叉脱敏，并耗尽外周血嗜碱性粒细胞中的Syk。这项临床研究将开始将我们的体外研究结果转化为体内情况。脱敏引起的临床耐受性与免疫疗法所致的耐受性不同，因为一旦停用变应原，其诱导速度快(小时)，持续时间短(天)。我们假设脱敏主要针对肥大细胞和嗜碱性粒细胞。更准确地了解脱敏的特征和脱敏背后的机制(S)将使医生能够更好地利用这一方法来减少肥大细胞/嗜碱粒细胞介导的哮喘和过敏性疾病的作用。

DESCRIPTION (provided by applicant): Asthma and allergic diseases are multifactorial, complex diseases involving the innate and adaptive immune systems as well as environmental factors. Allergic asthma is characterized by airway hyperreactivity (AHR), inflammatory infiltrates containing eosinophilic leukocytes, lymphocytes, and mast cells, increased mucus secretion, and elevated serum IgE levels. Type 2 helper T lymphocytes (Th2) play a critical role in orchestrating allergic airway inflammation. Upon recognition of their cognate antigen, Th2 cells produce cytokines that regulate IgE synthesis (IL-4 and IL-13), and growth and activation of eosinophils (IL-5) and mast cells (IL-3 and IL-4). IL-13 and IL-9 control mucus production and AHR. Allergen-induced airway inflammation can be triggered by NKT cells and is antagonized by regulatory T (Treg) cells. Despite these progresses in our understanding of allergy pathogenesis and improved therapeutics, there remains a great deal to be learned to better control asthma and other allergic diseases. To attack these complex diseases, our approaches in investigation need to be multi-faceted. In this group project, we will investigate how allergic inflammation orchestrated by Th2 cells is regulated at cellular and molecular levels. To fulfill this common goal, we will study innate immune (dendritic cell and NKT cell) responses to an environmental factor, house dust extracts (HDEs), in Project 1. We will study how Th2 cells are regulated by protein kinase C? (PKC?) in Project 2, how different IgEs differentially affect mast cell activation in Project 3, and how Treg cells are regulated by Itch, an E3 ubiquitin ligase, in Project 4. Therefore, we will study the pathogenetic roles of the cells that belong to the innate and adaptive immune systems. The molecules we characterize with regard to allergy pathogenesis are widely varied, encompassing an environmental factor (HDEs), a secreted molecule (IgE), and intracellular signaling molecules (PKC9 and Itch). As described above, these cellular and molecular elements all likely contribute to various aspects of the pathogenesis of allergic asthma and other allergic diseases. Each component in this group can stand alone as an individual research project deals with an important, unique aspect of allergic diseases. However, cooperation among individual components will be multi-layered, e.g., exchanges of ideas, sharing reagents, protocols, and data, and formal and informal collaborations, to achieve our common goal of better understanding the diseases, just as allergic diseases involve various layers of extracellular, cellular, and intracellular elements. Upon completion of the program project, we will have gained a novel, unique, integrated set of insights into allergic diseases at all these layers. PROJECT 1: Desensitization of human mast cells: mechanisms and potential utility of attenuating asthma and allergic disease (Schwartz, L) PROJECT 1 DESCRIPTION (provided by applicant): Asthma and allergic diseases are important health concerns, and mast cells and possibly basophils are the major effector cells of IgE-mediated immediate hypersensitivity in humans. Previous work by the investigators involved in Project 1 includes developing tryptase as a clinical marker for mast cell activation; finding activation of mast cells in the asthmatic airway and during systemic anaphylaxis; identifying two types of human mast cells (MCT and MCTC) based on the protease content of their secretory granules and the surface expression of CD88; discovering the activating form of FcyRII, CD32a, constitutively expressed on the surface of skin MCTC cells; and finding Syk-deficiency in basophils with the non-releaser phenotype and in mast cells after antigen desensitization in vitro. The three specific aims of the current project are to: 1. Test the hypothesis that human mast cells and basophils in vitro undergo cross-desensitization to different antigens and heterologous desensitization through FcyRI and FcyRlla. Indeed, preliminary data suggest that when mast cells of the MCTC type are IgE anti-DNP-sensitized and then desensitized with low doses of DNP-BSA, both cross-desensitization and heterologous desensitization occurs. 2. Explore in vitro the mechanism(s) for desensitization of human mast cells involving Src and/or Syk tyrosine kinases. Although Syk depletion seems likely, the involvement of Lyn and/or Fyn is uncertain. Further, the possibility that subcellular compartmentalization of signaling differs for desensitization and activation will be examined. Collaborations with Project 3 on studies of Lyn kinase involvement in desensitization, and with Project 4 on the involvement of sphingosine kinase-1 in desensitization of human mast cells and basophils facilitate these mechanistic studies. 3. Determine whether penicillin desensitization of human subjects in vivo produces antigen cross-desensitization of mast cells and basophils and depletes Syk from peripheral blood basophils. This clinical study will begin to translate our in vitro findings to the in vivo situation. Clinical tolerance due to desensitization can be distinguished from that due to immunotherapy by its rapid induction (hours) and short persistence (days) once allergen administration ceases. We hypothesize that desensitization targets primarily mast cells and basophils. Understanding more precisely the characteristics of and the mechanism(s) behind desensitization will enable physicians to better utilize this approach to reduce mast cell/basophil-mediated contributions to asthma and allergic diseases.