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

描述（由申请人提供）：哮喘和过敏性疾病是多因素的复杂疾病，涉及先天和适应性免疫系统以及环境因素。过敏性哮喘的特点是气道高反应性（AHR），炎性浸润含有嗜酸性白细胞、淋巴细胞和肥大细胞，粘液分泌增加，血清IgE水平升高。2型辅助性T淋巴细胞（Th2）在过敏性气道炎症中起关键作用。在识别同源抗原后，Th2细胞产生细胞因子，调节IgE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控制黏液产生和AHR。过敏原诱导的气道炎症可由NKT细胞触发，并可由调节性T （Treg）细胞拮抗。尽管我们对过敏发病机制的理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，仍有很多东西需要学习。为了攻克这些复杂的疾病，我们的研究方法需要是多方面的。在这个小组项目中，我们将研究Th2细胞如何在细胞和分子水平上调控过敏性炎症。为了实现这一共同目标，我们将在项目1中研究先天免疫（树突状细胞和NKT细胞）对环境因素，房屋灰尘提取物（HDEs）的反应。我们将研究Th2细胞是如何被蛋白激酶C调控的？在项目2中，不同的ige如何影响肥大细胞的活化，以及在项目4中，Treg细胞如何受到E3泛素连接酶Itch的调节。因此，我们将研究属于先天免疫系统和适应性免疫系统的细胞的发病作用。我们描述的有关过敏发病机制的分子多种多样，包括环境因素（HDEs），分泌分子（IgE）和细胞内信号分子（PKC9和Itch）。如上所述，这些细胞和分子因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起作用。这组中的每个组成部分都可以单独作为一个单独的研究项目来处理过敏性疾病的一个重要的、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，交流思想，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，细胞内和细胞内的各个层面一样。完成该项目后，我们将在所有这些层面上获得一套新颖、独特、综合的过敏性疾病见解。

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.