Regulation of adaptive immunity by the NOD-like receptor NLRP10

描述(由申请人提供)：该提案中概述的研究旨在阐明调节树突状细胞诱导T细胞对肺内变应原敏感的基本途径。过去15年的工作已经确定，来自肺的成熟的肺树突状细胞(DC)调节哮喘患者2型CD4T细胞(Th2)对变应原的反应，模式识别受体(如Toll样受体(TLRs)的激活是DC成熟驱动致敏的主要决定因素。尽管TLR诱导的DC成熟的早期步骤和趋化因子引导的向引流淋巴结迁移的后期步骤已被很好地描述，但对DC从炎症组织中分离的中间步骤知之甚少。我们最近在DC中发现了一种新的先天免疫途径，该途径可以特异性地调节其从炎症组织中排出的能力，同时保持炎症和抗原递呈功能的完整性。NLRP10是模式识别受体中NOD样受体类的一员，在它缺失的情况下，DC不能将抗血清运输到淋巴结，因此CD4T细胞的启动受到严重损害。我们将通过以下两个具体目标来描述NLRP10是如何调节树突状细胞的运动，在哪种类型的DC中，以及在缺乏NLRP10的情况下，肺免疫的哪些方面受到损害。目的1)鉴定肺组织中NLRP10依赖和非依赖的树突状细胞亚群，并确定其活化CD4和CD8T细胞的能力。初步数据表明，NLRP10的缺失只影响DC的一部分(表达标记CD11b)，这些DC优先启动CD4而不是CD8T细胞。我们假设，肺内依赖NLRP10的DC的瘫痪将导致耐受，而不是在暴露于空气变应原后导致Th2启动，同时保持抗病毒CD8 T细胞的NLRP10依赖的DC启动不变。我们将在目标1中使用体内空气变应原致敏模型(Th2)和流感感染(CD8T细胞)来验证这一假设。NLRP10缺陷小鼠提供了唯一一种迁移性CD11b DC亚群功能受到特定影响的动物模型，从而首次确定了这些DC在肺免疫反应中的确切作用。目的2)确定DC向淋巴结转运失败是否是由于DC从肺细胞外基质分子上分离受损所致。为了明确调控DC从肺释放的分子相互作用，我们将开发带有重组基质分子的基质，以测试NLRP10缺陷的DC在体外的黏附和迁移；进一步，我们将在体内阻断DC附着到肺实质的主要决定因素，以克服NLRP10缺陷小鼠对空气变应原的Th2免疫失败。如果NLRP10的缺失选择性地取消了DC介导的CD4T细胞对空气变应原的启动，那么靶向这一途径可能允许我们控制过敏性疾病的敏化和耐受性之间的平衡，同时潜在地保持保护性CD8T细胞免疫不变。因此，在这些研究完成后，我们的长期目标是开发一种基于DC的方法，通过抑制NLRP10通路来治疗过敏性疾病。

DESCRIPTION (provided by applicant): The research outlined in the proposal aims to elucidate a fundamental pathway regulating dendritic cell induction of T cell sensitization to allergens in the lung. Work over the past 15 years has determined that mature pulmonary dendritic cells (DC) from the lung regulate type 2 CD4+ T cell (Th2) responses to allergens in asthma and that activation of pattern recognition receptors such as Toll-like receptors (TLRs) is a primary determinant of DC maturation driving sensitization. Although the early steps of TLR-induced DC maturation and the later steps of chemokine guided migration to draining lymph nodes are well characterized, relatively little is known about the intermediate step of DC detachment from inflamed tissues. We recently discovered a new innate immune pathway within the DC that specifically regulates its ability to egress from inflamed tissues while leaving the ret of the inflammatory and antigen presenting functions intact. NLRP10 is a member of the NOD-like receptor class of pattern recognition receptors and in its absence, DCs fail to traffic antige to lymph nodes and consequently CD4+ T cell priming is profoundly impaired. We will delineate how NLRP10 regulates dendritic cell movement, in exactly which type of DC and what aspects of lung immunity are impaired in the absence of NLRP10 through the following two specific aims. Aim 1) Identify NLRP10-dependent and - independent dendritic cell subsets in the lung and define their ability to activate CD4+ and CD8+ T cells. Preliminary data suggests that loss of NLRP10 only affects a subset of DCs (expressing the marker CD11b), which preferentially prime CD4+ but not CD8+ T cells. We hypothesize that paralysis of NLRP10-dependent DCs in the lung will result in tolerance rather than Th2 priming following aeroallergen exposure while leaving NLRP10-independndent DC priming of anti-viral CD8+ T cells intact. We will test this hypothesis in Aim 1 using in vivo aeroallergen sensitization models (Th2) and influenza infection (CD8+ T cell). NLRP10-deficient mice provide the only animal model in which the function of the migratory CD11b+ DC subset is specifically affected and therefore allows for the first time determination of the exact role of these DCs in pulmonary immune responses. Aim 2) Determine whether failed DC trafficking to lymph nodes is due to impaired DC detachment from lung extracellular matrix molecules. To define the molecular interactions regulating DC release from the lung we will develop matrices with recombinant matrix molecules to test NLRP10-deficient DC adhesion and migration in vitro; further we will block primary determinants of DC attachment to the lung parenchyma in vivo to overcome failed Th2 priming to aeroallergens in NLRP10-deficient mice. If loss of NLRP10 selectively abrogates DC-mediated CD4+ T cell priming to aeroallergens, then targeting this pathway might allow us to control the balance between sensitization and tolerance in allergic disease while potentially leaving protective CD8+ T cell immunity intact. Therefore our long-term goal following completion of these studies is to develop a DC-based approach to treat allergic disease through inhibition of NLRP10 pathways.