Novel IL-1 Family Members in Lung Innate Immunity

肺先天免疫中的新 IL-1 家族成员

• 批准号: 8885102
• 负责人: Theodore J. Standiford
• 金额: $ 60.69万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-04-01 至 2019-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8885102
• 关键词: Adoptive Transfer; Adult Respiratory Distress Syndrome; Alveolar Macrophages; Bacterial Pneumonia; Biological; Bone Marrow; Cell membrane; Cells; Cessation of life; Clinical; Communities; Cytokine Activation; Data; Dendritic Cells; Elderly; Epidemiology; Epithelial Cells; Family; Family member; Foundations; Generations; Genetic; Golgi Apparatus; Human; Immune; Immune response; Immunity; Impairment; In Vitro; Incidence; Infection; Inflammatory; Interleukin-1; Interleukin-17; Leukocytes; Lung; Lung Inflammation; Macrophage Activation; Mediating; Morbidity - disease rate; Mucosal Immunity; Mus; Mutant Strains Mice; Natural Immunity; Outcome; Pathway interactions; Patients; Peptide Signal Sequences; Phenotype; Pneumococcal Infections; Pneumococcal Pneumonia; Pneumonia; Populations at Risk; Protein Isoforms; Role; Source; Streptococcus pneumoniae; Surface; System; United States; Virulence Factors; antimicrobial peptide; chemokine; cytokine; in vivo; insight; macrophage; member; mortality; neutralizing antibody; novel; pathogen; public health relevance; receptor; reconstitution; research study; response; restoration

 DESCRIPTION (provided by applicant): Lung infection due to Streptococcus pneumoniae (Sp) is the leading cause of community acquired pneumonia and a major cause of both morbidity and mortality in the United States and worldwide. The incidence of pneumococcal pneumonia is increasing, due, in part, to the advancing age of the at-risk population. The changing epidemiology of pneumococcal pneumonia highlights the importance of more fully understanding innate immune responses to Sp and other bacterial pathogens of the lung. The IL-36 family is a group of novel IL-1-like pro-inflammatory cytokines that are highly expressed in mucosal surfaces by both epithelial cells and bone-marrow derived immune cells. Two members of the IL-36 family, IL-36α and IL-36γ, have recently been shown to induce lung inflammation and the expression of inflammatory cytokines and chemokines in vivo. However, nothing is known regarding their role in innate immunity, particularly protective lung mucosal immunity. In preliminary studies, we have found that one member of the IL-36 family, IL-36γ, is produced by lung macrophages in response to Sp infection. The mechanism(s) by which IL-36 family members are secreted is not well understood. Like IL-1β, IL-36 family members lack a secretory signal sequence, and our preliminary studies suggest that IL-36γ may be released in plasma membrane containing microparticles and/or exosomes rather than by classical golgi-dependent secretion. Importantly, IL-36γ potently skews dendritic cells (DC) to produce type 1 and IL-17 cytokines. Moreover, we have found that IL-36γ blockade/deletion results in marked impairment in lung bacterial clearance, which is associated with reduced generation of type 1 and IL-17 cytokines and chemokines. These exciting preliminary studies provide the foundation for our hypothesis that IL-36 family members are important components of effective type 1- and IL-17-mediated immunity against Gram-positive bacterial pathogens of the lung. Moreover, IL-36γ is secreted in microparticles and/or exosome that may maximize distribution and/or biological activity. To further understand the contribution of IL-36 family members to the innate immune responses to infection, we propose the following specific aims: Specific Aim 1: Determine the cellular sources and mechanisms of secretion of IL-36γ in the lung in response to pneumococcal infection. Experiments in this aim will define the cellular sources of IL-36 family members in the lung during murine S. pneumoniae infection, and determine mechanisms of secretion of IL-36 family members in mouse and human lung macrophages. In particular, we will determine whether: IL-36γ secretion by lung macrophages in response to Sp occurs in a non-golgi dependent fashion; requires Sp virulence factors; is released in microparticles and/or exosomes; and will identify truncated IL-36γ isoforms and other relevant cytokines in IL-36γ containing microparticles and/or exosomes. Specific Aim 2: Determine the effect of IL-36 family members on host innate lung antipneumococcal responses in-vivo and in-vitro. Experiments in this aim will seek to define the in vivo phenotype associated with IL-36γ or IL-36 receptor blockade (using neutralizing antibody and genetic deletion). Specific endpoints include: lung bacterial clearance, dissemination and survival; leukocyte recruitment; dendritic cell and lung macrophage activation; and type 1 and IL-17 cytokines, chemokine, and antimicrobial peptide expression. Effects of IL-36γ-mediated DC effector responses will be evaluated in-vitro. Specific Aim 3: Determine the effect of IL-36γ biological activity or IL-36γ responsiveness inmutant mice using i.t. reconstitution or DC adoptive transfer strategies. In this aim, we will employ proof-of-concept approaches to reconstitute IL-36γ biological activity or responsiveness by using direct i.t. administration of IL-36γ-containing microparticles, DC-derived type 1 or IL-17 cytokines, or adoptive transfer of wild-type DC or DC genetically deficient in selected cytokines. End points include bacterial clearance, cellular recruitment/activation, and cytokine/chemokine responses. The complementary strategies proposed in this application will identify a novel IL-36γ-mediated pathway of protective innate type 1 and IL-17 responses in pneumococcal pneumonia.

 描述(申请人提供)：由肺炎链球菌(Sp)引起的肺部感染是社区获得性肺炎的主要原因，也是美国和世界范围内发病率和死亡率的主要原因。肺炎球菌肺炎的发病率正在增加，部分原因是高危人群的高龄。肺炎球菌肺炎的不断变化的流行病学突显了更充分地了解对肺炎链球菌和其他肺部细菌病原体的先天免疫反应的重要性。IL-36家族是一组新型的IL-1类促炎细胞因子，在黏膜上皮细胞和骨髓源性免疫细胞中均有高表达。IL-36家族的两个成员，IL-36α和IL-36γ，最近被证明在体内诱导肺部炎症和炎性细胞因子和趋化因子的表达。然而，关于它们在先天免疫中的作用，特别是保护性肺粘膜免疫，人们知之甚少。在初步研究中，我们发现IL-36家族中的一个成员IL-36γ是由肺巨噬细胞对Sp感染作出反应而产生的。IL-36家族成员分泌IL-36的机制(S)尚不清楚。与IL-1β类似，IL-36家族成员缺乏分泌信号序列，我们的初步研究表明，IL-36γ可能通过含有微粒和/或外切体的质膜释放，而不是经典的高尔基体依赖的分泌。重要的是，IL-36γ能有效地扭曲树突状细胞(DC)，产生1型和IL-17细胞因子。此外，我们还发现，IL-36γ的阻断/缺失导致肺部细菌清除的显著障碍，这与1型和IL-17细胞因子和趋化因子的产生减少有关。这些令人兴奋的初步研究为我们的假设奠定了基础，即IL-36家族成员是有效的1型和IL-17介导的免疫系统的重要组成部分，以对抗革兰氏阳性细菌的肺部病原体。此外，IL-36γ分泌在微粒和/或外体中，可以最大化分布和/或生物活性。为了进一步了解IL-36家族成员对感染的先天免疫应答的作用，我们提出了以下具体目标：特异性目标1：确定肺炎球菌感染时肺组织中IL-36γ的细胞来源和分泌机制。本实验旨在明确小鼠肺炎链球菌感染时肺组织中IL-36家族成员的细胞来源，并确定IL-36家族成员在小鼠和人肺巨噬细胞中的分泌机制。特别是，我们将确定：肺巨噬细胞对Sp的反应是否以非高尔基体依赖的方式分泌IL-36γ；是否需要Sp毒力因子；是否以微粒和/或外切体形式释放；以及是否在含有微粒和/或外切体的IL-36γ中鉴定截短的IL-36γ异构体和其他相关细胞因子。特异性目的2：确定IL-36家族成员在体内和体外对宿主先天肺抗肺炎球菌应答的影响。这一目标的实验将寻求确定与IL-36γ或IL-36受体阻断相关的体内表型(使用中和抗体和基因缺失)。特定的终点包括：肺细菌的清除、扩散和存活；白细胞的招募；树突状细胞和肺巨噬细胞的激活；以及1型和IL-17细胞因子、趋化因子和抗菌肽的表达。IL-36γ介导的DC效应效应将在体外进行评估。具体目标3：用I.T.确定IL-36γ生物学活性或IL-36γ反应性对突变小鼠的影响。重构或DC采用迁移策略。在这个目标中，我们将使用概念验证方法通过使用直接I.T.来重建IL-36γ的生物学活性或反应性。给予含有IL-36γ的微粒、DC衍生的1型或IL-17细胞因子，或过继转移所选细胞因子基因缺陷的野生型DC或DC。终点包括细菌清除、细胞募集/激活和细胞因子/趋化因子反应。本申请中提出的补充策略将确定一种新的IL-36γ介导的肺炎球菌肺炎先天1型保护性反应和IL-17反应的途径。