The Role of Innate IL-17 Responses to Aspergillus fumigatus

先天 IL-17 对烟曲霉反应的作用

• 批准号: 8986087
• 负责人: Evelyn Vieira Santos
• 金额: $ 1.36万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-12-08 至 2016-04-24
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8986087
• 关键词: Acute; Adverse effects; Affect; Allergic Bronchopulmonary Aspergillosis; Amphotericin B; Antibodies; Antifungal Agents; Aspergillosis; Aspergillus fumigatus; Asthma; Autocrine Communication; Bacterial Infections; Bone Marrow; CCR; Cells; Chimera organism; Clinical; Cystic Fibrosis; Defect; Dendritic Cells; Development; Diagnosis; Disease; Enzyme-Linked Immunosorbent Assay; Family; Flow Cytometry; Goals; Granulopoiesis; Hepatotoxicity; Host Defense; Hour; Hyphae; Immune response; Immune system; Immunocompetent; Immunocompromised Host; Immunosuppressive Agents; Immunotherapy; In Vitro; Individual; Infection; Interleukin-12; Interleukin-17; Invaded; Knock-out; Knowledge; Lung; Lymphocyte; Measures; Methods; Modeling; Molecular; Monitor; Mus; Mycoses; Natural Immunity; Neutrophil Infiltration; Opportunistic Infections; Organism; Patients; Pattern; Persons; Play; Population; Production; Recruitment Activity; Reporting; Reproduction spores; Respiratory Mucosa; Respiratory physiology; Rest; Risk; Risk Factors; Role; Signal Transduction; Site; Source; Staining method; Stains; Structure; Survival Rate; T-Lymphocyte; Testing; Time; Toxic effect; Transplant Recipients; Transplantation; Triazoles; Vaccine Design; Vaccines; Wild Type Mouse; adaptive immunity; autocrine; cell type; combat; cytokine; diphtheria toxin receptor; eosinophil; fungus; immunosuppressed; in vivo; interleukin-23; killings; macrophage; member; monocyte; mortality; nephrotoxicity; neutrophil; pathogen; prevent; public health relevance; receptor; research study; respiratory; response; sialic acid binding Ig-like lectin

 DESCRIPTION (provided by applicant): The respiratory mucosa employs the innate and adaptive immune system to protect normal respiratory function from invading organisms. However, when there is a defect in one of these defenses the host becomes vulnerable to Aspergillus fumigatus (Af). This ubiquitous fungus enters the airways as a spore, or resting conidium but is generally cleared by intact respiratory defenses. However, when individuals are immunocompromised, Af conidia are more likely to germinate and form filamentous structures called hyphae. As this morphotype, Af can become invasive particularly in persons with low neutrophil counts. An estimated 200,000 people are diagnosed with invasive aspergillosis annually worldwide, and up to 90% die from the infection. Af can also colonize the airways of those who suffer from asthma or cystic fibrosis causing allergic bronchopulmonary aspergillosis (ABPA), which affects over 4 million people annually worldwide. Studies proposed here seek to further understand the intact innate immune response to Af conidia, particularly the involvement of interleukin-23 (IL-23) and interleukin-17 (IL-17). A better understanding of this response may uncover nuances associated with the host defects that predispose to infection with Af, as well as potentially inform rational vaccine design and immunotherapies against Af. Af conidia elicit IL-23 and IL-17 production from the host airways within the first 24 hours of infection. These cytokines are known to be important for the adaptive TH17 response. However their role in innate immunity against Af is largely unknown. IL-23 has been shown to augment IL-17 production, and in turn IL-17 elicits neutrophil recruitment. The relationship between IL-23 and IL-17 is referred to as the IL-23/IL-17 axis and this proposal aims to systematically characterize each portion of this axis in the innate response against Af conidia, and test whether this response is required for protection against this mycosis. In order to characterize the temporal production pattern of IL-23, we will measure levels of this cytokine at regular intervals in the fist 72 hours of infection by ELISA. From a preliminary screen, we have uncovered candidate cell types that may be involved in the production of IL-23. We aim to confirm these sources by in vivo and ex vivo intracellular cytokine staining. To test whether IL-23 production is protective against mortality in Af infection, the survival rates of wild-type (WT) mice will be compared to a functional IL-23 knock-out strain (IL-23p19-/-). Finally, we propose to create mixed bone marrow chimeras to test whether any specific cellular source of IL-23 is required for protection against Af (Specific Aim 1). The temporal pattern of production for IL-17 and its source will also be characterized in the first 72 hours of infection with Af using methods described above. To test whether IL-23 augments IL-17 production innately in response to Af, IL-17 levels will be assessed in IL-23p19-/- mice and WT mice. In addition, we have evidence that IL-23 and IL-17A are co-produced by one innate cell type in response Af, we propose to test and dissect any potential autocrine mechanisms in this cell type. Finally, the role of IL-17 in protection against f infection will also be tested by monitoring the survival of IL-17RA-/- mice and WT mice (Specific Aim 2). Because many at risk for IA are transplant patients who are iatrogenically immunosuppressed, knowledge of the factors leading to protection against aspergillosis could also inform development of targeted immunosuppressive agents that keep defenses against opportunistic infections intact.

 描述(由申请人提供)：呼吸道粘膜利用先天和适应性免疫系统来保护正常的呼吸功能不受入侵生物的侵袭。然而，当这些防御系统中的一个存在缺陷时，宿主就会对烟曲霉(Af)变得脆弱。这种无处不在的真菌以孢子或休眠分生孢子的形式进入呼吸道，但通常会被完整的呼吸防御系统清除。然而，当个体免疫受损时，Af分生孢子更有可能萌发并形成丝状结构，称为菌丝。由于这种形态，房颤可以成为侵袭性的，特别是在中性粒细胞计数较低的人。据估计，全世界每年有20万人被诊断为侵袭性曲霉病，高达90%的人死于这种感染。房颤还可以侵占那些患有哮喘或囊性纤维化的人的呼吸道，这些人会导致过敏性支气管肺曲霉菌病(ABPA)，这种疾病每年影响全球400多万人。本研究旨在进一步了解Af分生孢子的完整先天免疫反应，特别是IL-23和IL-17的参与。更好地了解这种反应可能会揭示与易感染Af的宿主缺陷相关的细微差别，并可能为合理的疫苗设计和针对Af的免疫治疗提供信息。AF分生孢子可在感染后24小时内诱导宿主呼吸道产生IL-23和IL-17。已知这些细胞因子对适应性TH17反应很重要。然而，它们在对Af的先天免疫中的作用在很大程度上是未知的。已有研究表明，IL-23可促进IL-17的产生，进而引起中性粒细胞募集。IL-23和IL-17之间的关系被称为IL-23/IL-17轴，本提案旨在系统地描述该轴对Af分生孢子的先天反应中的每一部分，并测试这种反应是否是预防这种真菌病所必需的。为了刻画IL-23的时间产生模式，我们将用ELISA法定期检测感染后72小时内这一细胞因子的水平。从初步筛选中，我们已经发现了可能参与IL-23产生的候选细胞类型。我们的目标是通过体内和体外细胞内细胞因子染色来确认这些来源。为了测试IL-23的产生是否对Af感染的死亡率具有保护作用，将野生型(WT)小鼠的存活率与具有功能的IL-23基因敲除株(IL-23p19-/-)进行比较。最后，我们建议创建混合骨髓嵌合体，以测试是否需要任何特定的IL-23细胞来源来保护Af(特定目标1)。IL-17的产生及其来源的时间模式也将在感染Af的前72小时内使用上述方法进行表征。为了测试IL-23是否在Af反应中先天增加IL-17的产生，将在IL-23p19-/-小鼠和WT小鼠中评估IL-17的水平。此外，我们有证据表明，IL-23和IL-17A是由一种天然细胞类型共同产生的，我们建议测试和剖析这种细胞类型的任何潜在的自分泌机制。最后，还将通过监测IL-17RA-/-小鼠和WT小鼠的存活情况(特定目标2)来测试IL-17在预防f感染中的作用。由于许多面临IA风险的移植患者是医源性免疫抑制的移植患者，因此了解导致预防曲霉病的因素也可以帮助开发靶向免疫抑制药，使其保持对机会性感染的防御完好无损。