Diesel-Induced Alterations of Influenza infectivity

描述（由申请方提供）：暴露于空气污染物（如柴油机废气（DE））与气道炎症、病毒感染易感性增加和基础呼吸系统疾病（包括过敏性哮喘）加重相关。根据我们实验室和其他人的研究，空气污染物引起这些不良影响的机制可能涉及与细胞氧化剂/抗氧化剂失衡相关的炎症和抗病毒信号通路的改变。自上一次资助以来，我们已经扩大了我们的实验模型，以研究1。预先存在的过敏性气道疾病如何改变DE增加对流感易感性的能力，2.）NK细胞和T细胞在流感诱导的应答中的作用，以及3.）使用减毒活流感病毒（LAIV）疫苗接种，研究环境污染物对人体体内流感病毒易感性的影响。因此，我们有能力测试以下假设：暴露于DE会增加人类过敏性炎症和对流感的易感性，氧化应激诱导的NK细胞功能抑制介导这些效应，补充SFN可以预防DE诱导的抗病毒免疫应答改变。目的1将确定DE暴露如何改变正常志愿者和过敏性鼻炎（AR）受试者对LAIV的炎症和抗病毒反应。这将是一项随机、前瞻性比较研究，比较随机接受DE（100-300（g/m3 x静息2小时））或安慰剂（清洁空气），随后接受标准剂量LAIV的正常或AR受试者队列。在导致的自限性感染期间，将定期采集鼻灌洗液和活检样本。终点将包括炎症介质、抗病毒因子、病毒清除和抗氧化剂基因型对暴露结果的影响。目的2将通过评估（a）LAIV感染前暴露于DE的受试者鼻NK和T细胞的活化、细胞毒性潜力和细胞因子产生的变化以及（B）体外模型中的变化，确定在流感感染的背景下暴露于DE如何改变NK和T细胞活化，以进一步确定DE诱导NK细胞活性变化的潜在机制。目的3将确定是否用萝卜硫素（SFN）补充抗氧化剂可以预防DE暴露对病毒诱导的炎症，抗病毒防御反应和免疫细胞能力的影响。这些研究有望增加我们对DE是否以及如何增强对流感病毒的易感性的理解，特别是在过敏性炎症的背景下，以及NK和T细胞在这些反应中的作用。我们进一步预计，这些研究将提供一个模型模板，用于评估其他环境因子对病毒感染背景下呼吸道粘膜防御的影响，并确定干预策略的有效性。 公共卫生相关性：该项目将利用一种新的、安全的、目前已批准的方案，在“现实生活”环境中对柴油废气和病毒暴露对过敏性鼻炎患者鼻腔炎症的综合影响进行受控评估。利用从志愿者身上获得的样本，该项目将研究暴露于空气污染物改变人类免疫反应的机制。它还将测试饮食抗氧化剂（富含萝卜硫素的西兰花芽）对柴油废气和病毒的鼻反应的影响。鉴于接触柴油机废气的频率很高，流感有大规模流行的趋势，过敏性气道疾病的发病率很高，该项目的潜在科学和公共卫生影响很大。

DESCRIPTION (provided by applicant): Exposure to air pollutants, such as diesel exhaust (DE), is associated with airway inflammation, increased susceptibility to viral infection, and exacerbation of underlying respiratory disorders including allergic asthma. Based on studies in our laboratory and others, the mechanisms by which air pollutants cause these adverse effects likely involve alteration of inflammatory and antiviral signaling pathways linked to cellular oxidant/antioxidant imbalance. Since the previous grant we have expanded our experimental models to investigate 1.) how pre-existing allergic airway disease modifies the ability of DE to increase susceptibility to influenza, 2.) the role of NK cells and T cells in influenza-induced responses, and 3.) the effects of environmental pollutants on susceptibility to influenza virus in humans in vivo using inoculation with the live-attenuated influenza virus (LAIV) vaccine. We are therefore well positioned to test the hypotheses that exposure to DE increases allergic inflammation and susceptibility to influenza in humans, that oxidative stress-induced suppression of NK cell function mediates these effects, and that supplementation with SFN can prevent DE-induced alterations of antiviral immune responses. Aim 1 will determine how DE exposure modifies inflammatory and antiviral responses to LAIV in normal volunteers and subjects with allergic rhinitis (AR). This will be a randomized, prospective comparison study comparing cohorts of normal or AR subjects randomized to receive either DE (100-300 (g/m3 x 2hr at rest) or placebo (clean air), followed by a standard dose of LAIV. Nasal lavage fluids and biopsies will be sampled at intervals during the resulting self-limited infection. Endpoints will include inflammatory mediators, antiviral factors, virus clearance, and effects of antioxidant genotype on exposure outcomes. Aim 2 will determine how exposure to DE modifies NK and T cell activation in the context of influenza infection by assessing changes in activation, cytotoxic potential, and cytokine production (a) in nasal NK and T cells from subjects exposed to DE prior to infection with LAIV and (b) in in vitro models to further define potential mechanisms of DE-induced changes in NK cell activity. Aim 3 will determine whether antioxidant supplementation with Sulforaphane (SFN) prevents the effects of DE exposure on virus-induced inflammation, antiviral defense response, and immune cell competence. These studies are expected to increase our understanding of whether and how DE enhances susceptibility to influenza virus, especially in the setting of allergic inflammation and the role of NK and T cells in these responses. We further anticipate that these studies will provide a model template useful for assessment of the impact of other environmental agents on respiratory mucosal defense in the context of viral infections, and for determination of the efficacy of intervention strategies. PUBLIC HEALTH RELEVANCE: This project will utilize a novel, safe, and currently approved protocol for controlled assessment of the combined effects of diesel exhaust and virus exposures on nasal inflammation in humans with allergic rhinitis in a "real-life" setting. Using samples obtained from volunteers this project will examine mechanisms by which exposure to air pollutants modify immune responses in humans. It will also test the impact of dietary antioxidants (sulforaphane-rich broccoli sprouts) on the nasal response to diesel exhaust and virus. Given the high frequency of exposures to diesel exhaust, the tendency of influenza to occur in large scale epidemics, and the high prevalence of allergic airway diseases, the potential scientific and public health impact of the project is large.