Diesel-Induced Alterations of Influenza infectivity

描述(申请人提供)：暴露在空气污染物中，如柴油废气(DE)，与呼吸道炎症、对病毒感染的易感性增加以及包括过敏性哮喘在内的潜在呼吸系统疾病的恶化有关。根据我们实验室和其他实验室的研究，空气污染物导致这些不利影响的机制可能涉及与细胞氧化/抗氧化失衡有关的炎症和抗病毒信号通路的改变。自从上一次拨款以来，我们已经扩展了我们的实验模型，以研究1。)(先前存在的过敏性呼吸道疾病如何改变DE增加流感易感性的能力，2.)NK细胞和T细胞在流感诱导反应中的作用；环境污染物对接种减毒活流感病毒(LAIV)疫苗的人体内对流感病毒易感性的影响。因此，我们能够很好地检验这些假设，即暴露于DE会增加人类的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影响，补充SFN可以防止DE诱导的抗病毒免疫反应的改变。目的1将确定DE暴露如何改变正常志愿者和变应性鼻炎(AR)受试者对LAIV的炎症和抗病毒反应。这将是一项随机的前瞻性比较研究，比较正常或AR受试者的队列，随机接受DE(100-300克/立方米×2小时静息)或安慰剂(清洁空气)，然后接受标准剂量的LAIV。在自限性感染期间，将每隔一段时间对鼻灌洗液和活检进行采样。终点将包括炎症介质、抗病毒因子、病毒清除以及抗氧化剂基因对暴露结果的影响。目的2通过评估在感染LAIV前暴露于DE的受试者鼻NK和T细胞的活化、细胞毒潜能和细胞因子产生的变化，来确定DE暴露如何在流感感染的背景下改变NK和T细胞的激活，以及(B)在体外模型中进一步确定DE诱导NK细胞活性变化的潜在机制。目的3将确定补充抗氧化剂萝卜硫素(SFN)是否能阻止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。我们进一步预期，这些研究将提供一个模型模板，用于在病毒感染的情况下评估其他环境因素对呼吸道粘膜防御的影响，并确定干预策略的有效性。

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.