Cigarette Smoke and Susceptibility to Influenza Infection

描述（由申请人提供）：先前的研究表明，吸烟者的呼吸道病毒感染的发生率和严重程度高于非吸烟者，但介导这些反应的机制目前尚不清楚。我们的初步数据表明，吸烟者培养的鼻上皮细胞更容易受到流感病毒感染，脱落更多的病毒，并且1型干扰素的表达减少。因此，该体外模型为研究吸烟者对流感病毒易感性增强的细胞和分子基础提供了重要工具。此外，我们的初步数据表明，鼻腔给药减毒流感病毒（LAIV）提供了在体内安全地研究人类流感病毒感染的可能性。采用紧密相关的人体体外和体内实验方法，本研究旨在验证慢性暴露于香烟烟雾通过两种潜在的相关机制改变上皮细胞对流感病毒感染的抗病毒和炎症反应的假设：II期（抗氧化）酶的表达降低和1型干扰素（抗病毒）途径的抑制。我们进一步假设，通过营养补充SFN上调II期酶是一种潜在的治疗策略，可以减轻这些影响。特异性目的1将使用分化的人鼻上皮细胞体外模型来确定改变吸烟者流感诱导的抗病毒防御反应的机制，最初侧重于I型IFN抗病毒防御反应的作用以及香烟诱导的基因沉默的潜在作用。特异性目标2将使用我们现有的LAIV疫苗管理方案作为流感病毒感染模型，以确认吸烟者体内对流感感染易感性增强的介导机制。laiv诱导的病毒复制和抗病毒防御反应将在吸烟者和非吸烟者中进行评估，使用鼻腔活检组织和灌洗液测量终点。每个研究队列的结果将根据特异性目标1中发现的先天免疫防御基因表达的变化进行分组。特异性目的3将使用体外和体内模型来确定吸烟者和非吸烟者中抗氧化基因表达、抗病毒途径和病毒诱导炎症之间的关系。我们将评估补充SFN导致的HO-1上调如何改善与吸烟者相关的抗病毒途径和炎症/免疫反应变化的关键异常，如在Specific Aims 1和2中所确定的。从这些研究中获得的数据将有助于深入了解增强吸烟者对流感病毒感染易感性的机制，并利用转化研究设计探索潜在的治疗干预措施。

DESCRIPTION (provided by applicant): Previous studies have demonstrated that the incidence and severity of respiratory virus infections is greater in smokers than in non-smokers, but the mechanisms mediating these responses are currently not well understood. Our preliminary data demonstrate that cultured nasal epithelial cells from smokers are more susceptible to influenza virus infections, shed more virus, and have decreased expression of type 1 interferons. This in vitro model thus provides an important tool to investigate the cellular and molecular basis for enhanced susceptibility to influenza virus seen in smokers. In addition, our preliminary data demonstrate that nasal administration of live attenuated influenza virus (LAIV) offers the possibility of studying influenza virus infections safely in humans in vivo. Using tightly linked human in vitro and in vivo approaches, this proposal is designed to test the hypothesis that chronic exposure to cigarette smoke alters epithelial antiviral and inflammatory responses to influenza virus infection via two potentially related mechanisms: decreased expression of phase II (antioxidant) enzymes and suppression of type 1 interferon (antiviral) pathways. We further hypothesize that upregulation of phase II enzymes via nutritional supplementation with SFN is a potential therapeutic strategy to mitigate these effects. Specific Aim 1 will use an in vitro model of differentiated human nasal epithelial cells to determine mechanisms that modify influenza-induced antiviral defense responses in smokers, initially focusing on the role of type I IFN antiviral defense responses and the potential role of cigarette smoke-induced gene silencing. Specific Aim 2 will use our existing protocol of administration of LAIV vaccine as a model for influenza virus infections to confirm mechanisms that mediate enhanced susceptibility to influenza infections in smokers in vivo. LAIV-induced viral replication and antiviral defense responses will be assessed in smokers and non-smokers using endpoints measured in nasal biopsy tissue and lavage fluids. Outcomes within each study cohort will be grouped based on changes in innate immune defense gene expression found in Specific Aim 1. Specific Aim 3 will use both the in vitro and in vivo models to determine the relationships between antioxidant gene expression, antiviral pathways, and virus-induced inflammation in smokers and non-smokers. We will assess how upregulation of HO-1 as a result of supplementation with SFN can improve key abnormalities in antiviral pathways and inflammatory/immune response changes associated with smokers, as identified in Specific Aims 1 and 2. Data derived from these studies will yield insights into the mechanisms that enhance the susceptibility to influenza virus infections in smokers and explore potential therapeutic interventions using a translational research design. PUBLIC HEALTH RELEVANCE: Susceptibility to and severity of influenza infections is enhanced in smokers, but the mechanisms mediating this effect are largely unknown. We have established human in vitro and in vivo experimental models of influenza infections, which will be applied to determine cellular and molecular mechanisms mediating enhanced susceptibility to influenza virus in smokers and to explore potential therapeutic interventions. Knowledge obtained from these studies can be exploited to develop new therapeutic strategies aimed at mitigating respiratory virus infections and their effects in individuals chronically exposed to tobacco smoke.