Cigarette Smoke and Susceptibility to Influenza Infection

描述（由申请人提供）：既往研究表明，吸烟者呼吸道病毒感染的发生率和严重程度高于非吸烟者，但目前尚不清楚介导这些反应的机制。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，脱落更多病毒，并且1型干扰素的表达减少。因此，这种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，鼻腔给药减毒活流感病毒（LAIV）提供了研究流感病毒感染的人体内安全的可能性。使用紧密相连的人在体外和体内的方法，这个建议的目的是测试的假设，慢性暴露于香烟烟雾改变上皮细胞的抗病毒和炎症反应，流感病毒感染通过两个潜在的相关机制：减少表达的第二阶段（抗氧化）酶和抑制1型干扰素（抗病毒）途径。我们进一步假设，通过营养补充SFN上调II相酶是一种潜在的治疗策略，以减轻这些影响。具体目标1将使用分化的人鼻上皮细胞的体外模型来确定修改吸烟者中流感诱导的抗病毒防御反应的机制，最初关注I型IFN抗病毒防御反应的作用和香烟烟雾诱导的基因沉默的潜在作用。具体目标2将使用我们现有的LAIV疫苗给药方案作为流感病毒感染模型，以确认介导吸烟者体内流感感染易感性增强的机制。将使用鼻活检组织和灌洗液中测量的终点，在吸烟者和非吸烟者中评估LAIV诱导的病毒复制和抗病毒防御应答。每个研究队列中的结果将根据特异性目的1中发现的先天免疫防御基因表达的变化进行分组。具体目标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的炎症之间的关系。我们将评估由于补充SFN而导致的HO-1上调如何改善与吸烟者相关的抗病毒途径和炎症/免疫应答变化中的关键异常，如特定目标1和2所述。从这些研究中获得的数据将深入了解吸烟者对流感病毒感染易感性增强的机制，并使用转化研究设计探索潜在的治疗干预措施。 公共卫生相关性：吸烟者对流感感染的易感性和严重性增加，但介导这种影响的机制在很大程度上是未知的。我们已经建立了人流感病毒感染的体外和体内实验模型，这些模型将用于确定介导吸烟者对流感病毒易感性增强的细胞和分子机制，并探索潜在的治疗干预措施。从这些研究中获得的知识可用于开发新的治疗策略，旨在减轻呼吸道病毒感染及其对长期暴露于烟草烟雾的个体的影响。

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.