Cigarette Smoke and Susceptibility to Influenza Infection

描述(申请人提供)：以前的研究表明，吸烟者的呼吸道病毒感染的发生率和严重性比不吸烟者更高，但目前对这些反应的调节机制尚不清楚。我们的初步数据表明，吸烟者培养的鼻黏膜上皮细胞更容易受到流感病毒的感染，分泌更多的病毒，并减少1型干扰素的表达。因此，这一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，经鼻给药的减毒活流感病毒(LAIV)提供了在活体内安全研究流感病毒感染的可能性。利用紧密相连的人类体外和体内方法，这一建议旨在测试这一假说，即长期暴露在香烟烟雾中通过两个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：II相(抗氧化剂)酶表达减少和抑制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相酶是缓解这些影响的潜在治疗策略。特定目标1将使用体外分化的人鼻上皮细胞模型来确定改变流感诱导的吸烟者抗病毒防御反应的机制，最初重点是I型干扰素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。特定目标2将使用我们现有的LAIV疫苗给药方案作为流感病毒感染的模型，以确认体内介导吸烟者对流感感染易感性增加的机制。在吸烟者和非吸烟者中，将使用鼻活检组织和灌洗液中测量的终点来评估LAIV诱导的病毒复制和抗病毒防御反应。每个研究队列中的结果将根据在特定目标1中发现的先天免疫防御基因表达的变化进行分组。特定目标3将使用体外和体内模型来确定吸烟者和非吸烟者的抗氧化基因表达、抗病毒途径和病毒引起的炎症之间的关系。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/免疫反应变化中的关键异常，如特定目标1和2所确定的。从这些研究获得的数据将深入了解吸烟者对流感病毒感染的易感性的机制，并利用转译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，但调节这种影响的机制在很大程度上尚不清楚。我们已经建立了人体体外和体内流感感染的实验模型，将用于确定介导吸烟者对流感病毒易感性增加的细胞和分子机制，并探索潜在的治疗干预措施。从这些研究中获得的知识可被用来开发新的治疗策略，旨在减轻长期接触烟草烟雾的个人的呼吸道病毒感染及其影响。

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.