Diesel-Induced Alterations of Influenza Infectivity

描述（由申请人提供）：暴露于颗粒物（PM）会显著影响对感染性病原体的易感性。特别是在城市环境中，柴油废气（DE）排放有助于环境PM水平。尽管努力进行疫苗接种和抗病毒治疗，呼吸道病毒感染，如流感病毒感染，继续对公众健康构成重大威胁，特别是对幼儿和老年人。虽然在体外和体内研究了DE或流感病毒单独的影响，但急性或亚慢性DE暴露对随后流感感染易感性的影响在很大程度上是未知的。初步证据表明，暴露于DE会增加体外和小鼠体内上皮细胞中的流感病毒感染，并且这些影响不是由抑制干扰素依赖性抗病毒防御反应引起的。氧化应激介导了DE诱导的许多不良反应，添加谷胱甘肽能够逆转DE提取物（DEE）对体外流感感染的作用。因此，本项目将扩大我们在体外上皮细胞中进行的观察，并检查急性和亚慢性暴露于DE对体内小鼠流感感染的影响，并确定氧化应激在DE诱导的体内流感感染修饰中的作用。与我们的体外研究类似，本项目计划通过关注DE对收集物水平的影响和常驻巨噬细胞吞噬流感病毒的能力，来研究DE暴露后流感感染增加的潜在机制。体外实验表明，暴露于DEP可在感染后2小时内增强流感病毒的附着，从而增加流感感染。这里提出的实验将检查参与这种反应的潜在机制，重点是氧化修饰和集合的失活，以及增强的蛋白水解激活病毒进入细胞的能力。最近的数据表明，在树突状细胞中，流感诱导的炎症细胞因子的产生可能依赖于toll样受体（TLR） 3和TLR7。然而，目前尚不清楚TLR3、TLR7或两者是否参与呼吸道上皮细胞中流感诱导的应答，这将在本提案中确定。此外，我们的体外数据表明，暴露于DEP通过增加呼吸上皮细胞中TLR3的表达来增强TLR3依赖性信号。本文提出的实验将以这些数据为基础，研究DE暴露是否会增强TLR3或TLR7在体内和体外的水平和功能，并确定氧化应激在这些反应中的作用。从这些实验中获得的数据将为暴露于DE可增强流感感染易感性的分子机制提供重要见解。

DESCRIPTION (provided by applicant): Exposure to particulate matter (PM) can significantly affect the susceptibility to infectious agents. Especially in urban environments, diesel exhaust (DE) emissions contribute to ambient PM levels. Despite vaccination efforts and antiviral treatments, respiratory virus infections, such as influenza virus infections, continue to be a significant threat to public health, especially in young children and the elderly. While the effects of DE or influenza virus alone have been studied in vitro and in vivo, the effects of acute or subchronic DE exposures on the susceptibility to subsequent influenza infections are largely unknown. Preliminary evidence suggests that exposure to DE increases influenza virus infections in epithelial cells in vitro and in mice in vivo and that these effects are not caused by suppressed interferon-dependent antiviral defense responses. Oxidative stress mediates many of the adverse effects induced by DE and addition of GSH was able to reverse the effects of DE extract (DEE) on influenza infections in vitro. Therefore, this project will expand our observations made in epithelial cells in vitro and examine the effects of acute and subchronic exposure to DE on influenza infections in mice in vivo and determine the role of oxidative stress in DE-induced modifications of influenza infections in vivo. Similar to our in vitro studies, this project plans to examine potential mechanisms involved in the increased influenza infections following DE exposures by concentrating on the effects of DE on the levels of collectins and the ability of resident macrophages to phagocytize influenza virus. Experiments conducted in vitro indicate that exposure to DEP increases influenza infections by enhancing influenza virus attachment within 2 hours post-infection. The experiments proposed here will examine potential mechansims involved in this response, focusing on oxidative modification and inactivation of collectins, as well as the enhanced ability to proteolytically activate the virus to enter the cell. Recent data suggests that in dendritic cells influenza-induced inflammatory cytokine production may depend on both toll-like receptor (TLR) 3 and TLR7. However, it is not clear whether TLR3, TLR7, or both are involved in influenza-induced responses in respiratory epithelial cells, which will be determined in this proposal. In addition, our in vitro data indicate that exposure to DEP enhances TLR3-dependent signaling by increasing the expression of TLR3 in respiratory epithelial cells. The experiments proposed here will build on this data and examine whether DE exposure enhances TLR3 or TLR7 levels and function in vivo and in vitro and determine the role of oxidative stress in these responses. Data derived from these experiments will provide important insights into the molecular mechanisms by which exposure to DE could enhance the susceptibility to influenza infections.