Diesel-Induced Alterations of Influenza Infectivity

描述（由申请方提供）：暴露于颗粒物（PM）可显著影响对传染性病原体的敏感性。特别是在城市环境中，柴油机废气（DE）排放有助于环境PM水平。尽管进行了疫苗接种和抗病毒治疗，但呼吸道病毒感染，如流感病毒感染，仍然是对公共卫生的重大威胁，特别是在幼儿和老年人中。虽然已经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暴露对后续流感感染易感性的影响在很大程度上尚不清楚。 初步证据表明，暴露于DE增加了体外上皮细胞和体内小鼠的流感病毒感染，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DE诱导的许多不良反应，并且添加GSH能够逆转DE提取物（DEE）对体外流感感染的影响。因此，本项目将扩大我们在体外上皮细胞中的观察，并检查急性和亚慢性暴露于DE对小鼠体内流感感染的影响，并确定氧化应激在DE诱导的体内流感感染修饰中的作用。与我们的体外研究相似，该项目计划通过集中研究DE对胶原凝集素水平和常驻巨噬细胞吞噬流感病毒的能力的影响，来检查DE暴露后流感感染增加的潜在机制。在体外进行的实验表明，暴露于DEP通过在感染后2小时内增强流感病毒附着来增加流感感染。这里提出的实验将研究参与这种反应的潜在机制，重点是胶原凝集素的氧化修饰和失活，以及增强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，流感诱导的炎性细胞因子的产生可能依赖于Toll样受体（TLR）3和TLR 7。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反应，这将在本提案中确定。此外，我们的体外数据表明暴露于DEP通过增加呼吸道上皮细胞中TLR3的表达来增强TLR3依赖性信号传导。 本文提出的实验将建立在这些数据的基础上，并研究DE暴露是否会增强体内和体外TLR3或TLR7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提供重要的见解的分子机制，暴露于DE可以提高流感感染的易感性。

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.