Project 2

总结 由于包括铜绿假单胞菌（Pa）在内的各种病原体引起的医院获得性感染 美国的巨大经济负担。有效的感染治疗剂的开发已经成为一个挑战。 由于对感染目标的了解有限而受到阻碍。研究了 肺泡巨噬细胞（AM）对抗Pa感染可能有助于发现新的治疗方法 接近。自噬是一种细胞成分被隔离的机制， 自噬体通过泛素化降解。我们最近发现Pa感染 可以诱导自噬，并随后增加细菌降解。Toll样受体 在将自噬与巨噬细胞吞噬作用联系起来中暗示了TLR。有趣的是，我们 初步数据表明，林恩，与TLR-2相互作用，在促进 吞噬作用和杀菌活性。此外，林恩在Pa期间也可能与Atg-7相互作用 感染最后，自噬抑制剂3-甲基腺嘌呤（3 MA）降低吞噬作用， 随后通过AM进行细菌清除。在此，我们假设自噬增强了 吞噬功能，增加细菌清除，并降低炎症反应。的 本提案的目的是研究Lyn-Atg 7中自噬的生理意义， 在基因敲除（KO）小鼠中调节吞噬作用，其炎症反应可能是 抑制，导致较少的组织损伤。我们的长期目标是确定 AM防御Pa入侵，以设计新的策略来治疗这种感染。的 基本原理是，这项研究的执行将把自噬定义为一种新的防御机制， 抗Pa感染，从而提出新的治疗靶点。凭借强大的科学基础， 数据和其他资源，我们有能力测试以下具体目标。 具体目标1：剖析自噬对Pa吞噬效率的影响。我们 假设自噬将通过影响吞噬功能来增加细菌清除。 将小鼠和原代AM细胞用于研究自噬在吞噬杯中的作用 形成和细菌清除。具体目标2：研究林恩在引发和 执行自噬途径。我们假设林恩通过传递TLR 2信号， PA诱导的自噬的关键调节因子。这种信号通路的激活预计将 在新鉴定的免疫中增加自噬体的形成和成熟 在宿主中对抗入侵Pa的机制。具体目标3：确定Atg-7在 减轻小鼠的炎症。我们假设自噬可以控制炎症反应， 过程，从而限制受感染小鼠的组织损伤。使用一种新的动物成像技术， 包括新的发光试剂，我们将区分早期炎症反应和晚期炎症反应。 一个

Summary Hospital-acquired infections due to various pathogens including P. aeruginosa (Pa) impose huge financial burdens in the USA. Development of effective therapeutics for infection has been hampered due to limited knowledge in infection targets. Studying the molecular mechanisms of alveolar macrophages (AM) in fighting Pa infection may help discover novel therapeutic approaches. Aautophagy is a mechanism by which cellular components are sequestered to autophagosomes for degradation through ubiquitination. We recently revealed that Pa infection can induce autophagy, and subsequently increasing bacterial degradation. Toll like receptors (TLRs) are implied in linking autophagy with macrophage phagocytosis. Interestingly, our preliminary data indicate that Lyn, interacting with TLR-2, plays a critical function in facilitating phagocytosis and bactericidal activity. Moreover, Lyn may also interact with Atg-7 during Pa infection. Finally, autophagy inhibitor 3-methyladenine (3MA) decreased phagocytosis and subsequent bacterial clearance by AM. Herein, we hypothesize that autophagy enhances phagocytic function, increases bacterial clearance, and lowers inflammatory responses. The objective of this proposal is to examine the physiological significance of autophagy in Lyn-Atg7- modulated phagocytosis in knockout (KO) mice, whose inflammatory responses may be suppressed leading to less tissue injury. Our long-term goal is to identify the mechanisms of AM defense against Pa invasion in order to design novel strategies to treat this infection. The rationale is that execution of this research will define autophagy as a novel defense mechanism against Pa infection, thus suggesting new therapeutic targets. With the strong basis of scientific data and other resources available, we are well positioned to test the following specific aims. Specific Aim 1: Dissect the effects of autophagy on Pa phagocytosis efficiency. We hypothesize that autophagy will increase bacterial clearance by influencing phagocytic function. Mice and primary AM cells will be used to study the role of autophagy in phagocytic cup formation and bacterial clearance. Specific Aim 2: Study the activity of Lyn in initiating and executing autophagic pathway. We hypothesize that Lyn, by transmitting TLR2 signals, is a key regulator in Pa-induced autophagy. Activation of this signaling pathway is expected to increase the formation and maturation of autophagosomes in a newly identified immunity mechanism to combat invading Pa in the host. Specific Aim 3: Identify the role of Atg-7 in alleviating inflammation in mice. We hypothesize that autophagy can control the inflammatory process, thereby limiting tissue damage of infected mice. Using a novel animal imaging that includes novel luminescent reagents, we will distinguish early inflammatory responses from late ones.