Genetically engineered macrophages to treat pulmonary infections

项目摘要 细菌性肺炎是世界范围内发病率和死亡率的主要原因。增加抗菌剂 细菌性肺炎常见病原体的耐药性需要开发新的治疗药物， 战略布局在这个项目中，我们专注于两种对公共卫生构成威胁的耐药病原体。Burkholderia 类鼻疽（BP）是东南亚肺炎（肺炎类鼻疽病）的常见病因， 澳大利亚北方。尽管治疗，但在22-50%的病例中，类鼻疽是致命的。BP是一种兼性的 对许多抗生素具有内在抗性并需要延长疗程的细胞内病原体。 肺炎克雷伯氏菌（KP）是一种细胞外病原体，其是众所周知的引起群体性肺炎的原因， 医疗相关性肺炎KP对碳青霉烯类和第三代抗生素的耐药性越来越强 头孢菌素。由KP的耐药菌株引起的感染难以治疗，延长住院时间， 与高死亡率有关。BP和KP代表了开发新疗法的迫切需要， 治疗抗药性肺部感染。该项目汇集了来自不同学科的三名调查人员， 这个挑战。West博士和Skerrett博士是肺宿主防御细菌的研究人员。 肺部感染他们已经建立了细菌呼吸道感染的小鼠模型，包括BP（和替代物）。 有机体，B. thailandensis）感染和KP.这些细菌性呼吸道感染模型已被用于 研究宿主和细菌因素并评估治疗方法。起重机医生一种癌症免疫疗法 研究人员开发了一种新颖灵活的系统来创建基因工程巨噬细胞（GEM） 在体外或体内一个月内产生一系列分泌蛋白。对小鼠静脉给药， GEM在肺部以高水平积累至少4天。其他人已经报道， 巨噬细胞导致这些细胞在肺内持久定位数月。因此，静脉内或 GEM的肺部递送可能是一种新颖的、多用途的抗肺部感染的治疗策略。中央 该建议假设是，产生促炎和/或抗微生物肽的GEM 感染部位的宿主可以增强宿主对病原体引起的呼吸道感染的抵抗力， BP和KP。这个假设将被测试如下：目标1。使用增强的 产生细胞因子白细胞介素12（IL-12）或抗微生物肽CRAMP（ 人组织蛋白酶抑制素的小鼠同系物）。目标2.定义局部和炎症反应诱导的 表达IL-12或CRAMP的GEM在体内过继转移。目标3.确定收养人是否 表达IL-12或CRAMP的GEM的转移增强了对急性细菌性肺炎的抵抗力， B。thailandensis或K.肺炎。这个创新的项目测试了两种新的和潜在的协同疗法 有抵抗力但又不同的病原体引起的肺炎此外，高度适应性和可调的GEM 该平台可能与各种其他肺部感染和肺部疾病非常相关。

PROJECT SUMMARY Bacterial pneumonia is a leading cause of morbidity and mortality worldwide. Increasing antimicrobial resistance among common agents of bacterial pneumonia necessitates the development of new therapeutic strategies. In this project, we focus on two resistant pathogens that are public health threats. Burkholderia pseudomallei (BP) is a common etiology of pneumonia (pneumonic melioidosis) in Southeast Asia and northern Australia. Pneumonic melioidosis is lethal in 22-50% of cases despite treatment. BP is a facultative intracellular pathogen that is inherently resistant to many antibiotics and requires prolonged courses of therapy. Klebsiella pneumoniae (KP) is an extracellular pathogen that is a well known cause of community- and healthcare-associated pneumonia. KP has become increasingly resistant to carbapenems and third generation cephalosporins. Infections caused by resistant strains of KP are difficult to treat, prolong hospital stays, and are associated with high mortality. BP and KP are representative of the urgent need to develop new therapies to treat resistant lung infections. This project brings together three investigators from distinct disciplines to tackle this challenge. Drs. West and Skerrett are established researchers in pulmonary host defense against bacterial lung infections. They have created murine models of bacterial respiratory infection including BP (and surrogate organism, B. thailandensis) infection and KP. These bacterial respiratory infection models have been used to investigate host and bacterial factors and to evaluate therapeutics. Dr. Crane, a cancer immunotherapy researcher, has developed a novel and flexible system to create genetically engineered macrophages (GEMs) to produce a range of secreted proteins over a month in vitro or in vivo. Administered intravenously to mice, GEMs accumulate at high levels in the lungs for at least 4 days. Others have reported that airway delivery of macrophages results in durable localization of these cells within the lungs for months. Thus, intravenous or pulmonary delivery of GEMs may be a novel, versatile therapeutic strategy against lung infections. The central hypothesis of this proposal is that GEMs that produce pro-inflammatory and/or antimicrobial peptides and home to the site of infection can augment host resistance to respiratory infections caused by pathogens such as BP and KP. This hypothesis will be tested as follows: Aim 1. Develop and test GEMs with enhanced bacterial killing functions that produce the cytokine interleukin 12 (IL-12) or antimicrobial peptide CRAMP (the mouse homolog of human cathelicidin). Aim 2. Define localization and the inflammatory responses induced by IL-12- or CRAMP-expressing GEMs adoptively transferred in vivo. Aim 3. Determine whether the adoptive transfer of IL-12- or CRAMP-expressing GEMs augments resistance to acute bacterial pneumonia caused by B. thailandensis or K. pneumoniae. This innovative project tests two novel and potentially synergistic therapies for resistant yet distinct pathogens causing pneumonia. Moreover, the highly adaptable and tunable GEM platform is potentially very relevant to a wide variety of other lung infections and lung diseases.