Burkholderia: Characterizing Lung Innate Immunity

描述（由申请人提供）：马氏伯克氏菌是一种高度进化的革兰氏阴性菌，主要感染固体，但可通过摄入、皮肤或气溶胶暴露传播给人类。人们对这种细菌以及与之密切相关的假芽孢杆菌的担忧日益加剧，因为这种病原体似乎具有完美的特性，可以作为针对动物和人类的生物恐怖或生物战武器。在现代，它们对公共卫生的潜在破坏性影响已经升级，因为病原体在糖尿病和免疫功能受损人群中的机会性感染，这两个人群在世界范围内不断增长。关于伯克霍尔德菌与常驻人肺细胞之间的相互作用，特别是支气管呼吸上皮细胞（bREC）和肺泡上皮细胞（AEC）与潜在的人肺微血管内皮细胞（HPMEC）之间的相互作用，几乎一无所知。呼吸上皮是宿主与外界环境之间的动态接口。bREC和AEC对于维持肺内平衡和提供抵抗吸入病原体的物理屏障至关重要。bREC和AEC提供的两种诱导防御机制包括产生抗菌因子和分泌细胞因子以募集和激活免疫细胞。因此，我们将使用我们的新型生物相关transwell过滤模型，该模型由生理定位的人原代bREC或AEC和HPMEC共同培养组成，以确定B. mallei和B. pseudomallei在这些宿主细胞中的入侵和复制。此外，我们将使用B. mallei或B. pseudomallei来刺激共培养，并收集共培养条件培养基来量化细胞因子。本提案的第二个目标是评估共培养物和/或其分泌的可溶性因子是否有能力影响免疫细胞对伯克霍尔德菌的反应。这将是首次研究人类原代肺细胞对伯克霍尔德菌的相互作用和反应。这些研究对于深入了解伯克氏菌的肺部发病机制至关重要，并将确定靶向疫苗开发的新途径。公共卫生相关性：马尔氏伯克霍尔德菌和假马尔氏伯克霍尔德菌可被用作对付公众的生物武器。因此，该应用程序提出了更好地了解这种有机体如何与肺细胞相互作用以及肺细胞对伯克霍尔德菌的反应。这项提议的资金将提供对有效和无效先天免疫反应的关键见解，以帮助找到未来的疫苗和治疗发展。

DESCRIPTION (provided by applicant): Burkholderia (B.) mallei is a highly evolved Gram-negative bacterium that primarily infects solipeds but it is transmissible to humans by ingestion, cutaneous or aerosol exposures. Concern over this bacterium and the very closely related species B. pseudomallei has heightened because of the pathogens' seemingly perfect characteristics for malevolent uses as bioterror or biowarfare weapons against both animals and humans. In modern times their potential destructive impact on public health has escalated due to the pathogens' opportunistic infection of diabetic and immuno-compromised people, two growing populations worldwide. Virtually nothing is known about the interaction between Burkholderia and resident human lung cells, specifically bronchial respiratory epithelial cells (bREC) and alveolar epithelial cells (AEC) in combination with the underlying human pulmonary microvascular endothelial cells (HPMEC). The respiratory epithelium is a dynamic interface between the outside environment and the host. bREC and AEC are vital for maintaining lung homeostasis and providing a physical barrier against inhaled pathogens. Two inducible defense mechanisms provided by bREC and AEC include the production of antimicrobial factors and secreting cytokines for the recruitment and activation of immune cells. Therefore, we will use our novel biological relevant transwell filter model consisting of physiologically positioned human primary bREC or AEC and HPMEC in co-culture to determine invasion of and replication in these host cells by B. mallei and B. pseudomallei. Further, we will use B. mallei or B. pseudomallei to stimulate co-cultures and collect the co-culture conditioned medium to quantify cytokines. The second goal of this proposal we will assess if the co-cultures and/or their secreted soluble factors have the ability to influence how immune cells response to Burkholderia. This would be the first study to examine the interaction and response of human primary lung cells to Burkholderia. These studies are essential for gaining insight into the lung pathogenesis of Burkholderia, and will identify novel avenues for targeted vaccine development. PUBLIC HEALTH RELEVANCE: Burkholderia mallei and Burholderia pseudomallei can be used as a bioweapon against the public. Therefore, this application proposes to better understand how this organism interacts with lung cells and response of the lung cells to Burkholderia. This funding of this proposal will provide crucial insight into the effective and ineffective innate immune responses to help find future vaccines and therapeutic development.