Burkholderia: Characterizing Lung Innate Immunity

描述(申请人提供)：Burkholderia(B.)马利氏杆菌是一种高度进化的革兰氏阴性细菌，主要感染单足动物，但它可通过摄入、皮肤或气雾剂接触传播给人类。人们对这种细菌和非常接近的假鼻疽菌种的担忧加剧，因为这些病原体似乎完美的特征，可以恶意用作针对动物和人类的生物恐怖或生物武器。在现代，由于病原体对糖尿病和免疫受损人群的机会性感染，它们对公共卫生的潜在破坏性影响已经升级，这两个群体在全球范围内不断增长。关于伯克霍尔德氏菌与常驻人肺细胞，特别是支气管呼吸道上皮细胞(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。呼吸道上皮是外界环境与宿主之间的动态界面。BREC和AEC对于维持肺内环境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招募和激活免疫细胞。因此，我们将使用我们的新型生物相关Transwell过滤器模型，该模型由生理定位的人原代Brec或AEC与HPMEC共培养组成，以确定B.Mallei和B.Pomallei对这些宿主细胞的入侵和复制。此外，我们将使用马来杆菌或假鼻疽杆菌来刺激共培养，并收集共培养条件培养液来定量细胞因子。这项建议的第二个目标，我们将评估共培养物和/或它们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氏菌的反应。这将是第一次研究人类原代肺细胞对伯克霍尔德氏菌的相互作用和反应。这些研究对于深入了解伯克霍尔德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。与公共卫生相关：马来伯克霍尔德氏菌和假鼻疽伯霍尔德氏菌可用作对抗公众的生物武器。因此，这项应用提出了更好地了解这种微生物如何与肺细胞相互作用以及肺细胞对伯克霍尔德氏菌的反应。这项提议的资金将提供对有效和无效的先天免疫反应的关键洞察，以帮助寻找未来的疫苗和治疗开发。

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.