Early airway innate immune responses to F. tularensis

项目SuIVIMARY(请参阅说明)： 图拉氏方济氏菌(Francisella tularsis，Ft)是一种胞内革兰氏阴性细菌，在以下情况下具有高致病性 雾化了。我们推测，气雾化Ft的显著致病性反映了独特的微生物 使肺部的局部固有宿主防御在数量上或质量上无效和 假设Ft的特定表面特征，包括细胞外胶囊样材料(CLM)， 颠覆局部肺固有防御，导致肺和肺内宿主反应迟钝 因此，观察到的气雾化Ft.作为我们全面评估 FT-AIN/VAY天然宿主防御相互作用和CLM的贡献，项目2将检查肺泡 上皮细胞(AEC)、肺微血管内皮细胞(PMVEC)和中性粒细胞穿过Ft刺激的AEC和PMVEC(RPMN)--早期肺固有宿主反应的三个相互关联的元素。我们将追求以下两个目标： 目标1：表征Ft抗性的机制和功能后果 内源性肺泡上皮和内皮细胞防御 侵袭Ft或其CLM是否改变AEC和PMVEC的先天抗菌和促炎反应？入侵Ft是否改变了轮回过程中涉及的PECAM-CD99相互作用？AEC和PMVEC的Ft感染是否激活了炎症体？AEC或PMVEC与Ft的相互作用是否会改变微生物的表型，这种变化是否会影响毒力？CLM的结构变化如何影响Ft与AEC或PMVEC之间的相互作用，从而改变PMN的迁移？树突状细胞如何影响AEC的Ft侵袭及AEC对侵袭的反应？ 目标2：确定Ft招募的移行PMN的功能变化 FT毒力rPMN表型的形成是否需要接触Ft，脱落细菌成分，如CLM，PMVEC特异性因子(S)，或这些元素的组合？在跨AEC迁移的PMN中是否出现类似的表型？RPMN的功能表型是什么？是什么机制(S)抑制了rPMN的NADPH氧化酶？Ft CLM的结构变化是否改变了Ft与PMVEC/AEC的相互作用，进而对rPMN产生影响？摄取Ft的rPMN是正常进行caspase-3介导的细胞凋亡，还是重定向到caspase-1介导的促炎细胞死亡？

PROJECT SUIVIMARY (See instructions): Francisella tularensis (Ft) is an intracellular Gram-negative bacterium that is highly pathogenic when aerosolized. We reason that the remarkable pathogenicity of aerosolized Ft reflects unique microbial features that render local innate host defenses in the lung quantitatively or qualitatively ineffective and hypothesize that specific surface features of Ft, including extracellular capsule-like material (CLM), subvert local pulmonary innate defenses, resulting in blunted host response in the lung and consequently the observed virulence of aerosolized Ft. As part of our comprehensive assessment of Ft-ain/vay innate host defense interaction and the contribution of CLM, Project 2 will examine alveolar epithelial cells (AEC), pulmonary microvascular endothelial cells (PMVEC) and neutrophils that traverse Ftstimulated AEC and PMVEC (rPMN) - three interconnected elements of early pulmonary innate host response. We will pursue the following two aims: Aim 1: To characterize the mechanisms and functional consequences of Ft resistance to endogenous pulmonary alveolar epithelial and endothelial cell defenses Do invading Ft or its CLM alter innate antimicrobial and proinflammatory responses of AEC and PMVEC? Do invading Ft alter PECAM-CD99 interactions involved in transmigration? Does Ft infection of AEC and PMVEC activate the inflammasome? Do interactions of AEC or PMVEC with Ft alter microbial phenotype and do such changes influence virulence? How do structural changes in CLM influence interactions between Ft and AEC or PMVEC and thereby alter PMN transmigration? How do ainway dendritic cells influence Ft invasion of AEC and AEC responses to invasion? Aim 2: To define the functional alterations In transmigrated PMN recruited by Ft that contribute to Ft virulence Does development of the rPMN phenotype require contact with Ft, shed bacterial components such as CLM, PMVEC-specific factor(s), or a combination of these elements? Does a similar phenotype develop in PMN that migrate across AEC? What is the functional phenotype of rPMN? What mechanism(s) underlie the depressed NADPH oxidase of rPMN? Do structural changes in Ft CLM alter interactions of Ft with PMVEC/AEC with subsequent effects on rPMN? Do rPMN that ingest Ft progress normally to undergo caspase-3-mediated apoptosis or are they redirected to a caspase-1-mediated proinflammatory cell death?