Early airway innate immune responses to F. tularensis

项目随附资料（见说明）： 土拉热弗朗西丝氏菌（Ft）是一种细胞内革兰氏阴性细菌，当 雾化。我们推断，Ft气溶胶的显著致病性反映了独特的微生物 使肺中的局部先天宿主防御在数量上或质量上无效的特征， 假设Ft特异性表面特征，包括细胞外囊样物质（CLM）， 破坏局部肺部先天防御，导致肺部宿主反应迟钝， 因此，所观察到的气溶胶化的Ft.作为我们全面评估 Ft-ain/vay固有宿主防御相互作用和CLM的贡献，项目2将研究肺泡 上皮细胞（AEC）、肺微血管内皮细胞（PMVEC）和穿过Ft刺激的AEC和PMVEC（rPMN）的中性粒细胞-早期肺先天宿主应答的三个相互关联的要素。我们将追求以下两个目标： 目的1：描述Ft耐药的机制和功能后果， 内源性肺泡上皮和内皮细胞防御 侵入性Ft或其CLM是否改变AEC和PMVEC的先天性抗菌和促炎反应？侵入性Ft改变了PECAM-CD 99的相互作用吗？Ft感染AEC和PMVEC是否激活炎性小体？AEC或PMVEC与Ft的相互作用是否改变了微生物的表型，这些变化是否影响了毒力？CLM的结构变化如何影响Ft和AEC或PMVEC之间的相互作用，从而改变PMN的迁移？树突状细胞是如何影响AEC的Ft侵袭和AEC对侵袭的反应的？ 目的2：确定由Ft募集的移行PMN的功能改变， Ft毒力rPMN表型的形成是否需要接触Ft、脱落的细菌成分，如CLM、PMVEC特异性因子或这些成分的组合？跨AEC迁移的中性粒细胞是否也有类似的表型？rPMN的功能表型是什么？rPMN的NADPH氧化酶被抑制的机制是什么？Ft CLM的结构变化是否会改变Ft与PMVEC/AEC的相互作用，并随后影响rPMN？摄取Ft的rPMN是否正常进展为经历caspase-3介导的凋亡或重定向为caspase-1介导的促炎性细胞死亡？

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?