HAEMOPHILUS--RAMIFICATIONS OF PILUS MEDIATED ADHERENCE

流感嗜血杆菌是一种病原体，介导广泛的人类疾病，包括中耳炎，鼻窦炎和肺炎，通常与鼻咽定植密度增加有关。与其他细菌性呼吸道病原体的情况一样，该过程的流行病学相关风险因素是与呼吸道病毒感染和环境刺激物（例如吸烟）相关的呼吸道粘膜先前损伤。上呼吸道的定植是疾病发病机制中的重要事件，并且由识别真核细胞上的特异性受体基序的细菌粘附素促进。hemglutinating菌毛可能是研究最充分的H.流感病毒粘附素，并且由非分型和血清分型菌株表达。我们的初步证据表明，这种结构介导粘附受损和挤压非纤毛呼吸上皮。本提案中要追求的双重假设是，这种微生物毒力因子对呼吸道粘膜的受损区域发挥作用，导致随后的致病事件，然后通过诱导呼吸道上皮细胞凋亡进一步增强粘膜防御的破裂。利用H.流感菌毛作为一个模型系统，我们将通过使用有毛/无毛的同基因菌株和微球连接的菌毛粘附素探针来剖析人呼吸道上皮上特异性菌毛受体结构的多重作用。然后，我们将使用这些工具来表征菌毛受体分布在重组粘膜表面上的动态，以确定这种粘附是否识别与其受体相关的焦点区域，从而导致真核细胞信号转导机制的操纵，增加上皮细胞的凋亡指数，并破坏细胞之间紧密连接的屏障。呼吸道细菌定植的动力学超越黏膜纤毛清除并导致疾病。通过专注于这种微生物毒力因子，我们将能够开发出广泛适用的实验系统，可用于解剖呼吸道疾病中宿主-病原体相互作用的分子细节。

Haemophilus influenzae is a pathogen that mediates a wide range of human disease including otitis media, sinusitis, and pneumonia often in association with an increased density of nasopharyngeal colonization. As is the case with other bacterial respiratory pathogens, an epidemiologically relevant risk factor for this process is prior injury of the respiratory mucosa associated with respiratory viral infections and environmental irritants (e.g. smoking). Colonization of the upper respiratory tract is an essential event in the pathogenesis of disease and is facilitated by bacterial adhesins that recognize specific receptors motifs on eukaryotic cells. The hemgglutinating pilus is perhaps the most well- studied H. influenzae adhesin and is expressed by both non-typable and serotypable strains. Our preliminary evidence suggests that this structure mediates adherence to damaged and extruding non-ciliated respiratory epithelium. A two-fold hypothesis to be pursued in this proposal is that this microbial virulence factor functions to compromised areas of the respiratory mucosa for subsequent pathogenic events and then further enhances the rupture of mucosal defenses by inducing respiratory epithelial cell apoptosis. Using the H. influenzae pilus as a model system, we will dissect the multiple roles in specific pilus receptor structure(s) on human respiratory epithelium by using piliated/non-piliated isogenic strains and microsphere-linked pilus adhesin probes. We will then use these tools to characterize the dynamics of pilus receptor distribution on a re-organizing mucosal surface to determine whether this adhesion recognizes focal areas associated with its receptor can result in the manipulation of eukaryotic cell signal transduction mechanisms, increases the apoptotic index of epithelial cells, and disrupts the barrier of tight junctions between cells. The dynamics of respiratory colonization to surmount mucociliary clearance and cause disease. By focusing on this microbial virulence factor, we will be able to develop broadly applicable experimental systems that can be used to dissect the molecular details of host-pathogen interactions in respiratory disease.