Bordetella Biofilms and Pathogenesis

描述（由申请方提供）：尽管疫苗接种覆盖率很高，但由百日咳杆菌引起的百日咳在美国仍然是一个相当大的经济和健康负担。目前的百日咳疫苗虽然能有效预防严重的疾病，但不能预防携带者。成人和青少年携带者负责将细菌传播给婴儿和幼儿，这些疾病严重，有时致命。目前迫切需要确定新的因素，将保护对细菌的运输，并将包括在无细胞疫苗。推测鼻咽部携带B。百日咳在人类中的传播是由于其能够以称为生物膜的固着形式存在。初步结果表明，B.百日咳在小鼠中作为附着于鼻上皮的多细胞群落存在，其使人联想到生物膜。本研究的总体目标是研究生物膜相关Bps多糖在生物膜发育和发病机制中的作用，并深入了解控制生物膜和呼吸道中Bps表达的调节电路。Bps类似于PGA/PIA/PNAG（聚-2-1，6-N-乙酰葡糖胺）多糖，包括许多病原体。在具体目标1中，将利用生物学相关的体外模型系统研究Bps在生物膜形成中作用的机制基础。Bps在提供抗微生物化合物保护方面的重要性将通过测试其在赋予对抗生素、抗微生物肽和活性氧的抗性中的作用来检查。假设Bps介导B的存活和持续。通过发挥免疫调节作用和通过靶向免疫系统的一种或多种成分来治疗呼吸道中的百日咳。B.将采用百日咳鼻内感染来检验这些假设。在具体目标2中，生物膜形成期间和呼吸道中bps的时间和空间表达梯度的建立将通过真实的时间RT PCR测定和GFP荧光的测量来检查。最后，提供洞察复杂的网络，控制bps的表达，调节蛋白BpsR在控制生物膜和小鼠呼吸道中的bps基因座的表达的作用将被检查。与公共卫生的相关性。本项目将提供对B的致病机制和感染周期的更好理解。哺乳动物宿主的百日咳。我们的研究将刺激基于Bps的疫苗和试剂（如用于治疗百日咳的抗体）的开发。由于Bps样多糖是由许多病原体如葡萄球菌、E.大肠杆菌和耶尔森氏菌，并可能其他，我们的研究结果将有助于治疗和了解各种细菌感染。

DESCRIPTION (provided by applicant): Pertussis, caused by Bordetella pertussis remains a considerable economic and health burden in the USA, despite very high coverage of vaccination. Current pertussis vaccines although effective at preventing the severe form of disease do not prevent the carrier state. Adult and adolescent carriers are responsible for the transmission of the bacterium to infants and young children, in whom the disease is severe and sometimes lethal. There is an urgent need to identify new factors that will be protective against bacterial carriage and will be included in the acellular vaccine. It is hypothesized that nasopharyngeal carriage of B. pertussis in humans is due to its ability to exist in a sessile form known as biofilms. Our preliminary results demonstrate that B. pertussis exists in mice as multicellular community adherent to the nasal epithelium, which are reminiscent of biofilms. The overall objectives of this research are to study the role of the biofilm-associated Bps polysaccharide in biofilm development and pathogenesis and to gain insight into the regulatory circuitry that controls bps expression in biofilms and in the respiratory tract. Bps is similar to PGA/PIA/PNAG (poly-2-1,6-N- acetylglucosamine) polysaccharides of other bacteria including a number of pathogens. In Specific Aim 1, biologically relevant in vitro model systems will be utilized to study the mechanistic basis of the role of Bps in biofilm formation. The importance of Bps in providing protection from anti-microbial compounds will be examined by testing its role in conferring resistance against antibiotics, antimicrobial peptides and reactive oxygen species. It is hypothesized that Bps mediates survival and persistence of B. pertussis in the respiratory tract by playing an immunomodulatory role and by targeting one or more components of the immune system. Mouse models of B. pertussis intranasal infection will be employed to test these hypotheses. In Specific Aim 2, the establishment of temporal and spatial expression gradient of bps during biofilm formation and in the respiratory tract will be examined by real time RT PCR assays and measurement of GFP fluorescence. Finally, to provide insights into the complex networks that operate to control bps expression, the role of a regulatory protein BpsR in controlling the expression of the bps locus in biofilms and in the mouse respiratory tract will be examined. Relevance to public health. This project will provide a better understanding of the pathogenic mechanisms and the infectious cycle of B. pertussis in mammalian hosts. Our studies will stimulate the development of Bps-based vaccines and reagents like antibodies for treatment of pertussis. Since Bps-like polysaccharides are produced by a number of pathogens like Staphylococci, E. coli and Yersinia Spp, and possibly others, our results will contribute towards the treatment and the understanding of a wide variety of bacterial infections.