Bordetella cell surface modification and pathogenesis

革兰氏阴性杆菌百日咳杆菌是一种人类限制的病原体，可引起严重的 呼吸道感染和百日咳或百日咳。尽管高水平和广泛的 在接种疫苗后，世界各地的百日咳杆菌感染和百日咳病例呈上升趋势。这种复兴是 归因于目前的无细胞百日咳疫苗在控制细菌数量方面效果不佳 鼻咽、细菌传播和产生短命免疫。百日咳杆菌如何存活 有效地在呼吸道和在社区中循环的人对此知之甚少。为了控制 百日咳的死灰复燃，关键是发现新的策略和确定新的发病相关基因 以及各种因素。 本实验室鉴定的DRAABCD基因座在体外促进(I)抗菌素杀伤的抗性 多肽和蛋白质(AMP)；(Ii)多形核白细胞；(Iii)生物膜的形成。我们 假设DRA对百日咳杆菌在小鼠呼吸道中的存活至关重要。在具体目标1中，我们将 利用已建立的小鼠鼻内感染模型研究其在定植和生物被膜中的作用 在呼吸道器官中形成。我们还将测试dra是否促进对呼吸系统的依从性。 用上皮细胞系和呼吸道外植体培养上皮细胞。 Dra蛋白催化D-丙氨酸在外膜相关的敏感蛋白中的加成 组件。这种表面修饰机理不同于进行的多糖改性 由其他已知的细菌基因座决定。Dra修饰表面因子(DMF)是未知的。在具体目标2中，使用 分馏技术和质谱学，我们将鉴定DMF。 这项工作将揭示新的毒力策略，从而了解百日咳死灰复燃的原因。 对DRA基因座的研究和发现DMF的身份将为我们提供重要的生化和生物学 洞察导致对百日咳杆菌表面变化的深入了解。这项研究的结果 将导致以DRA基因和DMF为靶点，以开发更好的疫苗和替代疗法。

The Gram-negative bacterium Bordetella pertussis is a human-restricted pathogen that causes severe respiratory infections and the disease whooping cough or pertussis. Despite high levels and widespread vaccination, there has been a world-wide rise in B. pertussis infections and pertussis. This resurgence is attributed to the ineffectiveness of the current acellular pertussis vaccines to control bacterial numbers in the nasopharynx, bacterial transmission and generation of shorter-lived immunity. How B. pertussis survives effectively in the respiratory tract and circulates in the community is poorly understood. In order to control the resurgence of pertussis, it is critical to discover new strategies and identify new pathogenesis-associated loci and factors. The draABCD locus identified in our laboratory promotes in vitro (i) the resistance to killing by anti-microbial peptides and proteins (AMPs); (ii) polymorphonuclear leukocytes and (iii) the formation of biofilms. We hypothesize that dra is critical for survival of B. pertussis in the mouse respiratory tract. In Specific aim 1, we will utilize well-established mouse models of intranasal infection to examine its role in colonization and biofilm formation in the respiratory tract organs. We will also test whether dra promotes adherence to respiratory epithelium by using epithelial cells lines and respiratory explants. The Dra proteins catalyze the addition of D-alanine in an outer membrane-associated protease-susceptible component. This mechanism of surface modification is distinct from the polysaccharide modification carried out by other known bacterial loci. The Dra-modified surface factor (DMF) is unknown. In Specific Aim 2, using fractionation techniques and mass spectrometry, we will identify the DMF. This work will uncover new virulence strategies that will inform on the reasons of the resurgence of pertussis. Studies of the dra locus and discovering the identity of the DMF will provide important biochemical and biological insights resulting in advanced understanding of surface alterations in B. pertussis. Outcomes from this research will result in targeting of the dra locus and DMF for developing better vaccines and alternative therapeutics.