Host: Pathogen Interaction in Plague

我们的项目以前专注于开发新的疫苗和治疗策略，使用 鼠疫耶尔森氏菌模型。我们检测了类脂A(氨基烷基氨基葡萄糖磷酸盐，AGPS)，Tolllike 受体(TLR)4激动剂。我们发现AGP直接预防肺炎鼠疫，戏剧性地 加强抗生素治疗，是鼻腔(I.N.)的有效佐剂或皮下(S.C.) 含有鼠疫杆菌囊膜(F1)和/或V抗原的疫苗。我们的疫苗接种方案产生了快速的 和持续的获得性TH1免疫反应，对小鼠和大鼠模型具有保护作用。我们也是 几种新发现的鼠疫耶尔森菌毒力因子的特征及其调控。重大进展 已经通过筛选减毒菌株来鉴定额外的毒力机制 利用先进的生物信息学分析，全面的转座子文库，并通过动物和 秀丽线虫模特。我们在这项提案中的具体目标是在这些成功的基础上展开的： 具体目标1：进一步研究TLR诱导天然免疫的过渡 针对肺炎鼠疫的激动剂和特异性免疫。AGPS的产品开发 需要描述小鼠和人类免疫反应之间的差异。转基因 人源化TLR4/MD-2小鼠将被用来评估对AGPs作为治疗药物和疫苗的反应 佐剂。此外，我们将研究各种TLR激动剂的组合以增强保护作用。 特定目标2：确定调控基因和表面/胞外蛋白在鼠疫杆菌中的作用 感染和/或跳蚤媒介维护。我们将系统地描述调节性突变，细胞 表面/胞外蛋白和葡萄糖调节基因在毒力中的作用，最终目标是 确定新的产品开发目标。 具体目标3：确定对鼠疫杆菌至关重要的自然突变(假基因) 发病机制。我们将检验这一假设，即细菌毒力的增加部分是由于进化 在适应宿主的过程中丢失遗传信息。我们将使用生物信息学来识别失踪者和/或 鼠疫耶尔森氏菌基因组中与鼠疫菌功能密切相关但较少的功能 致病耶尔森氏菌。这些已鉴定的鼠疫耶尔森氏菌“假基因”将被修复以确定 这种恢复会减弱毒力。我们把这个过程称为“反向分子科赫公设”。

Our project previously focused on the development of novel vaccine and therapeutic strategies using Yersinia pestis models. We examined lipid A mimetics (aminoalkyl glucosaminide phosphates, AGPs), Tolllike receptor (TLR) 4 agonists. We found that AGPs directly protect against pneumonic plague, dramatically augment antibiotic therapy, and are efficacious adjuvants for either intranasal (i.n.) or subcutaneous (s.c.) vaccines containing Y. pestis capsular (F1) and/or V-antigens. Our vaccination regimen results in a rapid and sustained acquired TH1 immune response which protects in mouse and rat models. We also are characterizing several newly identified Y. pestis virulence factors and their regulation. Significant advances have been made toward identifying additional virulence mechanisms by screening for attenuated strains using advanced bioinformatic analyses, comprehensive transposon libraries, and through animal and Caenorhabditis elegans models. Our specific aims in this proposal expand on these successes: Specific Aim 1: To further examine the transition between induction of innate immunity with TLR agonists and specific immunity directed against pneumonic plague. The product development of AGPs requires delineation of the differences between murine and human immune responses. Transgenic humanized TLR4/MD-2 mice will be used to assess responses to AGPs as therapeutics and as vaccine adjuvants. In addition we will examine combinations of various TLR agonists to increase protection. Specific Aim 2: Determine the role of regulatory genes and surface/extracellular proteins in Y. pestis infection and/or flea vector maintenance. We will systematically characterize regulatory mutations, cell surface/extracellular proteins, and glucose-regulated genes for their role in virulence with the ultimate goal of identifying novel targets for product development. Specific Aim 3: Identify natural mutations (pseudogenes) that are essential for Y. pestis pathogenesis. We will test the hypothesis that increased bacterial virulence is, in part, due to evolutionary loss of genetic information during adaptation to the host. We will use bioinformatics to identify the lost and/or inactivated functions in the genomes of Y. pestis strains which are functional in the closely related but less virulent Yersinia enteropathogens. These identified Y. pestis 'pseudogenes' will be repaired to determine if this restoration attenuates virulence. We refer to this process as 'reverse molecular Koch's postulates'.