Identification of New Antigens for a Plague Vaccine

描述(申请人提供)：鼠疫耶尔森氏菌，一种急性疾病，腺鼠疫和肺鼠疫的病原体，也是人类经历过的最具破坏性的流行细菌之一，现在被世界卫生组织归类为重新出现的人类病原体。潜在的传染，缺乏有效的疫苗，以及出现多种抗药性菌株，使鼠疫杆菌作为一种潜在的生物恐怖主义因子，位居美国选择制剂名单的首位。我们的长期目标是阐明鼠疫杆菌急性细菌感染过程的分子机制。更紧迫的目标是识别和评估新的和现有的鼠疫杆菌抗原，以开发新一代鼠疫疫苗。鼠疫耶尔森氏菌的完整基因组序列现已知晓。提出了四个目标。在目标1中，基于我们最近的数据，我们将制备鼠疫杆菌的Braun/murein脂蛋白(LPP)缺失突变体，基于我们最近的数据，即获得专利的鼠伤寒沙门氏菌和Y假结核杆菌的Ipp等基因突变体在小鼠中是无毒的，并提供抵抗野生型细菌攻击的保护。我们将检查这些突变体在小鼠身上的免疫反应，以开发鼠疫减毒活疫苗或使用假结核杆菌作为鼠疫杆菌抗原的载体。目的2通过基因组学和蛋白质组学鉴定鼠疫耶尔森氏菌差异表达或独占表达的基因(潜在毒力相关)，以评估新的抗原用于重组亚单位鼠疫疫苗。目的3将通过开发同基因突变株并在小鼠模型中评估它们的致死性，来检测选定的体内表达的鼠疫菌基因的毒力潜力，并评估选定的抗原提供对鼠疫菌攻击的免疫力的能力。目的研究利用假结核杆菌和鼠伤寒沙门氏菌的ipp阴性突变体作为载体，通过在减毒假结核杆菌和鼠伤寒沙门氏菌的可诱导启动子和/或染色体下或通过DMA疫苗表达所选基因来传递鼠疫杆菌抗原的可能性。或者，也可以使用伤寒沙门氏菌(Ty21a)的疫苗株。我们相信，这些多重方法将确定候选抗原，用于新的有效鼠疫疫苗。

DESCRIPTION (provided by applicant): Yersinia pestis, an etiological agent of the acute diseases bubonic and pneumonic plague and one of the most devastating epidemic-causing bacteria experienced by mankind, is now classified as a re-emerging human pathogen by the WHO. The potential for contagion, lack of an effective vaccine, and emergence of multiple antibiotic- resistant strains place Y. pestis at the top of the U.S. select agent list as a potential bioterrorism agent. Our long-term goal is to elucidate molecular mechanisms underlying the acute bacterial infectious process of Y. pestis . The more immediate objective is to identify and evaluate new and existing antigens of Y. pestis to develop a new generation plague vaccine. The complete genome sequence of Y. pestis is now known. Four aims are proposed. In Aim 1 we will prepare a Braun/murein lipoprotein (lpp)-minus mutant of Y. pestis , based on our recent data that the patented Ipp isogenic mutants of Salmonella Typhimurium and of Y pseudotuberculosis are avirulent in mice and provide protection against challenge with the wild-type bacterium. We will examine these mutants for immunological responses in mice to develop a live attenuated Y. pestis vaccine or use Y. pseudotuberculosis as a carrier for Y. pestis antigens. Aim 2 will identify differentially or exclusively expressed genes (potentially virulence-associated) of Y. pestis by genomics and proteomics to evaluate new antigens for use in a recombinant subunit plague vaccine. Aim 3 will examine the virulence potential of selected in vivo-expressed genes of Y. pestis by developing isogenic mutants and evaluating them for lethality in a mouse model and assess selected antigens' ability to provide immunity against Y. pestis challenge. Aim 4 will examine potential use of the Ipp-minus mutants of Y. pseudotuberculosis and S. Typhimurium as carriers to deliver Y. pestis antigens by expressing selected genes either from a plasmid under an inducible promoter and/or chromosome of attenuated Y. pseudotuberculosis/S. Typhimurium or by DMA vaccination. Alternatively, a vaccine strain of S. Typhi (Ty21a) could also be used. We believe these multiple approaches will identify candidate antigens for a use in a new, efficacious plague vaccine.