Identification of New Antigens for a Plague Vaccine

描述（由申请人提供）：鼠疫耶尔森氏菌是急性疾病腺鼠疫和肺鼠疫的病原，是人类所经历的最具破坏性的引起流行病的细菌之一，现已被世界卫生组织列为重新出现的人类病原体。潜在的传染，缺乏有效的疫苗，以及多种抗生素耐药菌株的出现，使鼠疫杆菌成为美国首选的潜在生物恐怖主义制剂。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。更直接的目标是鉴定和评价新的和现有的鼠疫耶尔森氏菌抗原，以开发新一代鼠疫疫苗。现在已知鼠疫杆菌的完整基因组序列。提出了四个目标。在Aim 1中，我们将制备鼠疫杆菌的Braun/鼠蛋白（lpp）负突变体，基于我们最近的数据，鼠伤寒沙门菌和Y型假结核杆菌的专利Ipp等基因突变体在小鼠中是无毒的，并且可以保护小鼠免受野生型细菌的攻击。我们将在小鼠中检测这些突变体的免疫反应，以开发鼠疫杆菌减毒活疫苗或使用假结核杆菌作为鼠疫杆菌抗原的载体。目标2将通过基因组学和蛋白质组学鉴定鼠疫耶尔森氏菌的差异或特异性表达基因（可能与毒力相关），以评估用于重组亚单位鼠疫疫苗的新抗原。目的3将通过开发等基因突变体并在小鼠模型中评估其致病性来检查选定的鼠疫菌体内表达基因的毒力潜力，并评估选定抗原对鼠疫菌攻击提供免疫的能力。目的4将研究假结核杆菌和鼠伤寒沙门氏菌的ipp -负突变体作为载体的潜在用途，通过在诱导启动子下的质粒和/或减毒假结核杆菌/S的染色体上表达选定的基因来传递鼠疫杆菌抗原。斑疹伤寒或通过DMA疫苗接种。另外，也可以使用伤寒沙门氏菌（Ty21a）疫苗株。我们相信这些多种方法将确定候选抗原，用于一种新的、有效的鼠疫疫苗。

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.