Identification of new antigens for a plague vaccine

鼠疫疫苗新抗原的鉴定

• 批准号: 8188007
• 负责人: ASHOK K CHOPRA
• 金额: $ 34.43万
• 依托单位: UNIVERSITY OF TEXAS MED BR GALVESTON
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-02-01 至 2016-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8188007
• 关键词: Accounting; Address; Aerosols; Animal Model; Animals; Antibiotic Resistance; Antigens; Apoptotic; Attenuated; Attenuated Live Virus Vaccine; Bacteria; Bacterial Antigens; Binding; Biological Assay; Bubonic Plague; Categories; Cellular Stress; Cessation of life; Clinical; Clinical Trials; Data; Development; Disease; Disease Outbreaks; Dose; Down-Regulation; Drug Formulations; Emerging Communicable Diseases; Environment; Enzymes; Epidemic; Exoribonuclease II; Exoribonucleases; Funding; Gene Deletion; Generations; Genes; Global Warming; Goals; Grant; Human; Immune Sera; Immune response; Immunity; Immunization; Infection; Inflammatory Response; Lesion; Levaquin; Link; Lipid A; Lipoproteins; Mediating; Memory; Microarray Analysis; Modeling; Mus; Myristic Acids; Paper; Pasteurella pseudotuberculosis; Pathogenesis; Peptide Hydrolases; Pigmentation physiologic function; Plague; Plague Vaccine; Plasmids; Plasminogen; Pneumonic Plague; Polyribonucleotide Nucleotidyltransferase; Prevalence; Protease Gene; Proteins; Publications; Publishing; Rattus; Recombinants; Ribonucleases; Rodent; Role; Serum; Signal Pathway; Signal Transduction; Smallpox; Splenocyte; Stress; Subunit Vaccines; Survivors; Systemic infection; Testing; Tissues; Toll-Like Receptor 2; Vaccines; Virulence; Virulent; Western Blotting; Yersinia pestis; attenuation; base; biological adaptation to stress; biothreat; cell envelope; coping; immunogenic; killings; macrophage; mouse model; mutant; novel; pandemic disease; programs; protective effect; resistant strain; response; transmission process; vaccine candidate

DESCRIPTION (provided by applicant): Historically, plague is one of the most devastating epidemic diseases known to mankind (second only to smallpox), resulting overall in more than 200 million deaths related to three recorded plague pandemics. Since Y. pestis has the potential to cause large-scale outbreaks, the WHO has categorized plague as a re-emerging infectious disease, and there is a concern for a possible fourth pandemic because of global warming, resulting in an increased prevalence of plague in rodent hosts. The current relevance of Y. pestis as a bioweapon is due to its high virulence and the development of multi-antibiotic-resistant strains. Although immunization of humans with plague vaccine will discourage the use of Y. pestis as a bioweapon, currently there is no vaccine against plague. During the current funding of the grant, we identified a new antigen (Braun lipoprotein) of Y. pestis that contributed to the development of bubonic and pneumonic plague. Our studies indicated that mice immunized with the mutant strain of Y. pestis deleted for the lpp and pigmentation locus (pgm) genes were protected against developing pneumonic plague caused by the highly virulent Y. pestis CO92 strain. We have now delineated the signaling pathways initiated by Lpp to cause host damage. Most importantly, our data indicated that the lpp mutant was unable to survive within macrophages, which was linked to the down-regulation of a stress response gene (htrA) in this mutant. We inferred from these data that other stress-associated genes (e.g., exoribonucleases) could also be involved in lpp-mediated, attenuated virulence of the bacterium. Indeed, deletion of the gene encoding polynucleotide phosphorylase (PNPase) also attenuated Y. pestis in a mouse model of systemic infection and provided protection against plague. We have proposed 3 specific aims for this grant. Aim 1 is to generate double mutants of Y. pestis CO92 in which genes encoding plasminogen-activating protease (pla), pnp, and two other predominant exoribonucleases (e.g., rnb [RNase II] and rnr [RNAse R]) will be deleted from the lpp gene minus background strain of Y. pestis CO92. These mutants will be tested for their attenuation in bubonic and pneumonic plague models (mice and rats). In aim 2, we will characterize protective immune responses of the most highly attenuated mutant in an animal model and the protection afforded by such a mutant against challenge with the parental CO92 strain. We have identified several immunogenic proteins in the WT CO92 strain that reacted with the immune sera of rats infected with CO92 strain. These antigens may represent excellent candidates for addition in the recombinant plague vaccine. Therefore in aim 3, we will first delete these genes from the WT bacterium to demonstrate their effects on bacterial virulence. Second, we will purify such immunogenic proteins and evaluate their protective effects after immunization of mice and rats followed by subsequent infection with the virulent Y. pestis. Overall, our studies are focused on identifying new live-attenuated vaccine strains of Y. pestis and to characterize the new immuno-protective CO92 antigens that could be important for the recombinant plague vaccine. PUBLIC HEALTH RELEVANCE: Y. pestis is a category A select agent and its potential to be used as a biothreat agent has caused significant concerns. In addition, plague represents a re-emerging infectious disease because of an increased number of cases worldwide. Currently, there is no vaccine available against this deadly disease, and hence our efforts are to develop new and novel countermeasures against plague, as well as to study new mechanisms of pathogenesis in Y. pestis.

描述（由申请人提供）：历史上，鼠疫是人类已知的最具破坏性的流行病之一（仅次于天花），总共造成2亿多人死亡，与三次记录在案的鼠疫大流行有关。自从Y.鼠疫有可能引起大规模爆发，世卫组织已将鼠疫归类为重新出现的传染病，并且由于全球变暖，人们担心可能发生第四次大流行，导致鼠疫在啮齿动物宿主中的流行率增加。目前，Y。鼠疫作为一种生物武器，是由于其高毒性和对多种抗生素产生耐药性的菌株。虽然用鼠疫疫苗免疫人类将阻止使用Y。鼠疫作为一种生物武器，目前还没有针对鼠疫的疫苗。在目前的资助资金，我们确定了一个新的抗原（布劳恩脂蛋白）的Y。鼠疫，促成了淋巴腺鼠疫和肺鼠疫的发展。本研究表明，用Y. lpp和pgm基因缺失的鼠疫菌可保护其免受由高毒力的Y.鼠疫CO92菌株。我们现在已经描述了Lpp引发的导致宿主损伤的信号通路。最重要的是，我们的数据表明，lpp突变体无法在巨噬细胞内存活，这与该突变体中应激反应基因（htrA）的下调有关。我们从这些数据推断，其他与压力相关的基因（例如，外切核糖核酸酶）也可能参与LPP介导的细菌的减弱的毒力。事实上，缺失编码多核苷酸磷酸化酶（PNIPs）的基因也会减弱Y。鼠疫杆菌在全身感染的小鼠模型中，并提供针对鼠疫的保护。我们为这笔赠款提出了三个具体目标。目的1是获得Y染色体双突变体。鼠疫CO92，其中编码纤溶酶原激活蛋白酶（pla）、pnp和两种其它主要的核糖核酸外切酶（例如，rnb [RNA酶II]和rnr [RNA酶R]）将从lpp基因减去Y的背景菌株中缺失。鼠疫CO92。将在腺鼠疫和肺鼠疫模型（小鼠和大鼠）中检测这些突变体的减毒作用。在目标2中，我们将表征动物模型中最高度减毒的突变体的保护性免疫应答，以及这种突变体针对亲本CO92菌株攻击所提供的保护。我们已经鉴定了WT CO92株中的几种免疫原性蛋白，其与感染CO92株的大鼠的免疫血清反应。这些抗原可能是添加到重组鼠疫疫苗中的优秀候选抗原。因此，在目标3中，我们将首先从WT细菌中删除这些基因，以证明它们对细菌毒力的影响。其次，我们将纯化这些免疫原性蛋白质，并在小鼠和大鼠免疫后，随后用强毒Y.鼠疫总之，我们的研究集中在鉴定新的Y.鼠疫和表征新的免疫保护性CO92抗原，可能是重要的重组鼠疫疫苗。 公共卫生相关性：是。鼠疫是一种A类选择性病原体，其被用作生物威胁病原体的可能性引起了极大的关注。此外，鼠疫是一种重新出现的传染病，因为全世界病例数量增加。目前，还没有针对这种致命疾病的疫苗，因此，我们的努力是开发新的和新颖的对策，对鼠疫，以及在Y.鼠疫