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）：从历史上看，瘟疫是人类已知的最具破坏性的流行病之一（仅次于天花），总体上导致了与三种记录的瘟疫大流行有关的2亿多人。由于Pestis有可能引起大规模爆发，因此，WHO将瘟疫归类为一种重新出现的传染病，并且由于全球变暖，人们可能会担心可能会出现第四大流行，导致啮齿动物宿主的瘟疫患病率增加。当前的鼠疫与生物武器的相关性是由于其高毒力和多种抗生素抗性菌株的发展所致。尽管对瘟疫疫苗的人类免疫会阻止使用Y. Pestis作为生物武器的使用，但目前尚无针对鼠疫的疫苗。在目前的赠款资金中，我们确定了Y. Pestis的一种新的抗原（Braun脂蛋白），该抗原有助于发育和肺炎鼠疫的发展。我们的研究表明，用pestis的突变菌株被删除的LPP和色素沉着基因座（PGM）基因免疫的小鼠受到保护，免受由高毒性pestis co92菌株引起的肺炎瘟疫的发展。现在，我们已经描述了LPP发起的信号通路，以造成宿主损坏。最重要的是，我们的数据表明，LPP突变体无法在巨噬细胞中生存，这与该突变体中应力反应基因（HTRA）的下调有关。我们从这些数据中推断出，其他与胁迫相关的基因（例如，驱虫核酸酶）也可能参与LPP介导的细菌的毒力。实际上，编码多核苷酸磷酸化酶（PNPase）的基因的缺失也减弱了全身感染的小鼠模型中的鼠疫，并提供了防止鼠疫的保护。我们已经提出了3个针对这笔赠款的特定目标。目的1是生成Y. Pestis co92的双突变体，其中编码纤溶酶原激活蛋白酶（PLA），PNP和其他两个主要的驱虫核酸酶（例如RNB [RNBASE II]和RNR [RNASE R]）将从LPP Gene MAN MAN MIN MAIS COR中删除。这些突变体将在泡泡糖和肺鼠疫模型（小鼠和大鼠）中测试它们的衰减。在AIM 2中，我们将表征动物模型中最高度减弱的突变体的保护性免疫反应，并通过这种突变体对父母CO92菌株的挑战提供的保护。我们已经确定了WT CO92菌株中的几种免疫原性蛋白，它们与感染了CO92菌株的大鼠的免疫血清反应。这些抗原可能代表在重组瘟疫疫苗中添加的出色候选者。因此，在AIM 3中，我们将首先将这些基因从WT细菌中删除，以证明它们对细菌毒力的影响。其次，我们将纯化这种免疫原性蛋白质，并在小鼠和大鼠免疫后评估其保护作用，然后随后感染了毒性的鼠疫菌。总体而言，我们的研究集中在鉴定鼠疫的新的活疫苗菌株，并表征新的免疫保护二氧化碳抗原，这对于重组瘟疫疫苗可能很重要。 公共卫生相关性：Y. Pestis是选择的类别，其用作生物疗法的潜力引起了重大关注。此外，由于全球案例数量增加，瘟疫代表了一种重新出现的传染病。目前，尚无针对这种致命疾病的疫苗，因此，我们的努力是开发针对瘟疫的新的和新颖的对策，并研究Y. Pestis中的发病机理的新机制。