Immunological characterization of rationally-designed vaccines against plague in mice and non-human primate models

合理设计的鼠疫疫苗和非人灵长类动物模型的免疫学特征

• 批准号: 10213974
• 负责人: ASHOK K CHOPRA
• 金额: $ 22.45万
• 依托单位: UNIVERSITY OF TEXAS MED BR GALVESTON
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-05 至 2021-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10213974
• 关键词: Acyltransferase; African American; African Green Monkey; Animals; Antibiotic Resistance; Antibodies; Antibody Formation; Antibody Response; Antibody titer measurement; Antigens; Asian Americans; Attenuated; Attenuated Live Virus Vaccine; Bacteria; Bacterial Antigens; Binding; Bite; Bubonic Plague; Calcium; Case Fatality Rates; Categories; Cells; Cellular Immunity; Centers for Disease Control and Prevention (U.S.); Cessation of life; Clinical; Clinical Research; Clinical Trials; Country; Data; Disease; Disease Outbreaks; Dose; Engineering; Etiology; Exposure to; FDA approved; Fleas; Fright; Future; Generations; Genes; Goals; Human; Immune response; Immunity; Immunization; Immunize; Immunoglobulin A; Immunoglobulin G; Immunologics; Infection; Injections; Interferon Type II; Interleukin-17; Intramuscular; Iron; Laboratories; Lauric Acids; Left; Legal patent; Lesion; Link; Lipopolysaccharides; Lipoproteins; Macaca; Macaca fascicularis; Madagascar; Military Personnel; Modeling; Mucosal Immunity; Mus; Nature; Nepal; Neutrophil Infiltration; Patients; Peptide Hydrolases; Plague; Plague Vaccine; Plasminogen Activator; Pneumonic Plague; Public Health; Rattus; Resistance; Risk; Rodent; Rodent Model; Role; Safety; Serum; Signal Transduction; Site; South American; Subunit Vaccines; Symptoms; T-Lymphocyte; TLR2 gene; TLR4 gene; Testing; Th1 Cells; Toxicology; Type III Secretion System Pathway; Vaccinated; Vaccine Design; Vaccines; Variant; Virulence; Yersinia pestis; Zoonoses; arm; base; bioweapon; cell mediated immune response; climate change; combat; cytokine; design; efficacy testing; emerging human pathogen; good laboratory practice; immunogenicity; innovation; mass casualty; mouse model; mutant; nonhuman primate; novel; pandemic disease; pathogen; pre-clinical; preclinical study; response; translational approach; vaccine candidate; vaccine efficacy; vaccine evaluation

Yersinia pestis (Yp) is the causative agent of bubonic and pneumonic plague. The increasing number of plague cases globally (2010-2017), including the U.S., with a ~18% case fatality rate may reflect climate changes and a rodent carrier range shift. An outbreak of 2017 in Madagascar with ~2400 cases (>75% pneumonic) and ~9% causalities has led WHO (April 2018) to intensify the need for developing new generation subunit and live- attenuated plague vaccines. Yp’s ability to persist in dead hosts, and then resurge after years of silence, is alarming. Also, antibiotic-resistant Yp strains occur naturally or have been intentionally developed and currently no FDA-approved plague vaccine is available. Finally, two-component subunit vaccines composed of capsular antigen F1 and a T3SS component and effector LcrV (low calcium response V antigen), which only generate a humoral immune response, provide variable protection in African green monkeys (AGM) and generate poor T cell-mediate immune responses in humans. Since the cellular immunity is also critical for protection, we focused first on identifying new virulence genes of Yp and then to delete such genes in combination to develop novel live-attenuated vaccine strains. Our data indicated that two such vaccine candidates were 100% attenuated in inducing bubonic/pneumonic plague in mice/rats and generated long-term robust humoral and cellular immune responses to provide 100% protection to rodents against developing pneumonic plague. No clinical symptoms of the disease or histopathological lesions were noted either during immunization or when the vaccinated animals were subsequently exposed to wild-type Yp CO92 in a pneumonic plague model. We hypothesize that further immunological characterization of these mutants and their testing in higher animals, such as cynomolgus macaques (CM) and AGM, will provide a rationale for future preclinical and clinical studies. There is a precedent for using a live-attenuated vaccine against plague, as EV76 strain is used in humans in some parts of the world where plague is endemic. However, the vaccine is reactogenic, represents a spontaneous mutant, and causes disease in patients with over iron load. Three Aims have been proposed: Aim 1, to demonstrate efficacy and immune responses of two vaccine candidates generated from Yp CO92 (biovar Orientalis) against other Yp biovars (Antiqua and Medievalis), and the F1-minus mutant of CO92 in bubonic and pneumonic mouse models. Our data with the mutants indicated a potential role of IL-17 (a Th17 cytokine), Th1-IFN-γ, and antibodies in protection. In Aim 2, we will study the mechanistic basis of this protection (one chosen mutant) by using RORt- /- mice, which lack Th17 cells, as well as IFN-γ, and IgA k/o mice and to discern their links to neutrophil recruitment and mucosal immunity, to combat Yp infection in bubonic/pneumonic plague models. In Aim 3, CM and AGM will be used with one mutant to demonstrate its short- and long-term efficacy in causing bubonic and/or pneumonic plague as well as reactogenicity. The correlates of protective immunity will then be established. These innovative mechanistic/translational approaches will result in effective new generation plague vaccines.

鼠疫耶尔森氏菌(Yp)是引起腺鼠疫和肺鼠疫的病原体。越来越多的鼠疫 全球(2010-2017)病死率约为18%的病例(包括美国)可能反映了气候变化和 啮齿动物航母的射程转移。2017年马达加斯加暴发，约2400例(75%为肺炎)和~9% 伤亡事故导致世卫组织(2018年4月)加强了开发新一代亚单位和活体的需要 减毒鼠疫疫苗。YP在死亡的宿主中坚持下来，然后在沉寂多年后复活的能力，是 令人震惊。此外，对抗生素具有抗药性的yp菌株是自然产生的，或者是故意开发的，目前 目前还没有FDA批准的鼠疫疫苗。最后，由胶囊组成的双组分亚单位疫苗 抗原F1和T3SS组件和效应器LcrV(低钙反应V抗原)，它们只产生 体液免疫反应，在非洲绿猴(AGM)中提供可变保护并产生较差的T细胞 在人类中，细胞介导免疫反应。由于细胞免疫也是保护的关键，我们把重点放在 首先确定新的致病基因，然后将这些基因联合删除以开发新的毒力基因 减毒活疫苗株。我们的数据表明，两个这样的候选疫苗在 在小鼠/大鼠中诱导腺鼠疫/肺炎鼠疫，并产生长期强劲的体液和细胞免疫 应对措施为啮齿动物提供100%保护，使其免受肺炎鼠疫的侵袭。无临床症状 在免疫期间或在接种疫苗的动物身上发现疾病或组织病理学损害 随后在肺鼠疫模型中暴露于野生型YP CO92。我们进一步假设 这些突变体的免疫学特征及其在高等动物(如食蟹)中的检测 猕猴(CM)和AGM，将为未来的临床前和临床研究提供理论基础。有先例可循 因为使用了针对鼠疫的减毒活疫苗，因为在世界一些地区的人类身上使用了EV76毒株 在那里鼠疫是地方病。然而，疫苗是反应性的，代表着一种自发的突变，并导致 铁负荷过高患者的疾病。提出了三个目标：目标1，展示有效性和 YPCO92(东方生物群)的两种候选疫苗对其他YP型疫苗的免疫应答 在肺炎性和肺炎性小鼠模型中，CO92的F1减去突变体。 我们对突变体的数据表明IL-17(一种Th17细胞因子)、Th1-干扰素-γ和抗体在 保护。在目标2中，我们将利用RoRt-来研究这种保护的机制基础(一个选定的突变体)。 /-缺乏Th17细胞的小鼠，以及干扰素-γ和IgA k/o小鼠，并辨别它们与中性粒细胞的联系 招募和粘膜免疫，以对抗腺/肺炎鼠疫模型中的yp感染。在目标3中，CM AGM将与一种突变体一起使用，以证明其在引起腺瘤和/或 肺炎鼠疫以及反应性。然后将建立保护性免疫的相关性。 这些创新的机械/转化方法将产生有效的新一代鼠疫疫苗。