Protective immunity elicited by distinct polysaccharide antigens of classical and hypervirulent Klebsiella

经典和高毒力克雷伯氏菌的不同多糖抗原引发的保护性免疫

• 批准号: 10795212
• 负责人: David A. Rosen
• 金额: $ 66.9万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2028-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10795212
• 关键词: Animals; Antibiotic Resistance; Antibodies; Antibody Response; Antigens; Bacteremia; Bacteria; Bacteriology; Binding; Biological Assay; Carrier Proteins; Cells; Cessation of life; Communities; Complement; Conjugate Vaccines; DNA Sequence Alteration; Data; Dependence; Development; Dose; Effectiveness; Encapsulated; Engineering; Enrollment; Enzyme-Linked Immunosorbent Assay; Escherichia coli; Europe; Exhibits; Goals; Hospitalization; Human; Humoral Immunities; Immune Sera; Immune response; Immune system; Immunity; Immunization; Immunize; Immunoelectron Microscopy; Immunofluorescence Microscopy; Immunoglobulin G; Infection; Infection prevention; Interferometry; Klebsiella; Klebsiella pneumoniae; Licensing; Link; Liver Abscess; Measures; Meningitis; Modeling; Monitor; Multi-Drug Resistance; Mus; Names; O Antigens; Organism; Ozone; Parents; Pathogenesis; Patients; Pneumonia; Polysaccharides; Pulmonary Challenge; Recombinants; Research Personnel; Sepsis; Serum; Specificity; Structure; Surface; Techniques; Testing; Time; Transmission Electron Microscopy; Urinary tract infection; Vaccinated; Vaccination; Vaccines; Virulent; Work; adaptive immune response; bactericidal immunity; bactericide; capsule; carbapenem resistance; chemical conjugate; cross immunity; efficacy evaluation; experimental study; healthcare-associated infections; human pathogen; in vivo; inhibiting antibody; inhibitor; longitudinal human study; manufacturing process; mouse model; mutant; novel; participant enrollment; pathogen; prevent; relative effectiveness; resistant Klebsiella pneumoniae; response; sugar; transmission process; vaccine access; vaccine development; vaccine failure; vaccine formulation

PROJECT SUMMARY This project will enhance our understanding of the humoral immune response to Klebsiella pneumoniae (Kp) and its polysaccharide antigens with the long-term goal of guiding and optimizing broad vaccine development. Kp infections, including pneumonia, urinary tract infection, and bacteremia, are sharply on the rise among hospitalized patients; CDC has declared infections with Kp and other carbapenem-resistant Enterobacteriales (CRE) demand a threat level of urgent. Beyond classical Kp typically seen in the US, emerging hypervirulent Kp strains, capable of causing liver abscess, bacteremia, and meningitis in healthy hosts, are spreading globally. This work builds on the PI's background in bacteriology, Gram-negative bacterial pathogenesis, and modeling of host adaptive immune responses, to investigate antibodies targeting Kp's polysaccharide capsule (K-type) and O-antigen. We have found that, while mice are able to produce antibodies targeting Kp capsule and O- antigen, capsule may directly interfere with O-antibody binding and killing of Kp. With our collaborators at Omniose, we have developed and are testing novel bioconjugate vaccines targeting the most prevalent K- and O-types. Bioconjugation is an alternative manufacturing process that uses recombinant E. coli strains to concurrently produce the capsule or O-antigen and an engineered carrier protein, and to enzymatically link the two. We have produced multiple K- and O-bioconjugates that have demonstrated promising efficacy in mice. As both O- and K- vaccines are under development, we will use our novel bioconjugate vaccines in murine protection experiments to determine the relative effectiveness of O-antigen or K-antigen bioconjugates against classical and hypervirulent Kp isolates. Further, we will challenge O-immunized mice with strains of closely related O-antigen structural subtypes that have not been included to date in vaccine formulations being developed commercially. Potential masking of O-antigen by capsule will be determined through mouse serum IgG ELISAs. Serum bactericidal assays (SBAs) and opsonophagocytic killing assays (OPKAs) will be developed and correlated with murine protection. Further, with bacterial mutants, complemented strains, and capsule inhibitors, we will determine the specificity of Kp O-antibody inhibition by capsule, utilizing multiple techniques including biolayer interferometry, immunofluorescence microscopy, and transmission immunoelectron microscopy. Finally, we will perform a first-ever longitudinal study of human patients with Kp infection, analyzing their sera for antibodies specific to Kp polysaccharides and their functional activity against the inciting Kp strain. At the conclusion of these studies, the relative efficacy of both K- and O-type bioconjugate vaccines will be determined, cross-protection among O-antigen subtypes will be resolved, correlates of protective immunity will be established, and mechanisms of O-antigen masking will be defined. Our results will illuminate human antibody responses to Kp infection and guide vaccine development to target this worrisome pathogen.

项目摘要 该项目将增强我们对肺炎克雷伯氏菌的体液免疫反应（KP）和 其多糖抗原具有指导和优化广泛疫苗开发的长期目标。 KP 包括肺炎，尿路感染和菌血症在内的感染急剧上升 住院的患者；疾病预防控制中心已宣布感染KP和其他耐碳酸碳纤维的肠杆菌 （CRE）要求紧急的威胁水平。除了通常在美国出现的经典KP之外，还出现了高毒性的KP 能够在健康宿主中引起肝脓肿，菌血症和脑膜炎的菌株在全球范围内传播。 这项工作建立在PI的细菌学，革兰氏阴性细菌发病机理和建模的基础上 宿主自适应免疫反应的研究，以研究针对KP多糖胶囊（K-Type）的抗体 和O-Antigen。我们发现，尽管小鼠能够产生靶向KP胶囊和O-的抗体。 抗原，胶囊可能直接干扰KP的O抗体结合并杀死。与我们的合作者在 Omniose，我们已经开发并正在测试针对最普遍的K-和最普遍的生物偶联疫苗 O型。 BioConjugation是一种使用重组大肠杆菌菌株的替代制造过程 同时产生胶囊或O-抗原和工程载体蛋白，并酶上将 二。我们已经产生了多个K-和O-Bioconjugates，这些K-和O-Bioconjugates在小鼠中表现出了有希望的功效。 由于O-和K-疫苗都在开发中，我们将在鼠中使用新型的生物偶联疫苗 保护实验以确定O-抗原或K-抗原生物偶联物的相对有效性 经典且高毒性的KP分离株。此外，我们将与菌株紧密地挑战O-免疫小鼠 迄今为止尚未包含在疫苗制剂中的相关O抗原结构亚型 商业发展。胶囊对O-抗原的潜在掩盖将通过小鼠血清确定 IgG Elisas。将开发血清杀菌测定（SBA）和opsonoponophocytic杀戮测定法（OPKA） 并与鼠保护相关。此外，具有细菌突变体，补充菌株和胶囊 抑制剂，我们将使用多种技术来确定胶囊抑制KP O-抗体抑制的特异性 包括生物层干涉法，免疫荧光显微镜和透射免疫电子 显微镜。最后，我们将对具有KP感染的人类患者进行第一个纵向研究，分析 它们针对KP多糖特异性抗体的血清及其针对煽动KP菌株的功能活性。 在这些研究的结论下，K-和O型生物偶联物疫苗的相对功效将是 确定的，在O-抗原亚型之间的交叉保护将解决，保护性免疫的相关性将会 必须确定，将定义O-抗原掩蔽的机制。我们的结果将照亮人类抗体 对KP感染的反应并引导疫苗发育以靶向这种令人担忧的病原体。