A multivalent O-antigen bioconjugate vaccine for the prevention of Klebsiella pneumoniae infections

用于预防肺炎克雷伯菌感染的多价 O 抗原生物结合疫苗

基本信息

批准号：
10661057
负责人：
Christian Harding
金额：
$ 29.83万
依托单位：
VAXNEWMO, LLC
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-07-15 至 2024-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10661057
关键词：
Acceleration Animal Model Antibiotic Resistance Antibiotics Antibodies Antibody Response Awareness Bacteria Bacterial Infections Bacterial Polysaccharides Biological Assay Bioreactors Carbapenems Carrier Proteins Cells Cephalosporins Cessation of life Clinic Clinical Communities Complex Conjugate Vaccines Development Disease Dose Drug resistance Encapsulated Enzyme-Linked Immunosorbent Assay Enzymes Epitopes Escherichia coli Europe Formulation Future Generations Genetic Glean Goals Healthcare Immune Immune response Immunity Immunization Immunize Immunoglobulin Class Switching Immunoglobulin G Immunoglobulin M Immunologics Individual Infection Inferior Investments Klebsiella Klebsiella pneumoniae Life Light Link Lipopolysaccharides Meta-Analysis Methods Minor Mus O Antigens Oryctolagus cuniculus Ozone Patients Phase Placebos Polysaccharides Prevention Process Production Resistance Scheme Serotyping Serum Structure Surface System Technology Testing Vaccinated Vaccination Vaccine Design Vaccine Production Vaccines Work bactericide carbapenem resistance chemical conjugate combat comparison control cross immunity efficacy evaluation genetic information glycosylation immunogenicity manufacture microbial novel pathogen pathogenic bacteria pre-clinical preclinical development prevent resistant Klebsiella pneumoniae response vaccine candidate vaccine development vaccine efficacy vaccine immunogenicity

项目摘要

PROJECT SUMMARY Klebsiella pneumoniae is a leading cause of healthcare- and community-associated infections. Moreover, K. pneumoniae is frequently resistant to last line antibiotics like third generation cephalosporins and carbapenems. In fact, carbapenem-resistant Klebsiella is considered an Urgent Threat by the CDC requiring aggressive, immediate action. One of the five core actions proposed by the CDC to combat antibiotic resistance is for continued investment and development of vaccines to prevent K. pneumoniae as well as other drug resistant bacterial infections. As such, VaxNewMo developed a multivalent conjugate vaccine targeting the majority of K. pneumoniae clinical isolates. Conjugate vaccines, composed of a polysaccharide covalently linked to a carrier protein, are life-saving vaccines used to prevent disease from multiple bacterial pathogens. Conventionally, conjugate vaccines are manufactured using chemical conjugation, which is notoriously complex, labor intensive, and imprecise, hindering the development of new conjugate vaccines against existing and emerging bacterial threats, like K. pneumoniae. Well aware of these drawbacks, VaxNewMo has been advancing an alternative method for manufacturing conjugate vaccines that utilizes prokaryotic glycosylation systems in a process termed bioconjugation. VaxNewMo’s proprietary bioconjugation platform relies on a conjugating enzyme to transfer a bacterial polysaccharide to a carrier protein all within the lab safe bacterium E. coli. Moreover, since bioconjugation is an enzyme driven process, the conjugates produced are non-derivatized and are therefore structurally identical to those presented to immune cells by the pathogen itself. Bioconjugation can be used to rapidly produce many conjugates simply by introducing new genetic information encoding for a different polysaccharide serotype into a bioconjugation competent strain of E. coli. As an example of this, we developed a multivalent O-antigen bioconjugate vaccine targeting >80% of K. pneumoniae isolates encountered in the clinic. In this Fast-Track application, we will validate the vaccine for immunogenicity and subsequently determine optimized doses in mice and rabbits, assess functional antibody responses as well as vaccine efficacy by performing challenge studies. In Phase I, we will assess immunogenicity of monovalent and multivalent O- antigen bioconjugate formulations by performing dose-escalation studies in mice. Immunogenicity will be assessed by ELISA for serotype-specific total IgG and IgG subtype antibody concentrations pre- and post- immunizations to each O-antigen formulated into the vaccine. Once validated for immunogenicity, we will proceed to Phase II. In Phase II, we will produce the vaccine in larger batches using a scalable microbial bioreactor system. Subsequently, we will assess functional antibody responses via a serum bactericidal assay (SBA) and an opsonophagocytic killing assay (OPKA) as well as perform challenge studies in mice vaccinated with a mouse optimized dose of the multivalent O-antigen bioconjugate vaccine. Finally, we will confirm immunogenicity and functional antibody responses (SBA and OPKA) of monovalent and multivalent O-antigen bioconjugate formulations in rabbits, a widely utilized animal model for conjugate vaccine development.

项目概要肺炎克雷伯菌是医疗保健和社区相关感染的主要原因。肺炎克雷伯菌经常对最后一线抗生素如第三代头孢菌素和事实上，CDC 认为耐碳青霉烯类克雷伯菌是一种紧急威胁。疾病预防控制中心提出的对抗抗生素耐药性的五项核心行动之一。用于持续投资和开发预防肺炎克雷伯菌的疫苗以及其他药物因此，VaxNewMo 开发了一种针对耐药细菌感染的多价结合疫苗。大多数肺炎克雷伯菌临床分离株由共价连接的多糖组成。载体蛋白是挽救生命的疫苗，用于预防多种细菌病原体引起的疾病。传统上，结合疫苗是使用化学结合来制造的，这是出了名的复杂，劳动密集型且不精确，阻碍了针对现有和现有疫苗的新结合疫苗的开发 VaxNewMo 充分意识到了肺炎克雷伯菌等新出现的细菌威胁，一直在不断进步。一种利用原核糖基化系统制造结合疫苗的替代方法 VaxNewMo 的专有生物共轭平台依赖于共轭酶。将细菌多糖转移到载体蛋白上，全部在实验室安全细菌大肠杆菌内进行。生物共轭是酶驱动的过程，产生的共轭物是非衍生化的，因此其结构与病原体本身呈递给免疫细胞的结构相同，可用于生物共轭。只需引入新的遗传信息编码即可快速产生许多缀合物作为一个例子，我们开发了一种具有生物共轭能力的大肠杆菌菌株。一种多价 O 抗原生物结合疫苗，针对临床中遇到的 > 80% 的肺炎克雷伯菌分离株。在此快速通道应用中，我们将验证疫苗的免疫原性，并随后确定在小鼠和兔子中优化剂量，通过以下方式评估功能性抗体反应以及疫苗功效在第一阶段，我们将评估单价和多价 O-的免疫原性。通过在小鼠中进行剂量递增研究来确定抗原生物结合制剂的免疫原性。通过 ELISA 评估前后血清型特异性总 IgG 和 IgG 亚型抗体浓度一旦验证了疫苗的免疫原性，我们将针对每种 O 抗原进行免疫接种。进入第二阶段。在第二阶段，我们将使用可扩展的微生物大批量生产疫苗。随后，我们将通过血清杀菌测定评估功能性抗体反应。 (SBA) 和调理吞噬杀伤测定 (OPKA) 以及在小鼠疫苗接种中进行挑战研究最后，我们将确认小鼠优化剂量的多价 O 抗原生物结合疫苗。单价和多价 O 抗原的免疫原性和功能性抗体反应（SBA 和 OPKA）兔子生物结合制剂，一种广泛用于结合疫苗开发的动物模型。