Development of nucleic acid-based vaccines against gonorrhea

开发基于核酸的淋病疫苗

基本信息

批准号：
10624940
负责人：
Lisa Ann Lewis
金额：
$ 20.94万
依托单位：
UNIV OF MASSACHUSETTS MED SCH WORCESTER
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：
2022-05-19 至 2025-04-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10624940
关键词：
Acceleration Affect Animal Model Antibiotic Resistance Antibiotics Antibodies Antibody Formation Antibody titer measurement Antigen Targeting Antigen-Presenting Cells Antigens Antimicrobial Resistance Attenuated Biology Biotechnology COVID-19 pandemic Ceftriaxone Cell Nucleus Cell division Chimera organism Chimeric Proteins Chlamydia Clinical Complement Complement Membrane Attack Complex Country Cryopreservation Cytoplasm DNA Vaccines Data Development Disease Ectopic Pregnancy Epitopes Equity Formulation Gonorrhea HIV Immune response Immunize Immunoglobulin A Immunoglobulin G Immunology In Vitro Incidence Individual Infection Infertility Inflammation Lead Link Measures Mediating Messenger RNA Microbe Modeling Monoclonal Antibodies Mucous Membrane Multi-Drug Resistance Mus Neisseria gonorrhoeae Nucleic Acid Vaccines Nucleic Acids Peptides Persons Play Proteins RNA vaccine Recommendation Reporting Resistance Resistance development Resources Role Serum Sexually Transmitted Diseases Sialic Acids Surface T cell response Testing United States Vaccine Antigen Vaccines Vagina Virulence Virulence Factors Woman Work bactericide cervicovaginal chronic pelvic pain combat cost density efficacy evaluation fast protein liquid chromatography fighting immunogenicity improved in silico in vivo infection burden lipid nanoparticle lipooligosaccharide low income country mRNA Stability mRNA delivery mouse model mutant nanoparticle delivery novel vaccines optimism peptidomimetics phase 1 study plasmid DNA pre-clinical preclinical development public health priorities receptor reproductive tract response sialic acid binding Ig-like lectin sialylation success synergism technology platform transmission process trend vaccine candidate vaccine delivery vaccine development vaccine efficacy vaccine evaluation vaccine formulation vaccine platform vaginal fluid

项目摘要

ABSTRACT Gonorrhea affects over 87 million people annually globally. In 2019, over 600,000 cases of gonorrhea were reported to the CDC, a 92% increase since the historic low in the US in 2009. However, the true incidence of cases annually in the US is estimated to be ~1.5 million. The spread of antimicrobial resistance has severely limited treatment options – currently, ceftriaxone is the only approved first line of treatment. A safe and effective vaccine against gonorrhea is urgently needed. Lipooligosaccharide (LOS) is the most abundant molecule on the gonococcal surface and plays multifaceted roles in bacterial virulence. A LOS epitope recognized by mAb 2C7 (therefore called the 2C7 epitope) is expressed by >95% of Ng in vivo; Ng mutants that do not express the 2C7 epitope are attenuated in mice. Our group has developed a peptide mimic (mimitope) of the 2C7 epitope, which when configured as a multi-antigen peptide (MAP) elicits bactericidal Abs and attenuates Ng colonization in mice. Further, we have elucidated the mechanism of action of MAP as complement-mediated killing (killing through membrane attack complex), strongly suggesting serum bactericidal activity as a mechanistic correlate of protection. In a collaborative venture with Evaxion Biotech, we screened 30 antigens that were identified by EDEN, Evaxion’s proprietary in silico platform, for immunogenicity, bactericidal activity and efficacy in the mouse vaginal colonization model. These studies identified two cell division proteins as promising candidates based on efficacy in vivo. When configured as a fusion protein (chimera), the cell division proteins showed improved ac- tivity in vivo compared to individual proteins and currently is our lead protein vaccine candidate. DNA and mRNA vaccines have proven very successful in the fight against the Covid-19 pandemic. These platforms elicit high levels of protection, have proven safe, are rapidly adaptable and economical. Here, we will leverage these two newer vaccine platforms to deliver the protective gonococcal antigens. A multivalent vaccine has the advantage of broader strain coverage, improved efficacy and would also raise the barrier for development of resistance. In Aim 1, we will evaluate DNA vaccine constructs that contain the 2C7 LOS mimitope (PEP1) configured as an octameric concatemer (PEP1_OCT), the cell division protein chimera, or a combination of the two. Serum will be assessed for antibody titers and complement-dependent bactericidal activity, as well durability of responses. Comparisons will be made with the protein versions of these vaccines currently under development. Mucosal (vaginal) Ab responses will also be measured. T cell responses will be measured by ELISpot. Based on data in vitro, the lead DNA vaccine formulation(s) will be assessed for efficacy in the mouse vaginal colonization model. In Aim 2 the constructs described in Aim 1 will be expressed using an mRNA vaccine delivery platform. As in Aim 1, we will evaluate Ab titers in serum and vaginal fluid, measure serum bactericidal activity, T cell responses and efficacy of the lead mRNA vaccine formulation(s) in the mouse model of gonorrhea. Successful completion of the work in this proposal will identify a lead gonococcal DNA and/or mRNA vaccine for further pre-clinical development.

抽象的淋病每年影响全球超过 8700 万人，2019 年有超过 60 万例淋病病例。据 CDC 报告，自 2009 年美国历史最低点以来，该数字增加了 92%。然而，真实的发病率据估计，美国每年约有 150 万例抗生素耐药性蔓延。治疗选择有限——目前，头孢曲松是唯一被批准的安全有效的一线治疗方法。迫切需要针对淋病的疫苗。脂寡糖（LOS）是地球上最丰富的分子。 mAb 2C7 识别的 LOS 表位在淋球菌表面发挥多方面作用。（因此称为 2C7 表位）由 >95% 不表达 2C7 的 Ng 突变体表达；我们的小组开发了 2C7 表位的肽模拟物（模拟表位），该表位在小鼠中减弱。当配置为多抗原肽 (MAP) 时，可引发杀菌抗体并减弱 Ng 定植此外，我们还阐明了 MAP 的作用机制为补体介导的杀伤（杀伤通过膜攻击复合物），强烈表明血清杀菌活性与机械相关在与 Evaxion Biotech 的合作中，我们筛选了 30 种抗原，并通过 EDEN，Evaxion 的专有计算机平台，用于小鼠的免疫原性、杀菌活性和功效这些研究确定了两种细胞分裂蛋白作为有希望的候选者。当配置为融合蛋白（嵌合体）时，细胞分裂蛋白表现出改善的活性。与单个蛋白质相比，其体内活性更高，目前是我们的主要蛋白质疫苗候选者。事实证明，疫苗在对抗 Covid-19 大流行方面非常成功。保护级别，已被证明是安全的，具有快速适应性和经济性。在这里，我们将利用这两者。提供保护性淋球菌抗原的新疫苗平台具有优势。更广泛的菌株覆盖范围，提高功效，也会增加耐药性发展的障碍。目标 1，我们将评估包含配置为 2C7 LOS 模拟表位 (PEP1) 的 DNA 疫苗构建体八聚体串联体 (PEP1_OCT)、细胞分裂蛋白嵌合体或两者的组合。评估抗体滴度和补体依赖性杀菌活性以及反应的持久性。将与目前正在开发的这些疫苗的蛋白质版本进行比较。（阴道）抗体反应也将通过 ELISpot 进行测量。在体外，将评估先导 DNA 疫苗制剂在小鼠阴道定植模型中的功效。在目标 2 中，将使用 mRNA 疫苗递送平台表达目标 1 中描述的构建体。目标1，我们将评估血清和阴道液中的抗体滴度，测量血清杀菌活性、T细胞反应主要 mRNA 疫苗制剂在淋病小鼠模型中的功效和功效成功完成。该提案中的工作将确定一种主要的淋球菌 DNA 和/或 mRNA 疫苗，用于进一步的临床前研究发展。