Gonococcal peptide vaccine candidate display using HPV virus-like particles

摘要 全球每年新增淋病病例约8700万例。在2018年，报告了583,405例 自2009年的历史最低点以来，美国的发病率上升了82.6%。人乳头瘤病毒 是宫颈癌的诱因，宫颈癌是全球第四大最常见的女性癌症，导致 每年约有567,000例和311,000人死亡。其中约80%的病例发生在资源匮乏的发展中国家 国家。目前有三种获得许可的有效预防性HPV疫苗。尽管取得了巨大的成功， 在这些疫苗中，宫颈癌的负担仍然很高，特别是在发展中国家，因为这些 疫苗价格昂贵，且因类型而异。淋病的病原体淋病奈瑟菌(Ng) 对临床使用的几乎每一种抗生素都产生抗药性，预示着一个无法治愈的淋病时代。 开发安全有效的淋病疫苗是全球公共卫生的优先事项。 脂低聚糖(LOS)是淋球菌表面含量最丰富的分子，其作用是多方面的 在细菌毒力中的作用。单抗2C7识别的LOS表位(因此称为2C7表位)是 体内95%的Ng表达；不表达2C7表位的Ng突变体在小鼠体内减毒。这 是因为2C7 LOS表位可以用唾液酸修饰，这增加了细菌对 补体依赖的杀伤和参与Siglec受体下调宿主炎症。我们有 开发了一种模拟2C7表位的多肽，当配置为多抗原肽时 (MAP)以补体依赖的方式诱导杀菌抗体并减弱Ng在小鼠体内的定植。 该项目将利用HPV病毒样颗粒(VLP)平台来提供2C7模拟表位。VLP是一种 增强多肽免疫原性的极佳平台。我们已经生产了HPV VLP，可以表达 Ng模拟表位多肽(称为HPV-Ng)在烟草植物和哺乳动物细胞中的小规模存在。 烟草植物表达的生产可以降低成本，这是疫苗的一个重要考虑因素 对社会经济贫困人口造成不成比例影响的性传播感染。在目标1中，我们将测试 HPV-Ng诱导的抗体的免疫原性和体外功能我们将测量抗体的反应 雄性和雌性BALB/c、C57BL/6和CD1小鼠分别抗2C7 LOS表位和抗HPV16。一个 完整的补体系统是抗2C7表位抗体体内活性的必要条件和充分条件。 因此，我们将检测针对Ng的免疫抗体的补体依赖杀菌活性。的能力 用于中和假病毒粒子(PSV)的抗HPV抗体--一种体外衡量HPV有效性的指标--将 量过了。在目标2中，将在淋球菌阴道定植中测试HPV-Ng对Ng的疗效。 在小鼠中表达人补体抑制物的模型，以更好地模拟补体系统 并提供了更严格的疫苗效力测试。将测试HPV-Ng对HPV16的疗效 在小鼠的HPV PSV宫颈阴道模型中。

ABSTRACT About 87 million new cases of gonorrhea occur globally, annually. In 2018, 583,405 cases were reported in the U.S, an 82.6% increase in disease incidence since the historic low in 2009. Human papillomaviruses (HPVs) are the causative agents of cervical cancer, the 4th most common cancer in women globally, resulting in ~567,000 cases and 311,000 deaths every year. About 80% of these cases occur in resource-poor developing countries. There are currently three licensed effective prophylactic HPV vaccines. Despite the great success of these vaccines, the cervical cancer burden remains high, particularly in developing countries, as these vaccines are expensive and type-specific. Neisseria gonorrhoeae (Ng), the causative agent of gonorrhea, has become resistant to almost every antibiotic in clinical use and portends an era of untreatable gonorrhea. Development of a safe and effective vaccine against gonorrhea is a global public health priority. 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. This is because the 2C7 LOS epitope can be modified with sialic acid, which increases resistance of the bacteria to complement-dependent killing and engages Siglec receptors to down-regulate host inflammation. We have 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 in a complement-dependent manner. This project will leverage the HPV virus-like particle (VLP) platform to deliver the 2C7 mimitope. VLPs are an excellent platform to enhance immunogenicity of peptides. We have already produced HPV VLPs that express the Ng mimitope peptide (called HPV-Ng) in tobacco plants and in mammalian cells on a small scale. Production in tobacco plant expression could reduce costs, an important consideration for vaccines against STIs that disproportionately affect socio-economically underprivileged populations. In Aim 1 we will test the immunogenicity and in vitro function of antibodies (Abs) elicited by HPV-Ng. We will measure Ab responses in male and female BALB/c, C57BL/6 and CD1 mice against i) the 2C7 LOS epitope and ii) against HPV16. An intact complement system is necessary and sufficient for activity in vivo of Ab against the 2C7epitope. Therefore, we will test complement-dependent bactericidal activity of immune Ab against Ng. The ability of anti-HPV Ab to neutralize pseudovirions (PsVs) – an in vitro measure of efficacy against HPV – will be measured. In Aim 2, the efficacy of HPV-Ng against Ng will be tested in a gonococcal vaginal colonization model in mice that express human complement inhibitors, to better simulate the complement system of humans and provide a more stringent test of vaccine efficacy. Efficacy of HPV-Ng against HPV16 will be tested in a HPV PsV cervicovaginal model in mice.