Gonococcal peptide vaccine candidate display using HPV virus-like particles

摘要 全球每年约有8700万新发淋病病例。2018年，报告了583，405例病例， 在美国，疾病发病率自2009年历史低点以来增加了82.6%。人乳头瘤病毒（HPV） 是宫颈癌的病原体，宫颈癌是全球女性第四大常见癌症， 每年约56.7万例，31.1万例死亡。其中80%发生在资源贫乏的发展中国家， 国家目前有三种有效的预防性HPV疫苗。尽管取得了巨大的成功， 宫颈癌的负担仍然很高，特别是在发展中国家， 疫苗价格昂贵，而且针对特定类型。淋病奈瑟菌（Ng）是淋病的病原体， 对临床使用的几乎所有抗生素都产生了耐药性，预示着淋病无法治愈的时代的到来。 开发安全有效的淋病疫苗是全球公共卫生的优先事项。 脂寡糖（LOS）是淋球菌表面最丰富的分子， 在细菌毒力中的作用。由mAb 2C 7识别的LOS表位（因此称为2C 7表位）是 在体内由>95%的Ng表达;不表达2C 7表位的Ng突变体在小鼠中减毒。这 这是因为2C 7 LOS表位可以用唾液酸修饰，这增加了细菌对 补体依赖性杀伤并结合Siglec受体以下调宿主炎症。我们有 开发了2C 7表位的肽模拟物（模拟表位），当配置为多抗原肽时， (MAP)在小鼠中以补体依赖性方式增强杀菌Ab并减弱Ng定殖。 该项目将利用HPV病毒样颗粒（VLP）平台来递送2C 7模拟表位。VLP是一个 增强肽免疫原性的极好平台。我们已经生产出了表达 Ng模拟表位肽（称为HPV-Ng）在烟草植物和哺乳动物细胞中的小规模应用。 烟草植物表达中的生产可以降低成本，这是疫苗的一个重要考虑因素。 对社会经济地位低下的人群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引发的抗体（Ab）的免疫原性和体外功能。我们将测量Ab反应， 雄性和雌性BALB/c、C57 BL/6和CD 1小鼠针对i）2C 7 LOS表位和ii）针对HPV 16。一个 完整的补体系统对于抗2C 7表位的抗体的体内活性是必需的和充分的。 因此，我们将测试针对Ng的免疫Ab的补体依赖性杀菌活性。的能力 中和假病毒粒子（PsVs）的抗HPV Ab-抗HPV功效的体外测量-将是 测定了在目标2中，将在淋球菌阴道定殖中测试HPV-Ng针对Ng的功效。 在表达人补体抑制剂的小鼠中建立模型，以更好地模拟 并提供更严格的疫苗效力测试。将测试HPV-Ng针对HPV 16的功效 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.