Developing Vertebrate-Specific Replication-Defective Dengue Virus as Novel Single-CycleDengue Vaccine Candidate

脊椎动物特异性复制缺陷型登革病毒的研制 一种新的单循环登革热候选疫苗 摘要 据估计，每年至少有3.9亿登革热病毒（DENV）感染， 年，DENV流行被世界卫生组织列为世界十大公共卫生威胁之一。 2019.目前尚无特效治疗方法。迫切需要一种通用疫苗。 DENV疫苗开发的独特挑战是登革热疫苗必须诱导 同时对所有四种血清型提供长期保护。历史上，四价 活的减毒病毒疫苗已经表明， 对所有四种血清型。此外，灭活病毒疫苗不能赋予长期免疫力， 预防潜在的抗体依赖性增强（ADE）。考虑到这些障碍， 我们已经研究了单周期假感染性DENV作为候选疫苗， 诱导针对所有四种血清型平衡的长期免疫。一个重大障碍 这种方法的另一个优点是，复制假侵染性DENV通常需要复杂的 以及低效率的封装单元，使得规模化生产困难且成本高。 因此，为了实现开发安全、有效和负担得起的DENV的总体目标， 疫苗，我们将双嗜性DENV转化为人工昆虫特异性病毒， 克服了生产单循环病毒疫苗对包装细胞的依赖。 这些脊椎动物特异性复制缺陷型DENV（VSRD-DENV）是在 通过优化病毒前膜蛋白（prM）中的弗林蛋白酶切割位点。初步 VSRD-DENV 1和VSRD-DENV 2的动物实验证明， VSRD-DENV诱导了强大的保护性免疫力，具有固有的高安全水平， 小鼠基于这些非常有希望的初步结果，并考虑到迫切需要 需要一种有效的登革热疫苗，天正生物医学公司和霍华德大学 已经联手加速对基于VSRD-DENV的登革热的评估 疫苗为了实现这一目标，我们建议生成和表征VSRD-DENV 3 和VSRD-DENV 4疫苗候选病毒。然后我们将进行全面的 四价VSRD-DENV的免疫原性和保护效力的分析 敏感的AG 129小鼠模型。成功完成这些拟议的研究将 使登革热候选疫苗能够进行非人灵长类动物测试，并建立一个 为其他重要黄病毒的疫苗开发提供了平台。

Developing Vertebrate-Specific Replication-Defective Dengue Virus as a Novel Single-Cycle Dengue Vaccine Candidate Abstract With an estimated minimum of 390 million dengue virus (DENV) infections per year, the DENV epidemic was listed as one of the world's top 10 public health threats by WHO in 2019. At present, there is no specific treatment. A universal vaccine is urgently needed. DENV vaccine development's unique challenge is that a dengue vaccine must induce long-term protection against all four serotypes simultaneously. Historically, tetravalent live attenuated viral vaccines have shown that it is difficult to achieve balanced immunity to all four serotypes. Also, inactivated virus vaccines can't confer long-term immunity to prevent potential antibody-dependent enhancement (ADE). Mindful of these obstacles, we have investigated single-cycle, pseudoinfectious DENVs as vaccine candidates to induce balanced long-term immunity against all four serotypes. A significant impediment to this approach is that replicating pseudoinfecious DENVs usually require complicated and low-efficient packaging cells, making the scale-up production difficult and costly. Thus, towards the overall goal of developing a safe, effective, and affordable DENV vaccine, we converted dual-tropic DENVs into artificial insect-specific viruses to overcome the dependence on packaging cells to produce a single-cycle virus vaccine. These vertebrate-specific replication-defective DENVs (VSRD-DENV) were generated by optimizing the furin cleavage site in viral pre-membrane protein (prM). Preliminary animal experiments with VSRD-DENV1 and VSRD-DENV2 demonstrated that the VSRD-DENVs induced robust protective immunity with inherent high safety levels in mice. Based on these highly promising preliminary results and considering the urgent need for an effective dengue vaccine, Tengen Biomedical Co. and Howard University have teamed up to accelerate the evaluation of the VSRD-DENVs-based dengue vaccine. To achieve this goal, we propose to generate and characterize VSRD-DENV3 and VSRD-DENV4 vaccine candidate viruses. We will then perform a comprehensive analysis of the immunogenicity and protective efficacy of tetravalent VSRD-DENVs in a sensitive AG129 mouse model. Successful completion of these proposed studies will enable the dengue vaccine candidate into non-human primate testing and establish a platform for developing vaccines for other important flaviviruses.