Urakami Akane, Ngwe Tun Mya Myat, Moi Meng Ling, Sakurai Atsuko, Ishikawa Momoko, Kuno Sachiko, Ueno Ryuji, Morita Kouichi, Akahata Wataru
VLP Therapeutics, Gaithersburg, Maryland, USA.
Department of Virology, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan.
J Virol. 2017 Nov 14;91(23). doi: 10.1128/JVI.01181-17. Print 2017 Dec 1.
Dengue viruses (DENV) infect 50 to 100 million people each year. The spread of DENV-associated infections is one of the most serious public health problems worldwide, as there is no widely available vaccine or specific therapeutic for DENV infections. To address this, we developed a novel tetravalent dengue vaccine by utilizing virus-like particles (VLPs). We created recombinant DENV1 to -4 (DENV1-4) VLPs by coexpressing precursor membrane (prM) and envelope (E) proteins, with an F108A mutation in the fusion loop structure of E to increase the production of VLPs in mammalian cells. Immunization with DENV1-4 VLPs as individual, monovalent vaccines elicited strong neutralization activity against each DENV serotype in mice. For use as a tetravalent vaccine, DENV1-4 VLPs elicited high levels of neutralization activity against all four serotypes simultaneously. The neutralization antibody responses induced by the VLPs were significantly higher than those with DNA or recombinant E protein immunization. Moreover, antibody-dependent enhancement (ADE) was not observed against any serotype at a 1:10 serum dilution. We also demonstrated that the Zika virus (ZIKV) VLP production level was enhanced by introducing the same F108A mutation into the ZIKV envelope protein. Taken together, these results suggest that our strategy for DENV VLP production is applicable to other flavivirus VLP vaccine development, due to the similarity in viral structures, and they describe the promising development of an effective tetravalent vaccine against the prevalent flavivirus. Dengue virus poses one of the most serious public health problems worldwide, and the incidence of diseases caused by the virus has increased dramatically. Despite decades of effort, there is no effective treatment against dengue. A safe and potent vaccine against dengue is still needed. We developed a novel tetravalent dengue vaccine by using virus-like particles (VLPs), which are noninfectious because they lack the viral genome. Previous attempts of other groups to use dengue VLPs resulted in generally poor yields. We found that a critical amino acid mutation in the envelope protein enhances the production of VLPs. Our tetravalent vaccine elicited potent neutralizing antibody responses against all four DENV serotypes. Our findings can also be applied to vaccine development against other flaviviruses, such as Zika virus or West Nile virus.
登革病毒（DENV）每年感染5000万至1亿人。登革病毒相关感染的传播是全球最严重的公共卫生问题之一，因为目前尚无广泛可用的登革病毒疫苗或特异性治疗方法。为了解决这一问题，我们利用病毒样颗粒（VLP）开发了一种新型四价登革疫苗。我们通过共表达前体膜（prM）和包膜（E）蛋白，在E蛋白的融合环结构中引入F108A突变，以增加哺乳动物细胞中VLP的产量，从而构建了重组DENV1至4（DENV1-4）VLP。用DENV1-4 VLP作为单一单价疫苗进行免疫，可在小鼠体内引发针对每种登革病毒血清型的强烈中和活性。作为四价疫苗使用时，DENV1-4 VLP可同时引发针对所有四种血清型的高水平中和活性。VLP诱导的中和抗体反应显著高于DNA或重组E蛋白免疫诱导的反应。此外，在1:10血清稀释度下，未观察到针对任何血清型的抗体依赖性增强（ADE）现象。我们还证明，通过在寨卡病毒（ZIKV）包膜蛋白中引入相同的F108A突变，可提高ZIKV VLP的生产水平。综上所述，由于病毒结构的相似性，我们生产DENV VLP的策略适用于其他黄病毒VLP疫苗的开发，这些结果描述了一种针对流行黄病毒的有效四价疫苗的前景广阔的发展。登革病毒是全球最严重的公共卫生问题之一，由该病毒引起的疾病发病率急剧上升。尽管经过数十年的努力，仍没有针对登革热的有效治疗方法。仍然需要一种安全有效的登革热疫苗。我们利用病毒样颗粒（VLP）开发了一种新型四价登革疫苗，VLP由于缺乏病毒基因组而无传染性。其他团队此前使用登革病毒VLP的尝试通常产量较低。我们发现包膜蛋白中的一个关键氨基酸突变可提高VLP的产量。我们的四价疫苗引发了针对所有四种登革病毒血清型的强效中和抗体反应。我们的研究结果也可应用于针对其他黄病毒的疫苗开发，如寨卡病毒或西尼罗河病毒。
