Schweneker Marc, Laimbacher Andrea S, Zimmer Gert, Wagner Susanne, Schraner Elisabeth M, Wolferstätter Michael, Klingenberg Marieken, Dirmeier Ulrike, Steigerwald Robin, Lauterbach Henning, Hochrein Hubertus, Chaplin Paul, Suter Mark, Hausmann Jürgen
Bavarian Nordic GmbH, Martinsried, Germany
Universität Zürich, Virologisches Institut, Zürich, Switzerland.
J Virol. 2017 May 12;91(11). doi: 10.1128/JVI.00343-17. Print 2017 Jun 1.
There are currently no approved therapeutics or vaccines to treat or protect against the severe hemorrhagic fever and death caused by Ebola virus (EBOV). Ebola virus-like particles (EBOV VLPs) consisting of the matrix protein VP40, the glycoprotein (GP), and the nucleoprotein (NP) are highly immunogenic and protective in nonhuman primates against Ebola virus disease (EVD). We have constructed a modified vaccinia virus Ankara-Bavarian Nordic (MVA-BN) recombinant coexpressing VP40 and GP of EBOV Mayinga and the NP of Taï Forest virus (TAFV) (MVA-BN-EBOV-VLP) to launch noninfectious EBOV VLPs as a second vaccine modality in the MVA-BN-EBOV-VLP-vaccinated organism. Human cells infected with either MVA-BN-EBOV-VLP or MVA-BN-EBOV-GP showed comparable GP expression levels and transport of complex N-glycosylated GP to the cell surface. Human cells infected with MVA-BN-EBOV-VLP produced large amounts of EBOV VLPs that were decorated with GP spikes but excluded the poxviral membrane protein B5, thus resembling authentic EBOV particles. The heterologous TAFV NP enhanced EBOV VP40-driven VLP formation with efficiency similar to that of the homologous EBOV NP in a transient-expression assay, and both NPs were incorporated into EBOV VLPs. EBOV GP-specific CD8 T cell responses were comparable between MVA-BN-EBOV-VLP- and MVA-BN-EBOV-GP-immunized mice. The levels of EBOV GP-specific neutralizing and binding antibodies, as well as GP-specific IgG1/IgG2a ratios induced by the two constructs, in mice were also similar, raising the question whether the quality rather than the quantity of the GP-specific antibody response might be altered by an EBOV VLP-generating MVA recombinant. The recent outbreak of Ebola virus (EBOV), claiming more than 11,000 lives, has underscored the need to advance the development of safe and effective filovirus vaccines. Virus-like particles (VLPs), as well as recombinant viral vectors, have proved to be promising vaccine candidates. Modified vaccinia virus Ankara-Bavarian Nordic (MVA-BN) is a safe and immunogenic vaccine vector with a large capacity to accommodate multiple foreign genes. In this study, we combined the advantages of VLPs and the MVA platform by generating a recombinant MVA-BN-EBOV-VLP that would produce noninfectious EBOV VLPs in the vaccinated individual. Our results show that human cells infected with MVA-BN-EBOV-VLP indeed formed and released EBOV VLPs, thus producing a highly authentic immunogen. MVA-BN-EBOV-VLP efficiently induced EBOV-specific humoral and cellular immune responses in vaccinated mice. These results are the basis for future advancements, e.g., by including antigens from various filoviral species to develop multivalent VLP-producing MVA-based filovirus vaccines.
目前尚无经批准的治疗方法或疫苗可用于治疗或预防由埃博拉病毒（EBOV）引起的严重出血热和死亡。由基质蛋白VP40、糖蛋白（GP）和核蛋白（NP）组成的埃博拉病毒样颗粒（EBOV VLPs）具有高度免疫原性，并且在非人灵长类动物中对埃博拉病毒病（EVD）具有保护作用。我们构建了一种安卡拉-巴伐利亚北欧改良痘苗病毒（MVA-BN）重组体，其共表达EBOV Mayinga的VP40和GP以及泰伊森林病毒（TAFV）的NP（MVA-BN-EBOV-VLP），以便在接种MVA-BN-EBOV-VLP的生物体中作为第二种疫苗形式产生非感染性EBOV VLPs。感染MVA-BN-EBOV-VLP或MVA-BN-EBOV-GP的人类细胞显示出相当的GP表达水平，以及复杂的N-糖基化GP向细胞表面的转运。感染MVA-BN-EBOV-VLP的人类细胞产生了大量装饰有GP刺突但排除了痘病毒膜蛋白B5的EBOV VLPs，因此类似于真实的EBOV颗粒。在瞬时表达试验中，异源TAFV NP增强了EBOV VP40驱动的VLP形成，其效率与同源EBOV NP相似，并且两种NP都被整合到EBOV VLPs中。在MVA-BN-EBOV-VLP免疫和MVA-BN-EBOV-GP免疫的小鼠之间，EBOV GP特异性CD8 T细胞反应相当。两种构建体在小鼠中诱导的EBOV GP特异性中和抗体和结合抗体水平，以及GP特异性IgG1/IgG2a比率也相似，这就提出了一个问题，即产生EBOV VLP的MVA重组体是否可能改变GP特异性抗体反应的质量而非数量。最近爆发的埃博拉病毒（EBOV）已导致超过11,000人死亡，这突出了推进安全有效的丝状病毒疫苗开发的必要性。病毒样颗粒（VLPs）以及重组病毒载体已被证明是有前景的疫苗候选物。安卡拉-巴伐利亚北欧改良痘苗病毒（MVA-BN）是一种安全且具有免疫原性的疫苗载体，具有容纳多个外源基因的大容量。在本研究中，我们通过产生一种重组MVA-BN-EBOV-VLP，将VLPs和MVA平台的优势结合起来，该重组体将在接种疫苗的个体中产生非感染性EBOV VLPs。我们的结果表明，感染MVA-BN-EBOV-VLP的人类细胞确实形成并释放了EBOV VLPs，从而产生了高度真实的免疫原。MVA-BN-EBOV-VLP在接种疫苗的小鼠中有效诱导了EBOV特异性体液和细胞免疫反应。这些结果是未来进展的基础，例如通过纳入来自各种丝状病毒物种的抗原以开发基于MVA的多价产生VLP的丝状病毒疫苗。
