Assembly of Replication-Incompetent African Horse Sickness Virus Particles: Rational Design of Vaccines for All Serotypes.
Assembly of Replication-Incompetent African Horse Sickness Virus Particles: Rational Design of Vaccines for All Serotypes.
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DOI：
10.1128/jvi.00548-16
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发表时间：
2016-08-15
影响因子：
5.4
通讯作者：
Roy P
中科院分区：
文献类型：
--
作者：
Lulla V;Lulla A;Wernike K;Aebischer A;Beer M;Roy P
非洲马病病毒(AHSV)是呼肠孤病毒科的一种环状病毒，具有9种不同的血清型，可在马匹中引起毁灭性的疾病。病毒粒子由七种蛋白质组成，分为三个同心层，外层由VP2和VP5组成，中间层由VP7组成，内层由VP3组成，内层包裹着VP1、VP4和VP6的复制酶复合体和一个由10个双链RNA片段组成的基因组。在这项研究中，我们试图开发针对所有AHSV血清型的高效候选疫苗，不仅考虑了免疫原性和安全性，还考虑了病毒生产力和稳定性参数，这是疫苗候选的基本标准。为了实现这一目标，我们首先建立了针对AHSV 1型(AHSV1)的高效反向遗传学(RG)系统，随后建立了VP6缺陷AHSV1株与VP6的反式互补相结合的反向遗传学(RG)系统。然后，这被用来产生所有九种血清型的有缺陷的颗粒，这需要交换两到五个RNA片段来获得等量的颗粒滴度。所有重组缺陷型病毒都可以在补充了VP6的细胞中扩增并繁殖到高滴度，但在任何其他细胞中都完全无效。此外，在I型干扰素受体(IFNAR)基因敲除小鼠中，这些复制不具复制能力的AHSV颗粒被证明对同源毒力病毒的攻击具有高度保护作用。因此，这些有缺陷的病毒有可能被用于开发安全和稳定的候选疫苗。RG系统也为研究单个AHSV蛋白在病毒组装、形态发生和致病机制中的作用提供了一个强大的工具。非洲马病病毒通过叮咬的蚊子传播，并在马匹中引起非洲马病，幼马的死亡率高达95%。因此，由于马业遭受重大经济损失，开发高效疫苗极其重要。通过建立高效的RG系统，产生了所有9种AHSV血清型的复制缺陷病毒。这些缺陷病毒在与VP6互补的细胞系中获得了高滴度，但未能在野生型哺乳动物或昆虫细胞中繁殖。重要的是，这些候选疫苗株在IFNAR−/−小鼠模型中显示出对AHSV感染的强大保护效果。
African horse sickness virus (AHSV), an orbivirus in the Reoviridae family with nine different serotypes, causes devastating disease in equids. The virion particle is composed of seven proteins organized in three concentric layers, an outer layer made of VP2 and VP5, a middle layer made of VP7, and inner layer made of VP3 that encloses a replicase complex of VP1, VP4, and VP6 and a genome of 10 double-stranded RNA segments. In this study, we sought to develop highly efficacious candidate vaccines against all AHSV serotypes, taking into account not only immunogenic and safety properties but also virus productivity and stability parameters, which are essential criteria for vaccine candidates. To achieve this goal, we first established a highly efficient reverse genetics (RG) system for AHSV serotype 1 (AHSV1) and, subsequently, a VP6-defective AHSV1 strain in combination with in trans complementation of VP6. This was then used to generate defective particles of all nine serotypes, which required the exchange of two to five RNA segments to achieve equivalent titers of particles. All reassortant-defective viruses could be amplified and propagated to high titers in cells complemented with VP6 but were totally incompetent in any other cells. Furthermore, these replication-incompetent AHSV particles were demonstrated to be highly protective against homologous virulent virus challenges in type I interferon receptor (IFNAR)-knockout mice. Thus, these defective viruses have the potential to be used for the development of safe and stable vaccine candidates. The RG system also provides a powerful tool for the study of the role of individual AHSV proteins in virus assembly, morphogenesis, and pathogenesis. IMPORTANCE African horse sickness virus is transmitted by biting midges and causes African horse sickness in equids, with mortality reaching up to 95% in naive horses. Therefore, the development of efficient vaccines is extremely important due to major economic losses in the equine industry. Through the establishment of a highly efficient RG system, replication-deficient viruses of all nine AHSV serotypes were generated. These defective viruses achieved high titers in a cell line complemented with VP6 but failed to propagate in wild-type mammalian or insect cells. Importantly, these candidate vaccine strains showed strong protective efficacy against AHSV infection in an IFNAR−/− mouse model.