Onderstepoort Biological Products SOC Ltd, Onderstepoort, South Africa.
Council for Scientific and Industrial Research (CSIR) Biosciences, Pretoria, South Africa.
Vaccine. 2019 Sep 24;37(41):6068-6075. doi: 10.1016/j.vaccine.2019.08.042. Epub 2019 Aug 27.
Bluetongue (BT) is a hemorrhagic non-contagious, biting midge-transmitted disease of wild and domestic ruminants that is caused by bluetongue virus (BTV). Annual vaccination plays a pivotal role in BT disease control in endemic regions. Due to safety concerns of the current BTV multivalent live attenuated vaccine (LAV), a safe efficacious new generation subunit vaccine such as a plant-produced BT virus-like particle (VLP) vaccine is imperative. Previously, homogenous BTV serotype 8 (BTV-8) VLPs were successfully produced in Nicotiana benthamiana plants and provided protective immunity in sheep. In this study, combinations of BTV capsid proteins from more than one serotype were expressed and assembled to form chimaeric BTV-3 and BTV-4 VLPs in N. benthamiana plants. The assembled homogenous BTV-8, as well as chimaeric BTV-3 and chimaeric BTV-4 VLP serotypes, were confirmed by SDS-PAGE, Transmission Electron microscopy (TEM) and protein confirmation using liquid chromatography-mass spectrometry (LC-MS/MS) based peptide sequencing. As VP2 is the major determinant eliciting protective immunity, the percentage coverage and number of unique VP2 peptides detected in assembled chimaeric BT VLPs were used as a guide to assemble the most appropriate chimaeric combinations. Both plant-produced chimaeric BTV-3 and BTV-4 VLPs were able to induce long-lasting serotype-specific neutralizing antibodies equivalent to the monovalent LAV controls. Antibody levels remained high to the end of the trial. Combinations of homogenous and chimaeric BT VLPs have great potential as a safe, effective multivalent vaccine with the ability to distinguish between vaccinated and infected individuals (DIVA) due to the absence of non-structural proteins.
蓝舌病(BT)是一种由蓝舌病病毒(BTV)引起的、非接触性、吸血性、野生和家养反刍动物传染病。在流行地区,年度疫苗接种对于 BT 疾病控制起着关键作用。由于当前 BTV 多价活减毒疫苗(LAV)的安全性问题,迫切需要一种安全有效的新一代亚单位疫苗,如植物生产的 BT 病毒样颗粒(VLP)疫苗。以前,在本氏烟植物中成功生产了同质的 BTV 血清型 8(BTV-8)VLPs,并在绵羊中提供了保护免疫。在这项研究中,来自不止一种血清型的 BTV 衣壳蛋白被表达和组装,以在本氏烟植物中形成嵌合的 BTV-3 和 BTV-4 VLP。通过 SDS-PAGE、透射电子显微镜(TEM)和基于液相色谱-质谱(LC-MS/MS)的肽测序确认组装的同质 BTV-8 以及嵌合 BTV-3 和嵌合 BTV-4 VLP 血清型。由于 VP2 是引发保护性免疫的主要决定因素,因此组装嵌合 BT VLP 中检测到的 VP2 肽的覆盖率和独特性百分比被用作组装最合适嵌合组合的指南。植物生产的嵌合 BTV-3 和 BTV-4 VLPs 均能够诱导与单价 LAV 对照相当的持久的血清型特异性中和抗体。试验结束时,抗体水平仍保持较高水平。由于不存在非结构蛋白,同质和嵌合 BT VLP 的组合具有作为安全有效的多价疫苗的巨大潜力,并且能够区分接种和感染个体(DIVA)。