Biopharming Research Unit, Department of Molecular and Cell Biology, University of Cape Town, Private Bag X3, 22 University Ave, Rondebosch 7700, Cape Town, South Africa.
Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Anzio Road, Observatory 7925, South Africa.
Biotechnol J. 2019 Apr;14(4):e1800238. doi: 10.1002/biot.201800238. Epub 2018 Dec 18.
Rift Valley fever virus (RVFV) is an emerging mosquito-borne virus and hemorrhagic fever agent, which causes abortion storms in farmed small ruminants and potentially causes miscarriages in humans. Although live-attenuated vaccines are available for animals, they can only be used in endemic areas and there are currently no commercially available vaccines for humans. Here the authors describe the production of chimaeric RVFV virus-like particles transiently expressed in Nicotiana benthamiana by Agrobacterium tumefaciens-mediated gene transfer. The glycoprotein (Gn) gene is modified by removing its ectodomain (Gne) and fusing it to the transmembrane domain and cytosolic tail-encoding region of avian influenza H5N1 hemagglutinin. This is expressed transiently in N. benthamiana with purified protein yields calculated to be ≈57 mg kg fresh weight. Transmission electron microscopy shows putative chimaeric RVFV Gne-HA particles of 49-60 nm which are immunogenic, eliciting Gn-specific antibody responses in vaccinated mice without the use of adjuvant. To our knowledge, this is the first demonstration of the synthesis of Gne-HA chimaeric RVFV VLPs and the first demonstration of a detectable yield of RVFV Gn in plants.
裂谷热病毒（RVFV）是一种新兴的蚊媒病毒和出血热病原体，可导致养殖小反刍动物流产风暴，并可能导致人类流产。虽然有针对动物的减毒活疫苗，但只能在流行地区使用，目前尚无针对人类的商业疫苗。在这里，作者描述了通过农杆菌介导的基因转移在本氏烟中瞬时表达嵌合 RVFV 病毒样颗粒的生产。糖蛋白（Gn）基因通过去除其外域（Gne）并将其融合到禽流感 H5N1 血凝素的跨膜域和胞质尾编码区来修饰。这在本氏烟中瞬时表达，纯化蛋白的产量计算约为 57mg/kg 鲜重。透射电子显微镜显示出 49-60nm 的假定嵌合 RVFV Gne-HA 颗粒具有免疫原性，可在接种疫苗的小鼠中引起 Gn 特异性抗体反应，而无需使用佐剂。据我们所知，这是首次证明 Gne-HA 嵌合 RVFV VLPs 的合成，也是首次证明植物中 RVFV Gn 的可检测产量。
