Loop Isabelle, Ke Yuan-Dun, Chen Wei-June, Tsai Kun-Hsien, Hsu Wei-Li, Fan Yi-Chin
Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan.
Department of Public Health and Parasitology, Chang Gung University, Taoyuan, Taiwan.
Appl Microbiol Biotechnol. 2025 Mar 3;109(1):56. doi: 10.1007/s00253-025-13436-y.
Tick-borne severe fever with thrombocytopenia syndrome (SFTS) is an emerging zoonotic disease caused by the SFTS virus (SFTSV). Serological assays based on the nucleocapsid protein and partial glycoprotein of this virus have been used for detecting SFTSV infections in humans and animals. However, whether the complete SFTSV glycoprotein (Gn/Gc) can induce the assembly of virus-like particles (VLPs) which can be used for serological surveillance and vaccine production remains unclear. In this study, we successfully expressed and secreted SFTSV Gn/Gc antigens by using a single plasmid encoding the complete glycoprotein sequence of the dominant genotype B virus. HEK293T and COS-1 cells were transfected with the aforementioned plasmid; cultivating these cells at 32 °C, instead of 37 °C, led to 4.0- and 3.3-fold higher antigen recovery, respectively. The secreted Gn/Gc antigens at 32 °C retained epitopes resembling those of the virion; these epitopes were recognized by a SFTS human-derived monoclonal antibody. Sucrose density gradient centrifugation, followed by transmission electron microscopy, confirmed the formation of VLPs with a diameter of approximately 100 nm. Overall, our findings highlight the potential of SFTSV VLPs for serological surveillance and vaccine development. KEY POINTS: • Cultivating transfected cells at 32 °C boosts SFTSV glycoprotein production. • Complete SFTSV glycoprotein expression facilitates virus-like particle assembly. • The assembly does not require any other viral proteins or RNA.
蜱传发热伴血小板减少综合征（SFTS）是一种由SFTS病毒（SFTSV）引起的新发人畜共患病。基于该病毒核衣壳蛋白和部分糖蛋白的血清学检测方法已用于检测人和动物的SFTSV感染。然而，完整的SFTSV糖蛋白（Gn/Gc）能否诱导形成可用于血清学监测和疫苗生产的病毒样颗粒（VLP）仍不清楚。在本研究中，我们通过使用编码优势基因型B病毒完整糖蛋白序列的单质粒成功表达并分泌了SFTSV Gn/Gc抗原。用上述质粒转染HEK293T和COS-1细胞；在32℃而非37℃培养这些细胞，分别使抗原回收率提高了4.0倍和3.3倍。在32℃分泌的Gn/Gc抗原保留了与病毒粒子相似的表位；这些表位可被一种人源SFTS单克隆抗体识别。蔗糖密度梯度离心，随后进行透射电子显微镜观察，证实形成了直径约100nm的VLP。总体而言，我们的研究结果突出了SFTSV VLP在血清学监测和疫苗开发方面的潜力。要点：• 在32℃培养转染细胞可提高SFTSV糖蛋白产量。• 完整的SFTSV糖蛋白表达促进病毒样颗粒组装。• 组装不需要任何其他病毒蛋白或RNA。
