Siriwattananon Konlavat, Manopwisedjaroen Suwimon, Shanmugaraj Balamurugan, Rattanapisit Kaewta, Phumiamorn Supaporn, Sapsutthipas Sompong, Trisiriwanich Sakalin, Prompetchara Eakachai, Ketloy Chutitorn, Buranapraditkun Supranee, Wijagkanalan Wassana, Tharakhet Kittipan, Kaewpang Papatsara, Leetanasaksakul Kantinan, Kemthong Taratorn, Suttisan Nutchanat, Malaivijitnond Suchinda, Ruxrungtham Kiat, Thitithanyanont Arunee, Phoolcharoen Waranyoo
Research Unit for Plant-produced Pharmaceuticals, Chulalongkorn University, Bangkok, Thailand.
Department of Pharmacognosy and Pharmaceutical Botany, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok, Thailand.
Front Plant Sci. 2021 May 13;12:682953. doi: 10.3389/fpls.2021.682953. eCollection 2021.
The emergence of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has affected global public health and economy. Despite the substantial efforts, only few vaccines are currently approved and some are in the different stages of clinical trials. As the disease rapidly spreads, an affordable and effective vaccine is urgently needed. In this study, we investigated the immunogenicity of plant-produced receptor-binding domain (RBD) of SARS-CoV-2 in order to use as a subunit vaccine. In this regard, RBD of SARS-CoV-2 was fused with Fc fragment of human IgG1 and transiently expressed in by agroinfiltration. The plant-produced RBD-Fc fusion protein was purified from the crude extract by using protein A affinity column chromatography. Two intramuscular administration of plant-produced RBD-Fc protein formulated with alum as an adjuvant have elicited high neutralization titers in immunized mice and cynomolgus monkeys. Further it has induced a mixed Th1/Th2 immune responses and vaccine-specific T-lymphocyte responses which was confirmed by interferon-gamma (IFN-γ) enzyme-linked immunospot assay. Altogether, our results demonstrated that the plant-produced SARS-CoV-2 RBD has the potential to be used as an effective vaccine candidate against SARS-CoV-2. To our knowledge, this is the first report demonstrating the immunogenicity of plant-produced SARS-CoV-2 RBD protein in mice and non-human primates.
由严重急性呼吸综合征冠状病毒2（SARS-CoV-2）引起的2019冠状病毒病（COVID-19）的出现影响了全球公共卫生和经济。尽管付出了巨大努力，但目前只有少数疫苗获得批准，有些疫苗正处于临床试验的不同阶段。随着该疾病迅速传播，迫切需要一种负担得起且有效的疫苗。在本研究中，我们研究了植物生产的SARS-CoV-2受体结合域（RBD）的免疫原性，以便用作亚单位疫苗。在这方面，将SARS-CoV-2的RBD与人IgG1的Fc片段融合，并通过农杆菌浸润在植物中瞬时表达。通过蛋白A亲和柱色谱法从粗提物中纯化植物生产的RBD-Fc融合蛋白。用明矾作为佐剂配制的植物生产的RBD-Fc蛋白进行两次肌肉注射，在免疫的小鼠和食蟹猴中引发了高中和效价。此外，它诱导了混合的Th1/Th2免疫反应和疫苗特异性T淋巴细胞反应，这通过干扰素-γ（IFN-γ）酶联免疫斑点试验得到证实。总之，我们的结果表明，植物生产的SARS-CoV-2 RBD有潜力用作针对SARS-CoV-2的有效疫苗候选物。据我们所知，这是第一份证明植物生产的SARS-CoV-2 RBD蛋白在小鼠和非人类灵长类动物中具有免疫原性的报告。
