tetano
Editor, Senior Moderator
Emerg Microbes Infect
. 2020 Sep 8;1-44.
doi: 10.1080/22221751.2020.1821583. Online ahead of print.
SARS-CoV-2 spike produced in insect cells elicits high neutralization titers in non-human primates
Tingting Li[SUP] 1 2 [/SUP], Qingbing Zheng[SUP] 1 2 [/SUP], Hai Yu[SUP] 1 2 [/SUP], Dinghui Wu[SUP] 3 [/SUP], Wenhui Xue[SUP] 1 2 [/SUP], Hualong Xiong[SUP] 1 2 [/SUP], Xiaofen Huang[SUP] 1 2 [/SUP], Meifeng Nie[SUP] 1 2 [/SUP], Mingxi Yue[SUP] 1 2 [/SUP], Rui Rong[SUP] 1 2 [/SUP], Sibo Zhang[SUP] 1 2 [/SUP], Yuyun Zhang[SUP] 1 2 [/SUP], Yangtao Wu[SUP] 1 2 [/SUP], Shaojuan Wang[SUP] 1 2 [/SUP], Zhenghui Zha[SUP] 1 2 [/SUP], Tingting Chen[SUP] 1 2 [/SUP], Tingting Deng[SUP] 1 2 [/SUP], Yingbin Wang[SUP] 1 2 [/SUP], Tianying Zhang[SUP] 1 2 [/SUP], Yixin Chen[SUP] 1 2 [/SUP], Quan Yuan[SUP] 1 2 [/SUP], Qinjian Zhao[SUP] 1 2 [/SUP], Jun Zhang[SUP] 1 2 [/SUP], Ying Gu[SUP] 1 2 [/SUP], Shaowei Li[SUP] 1 2 [/SUP], Ningshao Xia[SUP] 1 2 4 [/SUP]
Affiliations
Abstract
The current coronavirus disease 2019 (COVID-19) pandemic was the result of the rapid transmission of a highly pathogenic coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), for which there is no efficacious vaccine or therapeutic. Toward the development of a vaccine, here we expressed and evaluated as potential candidates four versions of the spike (S) protein using an insect cell expression system: receptor binding domain (RBD), S1 subunit, the wild-type S ectodomain (S-WT), and the prefusion trimer-stabilized form (S-2P). We showed that RBD appears as a monomer in solution, whereas S1, S-WT, and S-2P associate as homotrimers with substantial glycosylation. Cryo-electron microscopy analyses suggested show that S-2P assumes an identical trimer conformation as the similarly engineered S protein expressed in 293 mammalian cells but with reduced glycosylation. Overall, the four proteins confer excellent antigenicity with convalescent COVID-19 patient sera in enzyme-linked immunosorbent assay (ELISA), yet show distinct reactivities in immunoblotting. RBD, S-WT and S-2P, but not S1, induce high neutralization titers (>3-log) in mice after a three-round immunization regimen. The high immunogenicity of S-2P could be maintained at the lowest dose (1 μg) with the inclusion of an aluminum adjuvant. Higher doses (20 μg) of S-2P can elicit high neutralization titers in non-human primates that exceed 40-times the mean titers measured in convalescent COVID-19 subjects. Our results suggest that the prefusion trimer-stabilized SARS-CoV-2 S-protein from insect cells may offer a potential candidate strategy for the development of a recombinant COVID-19 vaccine.
Keywords: COVID-19; Immunogenicity; Insect cell expression system; SARS-CoV-2; Spike.
. 2020 Sep 8;1-44.
doi: 10.1080/22221751.2020.1821583. Online ahead of print.
SARS-CoV-2 spike produced in insect cells elicits high neutralization titers in non-human primates
Tingting Li[SUP] 1 2 [/SUP], Qingbing Zheng[SUP] 1 2 [/SUP], Hai Yu[SUP] 1 2 [/SUP], Dinghui Wu[SUP] 3 [/SUP], Wenhui Xue[SUP] 1 2 [/SUP], Hualong Xiong[SUP] 1 2 [/SUP], Xiaofen Huang[SUP] 1 2 [/SUP], Meifeng Nie[SUP] 1 2 [/SUP], Mingxi Yue[SUP] 1 2 [/SUP], Rui Rong[SUP] 1 2 [/SUP], Sibo Zhang[SUP] 1 2 [/SUP], Yuyun Zhang[SUP] 1 2 [/SUP], Yangtao Wu[SUP] 1 2 [/SUP], Shaojuan Wang[SUP] 1 2 [/SUP], Zhenghui Zha[SUP] 1 2 [/SUP], Tingting Chen[SUP] 1 2 [/SUP], Tingting Deng[SUP] 1 2 [/SUP], Yingbin Wang[SUP] 1 2 [/SUP], Tianying Zhang[SUP] 1 2 [/SUP], Yixin Chen[SUP] 1 2 [/SUP], Quan Yuan[SUP] 1 2 [/SUP], Qinjian Zhao[SUP] 1 2 [/SUP], Jun Zhang[SUP] 1 2 [/SUP], Ying Gu[SUP] 1 2 [/SUP], Shaowei Li[SUP] 1 2 [/SUP], Ningshao Xia[SUP] 1 2 4 [/SUP]
Affiliations
- PMID: 32897177
- DOI: 10.1080/22221751.2020.1821583
Abstract
The current coronavirus disease 2019 (COVID-19) pandemic was the result of the rapid transmission of a highly pathogenic coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), for which there is no efficacious vaccine or therapeutic. Toward the development of a vaccine, here we expressed and evaluated as potential candidates four versions of the spike (S) protein using an insect cell expression system: receptor binding domain (RBD), S1 subunit, the wild-type S ectodomain (S-WT), and the prefusion trimer-stabilized form (S-2P). We showed that RBD appears as a monomer in solution, whereas S1, S-WT, and S-2P associate as homotrimers with substantial glycosylation. Cryo-electron microscopy analyses suggested show that S-2P assumes an identical trimer conformation as the similarly engineered S protein expressed in 293 mammalian cells but with reduced glycosylation. Overall, the four proteins confer excellent antigenicity with convalescent COVID-19 patient sera in enzyme-linked immunosorbent assay (ELISA), yet show distinct reactivities in immunoblotting. RBD, S-WT and S-2P, but not S1, induce high neutralization titers (>3-log) in mice after a three-round immunization regimen. The high immunogenicity of S-2P could be maintained at the lowest dose (1 μg) with the inclusion of an aluminum adjuvant. Higher doses (20 μg) of S-2P can elicit high neutralization titers in non-human primates that exceed 40-times the mean titers measured in convalescent COVID-19 subjects. Our results suggest that the prefusion trimer-stabilized SARS-CoV-2 S-protein from insect cells may offer a potential candidate strategy for the development of a recombinant COVID-19 vaccine.
Keywords: COVID-19; Immunogenicity; Insect cell expression system; SARS-CoV-2; Spike.