Enhanced elicitation of potent neutralizing antibodies by the SARS-CoV-2 spike receptor binding domain Fc fusion protein in mice. Issue 46 (27th October 2020)

• Record Type: Journal Article
• Authors: Liu, Xianglei; Drelich, Aleksandra; Li, Wei; Chen, Chuan; Sun, Zehua; Shi, Megan; Adams, Cynthia; Mellors, John W.; Tseng, Chien-Te; Dimitrov, Dimiter S.
• Is Part Of: Vaccine. Volume 38:Issue 46(2020)
• Page Start: 7205
• Page End: 7212
• Publication Date: 2020-10-27
• Subjects: SARS-CoV-2 -- Subunit vaccine -- Receptor-binding domain (RBD) -- Cell–cell fusion assay; Vaccines -- Periodicals; 615.372
• DOI: 10.1016/j.vaccine.2020.09.058
• Languages: English
• ISSNs: 0264-410X

Abstract

Highlights: SARS-CoV-2 RBD-Fc elicited higher neutralizing antibodies titer than RBD. Cell–cell fusion assay showed a strong correlation with the neutralization assay. Anti-RBD sera did not enhance the pseudotyped SARS-CoV-2 infection of K562 cells. Abstract: The development of an effective vaccine against SARS-CoV-2 is urgently needed. We generated SARS-CoV-2 RBD-Fc fusion protein and evaluated its potency to elicit neutralizing antibody response in mice. RBD-Fc elicited a higher neutralizing antibodies titer than RBD as evaluated by a pseudovirus neutralization assay and a live virus based microneutralization assay. Furthermore, RBD-Fc immunized sera better inhibited cell–cell fusion, as evaluated by a quantitative cell–cell fusion assay. The cell–cell fusion assay results correlated well with the virus neutralization potency and could be used for high-throughput screening of large panels of anti-SARS-CoV-2 antibodies and vaccines without the requirement of live virus infection in BSL3 containment. Moreover, the anti-RBD sera did not enhance the pseudotyped SARS-CoV-2 infection of K562 cells. These results demonstrate that Fc fusion can significantly improve the humoral immune response to recombinant RBD immunogen, and suggest that RBD-Fc could serve as a useful component of effective vaccines against SARS-CoV-2.