Elsevier

Vaccine

Volume 38, Issue 46, 27 October 2020, Pages 7205-7212
Vaccine

Short communication
Enhanced elicitation of potent neutralizing antibodies by the SARS-CoV-2 spike receptor binding domain Fc fusion protein in mice

https://doi.org/10.1016/j.vaccine.2020.09.058Get rights and content

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.

Keywords

SARS-CoV-2
Subunit vaccine
Receptor-binding domain (RBD)
Cell–cell fusion assay

Cited by (0)

View Abstract