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Updated: Aug 21, 2025
Protocol for Recombinant RBD-based SARS Vaccines: Protein Preparation, Animal Vaccination and Neutralization Detection
Published on: May 2, 2011
SARS-CoV-2 tetrameric RBD protein blocks viral infection and induces potent neutralizing antibody response
Zheng Liu1, Chenglu Yang1, Haokun Zhang1
1Laboratory of Epigenetics and Translational Medicine, School of Life Sciences, Henan University, Kaifeng, Henan, China.
Abstract:
The pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has posed serious threats to global health and economy and calls for the development of safe treatments and effective vaccines. The receptor-binding domain in the spike protein (SRBD) of SARS-CoV-2 is responsible for its binding to angiotensin-converting enzyme 2 (ACE2) receptor. It contains multiple dominant neutralizing epitopes and serves as an important antigen for the development of COVID-19 vaccines. Here, we showed that dimeric SRBD-Fc and tetrameric 2xSRBD-Fc fusion proteins bind ACE2 with different affinity and block SARS-CoV-2 pseudoviral infection. Immunization of mice with SRBD-Fc fusion proteins elicited high titer of RBD-specific antibodies with robust neutralizing activity against pseudoviral infections. As such, our study indicates that the polymeric SRBD-Fc fusion protein can serve as a treatment agent as well as a vaccine for fighting COVID-19.
Insights
Polymeric SARS-CoV-2 spike receptor-binding domain (SRBD)-Fc fusion proteins effectively neutralize the virus. These fusion proteins show potential as both a COVID-19 vaccine and a therapeutic treatment agent.
Area of Science:
- Virology
- Immunology
- Biotechnology
Background:
- The COVID-19 pandemic, caused by SARS-CoV-2, necessitates novel vaccines and treatments.
- The SARS-CoV-2 spike protein's receptor-binding domain (SRBD) is crucial for viral entry via ACE2 binding and contains key neutralizing epitopes.
Purpose of the Study:
- To investigate the potential of dimeric and tetrameric SRBD-Fc fusion proteins as COVID-19 therapeutics and vaccines.
- To evaluate the binding affinity of SRBD-Fc fusion proteins to ACE2 and their efficacy in blocking viral infection.
Main Methods:
- Construction and characterization of dimeric SRBD-Fc and tetrameric 2xSRBD-Fc fusion proteins.
- Assessment of fusion protein binding to ACE2 and inhibition of SARS-CoV-2 pseudoviral infection.
- Immunization of mice with SRBD-Fc fusion proteins to evaluate antibody response and neutralizing activity.
Main Results:
- Dimeric and tetrameric SRBD-Fc fusion proteins exhibited distinct binding affinities to ACE2.
- Fusion proteins demonstrated significant blockade of SARS-CoV-2 pseudoviral infection.
- Immunization induced high titers of SRBD-specific antibodies with potent neutralizing capabilities against pseudoviruses.
Conclusions:
- Polymeric SRBD-Fc fusion proteins are effective in neutralizing SARS-CoV-2.
- These fusion proteins represent a promising strategy for both COVID-19 vaccine development and therapeutic intervention.
