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Updated: May 12, 2025
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Detection of SARS-CoV-2 Neutralizing Antibodies using High-Throughput Fluorescent Imaging of Pseudovirus Infection
Published on: June 5, 2021
4.2K
Integrating immune library probing with structure-based computational design to develop potent neutralizing
Lidia Cerdán1, Katixa Silva2, Daniel Rodríguez-Martín3
1Department of Microbial Biotechnology, Consejo Superior de Investigaciones Científicas (CNB-CSIC), Madrid, Spain.
Mabs
|May 7, 2025
Summary
Researchers engineered a potent antibody against SARS-CoV-2 variants. This heavy chain antibody (hcAb4) targets the receptor-binding domain (RBD) and shows therapeutic potential, neutralizing multiple strains including Omicron subvariants.
Area of Science:
- Immunology and Virology
- Structural Biology
- Biotechnology
Background:
- Emerging SARS-CoV-2 variants necessitate the development of broadly neutralizing antibodies.
- Existing antibodies may exhibit reduced efficacy against new strains, particularly Omicron sublineages.
- Targeting the receptor-binding domain (RBD) of the spike protein is a key strategy for antibody development.
Purpose of the Study:
- To engineer novel antibodies with broad neutralizing activity against SARS-CoV-2 variants.
- To characterize the binding mechanism and structural basis of antibody-RBD interactions.
- To adapt existing antibodies for improved efficacy against rapidly evolving SARS-CoV-2 strains.
Main Methods:
- Screening of an immune library to identify a nanobody (Nb) specific to the Omicron BA.1 RBD.
- Engineering of a heavy chain antibody (hcAb4) derived from the nanobody.
- High-resolution crystal structure determination of the VHH-RBD complex.
- In vitro neutralization assays against various SARS-CoV-2 variants.
- Structure-based computational analysis and site-saturation mutagenesis for antibody optimization.
Main Results:
- A nanobody (Nb4) and its derivative (hcAb4) were identified, recognizing multiple SARS-CoV-2 variants (Wuhan, Beta, Delta, BA.1, BA.5).
- Structural analysis revealed hcAb4 binds the RBD, including the RBM, blocking viral entry.
- Humanized hcAb4 demonstrated therapeutic potential in mouse models against the BA.1 variant.
- hcAb4 neutralized BQ.1.1 but showed reduced activity against XBB.1.5.
- Mutagenesis and trimerization strategies enhanced hcAb4 neutralization against XBB.1.5.
Conclusions:
- The study presents a successful strategy for generating and optimizing SARS-CoV-2 antibodies against emerging variants.
- Engineered antibodies like hcAb4 offer broad neutralization and therapeutic potential.
- Structure-guided engineering is crucial for adapting antibodies to rapidly evolving viruses like SARS-CoV-2.
Keywords:
Antibody evolutionSARS-CoV-2bioinformaticscrystallographynanobodiesprotein interactionsviral variantsvirus neutralization
