Structural basis for continued antibody evasion by the SARS-CoV-2 receptor binding domain

Area of Science:

• Virology and Immunology
• Molecular Biology
• Infectious Diseases

Background:

• Previous research focused on SARS-CoV-2 variants with fewer mutations.
• Understanding antibody neutralization resistance is crucial for therapeutic development.
• The emergence of SARS-CoV-2 variants necessitates evaluating further viral evolution.

Purpose of the Study:

• To investigate the impact of extensive mutations on SARS-CoV-2 neutralization.
• To explore mechanisms of antibody escape in advanced viral variants.
• To assess the efficacy of existing antibody therapies against evolving SARS-CoV-2 strains.

Main Methods:

• Construction and analysis of SARS-CoV-2 pseudotypes with up to seven RBD mutations.
• Evaluation of neutralization resistance using therapeutic antibodies and serum from vaccine recipients.
• Identification of specific antibody binding sites and viral escape mechanisms, including N-linked glycan acquisition.

Main Results:

• Pseudotypes with numerous simultaneous RBD mutations exhibit increased resistance to neutralization.
• Advanced variants show greater evasion of therapeutic antibodies and vaccine-induced immunity.
• A specific antibody targeting the RBD core can neutralize tested variants, but N-linked glycan acquisition confers escape.

Conclusions:

• The SARS-CoV-2 receptor binding domain can accommodate multiple antibody escape mutations, facilitating viral evolution.
• Emerging SARS-CoV-2 variants pose a significant threat to the effectiveness of current antibody-based interventions.
• Continuous adaptation of SARS-CoV-2 suggests ongoing challenges in controlling the pandemic and necessitates the development of broadly neutralizing antibodies.