A mouse-derived single-chain variable fragment phage display library is generated against the RBD of the SARS-CoV-2 spike protein to highlight the potential utility of these scFvs as candidate reagents for the development of improved diagnostic platforms and as scaffolds for next-generation monoclonal antibody-based therapeutics.
Abstract
The continued emergence of SARS-CoV-2 variants worldwide underscores the need for effective measures to combat the current and future outbreaks. The receptor-binding domain (RBD) of the spike glycoprotein plays a critical role in viral entry and represents a highly immunogenic target. In this study, we generated a mouse-derived single-chain variable fragment (scFv) phage display library against the RBD of the SARS-CoV-2 spike protein. Peptide ELISA-based epitope mapping demonstrated that selected monoclonal scFv phages exhibited broad epitope recognition and reactivity across multiple recently reported variants. In a SARS-CoV-2 pseudovirus neutralization assay, scFv C4 showed potent neutralizing activity against the wild-type, Gamma, and Delta variants, with IC50 values below 4 μg/mL. These findings highlight the potential utility of these scFvs as candidate reagents for the development of improved diagnostic platforms and as scaffolds for next-generation monoclonal antibody-based therapeutics.
Comparing wild-type XG83 and modified MuXG83 shows how allosteric tuning affects antibody-antigen compatibility in developing variations like Omicron, and indicates that non-epitope (potentially allosteric) changes to CDRH3 are also important while investigating potential development and neutralization before advancement.
Muhammad Waqas Nasir, Qi-Yun Liang, Jun He et al.· Microbiology spectrum· 0 citations
The utility of the LW25.13 peptide as a scaffold that can be adapted to different virus variants, which may prove useful for the development of peptides against new coronavirus variants of concern in the future, is illustrated.
Nina Raasch, L. Weissenborn, Elie Richel et al.· Journal of Medicinal Chemist...· 0 citations
Two human-derived monoclonal antibodies are characterized that recognize conserved epitopes on the SARS-CoV-2 RBD and retain activity across antigenically distinct variants, and conserved, mutationally constrained epitopes may serve as targets for vaccines designed to elicit antibody responses resilient to ongoing SARS-CoV-2 evolution and future sarbecovirus emergence.
M. Abernathy, William B. Foreman, Jasmyn A. Lopez et al.· bioRxiv· 0 citations
The continuous evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) highlights the value of broad-spectrum antiviral strategies. Antibody-engineering approaches targeting conserved regions of the Spike protein may enhance neutralizing potency and breadth.
A human antibody (P23) against the Spike protein of SARS-CoV-2 was identified using a human antibody phage display library panning and screening for binding affinity and breadth against multiple coronavirus Spike proteins using surface plasmon resonance (SPR). The epitope of P23 was characterized using the S1 and S2 subunits of SARS-CoV-2 Spike protein and hydrogen–deuterium exchange mass spectrometry (HDX-MS). An IgG–like bispecific fusion protein (Bs-ACE2-P23) was engineered by fusing the extracellular domain (ECD) of human angiotensin-converting enzyme 2 (ACE2) to the N-terminus of the P23 heavy chain (HC). Neutralizing activity was evaluated against both pseudotyped and authentic SARS-CoV-2 variants.
P23 cross-bound Spike proteins from SARS-CoV-2 wild type (WT), D614G and JN.1 variants, Pangolin-CoV, Bat coronavirus RaTG13, and SARS-CoV-1, recognizing an epitope on the S2 subunit adjacent to the fusion peptide (FP). While P23 was ineffective against D614G-containing SARS-CoV-2 variants, Bs-ACE2-P23 exhibited markedly enhanced neutralization potency. This bispecific architecture also improved the neutralizing activity of another FP-targeting antibody.
We developed a bispecific fusion protein with potent broad-spectrum neutralizing activity against SARS-CoV-2 variants. This architecture provides a promising strategy for next-generation coronavirus biologics.
Zhi-Zhong Wei, Ximing Liu, Kailun Wang et al.· Antibody Therapeutics· 0 citations
Evaluations utilizing surface plasmon resonance and pseudovirus assays demonstrate that these sublineages exhibit significantly reduced human ACE2 receptor engagement compared to their parental strain, which suggests these variants will soon spread globally and emphasize the critical need for ongoing surveillance to monitor D420N-carrying lineages.
