Sensitive amplification methods to detect and sequence human- parechoviruses, enteroviruses and adenoviruses in cerebrospinal fluid in sudden unexpected death in infancy cases
Year: 2025
Type: article
Abstract: minder of the potential for future outbreaks.This underscores the urgent need for the development of rapid and effective therapeutic and vaccine strategies to mitigate such threats.In this study, our objective is to characterize the spike protein of CoVs and explore vaccine strategies that can target multiple virus variants, aiming to bolster our defences against potential future outbreaks. Methods:In vitro studies were conducted to investigate the interactions between the SARS-CoV-2 spike protein and its receptors, along with assessing the mechanisms of viral entry using pseudotyped CoVs.Using a group of 74 experimentally proven neutralizing monoclonal antibodies, this method made it possible to find escape variants and map out the epitopes of SARS-CoV-2 variants.Furthermore, a self-assembled nanoparticle decorated with the SARS-CoV-2 spike protein, including escape mutants, as well as SARS-CoV-1 and MERS-CoV, was developed and subjected to various biochemical analyses for characterization.Subsequently, mice were immunized with these nanoparticles to evaluate their immunological responses.Results: In this study, we fully characterized the spike proteins of SARS-CoV-1, SARS-CoV-2, and MERS-CoV.This led to the creation of pseudotyped CoVs that bind specifically to their receptors, making entry into cells easier.In addition, our study includes mapping 74 experimentally proven neutralizing monoclonal antibodies (mAbs) binding epitopes for all major variants of SARS-CoV-2, such as Delta and Omicron, and structural annotation of these variants.Most of these neutralizing epitopes (87.84%) are found in the receptor-binding domain (RBD), where they overlap with other epitopes.A smaller percentage (12.16%) is found in the Nterminal domain (NTD), but it works less well than RBD antibodies.Moreover, we observed mutations in the antibody-binding epitope residues of 69 out of 74 mAbs, with the most potent RBD epitopes displaying higher mutation rates (4-10 amino acids) than less effective antibodies, indicating potential co-evolution with immune pressure.Subsequently, we engineered a self-assembled nanoparticle decorated with a SARS-CoV-2 spike and variants, demonstrating significantly enhanced immune responses against SARS-CoV-2 and its variants.Similarly, SARS-CoV-1 and MERS-CoV spike decorated nanoparticles elicit potent neutralizing antibodies against both viruses.Discussion: Our research underscores the invaluable utility of pseudotyped viruses in unraveling the intricacies of viral entry mechanisms.Furthermore, the multimeric presentation of selfassembled protein nanoparticles has shown to be very effective at producing strong antibodies that can neutralize SARS-CoV-2 antibody escape variants and also SARS-CoV-1, and MERS-CoV. Conclusion:In conclusion, the development of self-assembled protein nanoparticle vaccines represents a promising approach in our ongoing battle against coronaviruses.These innovative vaccines hold significant potential to serve as effective countermeasures, offering a versatile and robust strategy for combating future outbreaks.
Authors: Miss Nicky Byrne, Professor Gert Uves Van Zyl, Professor Corena de Beer
Institutions: National Health Laboratory Service, Stellenbosch University
Language: English
Subfield: Cardiology and Cardiovascular Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $2,900
OpenAlex ID: W4408046414