A cell based assay using virus-like particles to screen AM type mimics for SARS-CoV-2 neutralisation

Area of Science:

• Biochemistry
• Virology
• Drug Discovery

Background:

• Developing therapeutics against SARS-CoV-2 spike protein has faced challenges in accurately assessing binding affinity.
• Existing methods for determining therapeutic affinity often fail to replicate physiological host-virus interactions.
• A gap exists between in vitro and in vivo methods for screening therapeutic agents.

Purpose of the Study:

• To report an improved screening protocol for therapeutic candidates using SARS-CoV-2 virus-like particles (VLPs).
• To investigate the virus neutralization capabilities of AM type miniprotein mimics.
• To assess the stability of SARS-CoV-2 spike-miniprotein complexes using molecular dynamics simulations.

Main Methods:

• Developed a screening protocol utilizing SARS-CoV-2 virus-like particles (VLPs) with a small hemagglutinin (HA) tag for affinity studies.
• Probed VLP-bound HA tags with fluorescent anti-HA antibodies to quantify binding.
• Conducted molecular dynamic simulations to analyze the stability of the SARS-CoV-2 spike-miniprotein complex.

Main Results:

• The VLP screening method, using an HA tag, minimizes interference and provides a reliable readout for affinity.
• AM type miniprotein mimics demonstrated significant, previously unrecognized, virus neutralization capabilities.
• Molecular dynamics simulations confirmed highly stable intermolecular interactions between the SARS-CoV-2 receptor binding domain (RBD) and the AM1 miniprotein, along with stabilizing intramolecular interactions within AM1.

Conclusions:

• The developed VLP-based screening protocol offers an improved method for evaluating therapeutic candidates against SARS-CoV-2.
• AM type miniprotein mimics show promise as effective antiviral agents due to their neutralization capabilities.
• In vitro and in silico findings highlight the potential of mimic-based miniprotein therapeutics for future drug development.