A Safe and Accessible Cell-Based Spike-ACE2 Binding Assay for Evaluating SARS-CoV-2 Neutralization Activity in...

Area of Science:

• Virology
• Immunology
• Biotechnology

Background:

• Severe Acute Respiratory Syndrome-Coronavirus 2 (SARS-CoV-2) is a Risk Group 3 pathogen causing COVID-19.
• Handling live SARS-CoV-2 necessitates high-level biosafety containment (CL3 facilities).
• Traditional neutralization assays often require infectious viral agents, posing biosafety challenges.

Purpose of the Study:

• To describe a cell-based spike-ACE2 binding assay as a safer alternative for identifying SARS-CoV-2 neutralizing antibodies.
• To validate this assay as a reliable surrogate for neutralization activity.
• To highlight the biosafety advantages of using a non-replicating viral agent assay.

Main Methods:

• Utilized recombinant SARS-CoV-2 trimeric spike protein and human ACE2.
• Quantified the binding interaction using flow cytometry.
• Compared results with pseudotyped lentiviral and live virus neutralization assays.

Main Results:

• The cell-based spike-ACE2 binding assay effectively identifies potential neutralizing antibodies against SARS-CoV-2.
• The assay demonstrated a strong correlation with established neutralization methods.
• This surrogate assay successfully identified neutralizing antibodies without using infectious viral particles.

Conclusions:

• The described cell-based assay provides a biosafely enhanced method for detecting SARS-CoV-2 neutralizing antibodies.
• This approach is a valuable tool for antibody screening and research, applicable beyond SARS-CoV-2.
• The assay offers a reliable and safer alternative to traditional neutralization assays.