Engineering Genome-Free Bacterial Cells for Effective SARS-COV-2 Neutralisation

Area of Science:

• Virology
• Biotechnology
• Microbiology

Background:

• The COVID-19 pandemic necessitates innovative interventions for current challenges and future preparedness.
• The SARS-CoV-2 virus spike protein's receptor-binding domain (RBD) is crucial for viral entry and a key target for neutralization.

Purpose of the Study:

• To develop and evaluate a novel virus neutralization platform using engineered SimCells and mini-SimCells.
• To assess the efficacy of nanobody-displaying SimCells against SARS-CoV-2 and its variants.

Main Methods:

• Engineered SimCells and mini-SimCells (LPS-free Escherichia coli) to display nanobodies targeting the SARS-CoV-2 RBD.
• Utilized competitive enzyme-linked immunosorbent assay (ELISA) to measure RBD blocking efficiency.
• Performed live virus neutralization assays using SARS-CoV-2 variants and Vero cells.

Main Results:

• Nanobody-expressing SimCells achieved over 90% blocking efficiency against synthesized RBD from Wuhan and Beta variants.
• Mini-SimCells effectively neutralized live SARS-CoV-2 Victoria and Beta variants with low IC50 values.
• Mini-SimCells demonstrated protective effects on Vero cells against SARS-CoV-2 infection.

Conclusions:

• SimCell-based neutralization is a promising strategy for preventing and treating SARS-CoV-2 infections.
• This platform holds potential for addressing other viral infections.
• Engineered SimCells offer a novel approach to antiviral interventions.