Nanobody engineering for SARS-CoV-2 neutralization and detection

Area of Science:

• Biotechnology
• Immunology
• Virology

Background:

• Conventional antibodies face limitations in stability and cost for widespread therapeutic use.
• Nanobodies, derived from camelid antibodies, present advantages such as high stability and lower production costs.
• Emerging infectious diseases like COVID-19 necessitate innovative therapeutic and diagnostic solutions.

Purpose of the Study:

• To engineer multimodular nanobodies for potent neutralization of SARS-CoV-2 and its variants.
• To develop nanobody-based diagnostic tools for rapid detection of the SARS-CoV-2 spike protein.
• To explore the potential of nanobody engineering in combating emerging viral threats.

Main Methods:

• Engineering multimodular nanobody constructs by fusing domains targeting distinct SARS-CoV-2 epitopes.
• Evaluating the neutralization potency of engineered nanobodies against wild-type and variant SARS-CoV-2 strains.
• Developing a diagnostic assay by fusing nanobodies with NanoLuc luciferase fragments for spike protein detection.

Main Results:

• Engineered multimodular nanobodies achieved high potency neutralization of wild-type SARS-CoV-2, Alpha, and Delta variants (IC50 as low as 50 pM).
• Beta and Omicron variants showed increased resistance to neutralization, underscoring the challenge of antigenic drift.
• A single-step assay detected sub-nanomolar quantities of SARS-CoV-2 spike protein using nanobody-luciferase fusions.

Conclusions:

• Nanobody engineering provides a versatile platform for developing potent antiviral therapeutics.
• Engineered nanobodies can be adapted for rapid and sensitive diagnostic tools for outbreak management.
• This approach demonstrates significant potential for creating effective countermeasures against emerging infectious diseases.