Cell-free immuno-profiling on a genetically programmed biochip

Area of Science:

• Synthetic Biology
• Biotechnology
• Immunology

Background:

• Cell-free synthetic biology offers safe, affordable genetic tools for therapeutics.
• Accurate measurement of antibody responses is crucial for immuno-profiling and understanding immune reactions.
• Existing methods for antibody-antigen interaction analysis can be complex and time-consuming.

Purpose of the Study:

• To develop and validate a microfluidic-free biochip for quantitative analysis of cell-free synthesized antigens and antibodies.
• To enable high-throughput profiling of antibody specificity and affinity against multiple viral epitopes.
• To assess patient-specific immune responses using minimal sample volumes.

Main Methods:

• Utilized a biochip platform with photolithographically patterned compartments and localized gene brushes for cell-free antigen synthesis.
• Created continuous antigen density gradients within nanoliter compartments to generate antibody binding curves.
• Synthesized over 30 SARS-CoV-2 viral epitopes on-chip for simultaneous antibody profiling.
• Analyzed polyclonal antibodies from human serum and on-chip expressed protein-protein interactions (ACE2-RBD).

Main Results:

• Successfully profiled monoclonal and polyclonal antibody responses against numerous SARS-CoV-2 epitopes with high specificity and affinity determination.
• Revealed patient-specific epitope profiles from small volumes of human serum, highlighting limitations of conventional methods.
• Demonstrated the quantitative reconstitution of cell-free expressed human ACE2 receptor interaction with the viral receptor-binding domain on-chip.
• Achieved rapid and quantitative interrogation of complex protein-protein interactions without requiring protein purification.

Conclusions:

• The developed biochip platform provides a rapid, quantitative, and cost-effective method for immuno-profiling.
• This approach enhances preparedness for emerging infectious diseases by enabling swift analysis of immune responses.
• The cell-free, on-chip system offers a versatile tool for therapeutic antibody development and personalized medicine.