[Optimization of bacterial display technology based on antigen-antibody co-expression]

Area of Science:

• Molecular Biology
• Biotechnology
• Immunology

Background:

• Co-expression of antigens and antibodies in bacterial periplasm is challenging.
• Proper folding and binding are crucial for functional antibody-antigen interactions.
• Efficient methods for antibody screening and protein-protein interaction studies are needed.

Purpose of the Study:

• To develop a system for co-expressing human IL-1β (antigen) and anti-hIL-1β single chain variable fragment (antibody) in the E. coli periplasm.
• To ensure correct folding and binding between the co-expressed antigen and antibody.
• To validate the system's utility for antibody screening and protein-protein interaction analysis.

Main Methods:

• Constructed a recombinant plasmid (pBFD-Ab-Ag) for co-expression using NlpA and pelB leading peptides.
• Transformed E. coli DH5α with pBFD-Ab-Ag and induced co-expression.
• Analyzed antigen-antibody interaction using flow cytometry (FCM) after spheroplast formation and FITC-labeled antibody incubation.

Main Results:

• Flow cytometry detected a strong signal in E. coli DH5α transformed with pBFD-Ab-Ag.
• The positive detection rate for antigen-antibody interaction was significantly improved.

Conclusions:

• The developed E. coli periplasmic co-expression system facilitates efficient folding and binding of antigen and antibody.
• This system simplifies the antibody screening process.
• It provides a novel method for investigating protein-protein interactions.