Peptide epitope identification by affinity selection on bacteriophage MS2 virus-like particles

Area of Science:

• Biotechnology
• Molecular Biology
• Immunology

Background:

• Filamentous phages are common for phage display and epitope identification.
• However, their displayed peptides lack immunogenicity due to low epitope density, hindering B-cell activation.
• Virus-like particles (VLPs) offer high-density display but cannot perform peptide library display or affinity selection.

Purpose of the Study:

• To develop a novel peptide display platform based on MS2 bacteriophage VLPs.
• To combine the high immunogenicity of MS2 VLPs with the affinity selection capabilities of phage display systems.
• To create plasmid vectors for high-complexity random sequence peptide libraries on MS2 VLPs and control affinity selection stringency.

Main Methods:

• Construction of random sequence peptide libraries on MS2 VLPs using novel plasmid vectors.
• Manipulation of display valency to control affinity selection stringency.
• Application of the system for epitope identification against monoclonal antibody targets.

Main Results:

• Successful construction of high-complexity peptide libraries displayed on MS2 VLPs.
• Demonstrated control over affinity selection stringency via display valency.
• Identified epitopes for known monoclonal antibody targets.
• Elicited antibodies in mice with activities mimicking the selecting antibodies.

Conclusions:

• The MS2 VLP platform effectively combines high immunogenicity with affinity selection capabilities.
• This system facilitates epitope identification and the generation of functional antibodies.
• It represents a significant advancement over traditional phage display methods.