title: Peptide epitope identification by affinity selection on bacteriophage MS2 virus-like particles.
abstract: Filamentous phages are now the most widely used vehicles for phage display and provide efficient means for epitope identification. However, the peptides they display are not very immunogenic because they normally fail to present foreign epitopes at the very high densities required for efficient B-cell activation. Meanwhile, systems based on virus-like particles (VLPs) permit the engineered high-density display of specific epitopes but are incapable of peptide library display and affinity selection. We developed a new peptide display platform based on VLPs of the RNA bacteriophage MS2. It combines the high immunogenicity of MS2 VLPs with the affinity selection capabilities of other phage display systems. Here, we describe plasmid vectors that facilitate the construction of high-complexity random sequence peptide libraries on MS2 VLPs and that allow control of the stringency of affinity selection through the manipulation of display valency. We used the system to identify epitopes for several previously characterized monoclonal antibody targets and showed that the VLPs thus obtained elicit antibodies in mice whose activities mimic those of the selecting antibodies.
authors.affiliation: Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, Albuquerque, NM 87131, USA. bchackerian@salud.unm.edu
authors.forename: Bryce
authors.initials: B
authors.lastname: Chackerian
authors.forename: Jerri do Carmo
authors.initials: Jdo C
authors.lastname: Caldeira
authors.forename: Julianne
authors.initials: J
authors.lastname: Peabody
authors.forename: David S
authors.initials: DS
authors.lastname: Peabody
mesh_terms: D000345:Affinity Labels; D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000942:Antigens, Bacterial / Q000235:genetics / Q000276:immunology*; D001427:Bacterial Toxins / Q000235:genetics / Q000276:immunology*; D036022:Capsid Proteins / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000276:immunology*; D005822:Genetic Vectors / Q000276:immunology*; D017909:Levivirus / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D019151:Peptide Library; D010957:Plasmids; D017386:Sequence Homology, Amino Acid; D014771:Virion / Q000737:chemistry / Q000235:genetics / Q000276:immunology*
chemical_list: D000345:Affinity Labels; D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial; D001427:Bacterial Toxins; D036022:Capsid Proteins; D000939:Epitopes; D010446:Peptide Fragments; D019151:Peptide Library; C030325:anthrax toxin