Identification of mimotopes by screening of a bacterially displayed random peptide library and its use in eliciting an immune response to native HBV-preS.
Bacterially-displayed peptide libraries have been widely used as an alternative to phage-displayed peptide libraries in screening epitopes or mimotopes of antibodies. Using a protective monoclonal antibody (mAb) 3B9 against hepatitis B virus (HBV) preS protein as target, mimotopes were successfully screened from a FliTrx random peptide library. To monitor the enrichment ratios of each round and to isolate higher affinity clones from the library, a modified procedure was performed in which the titer of eluted bacteria from an antibody-coated well (P value) was compared with that from a non-coated well (N value). After sufficient enrichment of the library, bacterial colonies were randomly picked and identified further by the monoclonal bacterial P/N value assay and Western blotting analysis. Immunization of mice with the selected bacterially-displayed mimotopes, including the enriched populations without clone identification, elicited strong specific immune responses against the recombinant preS protein. The present study provides a potentially rapid and effective strategy for the development of engineered live bacterial vaccines without the need for information about the aetiological agents or their antigens.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000914:Antibodies, Viral / Q000032:analysis / Q000096:biosynthesis; D015153:Blotting, Western; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000276:immunology*; D005260:Female; D006514:Hepatitis B Surface Antigens / Q000276:immunology*; D006515:Hepatitis B virus / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D019151:Peptide Library; D011498:Protein Precursors / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D000939:Epitopes; D006514:Hepatitis B Surface Antigens; D019151:Peptide Library; D011498:Protein Precursors; C050807:presurface protein 2, hepatitis B surface antigen; D004247:DNA