title: DeltaPhage--a novel helper phage for high-valence pIX phagemid display.
abstract: Phage display has been instrumental in discovery of novel binding peptides and folded domains for the past two decades. We recently reported a novel pIX phagemid display system that is characterized by a strong preference for phagemid packaging combined with low display levels, two key features that support highly efficient affinity selection. However, high diversity in selected repertoires are intimately coupled to high display levels during initial selection rounds. To incorporate this additional feature into the pIX display system, we have developed a novel helper phage termed DeltaPhage that allows for high-valence display on pIX. This was obtained by inserting two amber mutations close to the pIX start codon, but after the pVII translational stop, conditionally inactivating the helper phage encoded pIX. Until now, the general notion has been that display on pIX is dependent on wild-type complementation, making high-valence display unachievable. However, we found that DeltaPhage does facilitate high-valence pIX display when used with a non-suppressor host. Here, we report a side-by-side comparison with pIII display, and we find that this novel helper phage complements existing pIX phagemid display systems to allow both low and high-valence display, making pIX display a complete and efficient alternative to existing pIII phagemid display systems.
authors.affiliation: Centre for Immune Regulation, Oslo University Hospital, N-0027, Oslo, Norway.
authors.forename: Nicolay R
authors.initials: NR
authors.lastname: Nilssen
authors.forename: Terje
authors.initials: T
authors.lastname: Frigstad
authors.forename: Sylvie
authors.initials: S
authors.lastname: Pollmann
authors.forename: Norbert
authors.initials: N
authors.lastname: Roos
authors.forename: Bjarne
authors.initials: B
authors.lastname: Bogen
authors.forename: Inger
authors.initials: I
authors.lastname: Sandlie
authors.forename: Geir Å
authors.initials: GÅ
authors.lastname: Løset
mesh_terms: D000818:Animals; D000941:Antigens / Q000032:analysis; D001435:Bacteriophages / Q000235:genetics* / Q000502:physiology; D002460:Cell Line; D004797:Enzyme-Linked Immunosorbent Assay; D005822:Genetic Vectors; D006378:Helper Viruses / Q000235:genetics* / Q000502:physiology; D051379:Mice; D019151:Peptide Library; D011948:Receptors, Antigen, T-Cell / Q000032:analysis
chemical_list: D000941:Antigens; D019151:Peptide Library; D011948:Receptors, Antigen, T-Cell