title: A ligand-pseudoreceptor system based on de novo designed peptides for the generation of adenoviral vectors with altered tropism.
abstract: BACKGROUND
  Delivery of transgenes into specific tissues by adenovirus vectors (AdVs) relies on ablations of their natural tropism and on introduction of a new tropism. If the interaction with its natural receptor is ablated, a new packaging cell line is required to produce the AdV. In the present study, we have used two de novo designed peptides (E-Coil and K-Coil) that interact with each other with high affinity to establish a new receptor-ligand system for the propagation of retargeted AdVs.
  
  
  METHODS
  We produced a cell line (293E) expressing on its surface a pseudoreceptor containing the E-Coil. An AdV (AdFK4m/GFP) lacking the interaction with the primary receptor for adenovirus (CAR) and containing the K-Coil inserted at the fiber C-terminus was constructed and tested using two strategies: (1) an RGD motif (Arg-Gly-Asp) was inserted into the HI-loop of the fiber; (2) AdFK4m/GFP was conjugated to a bispecific adaptor for the epidermal growth factor receptor (EGFR).
  
  
  RESULTS
  AdFK4m/GFP infected 293E cells more efficiently than cells lacking the pseudoreceptor. The transduction was due to the K-Coil/E-Coil specific interaction since it was competed by addition of soluble K-Coil, but not soluble fiber. We demonstrated that the modified AdV was retargeted toward alpha v integrin by inclusion of the RGD motif, or toward EGFR using the bispecific adaptor.
  
  
  CONCLUSIONS
  We have established a new system to produce AdVs ablated of natural tropism. This system should permit the retargeting of AdVs by inserting new ligands within the fiber or through the interaction with bispecific adaptors.
authors.affiliation: Biotechnology Research Institute, National Research Council Canada, Montréal, QC, Canada.
authors.forename: Yue
authors.initials: Y
authors.lastname: Zeng
authors.forename: Maxime
authors.initials: M
authors.lastname: Pinard
authors.forename: Jaïro
authors.initials: J
authors.lastname: Jaime
authors.forename: Lucie
authors.initials: L
authors.lastname: Bourget
authors.forename: Phuong
authors.initials: P
authors.lastname: Uyen Le
authors.forename: Maureen D
authors.initials: MD
authors.lastname: O'Connor-McCourt
authors.forename: Rénald
authors.initials: R
authors.lastname: Gilbert
authors.forename: Bernard
authors.initials: B
authors.lastname: Massie
mesh_terms: D000256:Adenoviridae / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D020816:Amino Acid Motifs; D002460:Cell Line; D062727:Coxsackie and Adenovirus Receptor-Like Membrane Protein; D005822:Genetic Vectors / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D049452:Green Fluorescent Proteins / Q000235:genetics; D006801:Humans; D008024:Ligands; D010455:Peptides / Q000235:genetics / Q000378:metabolism*; D011991:Receptors, Virus / Q000378:metabolism; D014161:Transduction, Genetic; D019065:Virus Assembly; D053586:Virus Internalization; D014779:Virus Replication
chemical_list: C568771:CLMP protein, human; D062727:Coxsackie and Adenovirus Receptor-Like Membrane Protein; D008024:Ligands; D010455:Peptides; D011991:Receptors, Virus; D049452:Green Fluorescent Proteins