title: Rational design and engineering of a modified adeno-associated virus (AAV1)-based vector system for enhanced retrograde gene delivery.
abstract: BACKGROUND
  After injection into muscle and peripheral nerves, a variety of viral vectors undergo retrograde transport to lower motor neurons. However, because of its attractive safety profile and durable gene expression, adeno-associated virus (AAV) remains the only vector to have been applied to the human nervous system for the treatment of neurodegenerative disease. Nonetheless, only a very small fraction of intramuscularly injected AAV vector arrives at the spinal cord.
  
  
  OBJECTIVE
  To engineer a novel AAV vector by inserting a neuronal targeting peptide (Tet1), with binding properties similar to those of tetanus toxin, into the AAV1 capsid.
  
  
  METHODS
  Integral to this approach was the use of structure-based design to increase the effectiveness of functional capsid engineering. This approach allowed the optimization of scaffolding regions for effective display of the foreign epitope while minimizing disruption of the native capsid structure. We also validated an approach by which low-titer tropism-modified AAV vectors can be rescued by particle mosaicism with unmodified capsid proteins.
  
  
  RESULTS
  Importantly, our rationally engineered AAV1-based vectors exhibited markedly enhanced transduction of cultured motor neurons, diminished transduction of nontarget cells, and markedly superior retrograde delivery compared with unmodified AAV1 vector.
  
  
  CONCLUSIONS
  This approach promises a significant advancement in the rational engineering of AAV vectors for diseases of the nervous system and other organs.
authors.affiliation: ‡Gene Therapy Center and ¶Battelle Center for Mathematical Medicine, The Research Institute at Nationwide Children's Hospital, Nationwide Children's Hospital, Columbus, Ohio; §Department of Neurosurgery, Emory University, Atlanta, Georgia; ‖Department of Pediatrics, College of Medicine and Public Health and #Department of Molecular Virology, Immunology, and Medical Genetics, College of Medicine and Public Health, The Ohio State University Columbus, Ohio; **Calimmune, Inc, Tucson, Arizona.
authors.forename: Adam S
authors.initials: AS
authors.lastname: Davis
authors.forename: Thais
authors.initials: T
authors.lastname: Federici
authors.forename: William C
authors.initials: WC
authors.lastname: Ray
authors.forename: Nicholas M
authors.initials: NM
authors.lastname: Boulis
authors.forename: Deirdre
authors.initials: D
authors.lastname: OʼConnor
authors.forename: K Reed
authors.initials: KR
authors.lastname: Clark
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Bartlett
mesh_terms: D000818:Animals; D036022:Capsid Proteins / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000235:genetics*; D000229:Dependovirus / Q000235:genetics; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods; D005822:Genetic Vectors / Q000138:chemical synthesis*; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D006899:Mixed Function Oxygenases; D020836:Protein Structure, Quaternary; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014161:Transduction, Genetic / Q000379:methods*
chemical_list: D036022:Capsid Proteins; D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; D006899:Mixed Function Oxygenases; C462539:TET1 protein, human