Transduction with recombinant adeno-associated virus for gene therapy is limited by leading-strand synthesis.
Adeno-associated virus is an integrating DNA parvovirus with the potential to be an important vehicle for somatic gene therapy. A potential barrier, however, is the low transduction efficiencies of recombinant adeno-associated virus (rAAV) vectors. We show in this report that adenovirus dramatically enhances rAAV transduction in vitro in a way that is dependent on expression of early region 1 and 4 (E1 and E4, respectively) genes and directly proportional to the appearance of double-stranded replicative forms of the rAAV genome. Expression of the open reading frame 6 protein from E4 in the absence of E1 accomplished a similar but attenuated effect. The helper activity of adenovirus E1 and E4 for rAAV gene transfer was similarly demonstrated in vivo by using murine models of liver- and lung-directed gene therapy. Our data indicate that conversion of a single-stranded rAAV genome to a duplex intermediate limits transduction and usefulness for gene therapy.
Fisher
K J
KJ
Institute for Human Gene Therapy, University of Pennsylvania Health System, Philadelphia, USA.
Gao
G P
GP
Weitzman
M D
MD
DeMatteo
R
R
Burda
J F
JF
Wilson
J M
JM
D017498:Adenovirus E1 Proteins / Q000235:genetics / Q000378:metabolism; D017504:Adenovirus E4 Proteins / Q000235:genetics / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D002522:Chlorocebus aethiops; D004277:DNA, Single-Stranded / Q000378:metabolism; D004279:DNA, Viral / Q000096:biosynthesis; D000229:Dependovirus / Q000235:genetics*; D015316:Genetic Therapy; D006367:HeLa Cells; D006801:Humans; D007763:Lac Operon; D008099:Liver / Q000821:virology; D008168:Lung / Q000821:virology; D051379:Mice; D008807:Mice, Inbred BALB C; D016366:Open Reading Frames; D011995:Recombination, Genetic; D014170:Transformation, Genetic; D014709:Vero Cells
D017498:Adenovirus E1 Proteins; D017504:Adenovirus E4 Proteins; D004277:DNA, Single-Stranded; D004279:DNA, Viral