title: The adenovirus E4 ORF6 and E1b 55 kDa proteins cooperate in a p53-independent manner to enhance transduction by recombinant adeno-associated virus vectors.
abstract: The observation that exposure of target cells to genotoxic stress or adenovirus infection enhances recombinant adeno-associated virus (rAAV) transduction is an important lead towards defining the rAAV transduction mechanism, and has significant implications for the exploitation of rAAV in gene therapy applications. The adenovirus-mediated enhancement of rAAV transduction has been mapped to the E4 ORF6 gene, and expression of E4 ORF6 alone has been considered necessary and sufficient to mediate this effect. Since p53 subserves an important function in the cellular response to genotoxic stress, and interacts with the E4 ORF6 gene product during adenovirus infection, we hypothesized that p53 function might be essential to the rAAV enhancement resulting from these cellular insults. In the current study, using the p53-null cell lines H1299 and Saos-2, we find that p53 is not essential to either genotoxic stress or adenovirus-mediated enhancement of rAAV transduction. We further demonstrate using HeLa, H1299 and Saos-2 cells that E4 ORF6 expression alone is not sufficient to enhance rAAV transduction and that coexpression of the adenovirus E1b 55 kDa protein is necessary. Together, these observations indicate that the mechanism by which adenovirus infection enhances rAAV transduction involves cooperative and interdependent functions of the E4 ORF6 and E1b 55 kDa proteins that are p53-independent.
authors.affiliation: Gene Therapy Research Unit of the Children's Medical Research Institute and The New Children's Hospital1, and The University of Sydney Department of Paediatrics and Child Health2, PO Box 3515, Parramatta, NSW 2124, Australia.
authors.forename: Toby N
authors.initials: TN
authors.lastname: Trahair
authors.affiliation: Gene Therapy Research Unit of the Children's Medical Research Institute and The New Children's Hospital1, and The University of Sydney Department of Paediatrics and Child Health2, PO Box 3515, Parramatta, NSW 2124, Australia.
authors.forename: Ian E
authors.initials: IE
authors.lastname: Alexander
authors.affiliation: Gene Therapy Research Unit of the Children's Medical Research Institute and The New Children's Hospital1, and The University of Sydney Department of Paediatrics and Child Health2, PO Box 3515, Parramatta, NSW 2124, Australia.
authors.forename: Peter B
authors.initials: PB
authors.lastname: Rowe
authors.affiliation: Gene Therapy Research Unit of the Children's Medical Research Institute and The New Children's Hospital1, and The University of Sydney Department of Paediatrics and Child Health2, PO Box 3515, Parramatta, NSW 2124, Australia.
authors.forename: Jason A
authors.initials: JA
authors.lastname: Smythe
mesh_terms: D000256:Adenoviridae / Q000235:genetics / Q000502:physiology; D017501:Adenovirus E1B Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017504:Adenovirus E4 Proteins / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D002460:Cell Line; D004274:DNA, Recombinant / Q000235:genetics; D000229:Dependovirus / Q000235:genetics*; D017353:Gene Deletion; D015870:Gene Expression; D015316:Genetic Therapy / Q000379:methods; D005822:Genetic Vectors / Q000235:genetics*; D016679:Genome, Viral; D006367:HeLa Cells; D006801:Humans; D008970:Molecular Weight; D016296:Mutagenesis / Q000235:genetics / Q000528:radiation effects; D016366:Open Reading Frames / Q000235:genetics; D010957:Plasmids / Q000235:genetics; D014161:Transduction, Genetic / Q000379:methods; D014162:Transfection; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000502:physiology*; D014466:Ultraviolet Rays
chemical_list: D017501:Adenovirus E1B Proteins; D017504:Adenovirus E4 Proteins; D004274:DNA, Recombinant; D016159:Tumor Suppressor Protein p53