title: A gene transfer vector-cell line system for complete functional complementation of adenovirus early regions E1 and E4.
abstract: The improvements to adenovirus necessary for an optimal gene transfer vector include the removal of virus gene expression in transduced cells, increased transgene capacity, complete replication incompetence, and elimination of replication-competent virus that can be produced during the growth of first-generation adenovirus vectors. To achieve these aims, we have developed a vector-cell line system for complete functional complementation of both adenovirus early region 1 (E1) and E4. A library of cell lines that efficiently complement both E1 and E4 was constructed by transforming 293 cells with an inducible E4-ORF6 expression cassette. These 293-ORF6 cell lines were used to construct and propagate viruses with E1 and E4 deleted. While the construction and propagation of AdRSV beta gal.11 (an E1-/E4- vector engineered to contain a deletion of the entire E4 coding region) were possible in 293-ORF6 cells, the yield of purified virus was depressed approximately 30-fold compared with that of E1- vectors. The debilitation in AdRSV beta gal.11 vector growth was found to correlate with reduced fiber protein and mRNA accumulation. AdCFTR.11A, a modified E1-/E4- vector with a spacer sequence placed between late region 5 and the right inverted terminal repeat, efficiently expressed fiber and grew with the same kinetic profile and virus yield as did E1- vectors. Moreover, purified AdCFTR.11A yields were equivalent to E1- vector levels. Since no overlapping sequences exist in the E4 regions of E1-/E4- vectors and 293-ORF6 cell lines, replication-competent virus cannot be generated by homologous recombination. In addition, these second-generation E1-/E4- vectors have increased transgene capacity and have been rendered virus replication incompetent outside of the new complementing cell lines.
authors.affiliation: GenVec Inc., Rockville, Maryland 20852, USA.
authors.forename: D E
authors.initials: DE
authors.lastname: Brough
authors.forename: A
authors.initials: A
authors.lastname: Lizonova
authors.forename: C
authors.initials: C
authors.lastname: Hsu
authors.forename: V A
authors.initials: VA
authors.lastname: Kulesa
authors.forename: I
authors.initials: I
authors.lastname: Kovesdi
mesh_terms: D017498:Adenovirus E1 Proteins / Q000096:biosynthesis / Q000235:genetics*; D017504:Adenovirus E4 Proteins / Q000096:biosynthesis / Q000235:genetics*; D000260:Adenoviruses, Human / Q000235:genetics*; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics; D002460:Cell Line; D002472:Cell Transformation, Viral; D015870:Gene Expression; D018014:Gene Transfer Techniques; D017781:Genes, Immediate-Early; D005816:Genetic Complementation Test; D005822:Genetic Vectors; D006801:Humans; D007700:Kinetics; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D013997:Time Factors; D014158:Transcription, Genetic; D001616:beta-Galactosidase / Q000096:biosynthesis
chemical_list: D017498:Adenovirus E1 Proteins; D017504:Adenovirus E4 Proteins; D001426:Bacterial Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D001616:beta-Galactosidase