Differential influence of the E4 adenoviral genes on viral and cellular promoters.
BACKGROUND
Strong and stable transgene expression is fundamental to the success of recombinant adenovirus vectors in human gene therapy. However, control of transgene expression is a complex process, involving both viral and cellular factors. In this study, the influence of the E4 adenoviral region on the activity of various promoters was investigated in vitro and in vivo.


METHODS
Pairs of isogenic E1o and E1oE4o vectors were generated and compared. Levels of transgene expression were determined by Northern blot, ELISA and FACS analysis. Initiation of transcription was studied by nuclear run-on assays.


RESULTS
Similar to the viral CMV and RSV promoters, the activity of the ubiquitous cellular PGK promoter required the presence of the E4 genes in vitro and in vivo. In contrast, transgene expression from selected liver- and tumor-specific promoters did not require E4 functions.


CONCLUSIONS
Together with the reported low liver toxicity of E1oE4o vectors, the independence of E4 of liver-specific promoters renders such vectors interesting alternatives to the use of gutless vectors.
Grave
L
L
Transgène SA, Strasbourg, France. grave@transgene.fr
Dreyer
D
D
Dieterle
A
A
Leroy
P
P
Michou
A I
AI
Doderer
C
C
Pavirani
A
A
Lusky
M
M
Mehtali
M
M
D016475:3T3 Cells; D017498:Adenovirus E1 Proteins / Q000235:genetics; D017504:Adenovirus E4 Proteins / Q000235:genetics*; D000818:Animals; D001358:Avian Sarcoma Viruses / Q000235:genetics*; D019556:COS Cells; D002460:Cell Line; D002522:Chlorocebus aethiops; D003587:Cytomegalovirus / Q000235:genetics*; D017353:Gene Deletion; D005786:Gene Expression Regulation; D018014:Gene Transfer Techniques; D005822:Genetic Vectors / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008815:Mice, Inbred Strains; D016513:Mice, SCID; D011401:Promoter Regions, Genetic; D014158:Transcription, Genetic; D019076:Transgenes / Q000235:genetics; D014407:Tumor Cells, Cultured; D014709:Vero Cells
D017498:Adenovirus E1 Proteins; D017504:Adenovirus E4 Proteins