VA
ITR/ψ
ITR
wt AV
E1A
Late transcription
E3
E1B
E4
E2A
E2B
ITR
ITR/ψ
AV Vector
1st generation
∆Ε1
∆Ε3
transgene
Figure 3. Schematic of the genome for a wild type adenovirus (wt AV) and the first generation
of recombinant adenoviral vector (AV vector) that are still used widely. ITR, inverted terminal
repeat; Ψ, packaging signal; E1-E4, early viral genes; Late transcription, late viral genes; VA, virusassociated RNA; transgene, gene expression cassette containing the gene of interest; ∆E1 or ∆E3,
deleted E1 or E3 gene. The AV vector can be produced through a homologous recombination between
a shuttle plasmid containing the transgene expression cassette with genomic AV DNA which has
deletions in Ψ, E1 and/or E3. Another method is to clone the expression cassette into a large plasmid
containing the whole adenovirus genome, and recombinant adenovirus can be rescued in 293 cells.