Gene Delivery Using Viral Vectors - Challenges in Delivery of Therapeutic Genomics and Proteomics - page 215

Ψ

ITR ITR

∆ E3

∆ E1

± 8.2 kb

First-generation adenoviral vectors with E1 deletion

∆ E2a

± 14 kb

Second-generation adenoviral vectors with E1 and E2 or E4 deletion

± 37 kb

Gutless (helper-dependent) adenoviral vectors

E2 E4

E1 E3

Ψ

ITR ITR

L1 L2 L3 L4 L5

Maximal transgene capacity

Figure 5.6 Genome structures of first-generation, second-generation, and gutted adenovirus
vectors.

100/0

Cre or FLP

Ap r

Foreign DNA

Ori

∆ E3
Pac I

Loxp frt

∆ψ ∆ E1

ITR S

ψ

+

Ap r

Loxp frt

Contransfect 293
cells

Orl

Shuttle plasmid

Genomic plasmid

Site-specfic recombination
10 days

Loxp frt

ITR I TR

ψ − +

∆ E1 ∆ E3

Recombination viral vector

Foreign DNA

Figure 5.7 Schematic outline of the AdMax system.

5.2.5.2 Construction and Propagation of First-Generation Viruses
First-generation Ad vectors constructions are relatively easy, and the vectors can be
produced with high titers [19] . This adenoviral vector system is reliable for efficient
transgene delivery in many mammalian cell types. This system can lead to high-
level transient expression. Several commercial kits, Adeno-X™ Expression System