Adenoviral vectors have a number of positive aspects. They infect dividing and non-dividing cells. Adenovirus has transient high-level protein expression, and it can accommodate inserts of up to 8 kb. Larger inserts can be added, provided that an equivalent part of the viral genome has been properly deleted. High viral titer can be produced (1x1012 pt/ml (1x1010 pfu/ml) to 1x1013 pt/ml (1x1011 pfu/ml).
The University of Iowa Gene Transfer Vector Core (GTVC) has developed the RAPAdTM system (U.S. Patent No. 6,830,920 B2). A description of the system can be found in "A simple method for the rapid generation of recombinant adenovirus vectors" published in Gene Therapy 7:1034-1038, 2000. This system eliminates problems in standard adenoviral production. The RAPAdTM construction plasmids have left-hand ITR, packaging signal, E1a, and partial E1b sequence deletions which greatly reduce wild type occurrence in the vectors. There is, therefore, no time-consuming plaque purification step involved. All virus preps are tested for replication competent adenovirus (RCA) contamination by immune-staining procedures. These vectors are ready within one month, literally cutting production time in half relative to other methods.
The RAPAdTM system offers a number of backbones which encode a separate reporter expression cassette, thus allowing ease in tracking infection efficiency and spread. This system also offers the possibility of expressing two separate proteins with custom made backbones. See available E3 shuttles for cloning. For more information contact Maria L. Scheel (email@example.com).