A Chimeric Integrase-Containing Expression Vector for Promoting
Targeted Integration of Foreign DNA into a Host Genome Topics in
This Section Viruses are useful as vectors for the delivery and
expression of genes because they enter cells efficiently and
their genetic material is directed to a subcellular compartment
where it is stable and can be efficiently expressed. However,
when applied to the field of human gene therapy, several
drawbacks to their use become apparent. They can stimulate
strong immune responses, revert to replication competent viruses
which are potentially pathogenic, and have been shown to cause
fatal neoplasms in primates. Therefore, prohibitively expensive
testing is required prior to therapeutic use. In addition, use
of retroviral vectors is essentially limited to ex vivo gene
therapy because their relatively low titre and sensitivity to
human complement makes them impractical for in vivo therapy. In
non-viral gene delivery systems, DNA is introduced directly into
cells. Non-viral gene