Finding Vehicles to Get Genes to Work

The first step in successful gene therapy is designing the right delivery system
to introduce a new gene or shut down an unwanted one. The delivery
system for gene therapy is called a vector. A perfect vector
 Must be innocuous so that the recipient’s immune system doesn’t reject
or fight the vector.
 Must be easy to manufacture in large quantities. Just one treatment may
require over 10 billion copies of the vector because you need one delivery
vehicle for each and every cell in the affected organ.
 Must be targeted for a specific tissue. Gene expression is tissue-specific
(see Chapter 10 for details), so the vector has to be tissue-specific, too.
 Must be capable of integrating its genetic payload into each cell of the
target organ so that new copies of each cell generated later on by mitosis
contain the gene therapy payload.