Selection of retrovirally transduced cells to enhance the efficiency of gene therapy.

Retrovirally mediated gene transfer is the approach of choice for many laboratories interested in gene therapy. One problem, however, is that the efficiency of therapeutic gene transfer to some important target cells is low. A strategy employed by a number of investigators to overcome this shortcoming is to construct recombinant viruses that employ selection modalities. These strategies can be classified broadly into either metabolic or cell-surface selection strategies. This article examines each selection approach and notes their important strengths and weaknesses. Further, the various gene products used in each approach to effect sorting of transduced cells is detailed.