How Gene Therapy Works
The ability to carry genetic information into cells makes viruses useful in gene therapy. Viruses don’t have nuclei or other cellular structures, but they do have nucleic acid, either DNA or RNA. This small packet of genetic information is packed inside a protein coat, which, in some cases, is wrapped in a membranous envelope.
Unlike other living things, viruses can’t reproduce on their own because they don’t have the necessary cellular machinery. They can, however, reproduce if they invade a cell and borrow the cell’s equipment and enzymes.
Scientists have discovered that they can replace a snippet of viral DNA with the DNA of a human gene and then let that virus infect a cell. The host cell, in turn, makes copies of the introduced gene and then follows the blueprint of the gene to churn out the associated protein. As long as scientists modify the virus to prevent it from causing disease or inducing an immune reaction by the host, it can become a vehicle, or vector, to deliver a specific gene therapy.