What are the basic steps involved in gene therapy?
In most gene therapy clinical trials, cells from the patient’s blood or bone marrow are removed and grown in the laboratory. The cells are exposed to the virus that is carrying the desired gene. The virus enters the cells, and the desired gene becomes part of the cells’ DNA. The cells grow in the laboratory and are then returned to the patient by injection into a vein. This type of gene therapy is called ex vivo, which means “outside the body”. The gene is transferred into the patient’s cells during the time the cells are outside the patient’s body. In other studies, vectors or liposomes (fat particles) are used to deliver the desired gene to cells in the patient’s body. This form of gene therapy is called in vivo, because the gene is transferred to cells inside the patient’s body.
