Nearly 600 organ transplants are performed each year in France, with a total number of transplant recipients exceeding 55 000 persons. The prevention of transplant rejection requires the long-term administration of immunosuppressive drugs which by decreasing all immune defences, are at the origin of an increased risk of infections and cancers.

The gene therapy may be able to better target the therapeutic action, directing the protective part of the immune system toward the graf, while preserving other immune responses. The same approach could be used in autoimmune diseases, which result from a failure of immune tolerance, by failure of the regulatory and protective response.

Another application of gene therapy concerns autoimmune syndromes related to the single (monogenic) gene defect. Depending on the genetic abnormality involved, one could either deliver a functional copy of the mutated gene or modulate or correct a dysfunctional gene with new approaches to genomic manipulation.