Gene therapy for T-cell immunodeficiencies

As the field of human gene therapy has developed over the past 15 years, T- cell immunodeficiencies have been a frequent target of investigation. The f irst of these was ADA deficiency (i.e., SCID) because of the availability o f the responsible gene. As the genes responsible for several of the other T -cell immunodeficiencies have been identified and cloned, these deficiencie s also have been investigated in preclinical studies and are now the subjec t of clinical trials. This article reviews the work that has been performed to date and future directions.