Targeted gene therapy of autoimmune diseases: advances and prospects.

Idealized gene therapy of autoimmune diseases would mean getting the right drug to the right place at the right time to affect the right mechanism of action. In other words, a specific gene therapy strategy needs to have functional, spatial and temporal specificity. Functional specificity implies targeting the cellular, molecular and/or genetic mechanisms relevant to the disease, without affecting nondiseased organs or tissues through mechanisms that cause adverse effects. Spatial specificity means the delivery of the therapeutic agent exclusively to sites and cells that are relevant to the disease. Temporal specificity is, in principle, synonymous with controlled on-demand expression of the therapeutic gene and thus represents a major safety feature. This article reviews recent advances in strategies to use gene therapy in the treatment of autoimmune diseases.