Cellular gene therapy: An overview

Recombinant DNA technology has provided the tools for gene-based cellular therapies. The increasing ability to characterize disease in molecular terms affords the scientific rationale for gene therapy, while advances in cell biology, cytokine physiology, and gene delivery have made somatic cell gene therapy feasible. In 1990, the first successful human gene therapy was performed to correct severe combined immunodeficiency resulting from an inherited disorder, adenosine deaminase deficiency. Peripheral blood lymphocytes were used to deliver a gene product as temporary therapy. Today more than a dozen clinical protocols, using a variety of cell types and gene vectors, are in different stages of development. Some promise to be curative. Potential target illnesses include a variety of inherited genetic diseases, as well as such acquired disorders as cancer and AIDS. Although basic problems relating to gene transfer efficiency and expression, assay systems, and quality assurance remain, the technology to collect large numbers of cells, to purify cell subsets, to gene-modify these cells, and to expand them for human infusion suggest practical new strategies for cellular gene therapy.