Transplantation of Cells in an lmmunoisolation Device for Gene Therapy

Abstract

Treatment of genetic deficiency diseases, the so-called inborn errors of metabolism has been fairly limited in scope. Whereas there has been significant success with injections of the missing gene product in cases such as diabetes and hemophilia, management of most genetic diseases has been limited to treatment of various clinical symptoms and not the underlying disease state. For the past decade, many groups have been working toward the goal of gene therapy, i.e., the correction of genetic deficiency diseases by the introduction of a correct copy of the defective gene into affected individuals. Many different diseases have been targeted (see ref. 1 for review) utilizing a variety of cells and animal models (1–14). Although many groups have been able to obtain high levels of gene expression in vitro, in vivo expression has been disappointing. In most cases, while the gene product could be detected within hours after introduction into the host, high level expression was not detectable after 30–45 d (4,5,11,12,14–19).