Adrenocortical cells immortalized by telomerase: Potential use for ex vivo gene therapy

Telomerization, the process of immortalization of normal cells by expression of telomerase reverse transcriptase (TERT), could be of great use in biomedicine if the process allows cells to retain their normal properties and does not promote neoplastic transformation. In this article, we review the data on the potential uses of telomerized cells in ex vivo gene therapy, and discuss the issue of the potential risks of the use of this technology. We present preliminary data on the transplantation of telomerized bovine adrenocortical cells in the rat brain. Like other cell types, adrenocortical cells may be engineered to secrete desirable gene products. Currently, problems of immune rejection limit the usefulness of this potential therapy. We discuss future improvements in this cell transplantation system that could address these questions. Telomerization, by removing the senescence barrier to unlimited cell proliferation, will greatly aid the genetic modification of cells in order to solve the issue of immune rejection and other problems.