Nature Biotechnology pp 297 - 305

What if there were an unlimited supply of neural cells that could be transplanted into patients to treat diseases and injuries of the brain and spinal cord? This futuristic scenario has become a shade more likely with the creation of 'immortal' progenitor cells that give rise only to neurons. The new research, by Steven Goldman and colleagues, is described in the March issue of Nature Biotechnology.

The authors began by collecting human fetal neural progenitor cells. Such cells turn into neurons and glia during normal development, and may therefore be useful in transplantation therapies. A major problem with these cells, however, is that their lifespan is limited. To overcome this, the authors introduced a gene called telomerase reverse transcriptase--a modification known to immortalize other types of cells--into cells extracted from the human spinal cord at a developmental stage when only certain types of neurons are produced.

The experiment yielded immortalized progenitor cells that gave rise only to neurons, or even specific types of spinal neurons, not only in culture but also after transplantation to the brain and spinal cord of live rats. Addressing a major safety concern of this approach, the authors found that the progenitor cells did not produce tumors, even at six months after implantation. Although this paper focused on the use of immortalized progenitor cells in spinal cord repair, such 'designer lines' of neuronal progenitor cells could be of great value in a wide variety of neurological diseases.