Olfactory ensheathing cells and CNS repair: going solo or in need of a friend?

Therapeutic transplantation using cell-based strategies has shown potential in promoting CNS repair, A range of cell types and tissues has been examined but over the past ten years olfactory ensheathing cells (OECs) have emerged as a leading candidate. Here, an appraisal of current literature on OEC transplantation is presented in the context of the basic biology of OECs and the varied cell populations that make up the peripheral olfactory system. Despite the early, intuitive belief that pure populations of OECs would be optimal for transplantation, recent evidence suggests that a more heterogeneous cellular composition might be preferable in enhancing the level of repair. Through a consideration of the different molecular and cell biological characteristics that these diverse cell types might contribute to the repair process, specific insights will be provided into the factors that could prove crucial in determining a favourable outcome for cell transplantation.