Cell vehicles for gene transfer to the brain

Gene products of therapeutic value have been delivered directly to the brain by viral and physical transfer methods and indirectly using cell delivery vehicles. Neural precursor cells, produced by immortalization or expansion with growth factors (e.g. fibroblast growth factor (FGF2)), offer promise both as vehicles for gene delivery to the brain and for their inherent ability to differentiate into neurons and glia in vivo. Their ability to migrate widely throughout the brain after injection, and to integrate in a functional and non-disruptive manner are key advantages over non-neural cells. In mouse models of neurodegenerative disease, transplanted neural precursor cells performed dual functions; they acted as a gene delivery vehicle, supplying a deficient enzyme, and provided some neuroglial cell functions which had been lost. Genetically modified neural precursor transplants influenced the development of inherited neurological disease, establishing the feasibility of this novel approach as a treatment for neurodegenerative disorders.