Cross-species neural grafting of cell lines immunoisolated by a permselective polymer membrane represents a promising source of neuroactive molecules for the treatment of neurodegenerative diseases. Utilization of a cell line of xenogeneic origin is advantageous since the transplanted cells will be rejected by the host immune system in case of breakage of the immunoisolating envelope. Polymer-encapsulated PC12 cells, a dopaminergic cell line derived from a rat pheochromocytoma, were transplanted in five Macaca fascicularis monkeys which had been previously rendered hemiparkinsonian by a unilateral carotid injection of 1-methyl-4-phenyl- 1,2,3,6-tetrahydropyridine. Well-preserved, tyrosine hydroxylase positive encapsulated PC12 cells were observed in the lesioned striatum for up to 5 months after implantation. Four out of five monkeys which received polymer-encapsulated PC12 cells showed significant behavioral improvement, whereas three monkeys implanted with either encapsulated bovine chromaffin cells or empty polymer envelopes showed no amelioration. (C) 1994 Academic Press, Inc.
