Multi-site partitioned delivery of human tyrosine hydroxylase gene with phenotypic recovery in Parkinsonian rats

Parkinson's disease (PD) is a leading candidate for neurological gene therapy, given our increasing knowledge of the functional anatomy of the striatonigral system and the localized nature of the affected cell populations. Here we report that stereotactic introduction of a human tyrosine hydroxylase (TH-2) gene using multi-site partitioned doses resulted in behavioral recovery in 6-OHDA-lesioned rats, with transient 100% recovery observed in some animals. We also show correlation between numbers of TH- immunoreactive cells and loss of apomorphine induced rotation, with a near- linear relationship between TH expression and phenotypic recovery. Furthermore the data suggest that only a fraction of striatal cells need to be transduced in order to exert phenotypic effects, and therefore TH partitioned gene transfer may have clinical potential in PD. (C) 2000 Lippincott Williams and Wilkins.